Low-temperature propellant supply valve and supply method

Abstract

The invention relates to a valve and a working method thereof, in particular to a supply valve for low-temperature propellants and a working method of the supply valve, and aims to solve the problem that when the low-temperature propellants are supplied, filler of an existing low-temperature valve is prone to failure, sealing performance is prone to decline, and supply of the low-temperature propellants is affected. The heat exchange valve comprises a valve body, a heat exchange cavity arranged at the upper end of the valve body, an air cylinder arranged at the upper end of the heat exchange cavity and a valve rod vertically arranged in the valve body, the heat exchange cavity and the air cylinder. The valve rod sequentially penetrates through the air cylinder, the heat exchange cavity and the middle pipeline and sequentially comprises a piston section, a heat exchange section, a middle section and a lower section from top to bottom. A piston is arranged at the top end of the valve rod piston section; the valve rod heat exchange section is arranged in the heat exchange cavity, the heat dissipation device is arranged on the heat exchange section, and a heat insulation ring is arranged at the lower end of the heat exchange cavity. The valve rod is a hollow cylinder, and the valve rod is filled with a composite phase change material which changes along with the temperature and can longitudinally flow.

Description

Technical Field

[0001] The present invention relates to a valve, in particular to a cryogenic propellant supply valve and a supply method. Background Art

[0002] Liquid oxygen-hydrocarbon rocket engines are commonly used in various types of rockets. During the development process, rocket engines require extensive testing (commissioning) to determine the engine's operating parameters and other key indicators.

[0003] At present, liquid oxygen hydrocarbon rocket engines mainly include green and environmentally friendly rocket engines such as liquid oxygen kerosene engines, hydrogen oxygen engines, and liquid oxygen methane engines, and the propellants of the above engines all have low-temperature characteristics.

[0004] Determining the reliability of an engine often requires a series of test runs. On the test bench, cryogenic valves are primarily used to isolate the cryogenic propellant supply. Current cryogenic valve stems have the following problems: (1) The traditional single-layer stem structure is prone to forming cold bridges, causing the cold energy of the cryogenic propellant to easily transfer to the valve's stuffing box area, causing the valve packing to freeze and fail; (2) The sealing performance is prone to degradation over extended periods of use. Summary of the Invention

[0005] The present invention aims to solve the problem that when supplying cryogenic propellant, the filler in the existing cryogenic valve is easily frozen, causing valve failure and sealing performance to deteriorate, thereby affecting the supply of cryogenic propellant, and to provide a cryogenic propellant supply valve and supply method.

[0006] To achieve the above objectives, the technical solutions provided by the present invention are:

[0007] A cryogenic propellant supply valve having the following characteristics:

[0008] It comprises a valve body, a heat exchange cavity arranged at the upper end of the valve body, a cylinder arranged at the upper end of the heat exchange cavity, and a valve stem vertically arranged in the valve body, the heat exchange cavity and the cylinder;

[0009] The valve body includes an input pipeline, an intermediate pipeline, and an output pipeline connected in sequence along the flow direction of the cryogenic propellant, wherein the input pipeline and the output pipeline are both arranged horizontally, and the intermediate pipeline is arranged vertically; the valve stem is arranged through the cylinder, the heat exchange cavity, and the intermediate pipeline in sequence, and includes, from top to bottom, a piston section, a heat exchange section, a middle section, and a lower section;

[0010] The piston section of the valve stem is arranged in the cylinder, and a piston is arranged at its top, and the piston divides the cylinder into an upper cavity and a lower cavity; a first convex ring for limiting is arranged at one end of the piston section close to the heat exchange section; a valve closing cavity vent interface is arranged on the side of the upper cavity of the cylinder, and a valve opening cavity vent interface is arranged on the side of the lower cavity;

[0011] The heat exchange section of the valve stem is arranged in the heat exchange cavity, a heat dissipation device is provided on the heat exchange section, a heat insulation ring is provided at the lower end of the heat exchange cavity, and a multi-layer sealing gasket is provided between the valve stem and the heat insulation ring;

[0012] The valve stem is a hollow cylinder, the interior of which is filled with a composite phase change material that changes with temperature and can flow longitudinally along the inner wall of the valve stem;

[0013] The middle section of the valve stem is arranged in the intermediate pipeline at a position corresponding to the input pipeline, the lower section of the valve stem is arranged in the intermediate pipeline and extends to a position corresponding to the output pipeline, and a second convex ring for limiting is arranged between the middle section and the lower section.

[0014] Furthermore, the heat exchange section of the valve stem includes a heat exchange exposed section and a heat exchange heat dissipation section connected in sequence from top to bottom, wherein the heat exchange exposed section is covered with an electric heating film, and the heat dissipation device is arranged on the heat exchange heat dissipation section.

[0015] Furthermore, the heat dissipation device includes four conical surfaces sequentially sleeved on the heat exchange and heat dissipation section, the distance between every two adjacent conical surfaces is equal, and the outer circle height of each conical surface is lower than the inner circle height.

[0016] Furthermore, the angle between each cone generatrix of the heat dissipation device and the horizontal plane is 30°.

[0017] Furthermore, the composite phase change material is a paraffin-based and nanographene combination material.

[0018] Furthermore, the material of the thermal insulation ring is an aerogel composite material, the thickness of the thermal insulation ring is 3 mm to 5 mm, and the thermal conductivity is ≤0.02 W / (m·K).

[0019] Furthermore, each of the sealing gaskets is a memory alloy gasket made of Ni-Ti, and the electric heating film is made of PTFE.

[0020] Furthermore, the valve stem is made of stainless steel.

[0021] At the same time, the present invention also provides a cryogenic propellant supply method, which is based on the above-mentioned cryogenic propellant supply valve and has the following characteristics:

[0022] Step 1: Assemble the cryogenic propellant supply valve and install it at a preset position on the supply line;

[0023] Step 2: Fill the vent port of the valve closing chamber with gas, so that the piston drives the valve stem downward, and closes the cryogenic propellant supply valve;

[0024] Step 3: Cryogenic propellant is charged from the inlet end of the input pipeline. The cold energy of the cryogenic propellant passes through the valve stem and the composite phase change material inside the valve stem in real time. When the composite phase change material is cooled, it expands and flows upward, transferring the cold energy to the heat sink. The heat sink exchanges heat with the atmospheric environment in the heat exchange chamber in real time. After the heat exchange is completed, the composite phase change material melts and flows downward.

[0025] Step 4: Fill the vent port of the valve opening cavity with gas, so that the piston drives the valve stem to move upward, and open the cryogenic propellant supply valve;

[0026] Step 5: The cryogenic propellant begins to flow from the intermediate pipeline to the outlet end of the output pipeline;

[0027] Step 6: When the cryogenic propellant supply is completed, gas is filled into the vent interface of the valve closing chamber, so that the piston drives the valve stem to move downward, and the cryogenic propellant supply valve is closed.

[0028] Furthermore, in step 2, after the cryogenic propellant supply valve is closed, the step also includes starting the electric heating film to heat the valve stem.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The cryogenic propellant supply valve provided by the present invention can transmit the cold energy brought by the cryogenic propellant to the heat dissipation device in real time through the composite phase change material in the valve stem, and exchange the cold energy with the external environment. The composite phase change material after the heat exchange can return to the bottom and continue to transfer the cold energy. Such a cycle can improve the reliability of the supply system in which the valve is located. The cycle effectively solves the problem that the valve stem may cause frost on the valve stem surface or the valve cannot be opened or closed due to untimely heat dissipation. In addition, the sealing performance remains good during long-term use.

[0031] 2. The cryogenic propellant supply valve provided by the present invention has a composite phase change material which is a paraffin-based and nanographene combination material, and is adaptable to the supply of cryogenic propellants.

[0032] 3. The cryogenic propellant supply valve provided by the present invention has an insulation ring made of aerogel composite material, which is particularly suitable for the stem insulation structure of large-diameter (DN ≥ 400mm) cryogenic valves used in media such as LNG (Liquefied Natural Gas), liquid nitrogen, and liquid oxygen.

[0033] 4. In the cryogenic propellant supply valve provided by the present invention, each sealing gasket is a memory alloy gasket made of Ni-Ti material, which can meet the cold compensation under low temperature conditions, thereby realizing the dynamic sealing function of the valve stem.

[0034] 5. In the cryogenic propellant supply valve provided by the present invention, the angle between each conical generatrix of the heat dissipation device and the horizontal plane is 30°, which can achieve rapid discharge of condensed water.

[0035] 6. The working method of the cryogenic propellant supply valve provided by the present invention can transmit the cold energy brought by the cryogenic propellant to the heat dissipation device on the upper part of the valve stem in real time, and exchange heat with the atmospheric environment, thereby ensuring the continuous and normal supply of cryogenic propellant. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 2 is a cross-sectional view of an embodiment of a cryogenic propellant supply valve according to the present invention, wherein “←” indicates the flow direction of the cryogenic propellant;

[0037] Description of reference numerals:

[0038] 1-cylinder, 2-piston, 3-heat dissipation device, 4-sealing gasket, 5-valve stem, 6-valve body, 7-valve closing chamber ventilation interface, 8-valve opening chamber ventilation interface, 9-heat exchange chamber, 10-insulation ring, 11-first convex ring, 12-second convex ring. DETAILED DESCRIPTION

[0039] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0040] A supply valve for cryogenic propellants, see Figure 1 , comprising a valve body 6, a heat exchange cavity 9 provided at the upper end of the valve body 6, a cylinder 1 provided at the upper end of the heat exchange cavity 9, and a valve stem 5 vertically provided in the valve body 6, the heat exchange cavity 9 and the cylinder 1;

[0041] The valve body 6 includes an input pipeline, an intermediate pipeline, and an output pipeline connected in sequence along the flow direction of the cryogenic propellant, wherein the input pipeline and the output pipeline are both arranged horizontally, and the intermediate pipeline is arranged vertically; the valve stem 5 is arranged through the cylinder 1, the heat exchange chamber 9, and the intermediate pipeline in sequence, and includes, from top to bottom, a piston section, a heat exchange section, a middle section, and a lower section;

[0042] The piston section of the valve stem 5 is disposed within the cylinder 1, with a piston 2 disposed at its top end. The piston 2 divides the cylinder 1 into an upper cavity and a lower cavity. A first convex ring 11 for limiting position is disposed at the end of the piston section near the heat exchange section. A valve closing cavity vent interface 7 is disposed on the side of the upper cavity of the cylinder 1, and a valve opening cavity vent interface 8 is disposed on the side of the lower cavity.

[0043] The heat exchange section of the valve stem 5 is located within the heat exchange chamber 9. A heat sink 3 is installed on this section. An insulation ring 10 is installed at the lower end of the heat exchange chamber 9. A multi-layer sealing gasket 4 is placed between the valve stem 5 and the insulation ring 10. The heat exchange section of the valve stem 5 consists of an exposed heat exchange section and a heat exchange and heat dissipation section, connected sequentially from top to bottom. The exposed heat exchange section is coated with an electric heating film, and the heat sink 3 is installed on the heat exchange and heat dissipation section. The heat sink 3 comprises four conical surfaces that are sequentially mounted on the heat exchange and heat dissipation section. The distance between each adjacent conical surface is equal, and the outer ring height of each conical surface is lower than the inner ring height. The angle between the generatrix of each conical surface of the heat sink 3 and the horizontal plane is 30°, which ensures the rapid discharge of condensed water.

[0044] The valve stem 5 is a hollow cylinder, the interior of which is filled with a composite phase change material that changes with temperature and can flow longitudinally along the inner wall of the valve stem 5;

[0045] The middle section of the valve stem 5 is arranged in the intermediate pipeline at a position corresponding to the input pipeline, the lower section of the valve stem 5 is arranged in the intermediate pipeline and extends to a position corresponding to the output pipeline, and a second convex ring 12 for limiting is arranged between the middle section and the lower section.

[0046] In this embodiment, the composite phase change material is a paraffin-based and nanographene composite material with a phase transition point of -50°C to -30°C, which can adapt to the supply of low-temperature propellants. The material of the thermal insulation ring 10 is an aerogel composite material, the thickness of the thermal insulation ring 10 is 3mm to 5mm, and the thermal conductivity is ≤0.02W / (m·K). Each sealing gasket 4 is a memory alloy gasket made of Ni-Ti material with a phase transition temperature of -30°C, which can meet the cold compensation under low temperature conditions, thereby achieving a dynamic sealing effect. The material of the electric heating film is PTFE; the material of the valve stem 5 is stainless steel with high strength.

[0047] At the same time, this embodiment also provides a cryogenic propellant supply method, based on the above-mentioned cryogenic propellant supply valve, comprising the following steps:

[0048] Step 1: Assemble the cryogenic propellant supply valve and install it at a preset position on the supply line;

[0049] Step 2: Fill the vent port 7 of the valve closing cavity with gas, so that the piston 2 drives the valve stem 5 to move downward, and closes the cryogenic propellant supply valve; start the electric heating film to heat the valve stem 5;

[0050] Step 3: Cryogenic propellant is charged from the inlet end of the input pipeline. The cold energy of the cryogenic propellant passes through the valve stem 5 and the composite phase change material inside the valve stem 5 in real time. When the composite phase change material is cooled, it expands and flows upward, transferring the cold energy to the heat sink 3. The heat sink 3 exchanges heat with the atmospheric environment in the heat exchange chamber 9 in real time. After the heat exchange is completed, the composite phase change material melts and flows downward. The purpose of this step is to pre-cool the supply pipeline.

[0051] Step 4: Fill the valve opening cavity vent interface 8 with gas, so that the piston 2 drives the valve stem 5 to move upward, and the cryogenic propellant supply valve is opened;

[0052] Step 5: The cryogenic propellant begins to flow from the intermediate pipeline to the outlet end of the output pipeline;

[0053] Step 6: When the cryogenic propellant supply is completed, gas is filled into the vent interface 7 of the valve closing chamber, so that the piston 2 drives the valve stem 5 to move downward, and the cryogenic propellant supply valve is closed.

Claims

1. A cryogenic propellant supply valve, characterized in that: It comprises a valve body (6), a heat exchange cavity (9) arranged at the upper end of the valve body (6), a cylinder (1) arranged at the upper end of the heat exchange cavity (9), and a valve stem (5) vertically arranged in the valve body (6), the heat exchange cavity (9), and the cylinder (1); The valve body (6) comprises an input pipeline, an intermediate pipeline and an output pipeline connected in sequence along the flow direction of the cryogenic propellant, wherein the input pipeline and the output pipeline are both arranged horizontally, and the intermediate pipeline is arranged vertically; the valve stem (5) passes through the cylinder (1), the heat exchange cavity (9) and the intermediate pipeline in sequence, and comprises a piston section, a heat exchange section, a middle section and a lower section in sequence from top to bottom; The piston section of the valve stem (5) is arranged in the cylinder (1), and a piston (2) is arranged on the top of the valve stem, and the piston (2) divides the cylinder (1) into an upper cavity and a lower cavity; a first convex ring (11) for limiting is arranged at one end of the piston section close to the heat exchange section; a valve closing cavity vent interface (7) is arranged on the side of the upper cavity of the cylinder (1), and a valve opening cavity vent interface (8) is arranged on the side of the lower cavity; The heat exchange section of the valve stem (5) is arranged in a heat exchange cavity (9), a heat dissipation device (3) is provided on the heat exchange section, a heat insulation ring (10) is provided at the lower end of the heat exchange cavity (9), and a multi-layer sealing gasket (4) is provided between the valve stem (5) and the heat insulation ring (10); The valve stem (5) is a hollow cylinder, the interior of which is filled with a composite phase change material that changes with temperature and can flow longitudinally along the inner wall of the valve stem (5); The middle section of the valve stem (5) is arranged in the intermediate pipeline at a position corresponding to the input pipeline, the lower section of the valve stem (5) is arranged in the intermediate pipeline and extends to a position corresponding to the output pipeline, and a second convex ring (12) for limiting is arranged between the middle section and the lower section.

2. The cryogenic propellant supply valve according to claim 1, characterized in that: The heat exchange section of the valve stem (5) comprises a heat exchange exposed section and a heat exchange heat dissipation section connected in sequence from top to bottom, wherein the heat exchange exposed section is coated with an electric heating film, and the heat dissipation device (3) is arranged on the heat exchange heat dissipation section.

3. The cryogenic propellant supply valve according to claim 2, characterized in that: The heat dissipation device (3) comprises four conical surfaces sequentially sleeved on the heat exchange and heat dissipation section, the distance between every two adjacent conical surfaces is equal, and the height of the outer circle of each conical surface is lower than the height of the inner circle.

4. The cryogenic propellant supply valve according to claim 3, characterized in that: The included angle between each cone generatrix of the heat dissipation device (3) and the horizontal plane is 30°.

5. The cryogenic propellant supply valve according to claim 4, characterized in that: The composite phase change material is a paraffin-based and nanographene combination material.

6. The cryogenic propellant supply valve according to claim 5, characterized in that: The material of the thermal insulation ring (10) is an aerogel composite material, the thickness of the thermal insulation ring (10) is 3 mm to 5 mm, and the thermal conductivity coefficient is ≤0.02 W / (m·K).

7. The cryogenic propellant supply valve according to claim 6, characterized in that: Each of the sealing gaskets (4) is a memory alloy gasket made of Ni-Ti, and the material of the electric heating film is PTFE.

8. The cryogenic propellant supply valve according to claim 7, characterized in that: The material of the valve stem (5) is stainless steel.

9. A cryogenic propellant supply method, based on the cryogenic propellant supply valve according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Assemble the cryogenic propellant supply valve and install it at a preset position on the supply line; Step 2: Fill the valve closing cavity vent interface (7) with gas, so that the piston (2) drives the valve stem (5) to move downward, and close the cryogenic propellant supply valve; Step 3: Low-temperature propellant is charged from the inlet end of the input pipeline. The cold energy of the low-temperature propellant passes through the valve stem (5) and the composite phase change material in the valve stem (5) in real time. The composite phase change material expands and flows upward when it is cooled, and transfers the cold energy to the heat dissipation device (3). The heat dissipation device (3) exchanges heat with the atmospheric environment in the heat exchange cavity (9) in real time. After the heat exchange is completed, the composite phase change material melts and flows downward. Step 4: Fill the valve opening cavity vent interface (8) with gas, so that the piston (2) drives the valve stem (5) to move upward, and open the cryogenic propellant supply valve; Step 5: The cryogenic propellant begins to flow from the intermediate pipeline to the outlet end of the output pipeline; Step 6: When the cryogenic propellant supply is completed, the valve closing chamber vent interface (7) is filled with gas, so that the piston (2) drives the valve stem (5) to move downward, and the cryogenic propellant supply valve is closed.

10. The cryogenic propellant supply method according to claim 9, characterized in that: In step 2, after the cryogenic propellant supply valve is closed, the method further includes starting the electric heating film to heat the valve stem (5).

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