Power plant at hydrogen peroxide. The method of ensuring improved combustion with the participation of hydrocarbon compounds. Requirements for the developed engine

This study would like to devote to one known substance. Marylin Monroe and White Threads, Antiseptics and Penoids, Epoxy Glue and Reagent for Blood Determination and Even Aquarium Reagents and Equal Aquarium Reagents and Equal Aquarium Reagents. We are talking about hydrogen peroxide, more precisely, about one aspect of its application - about her military career.

But before proceeding with the main part, the author would like to clarify two points. The first is the title of the article. There were many options, but in the end it was decided to take advantage of the name of one of the publications written by the captain engineer of the second rank L.S. Shapiro, as the most clearly responsible not only content, but also circumstances accompanying the introduction of hydrogen peroxide into military practice.

Second - Why is the author interested exactly this substance? Or rather - what exactly did it interest him? Oddly enough, with its completely paradoxical fate on a military field. The thing is that hydrogen peroxide has a whole set of qualities, which would seem to have referred to him a brilliant military career. And on the other hand, all these qualities turned out to be completely inapplicable to use it in the role of a military supplision. Well, not that call it absolutely unsuitable - on the contrary, it was used, and quite wide. But on the other hand, nothing extraordinary of these attempts turned out: hydrogen peroxide can not boast such an impressive track record as nitrates or hydrocarbons. It turned out to be faithful to everything ... however, we will not hurry. Let's just consider some of the most interesting and dramatic moments of military peroxide, and the conclusions each from readers will do it yourself. And since each story has its own principle, we will get acquainted with the circumstances of the birth of the narrative hero.

Opening Professor Tenar ...

Outside the window stood a clear frosty December day of 1818. A group of chemist students of the Paris Polytechnic School hurriedly filled the audience. Wishing to miss the lecture of the famous school professor and the famous Sorbonne (University of Paris) Lui Tenar was not: every his occupation was an unusual and exciting journey into the world of amazing science. And so, opening the door, a professor entered into the audience of a light spring gait (tribute to Gasconian ancestors).

According to the habit of naveling the audience, he quickly approached the long demonstration table and said something to the Preparator Starik Lesho. Then, having risen to the department, lies with students and gently began:

When with the front mast of the frigate, the sailor shouts "Earth!", And the captain first sees the unknown coast into the pylon tube, it is a great moment in the life of the navigator. But isn't it just a moment when the chemist first discovers the particles of a new one on the bottom of the flask, accounted for anyone who is not a well-known substance?

Tenar came across the department and approached the demonstration table, which Lesho had already managed to put a simple device.

Chemistry loves simplicity, - continued Tenar. - Remember this, gentlemen. There are only two glass vessels, external and internal. Between them Snow: a new substance prefers to appear at low temperatures. In the inner vessel, diluted six percent sulfuric acid is nanite. Now it is almost as cold as the snow. What happens if I broke into the acid pinch of barium oxide? Sulfuric acid and barium oxide will produce harmless water and white precipitate - sulfate barium. It all knows.

H. 2 SO4 + Bao \u003d Baso4 + H2 O

The audience was so quiet that the severe breathing of the cold lasho was clearly heard. Tenar, cautiously stirring a glass wand, slowly, in a grain, poured in a barium peroxide vessel.

The sediment, the usual sulfate barium, we filter, - said Professor, merging the water from the inner vessel to the flask.

H. 2 SO4 + BaO2 \u003d Baso4 + H2 O2

This is special water. It twice as many oxygen than in the usual. Water - hydrogen oxide, and this liquid is a hydrogen peroxide. But I like another name - "oxidized water". And on the right of the discoverer, I prefer this name.

When the navigator opens an unknown land, he already knows: someday the cities will grow on it, roads will be laid. We, chemists, can never be confident in the fate of their discoveries. What is waiting for a new substance through the century? Perhaps the same wide use as in sulfuric or hydrochloric acid. And maybe complete oblivion - as unnecessary ...

Audience Zarel.

But Tenar continued:

Nevertheless, I am confident in the great future of "oxidized water", because it contains a large number of "life-giving air" - oxygen. And most importantly, it is very easy to stand out from such water. Already one of this instills confidence in the future of "oxidized water". Agriculture and crafts, medicine and manufactory, and I do not even know yet, where the use of "oxidized water" will find! The fact that today still fits in the flask, tomorrow can be powerful to break into every house.

Professor Tenar slowly descended from the department.

Naive Parisian dreamer ... A convinced humanist, Tenar always believed that science should bring good to humanity, alleviating life and making it easier and happier. Even constantly having examples of the exactly opposite character before their eyes, he sacredly believed in a large and peaceful future of his discovery. Sometimes you begin to believe in the validity of the statements "Happiness - in ignorance" ...

However, the beginning of the career of hydrogen peroxide was quite peaceful. She worked fine on textile factories, whitening threads and canvas; In laboratories, oxidizing organic molecules and helping to receive new, non-existent substances in nature; He began to master the medical chambers, confidently proven himself as a local antiseptic.

But they soon turned out some negative sidesOne of which turned out to be low stability: it could only exist in solutions with respect to small concentration. And as usual, the concentration does not suit it, it must be enhanced. And here it started ...

... and find a walter engineer

1934 in European history turned out to be noted by quite many events. Some of them tremble hundreds of thousands of people, others passed quietly and unnoticed. To the first, of course, the appearance of the term "Aryan science" in Germany can be attributed. As for the second, it was a sudden disappearance of open printing of all references to hydrogen peroxide. The reasons for this strange loss have become clear only after the crushing defeat of the "Millennial Reich".

It all started with the idea that came to Helmut Walter - the owner of a small factory in Kiel for the production of accurate instruments, research equipment and reagents for German institutions. He was capable, erudite and, importantly, enterprising. He noticed that the concentrated hydrogen peroxide can remain for quite a long time in the presence of even small amounts of stabilizers, such as phosphoric acid or its salts. A particularly effective stabilizer was urinary acid: to stabilize 30 liters of high-concentrated peroxide, 1 g of uric acid was sufficient. But the introduction of other substances, decomposition catalysts leads to a rapid decomposition of the substance with the release of a large amount of oxygen. Thus, it was noticed by tempting the prospect of regulating the decomposition process with pretty inexpensive and simple chemicals.

In itself, all this was known for a long time, but, besides this, Walter drew attention to the other side of the process. Reaction decomposition of peroxide

2 H. 2 O2 \u003d 2 H2 O + O2

Kiel was the outpost of the German underwater shipbuilding, and the idea of \u200b\u200bthe underwater engine at the hydrogen peroxide captured the Walter. She attracted her novelty, and besides, the Walter engineer was far from beggar. He understood perfectly that in the conditions of the fascist dictatorship, the shortest way to prosperity - work for military departments.

Already in 1933, Walter independently made a study of the energy capabilities of solutions 2 O2.. It compiled a graph of the dependence of the main thermophysical characteristics from the concentration of the solution. And that's what I found out.

Solutions containing 40-65% n 2 O2., decomposing, is noticeably heated, but not enough to form a high pressure gas. When decomposing more concentrated heat solutions is highlighted much more: all water evaporates without a residue, and the residual energy is completely spent on the heating of the steamas. And what is still very important; Each concentration corresponded to a strictly defined amount of heat released. And strictly defined amount of oxygen. And finally, the third - even stabilized hydrogen peroxide is almost instantly decomposed under the action of potassium permanganates KMNO 4 Or Calcium CA (MNO 4 )2 .

Walter managed to see absolutely new area Applications of a substance known for more than a hundred years. And he studied this substance from the point of view of the intended use. When he brought his considerations to the highest military circles, an immediate order was received: to classify everything that is somehow connected with hydrogen peroxide. From now on, the technical documentation and correspondence appeared "Aurol", "Oxilin", "fuel t", but not well-known hydrogen peroxide.

The schematic diagram of a vapor turbine plant operating on a "cold" cycle: 1 - rowing screw; 2 - gearbox; 3 - turbine; 4 - separator; 5 - chamber of decomposition; 6 - regulating valve; 7-electrical pump of peroxide solution; 8 - elastic containers of peroxide solution; 9 - non-refundable removal valve overboard peroxide decomposition products.

In 1936, Walter presented the first installation of the underwater fleet, which worked on the specified principle, which, despite pretty high temperature, got the name "Cold". Compact and light turbine developed at the stand capacity of 4000 hp, fully exchanging the expectation of the designer.

The products of the decomposition reaction of a highly concentrated solution of hydrogen peroxide were fed into the turbine, rotating through a sloping gear of the propeller, and then retracted overboard.

Despite the obvious simplicity of such a decision, there were passing problems (and where without them!). For example, it was found that dust, rust, alkali and other impurities are also catalysts and sharply (and what is much worse - unpredictable) accelerate the decomposition of the peroxide than the danger of the explosion. Therefore, elastic containers from synthetic material applied to storing the peroxide solution. Such capacities were planned to be placed outside the durable case, which made it possible to rationally use the free volumes of intercorroduction space and, in addition, to create a sub-solution of the peroxide solution before the installation pump by pressure of the intake water.

But another problem was much more complicated. The oxygen contained in the exhaust gas is quite poorly dissolved in water, and the treacherously issued the location of the boat, leaving the mark on the surface of the bubbles. And this is despite the fact that the "useless" gas is a vital substance for the ship, designed to be at a depth as much time as possible.

The idea of \u200b\u200busing oxygen, as a source of fuel oxidation, was so obvious that Walter took up the parallel engine design that worked on the "hot cycle". In this embodiment, organic fuel was supplied to the decomposition chamber, which burned in the previously unlike oxygen. The installation capacity increased dramatically and, moreover, the track decreased, since the combustion product - carbon dioxide - significantly better oxygen dissolves in water.

Walter gave himself a report in the disadvantages of the "cold" process, but resigned with them, as he understood that in constructive terms such an energy installation would be easier to be easier than with a "hot" cycle, which means that it is much faster to build a boat and demonstrate its advantages .

In 1937, Walter reported the results of his experiments to the leadership of the German Navy and assured everyone in the possibility of creating submarines with vapor-gas turbine plants with an unprecedented accumulating speed of the underwater stroke of more than 20 nodes. As a result of the meeting, it was decided to create an experienced submarine. In the process of its design, issues were solved not only with the use of an unusual energy installation.

Thus, the project speed of the underwater move made unacceptable previously used housing overs. Affiliates were helped here by the sailors: several body models were tested in the aerodynamic tube. In addition, dual wreeds were used to improve the handling of the handling of the "Junkers-52" steering wheel.

In 1938, in Kiel, the first experienced submarine was laid in the world with an energy installation at hydrogen peroxide with a displacement of 80 tons, which received the designation V-80. Conducted in 1940 tests literally stunned - relatively simple and light turbine with a capacity of 2000 hp allowed the submarine to develop a speed of 28.1 knot under water! True, it was necessary to pay for such an unprecedented speed: the reservoir of the hydrogen peroxide was enough for one and a half or two hours.

For Germany during World War II, submarines were strategic, since only with their help it was possible to apply a tangible damage to the economy of England. Therefore, in 1941, the development begins, and then building a V-300 submarine with a vapor turbine operating in the "hot" cycle.

The schematic diagram of a vapor turbine plant operating in a "hot" cycle: 1 - propeller screw; 2 - gearbox; 3 - turbine; 4 - rowing electric motor; 5 - separator; 6 - combustion chamber; 7 - an outstanding device; 8 - valve of the cast pipeline; 9 - decomposition chamber; 10 - valve inclusion of nozzles; 11 - three-component switch; 12 - four-component regulator; 13 - hydrogen peroxide solution pump; 14 - fuel pump; 15 - water pump; 16 - condensate cooler; 17 - condensate pump; 18 - mixing condenser; 19 - gas collection; 20 - carbon dioxide compressor

Boat V-300 (or U-791 - it received such a letter and digital designation) had two motor installations (More precisely, three): Walter gas turbine, diesel engine and electric motors. Such an unusual hybrid appeared as a result of understanding that the turbine, in fact, is an forced engine. The high consumption of fuel components did it simply uneconomical to commit long "idle" transitions or a quiet "sneaking" to the vessels of the enemy. But it was simply indispensable for fast care from the position of attack, shifts of the place of attack or other situations when "smelled".

The U-791 was never completed, and immediately laid four pilot submarines of two episodes - WA-201 (WA - Walter) and WK-202 (WK - Walter-Krupp) of various shipbuilding firms. In its energy installations, they were identical, but was distinguished by a feed plumage and some elements of cutting and housing. Since 1943, their tests began, which were hard, but by the end of 1944. All major technical problems Were behind. In particular, the U-792 (WA-201 series) was tested for a full navigation range, when, having a stock of hydrogen peroxide 40 t, it was almost four and a half hours under the lesing turbine and four hours supported the speed of 19.5 node.

These figures were so struck by the leadership of Crymsmarine, which is not waiting for the end of testing experienced submarines, in January 1943 the industry issued an order to build 12 ships of two series - XVIIB and XVIIG. With a displacement of 236/259 t, they had a diesel-electrical installation with a capacity of 210/77 hp, allowed to move at a speed of 9/5 knots. In the event of a combat need, two PGTU with a total capacity of 5000 hp, which allowed to develop the speed of the submarine in 26 nodes.

The figure is conditionally, schematically, without compliance with the scale, the device of the submarine with PGTU is shown (one of these installations is depicted one). Some notation: 5 - combustion chamber; 6 - an outstanding device; 11 - peroxide decomposition chamber; 16 - three-component pump; 17 - fuel pump; 18 - Water pump (based on materials http://technicamolodezhi.ru/rubriki_tm/korabli_vmf_velikoy_otechestvennoy_voynyi_1972/v_nadejde_na_totalNuyu_NaYNU)

In short, the work of PGTU looks in this way. With the help of a triple pump a feed diesel fuel, hydrogen peroxide and clean water through a 4-position regulator of supplying the mixture into the combustion chamber; When the pump is operation of 24,000 rpm. The flow of the mixture reached the following volumes: fuel - 1,845 cubic meters / hour, hydrogen peroxide - 9.5 cubic meters / hour, water - 15.85 cubic meters / hour. The dosing of the three specified components of the mixture was performed using a 4-position regulator of the supply of the mixture in the weight ratio of 1: 9: 10, which also regulated the 4th component - sea water, compensating the difference in the weight of hydrogen peroxide and water in regulating chambers. Adjustable elements of the 4-position regulator were driven by an electric motor with a capacity of 0.5 hp And ensured the required consumption of the mixture.

After a 4-position regulator, hydrogen peroxide entered the catalytic decomposition chamber through the holes in the lid of this device; On the sieve of which there was a catalyst - ceramic cubes or tubular granules with a length of about 1 cm, impregnated with calcium permanganate solution. PARKAZ was heated to a temperature of 485 degrees Celsius; 1 kg of catalyst elements passed to 720 kg of hydrogen peroxide per hour at a pressure of 30 atmospheres.

After the decomposition chamber, it entered a high-pressure combustion chamber made of durable hardened steel. The input channels served six nozzles, the side openings of which were served to pass the steamer, and the central - for fuel. The temperature at the top of the chamber reached 2000 degrees Celsius, and at the bottom of the chamber decreased to 550-600 degrees due to the injection into the combustion chamber of pure water. The obtained gases were fed to the turbine, after which the spent the steamed mixture came to the condenser installed on the turbine housing. With the help of a water cooling system, the temperature of the outlet temperature dropped to 95 degrees Celsius, the condensate was collected in the condensate tank and with a pump for selection of condensate flowed into seawater refrigerators using flow marine water intake when the boat moves in the underwater position. As a result of the refrigerator passage, the temperature of the resulting water decreased from 95 to 35 degrees Celsius, and it returned through the pipeline as clean water for the combustion chamber. The remains of the vapor-gas mixture in the form of carbon dioxide and steam under pressure 6 The atmospheres were taken from the condensate tank with a gas separator and removed overboard. Carbon dioxide was relatively quickly dissolved in seawater, no leaving a noticeable track on the surface of the water.

As can be seen, even in such a popular presentation, the PSTU does not look like a simple device, which required the involvement of highly qualified engineers and workers for its construction. The construction of submarines with PGTU was conducted in an alignment of absolute secrecy. The ships allowed a strictly limited circle of persons by lists agreed in the highest instances of the Wehrmacht. In checkpoints stood gendarmes, moved into the form of firefighters ... In parallel, production facilities were increasing. If in 1939, Germany produced 6800 tons of hydrogen peroxide (in terms of 80% solution), then in 1944 already 24,000 tons, and additional capacity was built by 90,000 tons per year.

Not having full-fledged military submarines with PGTU, without having experience of their combat use, Gross Admiral Denitz broadcast:

The day comes when I declare Churchill a new underwater war. The underwater fleet was not broken by blows of 1943. He became stronger than before. 1944 will be a hard year, but a year who will bring great progress.

I wonder if Karl Denitz recalled these loud promises for those 10 years that he had to stumble in Prison Shpandau at the sentence of the Nureberg Tribunal?

The final of these promising submarine was deplorable: for all the time only 5 (according to other data - 11) boats with PGTU Walter, of which only three were tested and were enrolled in the combat composition of the fleet. Not having a crew that have not committed a single combat exit, they were flooded after the surrender of Germany. Two of them, flooded in a shallow area in the British occupation zone, were later raised and shipped: U-1406 in the USA, and U-1407 to the UK. There, experts carefully studied these submarines, and the British even conducted torture tests.

Nazi heritage in England ...

The Walter boats transported to England did not go on scrap metal. On the contrary, the bitter experience of both past world wars on the sea instilled in the British conviction in the unconditional priority of anti-submarine forces. Among other admiralty, the issue of creating a special anti-submarine pl. It was assumed to deploy them at approaches to the databases of the enemy, where they had to attack the enemy submarines overlooking the sea. But for this, the anti-submarine submarines themselves should have two important qualities: the ability to be secretly under the nose at the opponent for a long time and at least briefly develop high speed speeds for rapid rapprochement with the enemy and sudden attack. And the Germans presented them with a good back: RAP and gas turbine. The greatest attention was focused on PGTU, as a fully autonomous system, which, moreover, provided truly fantastic underwater speeds for that time.

The German U-1407 was escorted into England by the German crew, which was warned of death in any sabotage. There also delivered Helmut Walter. Restored U-1407 was credited to the Navy under the name "Meteorite". She served until 1949, after which it was removed from the Fleet and in 1950 dismantled for metal.

Later, in 1954-55 The British were built two of the same type of experimental PL "Explorer" and "Eccalibur" of their own design. However, the changes concerned only the appearance and the inner layout, as for the PSTU, then it remained almost in pristine form.

Both boats did not become the progenitors of something new in the English Fleet. The only achievement - the 25 nodes of the underwater movement received on the tests of the "Explorer", which gave the British the reason denies the whole world about their priority on this world record. The price of this record was also a record: constant failures, problems, fires, explosions led to the fact that most They spent time in the docks and workshops in repair than in hikes and testing. And this is not counting the purely financial side: one running hour of Explorer accounted for 5,000 pounds sterling, which at the rate of that time is 12.5 kg of gold. They were excluded from the fleet in 1962 (Explorer) and in 1965 ("Eccalibur") for years with a killing characteristic of one of the British submariners: "The best thing to do with hydrogen peroxide is to interest her potential opponents!"

... and in the USSR]
The Soviet Union, unlike the Allies, the boats of the XXVI series did not go, as did not get and technical documentation For these developments: "Allies" remained loyal to themselves, once again hidden a tidy piece. But the information, and quite extensive, about these failed novelties of Hitler in the USSR had. Since the Russians and Soviet chemists always walked in the forefront of world chemical science, the decision to study the possibilities of such an interesting engine on a purely chemical basis was made quickly. Intelligence authorities managed to find and collect a group of German specialists who previously worked in this area and expressed the desire to continue them on the former opponent. In particular, such a desire was expressed by one of the deputies of Helmut Walter, a certain French Stattski. Stattski and a group of "technical intelligence" on the export of military technologies from Germany under the direction of Admiral L.A. Korshunova, found in Germany, the Brunetra-Kanis Rider firm, which was a selection in the manufacture of turbine walter installations.

To copy the German submarine with the power installation of the Walter, first in Germany, and then in the USSR under the direction of A.A. Antipina was created by the Antipina Bureau, the organization, from which the efforts of the chief designer of submarines (Captain I Rank A.A. Antipina) were formed by LPM "Rubin" and SPMM "Malachite".

The task of the Bureau was to study and reproduce the achievements of Germans on new submarines (diesel, electric, steam-bubbin), but the main task was to repeat the velocities of German submarines with a walter cycle.

As a result of the work carried out, it was possible to fully restore the documentation, to manufacture (partially from German, partly from newly manufactured nodes) and test the steam-bourgebar installation of the German boats of the XXVI series.

After that, it was decided to build a Soviet submarine with the Walter engine. The topic of developing a submarine with PGTU Walter got the name project 617.

Alexander Tyklin, describing the biography of Antipina, wrote:

"... it was the first submarine of the USSR, which crossed the 18-nodal value of the underwater velocity: for 6 hours, its underwater velocity was more than 20 nodes! The case provided an increase in the depth of dive twice, that is, to a depth of 200 meters. But the main advantage of the new submarine was its energy setting, which was amazing at the time of innovation. And it was not by chance that the visit to this boat by academicians I.V. Kurchatov and A.P. Alexandrov - preparing for the creation of nuclear submarines, they could not not get acquainted with the first submarine in the USSR, which had a turbine installation. Subsequently, many constructive solutions were borrowed in the development of atomic energy plants ... "

C-99 was considered an experienced from the very beginning. It worked out the solution of issues related to high underwater velocity: body shape, controllability, movement stability. The data accumulated during its operation allowed rationally to design the first generation atoms.

In 1956 - 1958, large boats were designed project 643 with surface displacement in 1865 tons and already with two PSTU, which were supposed to provide a boat underwater speed in 22 nodes. However, due to the creation of the sketch project of the first Soviet submarines with atomic power plants, the project was closed. But the studies of the PSTU boat C-99 did not stop, and were transferred to the direction of consideration of the possibility of using the Walter engine in the developed giant T-15 torpedo with atomic charge proposed by Sugar to destroy naval databases and US ports. The T-15 was supposed to have a length of 24 m, a dive range of up to 40-50 miles, and carry the armonuclear warhead that can cause artificial tsunami to destroy the coastal cities of the United States. Fortunately, and from this project also refused.

Danger of hydrogen peroxide did not fail to affect the Soviet Navy. On May 17, 1959, an accident occurred on it - an explosion in the engine room. The boat miraculously did not die, but her recovery was considered inappropriate. The boat was handed over for scrap metal.

In the future, PGTU did not get distribution in the underwater shipbuilding either in the USSR or abroad. The successes of nuclear power make it possible to more successfully solve the problem of powerful underwater engines that do not require oxygen.

To be continued…

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In most devices that generate energy due to burning, the fuel combustion method is used. However, there are two circumstances when it may be desirable or necessary for the use of non-air, but another oxidizing agent: 1) if it is necessary to generate energy in such a place where the supply of air is limited, for example, under water or high above the ground surface; 2) When it is desirable to obtain a very large amount of energy from its compact sources for a short time, for example, in the gun throwing explosives, in installations for take-off aircraft (accelerators) or in rockets. In some such cases, in principle, air can be used, pre-compressed and stored in the appropriate pressure vessels; However, this method is often impractical, since the weight of cylinders (or other types of storage) is about 4 kg per 1 kg of air; The weight of the container for a liquid or solid product is 1 kg / kg or even less.

In the case when a small device is applied and the focus is on the simplicity of the design, for example, in the cartridges of firearms or in a small rocket, solid fuel, which contains closely mixed fuel and oxidizer. Liquid fuel systems are more complicated, but have two specific advantages compared to solid fuel systems:

1. Liquid can be stored in a vessel from a lightweight material and tighten into the combustion chamber, the dimensions of which must only be satisfied with the requirement to ensure the desired combustion rate (technique of blowing a solid in the combustion chamber under high pressureGenerally speaking, unsatisfactory; Consequently, the entire loading of solid fuel from the very beginning should be in the combustion chamber, which is therefore must be large and durable).
2. The energy generation rate can be changed and adjustable by appropriately changing the flow rate of the fluid. For this reason, the combination of liquid oxidants and flammable is used for various relatively large rocket engines, for engines of submarines, torpedoes, etc.

The ideal liquid oxidant must have many desirable properties, but the following three are most important from a practical point of view: 1) allocating a significant amount of energy during reaction, 2) comparative resistance to impact and elevated temperatures and 3) Low production cost. However, it is desirable that the oxidizing agent does not have corrosive or toxic properties to quickly react and possessed proper physical properties, such as a low freezing point, high boiling point, high density, low viscosity, etc. when used as an integral part of the rocket The fuel is particularly important and the reached flame temperature and the average molecular weight of combustion products. Obviously, no chemical compound can satisfy all the requirements for the ideal oxidizing agent. And very few substances that at all at least approximately have a desirable combination of properties, and only three of them found some application: liquid oxygen, concentrated nitric acid and concentrated hydrogen peroxide.

The hydrogen peroxide has the disadvantage that even at a 100% concentration contains only 47 wt.% Oxygen, which can be used to burn fuel, whereas in nitric acid, the content of active oxygen is 63.5%, and for pure oxygen it is possible Even 100% use. This disadvantage is compensated by significant heat release when decomposing hydrogen peroxide on water and oxygen. In fact, the power of these three oxidizing agents or thrust force developed by the weight of them, in any specific system, and with any form of fuel can vary by a maximum of 10-20%, and therefore the selection of a oxidizing agent for a two-component system is usually determined by other, considerations experimental research The hydrogen peroxide as a source of energy was supplied in Germany in 1934 in the search for new types of energy (independent air) for the movement of submarines, this potential military application stimulated the industrial development of the Electrochemische Werke method in Munich (E. W. M.) on the concentration of hydrogen peroxide to obtain aqueous solutions of high fortress, which could be transported and stored with an acceptable low decomposition rate. At first, 60% aqueous aqueous solution was produced for military needs, but later this concentration was raised and 85% peroxide began to receive. An increase in the availability of highly concentrated hydrogen peroxide at the end of the thirties of the current century led to its use in Germany during World War II as a source of energy for other military needs. Thus, hydrogen peroxide was first used in 1937 in Germany as auxiliary means in fuel for aircraft engines and rockets.

Highly concentrated solutions containing up to 90% of hydrogen peroxide were also made on an industrial scale by the end of World War II by Buffalo Electro-Chemical Co in the USA and "V. Laporte, Ltd. " In Great Britain. The embodiment of the idea of \u200b\u200bthe process of generating traction power from hydrogen peroxide in an earlier period is represented in the Lesholm scheme proposed by the energy generation procedure by thermal decomposition of hydrogen peroxide followed by combustion of fuel in the resulting oxygen. However, in practice, this scheme, apparently, did not find use.

The concentrated hydrogen peroxide can also be used as a single-component fuel (in this case, it is subjected to decomposition under pressure and forms a gaseous mixture of oxygen and superheated steam) and as an oxidizing agent for burning fuel. The mechanical one-componrate system is easier, but it gives less energy per unit weight of fuel. In a two-component system, it is possible to first decompose the hydrogen peroxide, and then burn fuel in hot decomposition products, or to introduce both fluids into the reaction directly without prior decomposition of hydrogen peroxide. The second method is easier to mechanically arrange, but it may be difficult to ensure ignition, as well as uniform and complete combustion. In any case, energy or thrust is created by expanding hot gases. Different kinds Rocket engines based on the action of hydrogen peroxide and used in Germany during World War II are very detailed by the Walter, which was directly related to the development of many types of martial use of hydrogen peroxide in Germany. The material published by them is also illustrated by a number of drawings and photographs.

The first sample of our liquid rocket engine (EDRD) operating on kerosene and highly concentrated hydrogen peroxide is assembled and ready for tests on the stand in MAI.

It all started about a year ago from the creation of 3D models and the release of design documentation.

We sent ready-made drawings to several contractors, including our main partner for metalworking "artmehu". All the work on the chamber was duplicated, and the manufacture of nozzles was generally obtained by several suppliers. Unfortunately, here we faced with all the complexity of the manufacture would seem like simple metal products.

Especially a lot of effort had to spend on centrifugal nozzles for spraying fuel in the chamber. On the 3D model in the context, they are visible as cylinders with blue nuts on the end. And so they look in the metal (one of the injectors is shown with a rejected nut, the pencil is given for scale).

We already wrote about the injectors' tests. As a result, many dozens of nozzles were selected seven. Through them, Kerosene will come to the chamber. The kerosene nozzles themselves are built into the upper part of the chamber, which is an oxidizer gasifier - an area where hydrogen peroxide will pass through a solid catalyst and decomposed on water vapor and oxygen. Then the resulting gas mixture will also go to the EDD chamber.

To understand why the manufacture of nozzles caused such difficulties, it is necessary to look inside - inside the nozzle channel there is a screw jigger. That is, the kerosene entering the nozzle is not just exactly flowing down, but twisted. The screw jigger has a lot of small parts, and on how accurately it is possible to withstand their size, the width of the gaps, through which the kerosene will flow and spray in the chamber. The range of possible outcomes - from "through the nozzle, the liquid does not flow at all" to "spraying evenly in all sides." The perfect outcome - kerosene is sprayed with a thin cone down. Approximately the same as in the photo below.

Therefore, obtaining an ideal nozzle depends not only on the skill and conscientiousness of the manufacturer, but also from the equipment used and, finally, the shallow motility of the specialist. Several series of tests of ready-made nozzles under different pressure Let us choose those, the cone spray from which is close to perfect. In the photo - a swirl that has not passed the selection.

Let's see how our engine looks in the metal. Here is the LDD cover with highways for the receipt of peroxide and kerosene.

If you raise the lid, then you can see that peroxide pumps through the long tube, and through short - kerosene. Moreover, kerosene is distributed over seven holes.

A gasifier is connected to the lid. Let's look at it from the camera.

The fact that we from this point seems to be the bottom of the details, in fact it is its upper part and will be attached to the LDD cover. Of the seven holes, kerosene in nozzles is poured into the chamber, and from the eighth (on the left, the only asymmetrically located peroxide) on the catalyst rushes. More precisely, it rushes not directly, but through a special plate with microcers, evenly distributing the flow.

In the next photo, this plate and nozzles for kerosene are already inserted into the gasifier.

Almost all free gasifier will be engaged in a solid catalyst through which hydrogen peroxide flows. Kerosene will go on nozzles without mixing with peroxide.

In the following photo, we see that the gasifier has already been closed with a cover from the combustion chamber.

Through seven holes ending with special nuts, Kerosene flows, and a hot steamer will go through the minor holes, i.e. Already decomposed on oxygen and water vapor peroxide.

Now let's deal with where they will drown. And they flow into the combustion chamber, which is a hollow cylinder, where kerosene flammives in oxygen, heated in the catalyst, and continues to burn.

Preheated gases will go to a nozzle, in which they accelerate to high speeds. Here is nozzle from different angles. A large (narrowing) part of the nozzle is called pretreatic, then a critical section is going on, and then the expanding part is the cortex.

As a result, the assembled engine looks like this.

Handsome, however?

We will produce at least one instance of stainless steel platforms, and then proceed to the manufacture of EDRs from Inkonel.

The attentive reader will ask, and for which fittings are needed on the sides of the engine? Our relocation has a curtain - the liquid is injected along the walls of the chamber so that it does not overheat. In flight the curtain will flow the peroxide or kerosene (clarify the test results) from the rocket tanks. During fire tests on the bench in a curtain, both kerosene and peroxide, as well as water or nothing to be served (for short tests). It is for the curtain and these fittings are made. Moreover, the curtains are two: one for cooling the chamber, the other - the pre-critical part of the nozzle and critical section.

If you are an engineer or just want to learn more of the characteristics and the EDD device, then an engineering note is presented in detail for you.

EDD-100S.

The engine is designed for the standsight of the main constructive and technological solutions. Engine tests are scheduled for 2016.

The engine works on stable high-boiling fuel components. The calculated thrust at sea level is 100 kgf, in vacuo - 120 kgf, the estimated specific impulse of the thrust at sea level - 1840 m / s, in vacuo - 2200 m / s, the estimated share is 0.040 kg / kgf. The actual characteristics of the engine will be refined during the test.

The engine is single-chamber, consists of a chamber, a set of automatic system units, nodes and parts of the general assembly.

The engine is fastened directly to the bearing stands through the flange at the top of the chamber.

The main parameters of the chamber
fuel:
- Oxidizer - PV-85
- Fuel - TS-1
traction, kgf:
- at sea level - 100.0
- in emptiness - 120.0
Specific pulse traction, m / s:
- at sea level - 1840
- in emptiness - 2200
Second consumption, kg / s:
- Oxidizer - 0,476
- Fuel - 0.057
Weight ratio of fuel components (O: D) - 8,43: 1
Oxidizer excess coefficient - 1.00
Gas pressure, bar:
- in the combustion chamber - 16
- in the weekend of the nozzle - 0.7
Mass of the chamber, kg - 4.0
Inner engine diameter, mm:
- cylindrical part - 80.0
- in the area of \u200b\u200bthe cutting nozzle - 44.3

The chamber is a precast design and consists of a nozzle head with an oxidizer gasifier integrated into it, a cylindrical combustion chamber and a profiled nozzle. The elements of the chamber have flanges and are connected by bolts.

On the head 88 single-component jet oxidizer nozzles and 7 single-component centrifugal fuel injectors are placed on the head. Nozzles are located on concentric circles. Each combustion nozzle is surrounded by ten nozzles of the oxidant, the remaining oxidizer nozzles are placed on free space Heads.

Cooling the camera internal, two-stage, is carried out by liquid (combustible or oxidizing agent, the choice will be made according to the results of bench tests) entering the chamber cavity through two veins of the veil - the upper and lower. The top belt curtain is made at the beginning of the cylindrical part of the chamber and provides cooling of the cylindrical part of the chamber, the lower - is made at the beginning of the subcritical part of the nozzle and provides cooling of the subcritical part of the nozzle and the critical section.

The engine uses self-ignition of fuel components. In the process of starting the engine, an oxidizing agent is improved in the combustion chamber. With the decomposition of the oxidant in the gasifier, its temperature rises to 900 K, which is significantly higher than the temperature of the self-ignition of fuel TC-1 in the air atmosphere (500 K). The fuel supplied to the chamber into the atmosphere of the hot oxidant is self-propagated, in the future the combustion process goes into self-sustaining.

Oxidizer gasifier works on the principle of catalytic decomposition of highly concentrated hydrogen peroxide in the presence of a solid catalyst. Frameing hydrogen peroxide formed by the decomposition of hydrogen (a mixture of water vapor and gaseous oxygen) is an oxidizing agent and enters the combustion chamber.

The main parameters of the gas generator
Components:
- stabilized hydrogen peroxide (weight concentration),% - 85 ± 0.5
hydrogen peroxide consumption, kg / s - 0,476
Specific load, (kg / s hydrogen peroxide) / (kg of catalyst) - 3.0
continuous work time, not less, C - 150
Parameters of the vapor of the output from the gasifier:
- Pressure, bar - 16
- Temperature, k - 900

The gasifier is integrated into the design of the nozzle head. Her glass, inner and middle bottom form the gasifier cavity. The bottoms are connected between fuel nozzles. The distance between the bottom is regulated by the height of the glass. The volume between fuel nozzles is filled with a solid catalyst.

Summary. As the sizes of the developed satellites decrease, it becomes more and more difficult to select motor installations (DF) for them, providing the necessary parameters of controllability and maneuverability. Compressed gas is traditionally used on the smallest satellites. To increase efficiency, and at the same time reducing the cost compared with hydrazine removal, hydrogen peroxide is proposed. Minimum toxicity and small required installation dimensions allow multiple tests in convenient laboratory conditions. Achievements are described in the direction of creating low-cost engines and fuel tanks with self-ad.

Introduction

IN last years Investigation of concentrated hydrogen peroxide was revived as rocket fuel for engines of various scales. The peroxide is most attractive when used in new developments, where previous technologies cannot compete directly. Such developments are the satellites weighing 5-50 kg. As one-component fuel, the peroxide has a high density (\u003e 1300 kg / cubic meters) and a specific impulse (UI) in a vacuum of about 150 ° C [approximately 1500 m / s]. Although it is significantly less than the hydrazine Ui, approximately 230 s [about 2300 m / s], alcohol or hydrocarbon in combination with peroxide are capable of lifting UI to the range of 250-300 s [from about 2500 to 3000 m / s].

The price is an important factor here, since it only makes sense to use peroxide if it is cheaper than to build reduced variants of classical DU technologies. Sharpness is very likely to consider that work with poisonous components increases the development, checking and launch of the system. For example, for testing rocket engines on poisonous components there are only a few stands, and their number gradually decreases. In contrast, microsatellite developers can themselves develop their own peroxidant technology. The fuel safety argument is especially important when working with little accelerated systems. It is much easier to make such systems if you can carry out frequent inexpensive tests. In this case, the accidents and spills of the components of rocket fuel should be considered as proper, just as, for example, an emergency to stop a computer program when debugging it. Therefore, when working with poisonous fuels, the standard are working methods that prefer evolutionary, gradual changes. It is possible that the use of less toxic fuels in microsteps will benefit from serious changes in the design.

The work described below is part of a greater research program aimed at studying new space technologies for small applications. Tests are completed by the completed prototypes of microsatellites (1). Similar topics, which are of interest, include small fills with a pumping supply of fuel for flights to Mars, Moon and back with small financial costs. Such possibilities can be very useful for sending small research apparatus to deductible trajectories. The purpose of this article is to create a Du technology that uses hydrogen peroxide and does not require expensive materials or development methods. Efficiency criterion in this case is a significant superiority over the possibilities provided by the remote control on the compressed nitrogen. A neat analysis of microsatellite needs helps to avoid unnecessary system requirements that increase its price.

Requirements for motor technology

If for electronic systems Typically, the characteristics are considered specified, then for Du it is not at all. This concerns the possibility of storing in orbit, sharp inclusions and shutdowns, the ability to withstand arbitrarily long periods of inaction. From the point of view of the engine engineer, the definition of the task includes a schedule showing when and how long each engine should work. This information may be minimal, but in any case it lowers engineering difficulties and cost. For example, the AU can be tested using relatively inexpensive equipment if it does not matter to observe the time of operation of the Du with an accuracy of milliseconds.

Other conditions, usually reducing the system, may be, for example, the need for accurate prediction of thrust and specific impulse. Traditionally, such information made it possible to apply precisely calculated speed correction with a predetermined time of operation of the Du. Given the modern level of sensors and computational capabilities available on board the satellite, it makes sense to integrate acceleration until a specified change in speed is reached. Simplified requirements allow you to reduce individual developments. It is possible to avoid accurate fitting pressure and streams, as well as expensive tests in a vacuum chamber. The thermal conditions of the vacuum, however, still have to take into account.

The easiest Motor Maswer - turn on the engine only once, at an early stage of the satellite. In this case, the initial conditions and time of heating Du affect the least. Fuel leakage deaches before and after the maneuver will not affect the result. Such a simple scenario may be difficult for another reason, for example, due to the large speed gain. If the required acceleration is high, then the size of the engine and its mass become even more important.

The most complex tasks of the work of Du are tens of thousands or more short pulses separated by clock or minutes of inaction over the years. Transition processes at the beginning and end of the pulse, thermal losses in the device, fuel leakage - all this should be minimized or eliminated. This type of thrust is typical for the task of 3-axis stabilization.

The problem of intermediate complexity can be considered periodic inclusions of the Du. Examples are changes orbit, atmospheric loss compensation, or periodic changes in the orientation of the satellite stabilized by rotation. Such a mode of operation is also found in satellites that have inertial flywheels or which are stabilized by the gravitational field. Such flights usually include brief periods of high-activity Du. This is important because the hot components of fuel will lose less energy during such periods of activity. You can use more simple devicesThan for long-term maintenance of orientation, so such flights are good candidates for the use of inexpensive liquid doors.

Requirements for the developed engine

Requirements for the service life also limit the allowable mass and size of the motor installation. For example, in the case of one-component fuel, the addition of the catalyst can increase the service life. The orientation system engine can operate in the amount of several hours during the time of service. However, the satellite tanks can be empty in minutes if there is a sufficiently large change of orbit. To prevent leaks and ensure the tight closing of the valve, even after many starts in the lines, several valves put in a row. Additional valves may be unjustified for small satellites.

Fig. 1 shows that liquid engines It is not always possible to reduce proportionally, for use for small thrust systems. Large engines Usually raise 10 - 30 times more than their weight, and this number increases to 100 for rocket carrier engines with pumping fuel. However, the smallest liquid engines cannot even raise their weight.

Engines for satellites is difficult to make small.

Even if a small existing engine is slightly easy to serve as the main engine maneuvering engine, select a set of 6-12 liquid engines for a 10-kilogram device is almost impossible. Therefore, microsavers are used for the orientation of compressed gas. As shown in Fig. 1, there are gas engines with a traction ratio to mass the same as large rocket engines. Gas engines It is simply a solenoid valve with a nozzle.

In addition to solving the problem of the mass of the propulsion, the system on compressed gas allows you to obtain shorter pulses than liquid motors. This property is important for continuous maintaining orientation for long flights, as shown in the application. As the sizes of spacecraft decrease, increasingly short pulses can be quite sufficient to maintain orientation with a given accuracy for this service life.

Although the systems on compressed gas look as a whole well for use on small spacecraft, gas storage containers occupy quite large volume and weigh quite a lot. Modern composite tanks for storing nitrogen, designed for small satellites, weigh as much as nitrogen itself prisonered in them. For comparison, tanks for liquid fuels in space ships can store fuel weighing up to 30 masses of tanks. Given the weight of both the tanks and engines, it would be very useful to store fuel in liquid form, and convert it to the gas for the distribution between different orientation system engines. Such systems were designed to use hydrazine in short subborital experimental flights.

Hydrogen peroxide as rocket fuel

Concentration and cleaning

For use in this project, 35% peroxide is bought in polyethylene containers with a volume of 1 gallon. First, it concentrates to 85%, then cleaned on the installation shown in Fig. 2. This variant of the previously used method simplifies the installation scheme and reduces the need to clean the glass parts. The process is automated, so that for obtaining 2 liters of peroxide per week requires only daily filling and emptying of vessels. Of course, the price per liter is high, but the full amount is still justified for small projects.

First, in two liter glasses on electric stoves in the exhaust closet, most of the water are evaporated during the period controlled by the timer at 18 o'clock. The volume of fluid in each glass decreases four-solid, to 250 ml, or about 30% of the initial mass. When evaporation, a quarter of the initial peroxide molecules is lost. The loss rate is growing with a concentration, so that for this method, the practical concentration limit is 85%.

Installation on the left is a commercially available rotary vacuum evaporator. 85% solution having about 80 ppm extraneous impurities is heated by the amounts of 750 ml on a water bath at 50c. Installation is supported by a vacuum not higher than 10 mm Hg. Art. that ensures fast distillation for 3-4 hours. Condensate flows into the container on the left below with losses less than 5%.

The bath with a water jet pump is visible for the evaporator. It has two electric pumps, one of which supplies water to the water jet pump, and the second circulates the water through the freezer, the water refrigerator of the rotary evaporator and the bath itself, maintaining the water temperature just above the zero, which improves both the condensation of the vapor in the refrigerator and the vacuum in System. Packey pairs that did not condensed on the refrigerator fall into the bath and bred to a safe concentration.

Pure hydrogen peroxide (100%) is significantly densely water (1.45 times at 20c), so that the floating glass range (in the range of 1.2-1.4) usually determines the concentration with an accuracy of up to 1%. As purchased initially, the peroxide and the distilled solution were analyzed to the content of impurities, as shown in Table. 1. The analysis included plasma-emission spectroscopy, ion chromatography and the measurement of the complete content of organic carbon (TOTAL ORGANIC CARBON - TOC). Note that phosphate and tin are stabilizers, they are added in the form of potassium and sodium salts.

Table 1. Analysis of hydrogen peroxide solution

Safety measures when handling hydrogen peroxide

Action on the eyes and lungs are more dangerous. Fortunately, the pressure of the peroxide vapor is quite low (2 mm Hg. Art. At 20c). Exhaust ventilation easily supports the concentration below the respiratory limit in 1 ppm installed by OSHA. The peroxide can be overflowing between open containers over the folds in case of spill. For comparison, N2O4 and N2H4 should be constantly in sealed vessels, a special breathing apparatus is often used when working with them. This is due to their significantly higher pressure of vapors and limiting concentration in air at 0.1 ppm for N2H4.

Washing spilled peroxide water makes it not hazardous. As for protective clothing requirements, uncomfortable suits can increase the probability of the strait. When working with small quantities, it is possible that it is more important to follow the issues of convenience. For example, work with wet hands is a reasonable alternative to work in gloves that can even skip splashes if they proceed.

Although the liquid peroxide does not decompose in the mass under the action of the source of fire, the pair of concentrated peroxide can be detected with insignificant effects. This potential danger puts the limit of the production volume of the installation described above. Calculations and measurements show a very high degree of security for these small production volumes. In fig. 2 The air is drawn into horizontal ventilation gaps located behind the device, at 100 CFM (cubic feet per minute, about 0.3 cubic meters per minute) along 6 feet (180 cm) of the laboratory table. The concentration of vapors below 10 ppm was measured directly over concentrating glasses.

The utilization of small amounts of peroxide after breeding them does not lead to environmental consequences, although it contradicts the most strict interpretation of the rules for the disposal of hazardous waste. Peroxide - oxidizing agent, and, therefore, potentially flammable. At the same time, however, it is necessary for the presence of combustible materials, and anxiety is not justified when working with small amounts of materials due to heat dissipation. For example, wet spots on tissues or loose paper will stop the ugly flame, since the peroxide has a high specific heat capacity. Containers for storing peroxide should have ventilating holes or safety valves, since the gradual decomposition of the peroxide per oxygen and water increases pressure.

Compatibility of materials and self-discharge when stored

Historical works include experiments on compatibility with samples of materials conducted in glass vessels with concentrated peroxide. In maintaining tradition, small sealing vessels were made of samples for testing. Observations for changing pressure and vessels show the rate of decomposition and peroxide leakage. In addition to this, the possible increase in volume or weakening of the material becomes noticeable, since the vessel walls are exposed to pressure.

Fluoropolymers, such as polytetrafluoroethylene (POLYTETRAFLUROTHYLENE), POLYCHLOCHLOROTRIFLUROTHYLENE) and Polyvinylidene fluoride (PLDF - Polyvinylidene Fluoride) are not decomposed under the action of peroxide. They also lead to a slowdown in the peroxide decomposition, so that these materials can be used to cover the tanks, or intermediate containers if they need to store fuel for several months or years. Similarly, the compactors from the fluorooelastomer (from the standard "Witon") and fluorine-containing lubricants are quite suitable for long-term contact with peroxide. Polycarbonate plastic is surprisingly not affected by concentrated peroxide. This material that does not form fragments is used wherever transparency is necessary. These cases include the creation of prototypes with a complex internal structure and tanks in which it is necessary to see the fluid level (see Fig. 4).

Decomposition When contacting the material AL-6061-T6 is only several times faster than with the most compatible aluminum alloys. This alloy is durable and easily accessible, while the most compatible alloys have insufficient strength. Open purely aluminum surfaces (i.e. al-6061-t6) are saved for many months upon contact with peroxide. This is despite the fact that water, for example, oxidizes aluminum.

Contrary to historically established recommendations, complex cleaning operations that use harmful to health cleaners are not necessary for most applications. Most parts of the devices used in this work with concentrated peroxide were simply washed off with water with washing powder at 110f. Preliminary results show that such an approach is almost the same nice resultsas recommended cleaning procedures. In particular, the washing of the vessel from PVDF during the day with 35% nitric acid reduces the decomposition rate of only 20% for a 6-month period.

It is easy to calculate that the decomposition of one percent of the peroxide contained in the closed vessel with 10% free volume, raises the pressure to almost 600psi (pounds per square inch, i.e. approximately 40 atmospheres). This number shows that reducing the efficiency of peroxide with a decrease in its concentration is significantly less important than security considerations during storage.

Planning space flights using concentrated peroxide requires a comprehensive consideration of the possible need to reset the pressure by ventilation of the tanks. If the operation of the motor system begins for days or weeks from the start of the start, the empty volume of the tanks can immediately grow several times. For such satellites, it makes sense to make all-metal tanks. Storage period, of course, includes the time assigned to the assuction.

Unfortunately, formal rules for working with fuel, which were developed taking into account the use of highly toxic components, usually prohibit automatic ventilation systems on the Flight Equipment. Usually used expensive pressure tracking systems. The idea of \u200b\u200bimproving safety by the prohibition of ventilation valves contradicts the normal "earthly" practice when working with liquid pressure systems. This question may have to have to revise depending on which the carrier rocket is used when starting.

If necessary, the decomposition of peroxide can be maintained at 1% per year or lower. In addition to compatibility with tank materials, the decomposition coefficient is highly dependent on temperature. It may be possible to store peroxide indefinitely in space flights if it is possible to freeze. The peroxide is not expanding during freezing and does not create threats for valves and pipes, as it happens with water.

Since the peroxide decomposes on the surfaces, an increase in the volume ratio to the surface can increase the shelf life. Comparative analysis With samples of 5 cubic meters. See and 300 cubic meters. cm confirm this conclusion. One experiment with 85% peroxide in 300 cu containers. See, made from PVDF, showed the decomposition coefficient at 70f (21c) 0.05% per week, or 2.5% per year. Extrapolation up to 10 liter tanks gives the result of about 1% per year at 20c.

In other comparative experiments using PVDF or PVDF coating on aluminum, peroxide, having 80 PPM stabilizing additives, decomposed only 30% slower than purified peroxide. This is actually good that stabilizers do not greatly increase the shelf life of peroxide in tanks with long flights. As shown in the next section, these additives are strongly interfere with the use of peroxide in engines.

Engine development

Silver-based catalyst

The composition of the surface and the mechanism of the catalyst operation is completely unclear, as follows from a variety of inexplicable and contradictory statements in the literature. The catalytic activity of the surface of pure silver can be enhanced by the application of samarium nitrate with subsequent calcination. This substance decomposes on samarium oxide, but can also oxidize silver. Other sources in addition to this refer to the treatment of pure silver nitric acid, which dissolves silver, but also is an oxidizing agent. An even easiest way is based on the fact that a purely silver catalyst can increase its activity when used. This observation was checked and confirmed, which led to the use of a catalyst without a nitrate of Samaria.

Silver oxide (AG2O) has a brownish-black color, and silver peroxide (AG2O2) has a gray-black color. These colors appeared one after another, showing that silver gradually oxidized more and more. The youngest color corresponded to the best action of the catalyst. In addition, the surface was increasingly uneven compared to the "fresh" silver when analyzing under a microscope.

A simple method for checking the activity of the catalyst was found. Separate mugs of the silver mesh (diameter 9/16 inch [approximately 14 mm] were superimposed on drops of peroxide on the steel surface. Only purchased silver grid caused a slow "hiss". The most active catalyst is repeatedly (10 times) caused a steam stream for 1 second.

This study does not prove that oxidized silver is a catalyst, or that the observed darkening is mainly due to oxidation. The mention is also worth mentioning that both silver oxide are known to decompose with relatively low temperatures. Excess oxygen during engine operation, however, can shift the reaction equilibrium. Attempts to experimentally find out the importance of oxidation and irregularities of the surface of the unequivocal result did not give. Attempts included an analysis of the surface using an X-ray photoelectron spectroscopy (X-Ray PhotooElectron Spectroscopy, XPS), also known as an electronic spectroscopic chemical analyzer (Electron Spectroscopy Chemical Analysis, ESCA). Attempts were also made to eliminate the likelihood of surface pollution in freshly pulled silver grids, which worsened catalytic activity.

Independent checks have shown that neither the Nitrate of Samaria nor its solid decomposition product (which is probably oxide) does not catalyze the decomposition of peroxide. It may mean that samarium nitrate treatment can work by oxidation of silver. However, there is also a version (without a scientific justification) that the treatment of samarium nitrate prevents the adhesion of bubbles of gaseous decomposition products to the surface of the catalyst. In the present work, ultimately, the development of light engines was considered more important than the solution of the Catalysis puzzles.

Engine scheme

Instead, in this paper, quite good results were obtained using the engine cameras made from bronze (Copper alloy C36000) on the lathe. Bronze is easily processed, and in addition, its thermal expansion coefficient is close to the silver coefficient. At the decomposition temperature of 85% peroxide, about 1200F [approximately 650c], the bronze has excellent strength. This relatively low temperature also allows you to use an aluminum injector.

Such a choice of easily processed materials and peroxide concentrations, easily achievable in laboratory conditions, is a rather successful combination for experiments. Note that the use of 100% peroxide would lead to the melting of both the catalyst and the walls of the chamber. The resulting choice is a compromise between price and efficiency. It is worth noting that the bronze chambers are used on the RD-107 and RD-108 engines applied on such a successful carrier as an alliance.

In fig. 3 is shown easy option The engine that screws itself directly to the base of the liquid valve of a small maneuvering machine. Left - 4 gram aluminum injector with fluoroalastomer seal. The 25-gram silver catalyst is divided to be able to show it from different sides. Right - 2-gram plate supporting the catalyst grid. Full mass Parts shown in the figure - approximately 80 grams. One of these engines was used for terrestrial controls of the 25-kilogram research apparatus. The system worked in accordance with the design, including the use of 3.5 kilograms of peroxide without a visible loss of quality.

150-gram commercially available solenoid valve of direct action, having a 1.2 mm hole and a 25-ohm coil controlled by a 12 volt source showed satisfactory results. The surface of the valve coming into contact with the liquid consists of stainless steel, aluminum and witon. The full mass is favorably different from mass over 600 grams for a 3-pound [approximately 13n] engine used to maintain the orientation of the Centaurian stage until 1984.

Engine testing

Fig. 4 shows the installation ready for the experiment. Direct experiments in laboratory conditions are possible due to the use of sufficiently harmless fuel, low rod values, operation under normal indoor conditions and atmospheric pressure, and applying simple devices. The protective walls of the installation are made of polycarbonate sheets of thicknesses in half: approximately 12 mm], which are installed on the aluminum frame, in good ventilation. The panels were tested for a flushing force in 365.000 N * C / m ^ 2. For example, a fragment of 100 grams, moving with a supersonic speed of 365 m / s, stop if the stroke of 1 kV. cm.

In the photo, the engine camera is oriented vertically, just below the exhaust pipe. Pressure sensors at the inlet in the injector and pressure inside the chamber are located on the platform of the scales that measure the craving. Digital performance and temperature indicators are outside the installation walls. The opening of the main valve includes a small array of indicators. Data recording is carried out by installing all indicators in the visibility field of the camcorder. The final measurements were carried out using a heat-sensitive chalk, which conducted a line along the length of the Catalysis chamber. Color change corresponded to temperatures above 800 F [approximately 430c].

The capacitance with concentrated peroxide is located on the left of the scales on a separate support, so that the change in the mass of the fuel does not affect the measurement of the thrust. With the help of reference weights, it was checked that the tubes, bringing peroxide to the chamber, are quite flexible to achieve measurement accuracy within 0.01 pounds [approximately 0.04n]. The peroxide capacitance was made of a large polycarbonate pipe and is calibrated so that the change in the level of the fluid can be used to calculate the UI.

Engine parameters

The initial short-term launch was carried out to avoid a "wet" start at which a visible exhaust appeared. Typically, the initial start was carried out within 5 s at consumption<50%, но вполне хватало бы и 2 с. Затем шёл основной прогон в течение 5-10 с, достаточных для полного прогрева двигателя. Результаты показывали температуру газа в 1150F , что находится в пределах 50F от теоретического значения. 10-секундные прогоны при постоянных условиях использовались для вычисления УИ. Удельный импульс оказывался равным 100 с , что, вероятно, может быть улучшено при использовании более оптимальной формы сопла, и, особенно, при работе в вакууме.

The length of the silver catalyst was successfully reduced from a conservative 2.5 inches [approximately 64 mm to 1.7 inches [approximately 43 mm]. The final engine scheme had 9 holes with a diameter of 1/64 inches [approximately 0.4 mm] in a flat surface of the injector. The critical section of the size of 1/8 inches made it possible to obtain a 3.3 pound of force of force at a pressure in the PSIG chamber 220 and the pressure difference 255 PSIG between the valve and the critical section.

Distilled fuel (Table 1) gave stable results and stable pressure measurements. After a run of 3 kg of fuel and 10 starts, a point with a temperature of 800F was on the chamber at a distance of 1/4 inches from the surface of the injector. At the same time, for comparison, the engine performance time at 80 ppm impurities was unacceptable. Pressure fluctuations in the chamber at a frequency of 2 Hz reached a value of 10% after spending only 0.5 kg of fuel. The temperature point is 800F departed over 1 inches from the injector.

A few minutes in 10% nitric acid restored a catalyst to a good condition. Despite the fact that, together with pollution, a certain amount of silver was dissolved, the catalyst activity was better than after the nitric acid treatment of a new, not used catalyst.

It should be noted that, although the engine warming time is calculated by seconds, significantly shorter emissions are possible if the engine is already heated. The dynamic response of the liquid subsystem of traction weighing 5 kg on the linear portion showed the pulse time in short, than in 100 ms, with a transmitted pulse about 1 H * p. In particular, the offset was approximately +/- 6 mm at a frequency of 3 Hz, with a limitation set by the system speed system.

Options for building Du

Traditional schemes

Embodiment B is the simplest liquid scheme, and was repeatedly tested in flights with hydrazine as fuel. Gas supporting pressure in the tank usually takes a quarter of a tank during start. Gas gradually expands during the flight, so they say that the pressure "blows out". However, the pressure drop reduces both cravings and ui. The maximum fluid pressure in the tank takes place during the launch, which increases the mass of the tanks for security reasons. A recent example is the device of Lunar Prospector, which had about 130 kg of hydrazine and 25 kg of weight of the Du.

The variant C is widely used with traditional poisonous single-component and two-component fuels. For the smallest satellites, it is necessary to add Du on compressed gas to maintain the orientation, as described above. For example, the addition of Du on a compressed gas to the variant C leads to option D. Motor systems of this type, working on nitrogen and concentrated peroxide, were built in the Laurenov Laboratory (LLNL) so that you can safely experience the orientation systems of microsteps prototypes operating on non-fuels .

Maintaining orientation with hot gases

To further reduce the mass of the equipment and simplify the storage system, it is desirable to generally avoid gas storage capacities. Option F is potentially interesting for miniature systems on peroxide. If prior to the start of work, a long-term storage of fuel in orbit is required, the system can start without initial pressure. Depending on the free space in the tanks, the size of the tanks and their material, the system can be calculated for pumping pressure at a predetermined moment in flight.

In version D, there are two independent fuel sources, to maneuvering and maintaining the orientation, which makes it separately to take into account the flow rate for each of these functions. E and F systems that produce hot gas to maintain fuel orientation used for maneuvering have greater flexibility. For example, unused when maneuvering fuel can be used to extend the life of the satellite, which needs to maintain its orientation.

Ideas Samonaduva

Variants G and H can be called liquid systems of "hot gas under pressure", or "blow-up", as well as "gas from liquid" or "self-trunk". For controlled supervision of the tank, the spent fuel is required to increase the pressure.

Embodiment G uses a tank with a membrane deflected by pressure, so first the fluid pressure above the gas pressure. This can be achieved using a differential valve or an elastic diaphragm that shares gas and liquid. Acceleration can also be used, i.e. Gravity in ground applications or centrifugal force in a rotating spacecraft. Option H is working with any tank. A special pump for maintaining pressure provides circulation through a gas generator and back to a free volume in the tank.

In both cases, the liquid controller prevents the appearance of feedback and the occurrence of arbitrarily greater pressures. For normal operation of the system, an additional valve is included in sequentially with the regulator. In the future, it can be used to control the pressure in the system within the pressure of the regulator being installed. For example, maneuvers on the change of orbit will be made under full pressure. The reduced pressure will allow to achieve a more accurate maintenance of orientation of 3 axes, while maintaining fuel to extend the service life of the device (see Appendix).

Over the years, experiments with pumps of difference area were carried out both in pumps and in tanks, and there are many documents describing such structures. In 1932, Robert H. Goddard and others built a pump driven by a machine to control liquid and gaseous nitrogen. Several attempts were made between 1950 and 1970, in which the options G and H were considered for atmospheric flights. These attempts to reduce volume were carried out in order to reduce windshield resistance. These works were subsequently discontinued with the widespread development of solid fuel missiles. Working on self-adequate systems and differential valves were performed relatively recently, with some innovations for specific applications.

Liquid fuel storage systems with self-ads were not considered seriously for long-term flights. There are several technical reasons why in order to develop a successful system, it is necessary to ensure well predictable properties of thrust during the entire service life of the Du. For example, a catalyst suspended in a gas supply gas can decompose fuel inside the tank. It will require the separation of tanks, as in the version G, to achieve performance in flights that require a long period of rest after the initial maneuvering.

The working cycle of thrust is also important from thermal considerations. In fig. 5G and 5H The heat released during the reaction in the gas generator is lost in the surrounding parts in the process of long flight with rare inclusions of the Du. This corresponds to the use of soft seals for hot gas systems. High-temperature metal seals have a greater leakage, but they will only be needed if the working cycle is intense. Questions about the thickness of thermal insulation and heat capacity of the components should be considered, well representing the intended nature of the work of the Du during the flight.

Pumping engines

Although fig. 5J is somewhat simplified, it is included here in order to show that this is a completely different option than H. In the latter case, the pump is used as an auxiliary mechanism, and the pump requirements differ from the engine pump.

Work continues, including testing rocket engines operating at concentrated peroxide and using pumping units. It is possible that easily repeated inexpensive tests of engines using non-toxic fuel will allow achieving even simpler and reliable schemes than previously achieved when using pumping hydrazine developments.

Prototype self-adhesive system tank

Fig. 6 depicts inexpensive test equipment that uses a differential valve pump made from a segment of an aluminum pipe with a diameter of 3 inches [approximately 75 mm with a wall thickness of 0.065 inches [approximately 1.7 mm], squeezed at the ends between sealing rings. Welding here is missing, which simplifies the system check after testing, changing the system configuration, and also reduces the cost.

This system with self-adequate concentrated peroxide was tested using solenoid valves available on sale, and inexpensive tools, as in engine development. An exemplary system diagram is shown in Fig. 7. In addition to the thermocouple immersed in gas, the temperature also measured on the tank and the gas generator.

The tank is designed so that the pressure of the liquid in it is a little higher than the pressure of the gas (???). Numerous starts were carried out using the initial air pressure of 30 psig [approximately 200 kPa]. When the control valve opens, the flow through the gas generator supplies steam and oxygen into the pressure maintenance channel in the tank. The first order of positive feedback of the system leads to exponential pressure growth until the liquid controller is closed when 300 psi is reached [Approximately 2 MPa].

Input sensitivity is invalid for gas pressure regulators, which are currently used on satellites (Fig. 5a and C). In the fluid system with self-admiration, the regulator's input pressure remains in the narrow range. Thus, it is possible to avoid many difficulties inherent in conventional regulators schemes used in the aerospace industry. A regulator weighing 60 grams has only 4 moving parts, not counting springs, seals and screws. The regulator has a flexible seal for closing when the pressure is exceeded. This simple axisymmetric diagram is sufficient due to the fact that it is not necessary to maintain the pressure at certain limits at the entrance to the regulator.

The gas generator is also simplified thanks to the low requirements for the system as a whole. When the pressure difference in 10 PSI, the fuel flow is sufficiently small, which allows the use of the simplest injectors schemes. In addition, the absence of a safety valve at the inlet in the gas generator leads only to small vibrations of about 1 Hz in the decomposition reaction. Accordingly, a relatively small reverse flow during the start of the system starts the regulator not higher than 100F.

Initial tests did not use the regulator; In this case, it was shown that the pressure in the system can be maintained by any in the limits of the compactor allowed by friction to the safe pressure limiter in the system. Such flexibility of the system can be used to reduce the required orientation system for most of the satellite service life, for the reasons specified above.

One of the observations that seem to be apparent later was that the tank is heated stronger if low-frequency pressure fluctuations occur in the system during control without using the regulator. Safety valve at the entrance to the tank, where compressed gas is supplied, could eliminate the additional heat flow occurring due to pressure fluctuations. This valve would also not give Baku to accumulate pressure, but it is not necessarily important.

Although the aluminum parts are melted at a decomposition temperature of 85% peroxide, the temperature is somewhat slightly due to the loss of heat and the intermittent gas flow. The tank shown in the photo had a temperature noticeably below 200f during testing with pressure maintenance. At the same time, the gas temperature at the outlet exceeded 400F during a rather energetic switching of a warm gas valve.

The gas temperature at the output is important because it shows that water remains in a state of superheated steam inside the system. The range from 400F to 600F looks perfect, as this is cold enough for cheap light equipment (aluminum and soft seals), and heat enough to obtain a significant part of the fuel energy used to support the orientation of the apparatus using gas jets. During periods of work under reduced pressure, an additional advantage is that the minimum temperature. Required to avoid moisture condensation, also decreases.

To work as long as possible in the permissible temperature limits, such parameters such as the thickness of the thermal insulation and the overall heat capacity of the design must be customized for a specific traction profile. As expected, after testing in the tank, the condensed water was discovered, but this unused mass is a small part of the total fuel mass. Even if all the water from the gas flow used for the orientation of the apparatus is condensed, any equal to 40% of the mass of the fuel will be gaseous (for 85% peroxide). Even this option is better than using compressed nitrogen, as water is easier than the dear modern nitrogen tank.

Test equipment shown in Fig. 6, obviously, far from being called a complete traction system. Liquid motors of an approximately the same type as described in this article may, for example, are connected to the output tank connector, as shown in Fig. 5G.

Plans for Supervising the Pump

It is planned to use a pair of pumping chambers that work alternately, instead of the minimum necessary single camera. This will ensure the permanent job of the orientation subsystem on warm gas at constant pressure. The task is to pick up the tank to reduce the mass of the system. The pump will work on the gas parts of the gas generator.

Discussion

This article addressed the possibility of using hydrogen peroxide using low-cost materials and techniques applicable in small scales. The results obtained can also be applied to the Du on a single-component hydrazine, as well as in cases where the peroxide can serve as an oxidizing agent in unseated two-component combinations. The latter option includes self-flameless alcohol fuels, described in (6), as well as liquid and solid hydrocarbons, which are flammable when contact with hot oxygen, resulting in decomposition of concentrated peroxide.

Relatively simple technology with peroxide, described in this article, can be directly used in experimental spacecraft and other small satellites. Just one generation back low near-earth orbits and even deep space were studied using actually new and experimental technologies. For example, the Lunar Sirewiper planting system included numerous soft seals, which can be considered unacceptable today, but were quite adequate to the tasks. Currently, many scientific tools and electronics are highly miniaturized, but the technology of the Du does not meet the requests of small satellites or small lunar landing probes.

The idea is that custom equipment can be designed for specific applications. This, of course, contradicts the idea of \u200b\u200b"inheritance" technologies, which usually prevails when selecting satellite subsystems. The base for this opinion is the assumption that the details of the processes are not well studied well to develop and launch completely new systems. This article was caused by the opinion that the possibility of frequent inexpensive experiments will allow to give the necessary knowledge to the designers of small satellites. Together with the understanding of both the needs of satellites and the capabilities of the technole, the potential reduction of unnecessary requirements for the system comes.

Thanks

The study was part of the Clementine-2 program and microsatellite technologies in Laureren's laboratory, with the support of the US Air Force Research Laboratory. This work used the US government funds and was held at the Louuren's National Laboratory in Livermore, the University of California as part of the W-7405-ENG-48 contract with the US Department of Energy.

Torpedo engines: yesterday and today

OJSC "Research Institute of Milte Treats" remains the only enterprise in the Russian Federation, carrying out the full development of thermal power plants

In the period from the founding of the enterprise and until the mid-1960s. The main attention was paid to the development of turbine engines for anti-worker torpedoes with a working range of turbines at depths of 5-20 m. Anti-submarine torpedoes were projected only on electric power industry. Due to the conditions for the use of anti-develop torpedoes, important requirements for powering plants were the highest possible power and visual imperceptibility. The requirement for visual imperceptibility was easily carried out due to the use of two-component fuel: kerosene and low-water solution of hydrogen peroxide (MPV) of a concentration of 84%. Products combustion contained water vapor and carbon dioxide. The exhaust of combustion products overboard was carried out at a distance of 1000-1500 mm from the torpedo control organs, while the steam condensed, and the carbon dioxide quickly dissolved in water so that gaseous combustion products not only did not reach the surface of the water, but did not affect the steering and Rowing screws torpedoes.

The maximum power of the turbine, achieved on the torpedo 53-65, was 1070 kW and ensured a speed at a speed of about 70 nodes. It was the most high-speed torpedo in the world. To reduce the temperature of fuel combustion products from 2700-2900 K to an acceptable level in the combustion products, marine water was injected. At the initial stage of work, salt from sea water was deposited in the flow part of the turbine and resulted in its destruction. This happened until the conditions for trouble-free operation were found, minimizing the influence of seawater salts on the operation of a gas turbine engine.

With all the energy advantages of hydrogen fluoride as an oxidizing agent, its increased fire supply during operation dictated the search for the use of alternative oxidizing agents. One of the variants of such technical solutions was the replacement of MPV on gas oxygen. The turbine engine, developed at our enterprise, was preserved, and Torpeda, who received the designation 53-65K, was successfully exploited and not removed from weapons the Navy so far. Refusal to use MPV in torpedo thermal power plants led to the need for numerous research and development work on the search for new fuels. In connection with the appearance in the mid-1960s. Atomic submarines having high sweating speeds, anti-submarine torpedoes with electric power industry turned out to be ineffective. Therefore, along with the search for new fuels, new types of engines and thermodynamic cycles were investigated. The greatest attention was paid to the creation of a steam turbine unit operating in a closed Renkin cycle. At the stages of pretreating both stand and sea development of such aggregates, as a turbine, steam generator, capacitor, pumps, valves and the entire system, fuel: kerosene and MPV, and in the main embodiment - solid hydro-reactive fuel, which has high energy and operational indicators .

Paroturban installation was successfully worked out, but the torpedo work was stopped.

In 1970-1980 Much attention was paid to the development of gas turbine plants of an open cycle, as well as a combined cycle using an ejector gas in the gas unit at high depths of work. As fuel, numerous formulations of liquid monotrofluid type OTTO-FUEL II, including with additives of metallic fuel, as well as using a liquid oxidizing agent based on hydroxyl ammonium perchlorate (NAR).

The practical yield was given the direction of creating a gas turbine installation of an open cycle on fuel like OTTO-FUEL II. A turbine engine with a capacity of more than 1000 kW for percussion torpedo caliber 650 mm was created.

In the mid-1980s. According to the results of the research work, the leadership of our company decided to develop a new direction - the development for universal torpedo caliber 533 mm axial-piston engines in fuel like Otto-Fuel II. Piston engines compared to turbines have a weaker dependence of the cost-effectiveness from the depth of the torpedo.

From 1986 to 1991 A axial-piston engine (model 1) was created with a capacity of about 600 kW for a universal torpedo caliber 533 mm. He successfully passed all types of poster and marine tests. In the late 1990s, the second model of this engine was created in connection with a decrease in torpedo length by modernizing in terms of simplifying the design, increasing the reliability, excluding scarce materials and the introduction of multi-mode. This model of the engine is adopted in the serial design of the universal deep-water sponge torpedo.

In 2002, OJSC "NII Morteterechniki" was charged with the creation of a powerful installation for a new mild anti-submarine torpedo of a 324 mm caliber. After analyzing all sorts of engine types, thermodynamic cycles and fuels, the choice was also made, as well as for heavy torpedoes, in favor of an axially piston engine of an open cycle in fuel type OTTO-FUEL II.

However, when designing the engine, the experience of the weaknesses of the engine design of heavy torpedo was taken into account. The new engine has a fundamentally different kinematic scheme. It does not have friction elements in the fuel feeding path of the combustion chamber, which eliminated the possibility of fuel explosion during operation. Rotating parts are well balanced, and drives of auxiliary aggregates are significantly simplified, which led to a decrease in vibroactivity. An electronic system of smooth control of fuel consumption and, accordingly, the engine power is introduced. There are practically no regulators and pipelines. When the engine power is 110 kW in the entire range of desired depths, at low depths it allows power to doubt the power while maintaining performance. A wide range of engine operating parameters allows it to be used in torpedoes, antistorpeted, self-apparatus mines, hydroacoustic counterattacks, as well as in autonomous underwater devices of military and civilian purposes.

All of these achievements in the field of creating torpedo powering facilities were possible due to the presence of unique experimental complexes created both by their own and at the expense of public facilities. Complexes are located on the territory of about 100 thousand m2. They are provided with all the necessary power supply systems, including air, water, nitrogen and high pressure fuels. The test complexes include the utilization systems of solid, liquid and gaseous combustion products. The complexes have stands for testing and full-scale turbine and piston engines, as well as other types of engines. There are also stands for fuels testing, combustion chambers, various pumps and appliances. The stands are equipped with electronic control systems, measurement and registration of parameters, visual observation of test objects, as well as emergency alarms and equipment protection.