KR101078212B1 - Tank for storing Rocket Propellant - Google Patents

Abstract

The present invention relates to a rocket propellant storage tank configured by dualizing the tank for storing the rocket propellant into an inner wall and an outer wall to simultaneously achieve propellant storage, strength reinforcement, and weight reduction.

More specifically, the tank inner wall containing the propellant; A tank outer wall formed to surround an outer surface of the tank inner wall and provided with a material different from that of the tank inner wall; A propellant inlet formed at one end of the tank inner wall and the tank outer wall and a propellant outlet formed at the other end; And a temperature controller for maintaining the temperature of the propellant; It relates to a rocket propellant storage tank comprising a.

Propellant tank, storage tank, hydrogen peroxide tank, rocket propellant

Description

Tank for storing Rocket Propellant

The present invention relates to a rocket propellant storage tank configured by dualizing the tank for storing the rocket propellant into an inner wall and an outer wall to simultaneously achieve propellant storage, strength reinforcement, and weight reduction.

The rocket engine is a device that generates thrust and is designed to include a thruster. The rocket engine is a device that allows the rocket engine to fly along a flight trajectory that is attached to a rocket projectile or satellite. Rocket engines can be divided into single-propellant rocket engines driven by a single propellant and binary-propellant rocket engines that burn fuel using oxidants.

Conventional rocket propellant tanks generally used tanks made of a single material. Accordingly, there was a problem that it is difficult to select a light tank material while maintaining the rigidity to withstand the high pressure inside the tank without reacting with the rocket propellant.

Therefore, when hydrogen peroxide is used as an oxidizing agent or a propellant among rocket propellants, it is required to develop a rocket propellant storage tank having a lightweight material that maintains rigidity without reacting with hydrogen peroxide.

The present invention is to provide a propellant storage tank composed of a material that does not react with the propellant by dualizing the tank inner wall and the tank outer wall and the tank outer wall is made of a material having a light rigidity.

The present invention is to provide a propellant storage tank for controlling the temperature of the propellant is formed between the outer circumferential surface of the tank outer wall or between the tank outer wall and the inner wall to maintain the propellant at an appropriate temperature to prevent the reaction in the storage tank. .

The present invention tank inner wall 110 for receiving the propellant 140; A tank outer wall 120 formed to surround an outer surface of the tank inner wall 110 and provided with a material different from that of the tank inner wall 110; Propellant inlets 111 and 121 formed at one end of the tank inner wall 110 and tank outer wall 120 and propellant outlets 112 and 122 formed at the other end thereof; And a temperature controller 130 for maintaining the temperature of the propellant 140. Characterized in that it comprises a.

On the other hand, the present invention is characterized in that the tank outer wall 120 is formed of any one selected from titanium-based, aluminum alloy-based, composite material.

The present invention is characterized in that the propellant 140 is hydrogen peroxide, the tank inner wall 110 is formed of a Class 1 material of a metal or non-metal material that does not react with hydrogen peroxide.

In the present invention, the Class 1 material may be selected from Al1060, Al1160, Al1260, Al1360, Al5052, Al5254, Al5652, Al7072, tantalum, zirconium or Kel-F, Viton B, Teflon (Teflon) is characterized in that the non-metal material selected from.

In addition, the present invention, the temperature control unit 130 is formed in a plurality of any one position selected from the outer circumferential surface of the tank outer wall 120 or between the tank outer wall 120 and the tank inner wall 110, the temperature sensing And a sensor 131.

The tank inner wall 110 is characterized in that the coating is formed on the inner side of the tank outer wall 120 to a thickness of 10 nm ~ 10 ㎛.

Rocket propellant storage tank according to the present invention,

First, the inner wall of the tank is formed of a material that does not react with the propellant has the advantage that can be stored for a long time to minimize the reaction of the propellant in the storage tank.

Second, the outer wall of the tank is formed of a material having rigidity to withstand high pressure and at the same time is formed of a lightweight material, it is economical because of the cost saving effect.

Third, because the temperature control unit is provided to maintain the propellant at an appropriate temperature there is an advantage that can be preserved by minimizing the reaction of the propellant that can occur in the propellant storage tank.

In general, a rocket is a device that obtains propulsion by exhaling high-pressure gas produced by burning fuel, and such an engine is called a rocket engine. Rocket engines are the most powerful engines of their size, producing more than 3,000 times the power of car engines of the same size. The rocket burns fast because of its high power, consuming a lot of fuel in a short time and generating high temperatures. Therefore, rocket engines need to be very complex and difficult because they have to withstand high temperatures, high pressures, and strong forces.

The working principle of a rocket is the law of action-reaction, which allows a powerful rocket to move forward by using reactions of the same magnitude but opposite direction when a force is applied to an object. When the propellant is combusted in the combustion chamber of the rocket, a very rapidly expanding gas is produced, the pressure of which is uniformly acting in all directions within the rocket, and the pressure applied in one direction is balanced with the pressure applied in the opposite direction. To achieve. However, the gas flowing behind the rocket is blown out through the nozzle and out of balance with the pressure in front of the rocket, causing the rocket to move forward. The gas exhaled through the nozzle corresponds to Newton's law of motion, and the propulsion to push the rocket toward the opposite direction of the exhaled gas corresponds to the reaction.

There are two main types of rockets, liquid fuel and solid fuel. The propulsion method by liquid fuel is a method of ejecting the gas generated by the combustion of fuel and oxidant filled in the gas at high speed to the rear of the gas and moving forward with the reaction force, or by directly dissolving the propellant and injecting the reaction force. The propulsion method using the solid fuel is advanced by using the propulsion force by the combustion of the solid fuel filled in the gas. Of the two propulsion methods, the non-thrust defining the thrust that can be produced by the unit mass propellant is larger than the solid fuel rocket, and the liquid fuel rocket is larger than the solid fuel rocket.

In addition, there is a single propellant method of obtaining a thrust using only one propellant, and a two-propellant method of burning a fuel using an oxidant to obtain a thrust. The single propulsion system is superior in terms of simplification and light weight of the system, but the non-thrust generated per unit mass of the propellant is relatively small while the dual propulsion system can be complicated, but the specific impulse is doubled compared to the single propulsion method. Highly efficient.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view showing the opening of the rocket propellant storage tank according to the present invention, Figure 2 is a cross-sectional view showing a state in which the temperature control unit according to the invention attached to the tank, Figure 3 is a tank inside the tank outer wall according to the present invention A cross-sectional view showing an embodiment in which the inner wall is formed by coating is shown.

1 and 2, the rocket propellant storage tank 100 may include a tank inner wall 110, a tank outer wall 120, propellant inlets 111 and 121, propellant outlets 112 and 122, and a temperature controller 130. The temperature controller 130 may optionally include a temperature sensor 131. It looks at in detail below.

The rocket or thruster will consume the propellant stored in the propellant tank. In the case of a single propellant, the propellant is reacted and injected directly. A tank for storing each propellant is then required.

When reviewing the requirements of a propellant storage tank, it is important to first preserve the properties of the rocket propellant injected from the ground in order to perform the mission for a fixed period of time. If the concentration of propellant contained in the storage tank is changed or impurities are generated, the designed thrust cannot be generated, which may interfere with mission performance. In particular, when the propellant reacts with the storage tank to generate gas, the internal temperature and pressure of the propellant storage tank are increased, and the physical properties of the tank material change depending on the reaction, which causes the tank to rupture during the mission. Therefore, the propellant storage tank needs to be a material compatible with the propellant so as not to react with the propellant. Next, the propellant storage tank must be maintained at a high pressure, so use a durable, high-strength material to withstand the pressure. At the same time, the weight of the propellant storage tank is directly related to the weight of the entire system, and if the overall system is heavy, the engine must generate higher propulsion and increase the cost of launching the rocket. Therefore, it is required to use a material having excellent strength and light weight. These requirements are specific to each type of propellant, but it is difficult to find a material for a propellant storage tank that meets all requirements and is often neglected. Accordingly, in the present invention, the material of the inner wall and outer wall of the propellant storage tank is dualized.

Referring to FIG. 1, the tank inner wall 110 is a space for receiving the propellant 140. Propellants of rockets include hydrogen peroxide (H ₂ O ₂ ), dinitrogen tetraoxide (Dinitrogen tetroxide, N ₂ O ₄ ), dinitrogen monoxide (Dinitrogen monoxide (N ₂ O), hydrazine (N ₂ H ₄ ), Kerosene (Kerosene), MMH (Mono methyl hydrazine, CH ₃ N ₂ H ₃ ), nitric acid (nitric acid, HNO ₃ ) and the like can be present in various kinds. Therefore, the tank inner wall 110 is preferably formed of a material that does not react with the propellant according to each type of propellant. 1A is a cross-sectional view showing a spherical propellant tank and FIG. 1B is a cross-sectional view showing a cylindrical propellant tank. The shape of the rocket propellant storage tank 100 is only one embodiment and may be formed in various shapes. A propellant inlet 111 may be formed at one end of the tank inner wall 110 to inject a propellant, and a propellant outlet 112 may be formed at the other end of the propellant to transfer the propellant to a reactor or an engine.

Hydrogen peroxide (H ₂ O ₂ ) is a material that is used as a rocket propellant because it has less human and property risks than hydrazine, including carcinogenic substances. When hydrogen peroxide is used as a propellant, the material of the tank inner wall 110 may also be formed of a compatible metal or non-metallic material that does not react with hydrogen peroxide. In the classification according to the degree of reaction with hydrogen peroxide, it is preferable to use a material corresponding to Class 1 as the tank inner wall 110 material.

The Class 1 material may be divided into a metal material and a nonmetal material. Metal materials include Al1060, Al1160, Al1260, Al1360, Al5052, Al5254, Al5652, Al7072, tantalum, zirconium, and non-metallic materials such as Kel-F, Viton B, Teflon, and polyethylene terephthalate ( PET) polyester film and the like.

Aluminum (Al) is used as a main material for aircraft, ships, and vehicles because of its light characteristics, and it is also used as a transmission line by using electricity transfer points. In addition, since oxidation does not occur well, food industry, tableware, etc. are also used, and also used for paint, building materials, and raw materials. In addition, because of its excellent ductility, it can be made very thin, and is widely used for making kitchen foils, printing plates, high-quality packaging paper, communication equipment, semiconductors, electronics, electronic parts, and leisure products. Al1060, Al1160, Al1260, Al1360, Al5052, Al5254, Al5652, Al7072 refer to aluminum alloy material and have different properties according to alloy number. Aluminum alloy numbers are represented by a four-digit number consisting of 'AL' and a number or letter, and are called a series including the first and second numbers. For example, in the case of AL5052 used as an aluminum alloy, it refers to any one aluminum alloy of the AL 50 series selected from the aluminum alloy group. The Al 50 series is an aluminum (Al)-magnesium (Mg) alloy is a typical work hardening alloy among aluminum alloys. Al1060, Al1160, Al1260, Al1360, Al5052, Al5254, Al5652, and Al7072 described above are metals corresponding to Class 1 materials.

Tantalum named it tantalum, reminiscent of the Greek mythology tantalose, which is troubled in hell because the oxide is not eroded by excess acid. It is a hard gray metal, rich in malleability and ductility, and its alloy with iron has high tensile strength. It does not oxidize well in air and is insoluble in acids other than hydrofluoric acid. It is soluble in fusion alkali, rare element, and number 40 in Clark number. The main ore is tantalite, fergusonite and column bite, which always coexist with niobium. Its main producers are Western Australia, Eastern Brazil, and Congo. The ore is melted by alkali to be extracted as tantalum acid salt and decomposed into acid to form tantalum acid. Since niobium is always mixed, it is separated from niobium by fractional crystals as a fluorine complex salt, and then electrolyzed to reduce metal. Get Since acid resistance is good, it is used as a material of the acid-resistant agent for chemical industry, and it is used also as materials, such as a vacuum tube and an electromagnetic tube for radar. Tantalum-tungsten alloys do not lose their elasticity when they are glowing. Tantalum carbides are used for tools such as dies due to their high hardness. Tantalum described above is a metal of Class 1 that does not react with hydrogen peroxide.

Zirconium was found in the mineral zircon, known as a gem. Then, in 1824, J. J. Vercelius reduced K2ZrF6 to potassium metal to isolate metal zirconium for the first time. It is relatively abundant in nature and ranks 20th at 165 ppm of Clark's number (average content of the earth's crust). 0.02 μg / L is present in seawater. The main minerals are zircon ZrSiO4 and baderite ZrO2. Other minerals are contained in minerals such as titanium, thorium, and rare earth elements, and are widely distributed in igneous rocks. Zirconium described above is a metal of Class 1 that does not react with hydrogen peroxide.

Teflon is a type of fluororescein. Fluororescein is a plastic containing fluorine, also called fluororesin, and has excellent thermal and chemical properties and many kinds. Fluororescein is polytetrafluoroethylene (PTFE), which was produced by Dupont under the name Teflon. In addition, fluororesins include raw polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), and polyvinyl fluoride (PVF). The unit of Teflon is tetrafluoroethylene. The unit is blown into a pressure cooker containing ammonium persulfate (polymerization initiator) and an aqueous solution of borax, heated to a high pressure, heated, polymerized, and polymerized. Specific gravity is not affected by any strong acid, strong alkali, solvent at 2.2, absorption rate 0.00%, and below 260 ℃, and does not age even after long use. The coefficient of friction is the smallest and non-tacky. It can be used at temperatures from -100 ℃ to 260 ℃. It is excellent in electrical insulation and is especially used for radio equipment and radar because it is excellent as a high frequency material. It is used for packing, gaskets, electrolytic diaphragms, baking sheeting rolls, household oven dishes and ski flooring. Teflon described above is a non-metal corresponding to Class 1 that does not react with hydrogen peroxide.

In addition, Mylar may be used as the non-metallic material of Class 1 used as the material of the tank inner wall 110. Mylar is an electrical insulation material manufactured by DuPont, USA under the trade name of polyethylene terephthalate (PET: condensate of ethylene glycol and terephthalic acid) polyester film. In addition, Mylar is a reinforced polyester film released from the late 1950 in place of cellulose acetate film. Mylar can be made into a thin film, has mechanical strength and heat resistance, and is widely used for insulation of electrical equipment and dielectrics of capacitors. In particular, the tank inner wall 110 according to the present invention is preferably used Mylar A, Mylar B manufactured by Dupont.

Referring to FIG. 1, the tank outer wall 120 is formed to surround the outer surface of the tank inner wall 110 so that the tank inner wall 110 is not deformed. The tank outer wall 120 is a structure for preventing the tank inner wall 110, which is exposed to a high pressure environment, from being deformed or damaged. As discussed in the requirements of the propellant storage tank described above, the storage tank should be made of a material that is durable and high strength to withstand high pressures. At the same time, the weight of the storage tank must be reduced. Therefore, the tank outer wall 120 is preferably formed of a material different from the tank inner wall 110. The tank outer wall 120 may be formed of any one selected from titanium-based, aluminum alloy-based, and composite materials. A propellant inlet 121 for injecting propellant to one end of the tank outer wall 120 is formed to correspond to the formation position of the propellant inlet 111 and propellant outlet 112 formed in the tank inner wall 110 and the tank The other end of the outer wall 120 is preferably formed with a propellant outlet 122 for transferring the propellant to the reactor or engine.

Titanium is a metal element of atomic number 22 belonging to group 4 of the periodic table, denoted by the symbol Ti, and is also called titanium. Titanium is a lightweight, hard and corrosion-resistant transition metal element with a silver-white metallic luster and used to make light and hard alloys of iron or aluminum. Titanium dioxide is also used as a white pigment for paints. Titanium is widely distributed in many minerals, mainly from titanium iron and rutile. Found in two isotopes and five natural isotopes, the most common being Ti-48. The most important property of titanium is that it is as hard as steel, but weighs only 60%. By utilizing this property, titanium or titanium alloy may be suitable as a material of the tank outer wall 120. The physical and chemical properties of titanium are similar to zirconium.

An aluminum alloy is an alloy in which metals such as copper and magnesium are added to aluminum, thereby improving the properties of aluminum and exhibiting excellent properties. High-strength aluminum alloys are made of copper added to aluminum and have high strength. Duralumin is a representative example. Structural aluminum alloys are made of magnesium and zinc. They are excellent in corrosion resistance and used for railway vehicles and bridges. When magnesium is added to duralumin, it becomes super duralumin, and zinc is added as an aircraft material. However, high-strength aluminum alloys have problems in corrosion resistance. For castings, a silicon-added alloy is used. In addition, other metals may be used depending on the purpose, such as heat resistance and brightness. The aluminum alloy described above may be used as a material of the tank outer wall 120 because it is light and excellent in strength. In addition, various composite materials may be used as the material of the tank outer wall 120 in addition to the above-described titanium and aluminum alloy series.

Referring to FIG. 3, an embodiment in which the tank inner wall 110 is coated on the inner side of the tank outer wall 120 may be considered. The tank outer wall 120 has a certain thickness because the strength is required as described above, but the tank inner wall 110 may be formed by a thin coating because only the reactivity with the propellant is considered. When hydrogen peroxide is used as the propellant 140 and the tank inner wall 110 is formed by being coated inside the tank outer wall 120, the tank inner wall 110 is preferably coated with a thickness of 0.1 to 1 μm. The thickness may vary depending on the type of propellant, the propellant storage pressure, and the material of the tank inner wall 110.

Referring to FIG. 2, the temperature controller 130 may be formed in plural at any one position selected from an outer circumferential surface of the tank outer wall 120 or between the tank outer wall 120 and the tank inner wall 110. . The temperature control unit 130 may be provided as a hot wire to wind the outer circumferential surface of the tank outer wall 120 or the outer circumferential surface of the tank inner wall 110 or attach it only to a portion thereof. The temperature control unit 130 is mainly responsible for the function of the heater to heat, but may consider a cooling function that can be cooled when overheated. In consideration of the cooling function, the temperature controller 130 may be formed of a Peltier device. The temperature controller 130 may include a temperature sensor 131 to perform a heating or cooling function according to the temperature of the propellant.

When the rocket propellant storage tank 100 is used for a rocket engine test on the ground, the propellant 140 is located at the lower end by gravity and does not need to separately control the position of the propellant 140. However, since the gravitational field does not work in space, it is necessary to control the position of the propellant 140. Therefore, two methods may be considered to control the position of the propellant 140 when utilized in space. First, an inert high pressure gas may be used to push the propellant 140 toward the propellant outlets 112 and 122. In this case, the propellant 140 and the inert high pressure gas may be partitioned using bellows, a diaphragm, and the like, and the inert high pressure gas may pressurize the propellant 140 and push it out to the rocket engine. Second, a passive method of allowing the propellant 140 to be collected at the propellant outlets 112 and 122 by using the surface tension of the liquid may be considered.

The technical idea should not be interpreted as being limited to the above-described embodiment of the present invention. Various modifications may be made at the level of those skilled in the art without departing from the spirit of the invention as claimed in the claims. Therefore, such improvements and modifications fall within the protection scope of the present invention as long as it is obvious to those skilled in the art.

1 is a cross-sectional view showing the modification of the rocket propellant storage tank according to the present invention.

2 is a cross-sectional view showing a state in which the temperature control unit according to the present invention is attached to the tank.

3 is a cross-sectional view showing an embodiment in which the tank inner wall is coated inside the tank outer wall formed according to the present invention.

<Description of the symbols for the main parts of the drawings>

100: Rocket Propellant Storage Tank

110: tank inner wall 111: propellant inlet

112: propellant exit

120: tank outer wall 121: propellant inlet

122: propellant exit

130: temperature controller 131: temperature detection sensor

140: propellant

Claims (6)

In the rocket propellant storage tank of the rocket or thruster using hydrogen peroxide as the propellant 140, A tank inner wall 110 containing a propellant 140; A tank outer wall 120 formed to surround an outer surface of the tank inner wall 110 and provided with a material different from that of the tank inner wall 110; Propellant inlets 111 and 121 formed at one end of the tank inner wall 110 and tank outer wall 120 and propellant outlets 112 and 122 formed at the other end thereof; And A temperature controller 130 for maintaining the temperature of the propellant 140; Formed to include, The tank inner wall 110 is formed of a Class 1 material of a metal or nonmetal material that does not react with hydrogen peroxide, The tank outer wall 120 is a rocket propellant storage tank, characterized in that formed of any one selected from titanium series, aluminum alloy series, composite materials. delete delete The method of claim 1, The Class 1 material is a metal material selected from Al1060, Al1160, Al1260, Al1360, Al5052, Al5254, Al5652, Al7072, tantalum, zirconium, or Kel-F, Viton B, Teflon Rocket propellant storage tank, characterized in that the non-metal material of the selected. The method of claim 4, wherein The temperature controller 130 is formed in a plurality of any one position selected from the outer circumferential surface of the tank outer wall 120 or between the tank outer wall 120 and the tank inner wall 110, the temperature sensor 131 A rocket propellant storage tank, characterized in that provided. Claim 6 was abandoned when the registration fee was paid. The method of claim 5, The tank inner wall (110) is a rocket propellant storage tank, characterized in that formed on the inside of the tank outer wall 120 to a thickness of 10 nm ~ 10 ㎛.

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