A turbine pump isolation cavity heat exchange coefficient testing device and thermal state analysis method

Abstract

The present application relates to a kind of rocket engine accessories, specifically, a kind of turbine pump isolation cavity heat transfer coefficient testing device and thermal state analysis method, the purpose is to solve the problem that the internal structure of existing turbine pump isolation cavity is difficult to obtain its thermal state by test method.This application includes fuel cavity simulation piece, isolation cavity simulation piece and oxidant cavity simulation piece connected in turn;Fuel cavity simulation piece is the first circular ring cavity, and oxidant cavity simulation piece is the third circular ring cavity, and isolation cavity simulation piece is the circular table with the one end of second circular ring cavity connected with big end, the small end of circular table is connected with the one end of first circular ring cavity, and the other end of second circular ring cavity is connected with the one end of third circular ring cavity;The other end of first circular ring cavity is provided with first circular ring plate, and the other end of third circular ring cavity is provided with third circular ring plate;First circular ring cavity and circular table, between second circular ring cavity and third circular ring cavity, are all provided with isolation circular ring plate.

Description

Technical Field

[0001] This invention relates to a rocket engine component, specifically to a device for testing the heat transfer coefficient of a turbopump isolation chamber and a method for analyzing its thermal state. Background Technology

[0002] The starting principle of a pump-fed liquid rocket engine is to use a turbopump to deliver propellant from the tank to the thrust chamber through pipelines, thereby achieving startup. The turbopump is a combination of a turbine and a propellant pump. The oxidizer pump and fuel pump are driven by the turbine, which is coaxial with the pump or driven by gears. In a liquid oxygen / kerosene engine, the working fluid of the oxidizer pump is liquid oxygen, a cryogenic propellant; the working fluid of the fuel pump is kerosene, a room-temperature propellant. An isolation chamber exists between the oxidizer pump and the fuel pump. This isolation chamber serves two purposes: first, it separates the room-temperature fuel pump from the cryogenic oxidizer pump; second, since the turbopump's seals often leak small amounts of propellant, the isolation chamber allows for the use of a purging air source to remove this leakage, thus preventing the accumulation of both propellants from adversely affecting pump performance.

[0003] The heat transfer coefficient within the isolation chamber is a crucial boundary condition for analyzing the heat transfer state of the turbopump isolation chamber. Due to the complex structure of turbopumps, involving numerous parts and materials, and considering the rotating components and high internal pressure, it is difficult to obtain the internal thermal state of the bearing cavity through experiments. Simulation analysis is more effective. Due to the structural limitations of turbopumps, the isolation chamber is typically annular, and nitrogen is usually the purge gas source, although helium or other gases are sometimes used. The purge gas enters through openings on the annular circumferential surface of the isolation chamber and exits through openings at intervals. The flow lines within the isolation chamber are quite chaotic after entering, making it difficult to obtain realistic boundary conditions through theoretical estimation. However, during engine testing, the analysis of the isolation chamber purge process is crucial for determining the capacity of the nitrogen cylinder carried by the engine during actual service. Accurate estimation of the purge state and the required purge gas volume is essential for simplifying the rocket engine structure and improving its thrust-to-weight ratio. Summary of the Invention

[0004] The purpose of this invention is to solve the problem that it is difficult to obtain the internal thermal state of the isolation chamber of a turbopump through experimental methods, and to provide a test device for the heat transfer coefficient of the isolation chamber of a turbopump and a method for thermal state analysis.

[0005] To achieve the above objectives, the technical solution provided by this invention is:

[0006] A device for testing the heat transfer coefficient of a turbine pump isolation chamber, characterized by:

[0007] It includes a fuel chamber simulator, an isolation chamber simulator, and an oxidizer chamber simulator that are coaxially connected in sequence;

[0008] The fuel chamber simulator is a first annular cavity, and the oxidant chamber simulator is a third annular cavity; the isolation chamber simulator includes a hollow frustum and a second annular cavity, one end of the frustum is connected to one end of the second annular cavity, the other end of the frustum is connected to one end of the first annular cavity, and the other end of the second annular cavity is connected to one end of the third annular cavity; a first annular plate is provided at the other end of the first annular cavity, and a third annular plate is provided at the other end of the third annular cavity; isolation annular plates are provided between the first annular cavity and the frustum, and between the second annular cavity and the third annular cavity;

[0009] The first annular plate is provided with a fuel inlet pipe and a fuel outlet pipe; the third annular plate is provided with an oxidant inlet pipe and an oxidant outlet pipe;

[0010] Multiple connectors are provided on the sidewall of the second annular cavity and / or frustum, with a total number of at least three connectors. At least two connectors are used to simulate the inflow and outflow of purging gas during purging, respectively, and at least one connector is used to monitor the internal temperature and pressure of the isolation cavity simulator.

[0011] Furthermore, temperature sensors and pressure sensors are installed in both the fuel inlet pipe and the oxidant inlet pipe; temperature sensors are installed in both the fuel outlet pipe and the oxidant outlet pipe.

[0012] Furthermore, the number of connectors is eight, with four connectors evenly distributed around the circumference of the frustum sidewall and the other four connectors evenly distributed around the circumference of the second annular cavity sidewall; the connectors used to simulate the inflow and outflow of purging gas are pipe connectors, and the connectors used to measure temperature and pressure are aviation plugs; the temperature sensor is a thermocouple.

[0013] Furthermore, the second and third annular cavities are connected by connecting flanges, and a sealing ring is provided between the two connecting flanges; the inner diameters of the first annular plate, the third annular plate, the isolation annular plate, the first annular cavity, the second annular cavity, the third annular cavity, and the frustum are equal.

[0014] Furthermore, the outer walls of the oxidant inlet pipe, the oxidant outlet pipe, and the oxidant cavity simulator are all covered with heat insulation material, which includes one or more of high-silica glass fiber cloth, Kevlar cloth, and silicone rubber cloth.

[0015] Furthermore, the fuel inlet pipe and the fuel outlet pipe are symmetrically arranged about the axis of the first annular plate, and the oxidant inlet pipe and the oxidant outlet pipe are symmetrically arranged about the axis of the third annular plate.

[0016] Meanwhile, the present invention also provides a method for analyzing the thermal state of a turbopump isolation chamber, which uses the aforementioned turbopump isolation chamber heat transfer coefficient testing device, and is characterized by including the following steps:

[0017] Step 1: Install the turbine pump isolation chamber heat transfer coefficient testing device to the preset position;

[0018] Step 2: Start filling the oxidant chamber simulation with oxidant from the oxidant inlet pipe. When the oxidant chamber simulation is full, the oxidant will automatically flow out from the oxidant outlet pipe. At the same time, monitor the temperature T1 and pressure P1 of the oxidant inlet pipe and the temperature T2 of the oxidant outlet pipe until T2 reaches the preset value. Maintain this state for t1 time.

[0019] Step 3: Start filling the fuel chamber simulator with fuel from the fuel inlet pipe. When the fuel chamber simulator is full, the fuel will automatically flow out from the fuel outlet pipe. At the same time, monitor the temperature T3 and pressure P2 of the fuel inlet pipe and the temperature T4 of the fuel outlet pipe until T4 reaches the preset value and maintain this state for t2.

[0020] Step 4: Start by introducing purging gas into the isolation cavity simulator through at least one connector. Once the isolation cavity simulator is filled, the purging gas will automatically flow out from the other connector. At the same time, monitor the temperature T5 and pressure P3 of the connector into which the purging gas is introduced, as well as the outer wall temperature T6, inner wall temperature T7, internal space temperature T8, and internal space pressure P4 of the isolation cavity simulator, until T6, T7, T8, and P4 all reach the preset steady-state range. Maintain this state for a duration t3, and then record the values ​​of T6, T7, T8, and P4 at this time.

[0021] Step 5: Change the temperature and pressure of the blow-off gas, then return to step 4, obtain and record the values ​​of T6, T7, T8 and P4 in another preset steady-state range, until the corresponding values ​​of T5 and P3 and T6, T7, T8 and P4 in N preset steady-state ranges are obtained. After sorting, the flow rate-heat transfer coefficient table of the inner surface of the isolation chamber at different temperatures is obtained, i.e., the qh table.

[0022] Step 6: Establish a heat transfer model of the actual turbopump. The heat transfer model includes an oxidant chamber, an isolation chamber, and a fuel chamber. Set several temperature check points on the heat transfer model and set an actual allowable temperature range for each temperature check point.

[0023] Step 7: Based on the qh table obtained in Step 5, set the boundary conditions for the heat transfer model;

[0024] Step 8: According to the boundary conditions of the heat transfer model, if the precooling and exhaust conditions of the turbopump do not change with time, the thermal state of the turbopump heat transfer model is obtained by steady-state analysis; if at least one of the precooling and exhaust conditions of the turbopump changes with time, the thermal state of the turbopump heat transfer model is obtained by transient analysis.

[0025] Step 9: Based on the thermal state of the turbine pump heat transfer model, determine whether the temperature at each temperature check point is within the actual allowable temperature range. If the temperature at each temperature check point is within its corresponding actual allowable temperature range, the boundary conditions of the heat transfer model meet the requirements, and the thermal state analysis of the turbine pump isolation chamber is completed. If the temperature at at least one temperature check point is not within its corresponding actual allowable temperature range, return to step 7 to modify the boundary conditions of the heat transfer model.

[0026] Furthermore, step 7 specifically includes:

[0027] Step 7.1: Set the inner surface of the oxidant chamber to convective heat transfer conditions or isothermal conditions according to the flow rate of the oxidant during the pre-cooling process, and set the outer surface of the oxidant chamber to adiabatic conditions.

[0028] Step 7.2: Set the inner surface of the fuel chamber to convective heat transfer conditions or isothermal conditions according to the fuel flow rate. The heat transfer coefficient h4 of the inner surface of the fuel chamber is calculated according to the DB formula, and the heat transfer temperature Th4 of the inner surface of the fuel chamber is the fuel temperature. Set the outer surface of the fuel chamber to natural convection heat transfer conditions. The heat transfer coefficient h1 of the outer surface of the fuel chamber is estimated according to the natural convection heat transfer formula, and the heat transfer temperature Th1 of the outer surface of the fuel chamber is the ambient temperature during the test.

[0029] Step 7.3: Set the inner surface of the isolation chamber to convective heat transfer conditions. The heat transfer coefficient h2 of the inner surface of the isolation chamber is set according to the qh table obtained in Step 5, and the heat transfer temperature Th2 of the inner surface of the isolation chamber is set according to the temperature of the blow-off gas in the blow-off chamber. Set the outer surface of the isolation chamber to natural convection heat transfer conditions. The heat transfer coefficient h3 of the outer surface of the isolation chamber is estimated according to the natural convection heat transfer formula, and the heat transfer temperature Th3 of the outer surface of the isolation chamber is the ambient temperature during the test.

[0030] Furthermore, if the temperature check point that does not meet the conditions is inside the isolation chamber, then a new set of qh values ​​that are different from the previously selected qh values ​​should be selected in the qh table; if the temperature check point that does not meet the conditions is inside the fuel chamber, then the heat transfer coefficient h4 and the heat transfer temperature Th4 of the inner surface of the fuel chamber should be adjusted.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] 1. The present invention provides a test device for the heat transfer coefficient of a turbopump isolation chamber, comprising a fuel chamber simulator, an isolation chamber simulator, and an oxidant chamber simulator, which can conveniently test the heat transfer coefficient and simulate the actual working conditions of the turbopump isolation chamber, providing a basis for the thermal state analysis of the turbopump isolation chamber;

[0033] 2. The present invention provides a method for analyzing the thermal state of a turbopump isolation chamber. By calculating the heat transfer coefficient of the isolation chamber, the temperature data of various important points in the turbopump, i.e., the thermal state, can be obtained more accurately to assess the state of the turbopump purging process and determine whether the temperature of the turbopump bearings and seals is within the allowable temperature range of the materials. If there is a risk of engine starting, this method can be used to predict the thermal state of the improvement scheme, optimize the test system process, and ensure that the engine turbopump starts normally. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of an embodiment of the heat transfer coefficient testing device for a turbine pump isolation chamber according to the present invention;

[0035] Figure 2 This is a cross-sectional view of an embodiment of a turbine pump isolation chamber heat transfer coefficient testing device according to the present invention;

[0036] Figure 3 for Figure 2 Enlarged view of point A;

[0037] Explanation of reference numerals in the attached figures:

[0038] 1-Fuel inlet pipe, 2-Fuel chamber simulator, 3-Connector, 4-Isolation chamber simulator, 5-Sealing ring, 6-Connecting flange, 8-Oxidant chamber simulator, 9-Oxidant inlet pipe, 10-Fuel outlet pipe, 11-Oxidant outlet pipe. Detailed Implementation

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

[0040] A device for testing the heat transfer coefficient of a turbine pump isolation chamber, see [link / reference]. Figures 1-3 It includes a fuel chamber simulator 2, an isolation chamber simulator 4, and an oxidizer chamber simulator 8, which are connected coaxially in sequence.

[0041] The fuel chamber simulator 2 is a first annular cavity, and the oxidant chamber simulator 8 is a third annular cavity; the isolation chamber simulator 4 includes a hollow frustum and a second annular cavity, the larger end of the frustum is connected to one end of the second annular cavity, the smaller end of the frustum is connected to one end of the first annular cavity, and the other end of the second annular cavity is connected to one end of the third annular cavity; a first annular plate is provided at the other end of the first annular cavity, and a third annular plate is provided at the other end of the third annular cavity; isolation annular plates are provided between the first annular cavity and the frustum, and between the second annular cavity and the third annular cavity; the first annular plate and the third annular plate... The inner diameters of the isolation annular plate, the first annular cavity, the second annular cavity, the third annular cavity, and the frustum are equal. The first annular plate is provided with a fuel inlet pipe 1 and a fuel outlet pipe 10. The third annular plate is provided with an oxidant inlet pipe 9 and an oxidant outlet pipe 10. Four connectors 3 are evenly distributed circumferentially on the side walls of the second annular cavity and the frustum, respectively. Four connectors 3 are located on the side wall of the frustum and four connectors 5 are located on the side wall of the second annular cavity. The connectors 3 used to simulate the introduction and exit of nitrogen gas during purging are pipe connectors, and the connectors 3 used to measure temperature and pressure data are aviation plugs.

[0042] To facilitate the assembly and disassembly of the isolation chamber simulation component 4, the second and third annular cavities are connected by a connecting flange 6; at the same time, to enhance the sealing performance, a sealing ring 5 is provided between the two connecting flanges 6.

[0043] In this embodiment, temperature sensors and pressure sensors are installed in both the fuel inlet pipe 1 and the oxidant inlet pipe 9; temperature sensors are installed in both the fuel outlet pipe 10 and the oxidant outlet pipe 10. All temperature sensors are thermocouples.

[0044] The fuel inlet pipe 1 and fuel outlet pipe 10 are arranged radially symmetrically about the first annular plate, and the oxidant inlet pipe 9 and oxidant outlet pipe 10 are arranged radially symmetrically about the third annular plate. This arrangement facilitates the entry and exit of oxidant and fuel. Since the oxidant is generally liquid oxygen, a cryogenic medium, it usually needs to be covered during testing to reduce heat leakage. Therefore, the outer walls of the oxidant inlet pipe 9, oxidant outlet pipe 10, and oxidant cavity simulation component 8 are all covered with heat-insulating material, including one or more of high-silica glass fiber cloth, Kevlar cloth, and silicone rubber cloth.

[0045] The purpose of calculating the thermal state of the isolation chamber is to ensure that the low temperature of liquid oxygen does not transfer to the kerosene pump chamber (i.e., the fuel chamber) before the test or launch of the liquid rocket engine, thus preventing low-temperature damage to the bearings, seals, and other sealing components of the kerosene pump chamber, and to confirm the pre-cooling and purging processes of the turbopump. To this end, this embodiment also provides a method for analyzing the thermal state of the turbopump isolation chamber, using the aforementioned turbopump isolation chamber heat transfer coefficient testing device, including the following steps:

[0046] Step 1: Install the turbine pump isolation chamber heat transfer coefficient testing device to the preset position;

[0047] Step 2: Start filling the oxidant chamber simulation component 8 with oxidant from the oxidant inlet pipe 9. When the oxidant chamber simulation component 8 is full, the oxidant will automatically flow out from the oxidant outlet pipe 10. At the same time, monitor the temperature T1 and pressure P1 of the oxidant inlet pipe 9 and the temperature T2 of the oxidant outlet pipe 10 until the preset value is reached (e.g., T2 < -153℃). Maintain this state for t1 ≥ 3 min.

[0048] Step 3: Start filling the fuel chamber simulation component 2 with fuel from the fuel inlet pipe 1. When the fuel chamber simulation component 2 is full, the fuel will automatically flow out from the fuel outlet pipe 10. At the same time, monitor the temperature T3 and pressure P2 of the fuel inlet pipe 1 and the temperature T4 of the fuel outlet pipe 10 until T4 reaches the preset value. Maintain this state for t2≥3min.

[0049] Step 4: Start by introducing purging gas into the isolation chamber simulation component 4 through the two connectors 3. When the isolation chamber simulation component 4 is filled, the purging gas will automatically flow out from the other connector 3. At the same time, monitor the temperature T5 and pressure P3 of the connector 3 through which the purging gas is introduced, as well as the outer wall temperature T6, inner wall temperature T7, internal space temperature T8, and internal space pressure P4 of the isolation chamber simulation component 4, until T6, T7, T8, and P4 all reach the preset steady state range. Maintain this state for t3≥3min, and then record the values ​​of T6, T7, T8, and P4 at this time.

[0050] Step 5: Change the temperature and pressure of the blow-off gas, then return to step 4, obtain and record the values ​​of T6, T7, T8 and P4 in another preset steady-state range, until the corresponding values ​​of T5 and P3 and T6, T7, T8 and P4 in N preset steady-state ranges are obtained. After sorting, the flow rate-heat transfer coefficient table of the inner surface of the isolation chamber at different temperatures is obtained, i.e., the qh table.

[0051] Step 6: Establish a heat transfer model of the actual turbopump using TMG, ANSYS THERMAL, or other heat transfer software. The heat transfer model includes an oxidant chamber, an isolation chamber, and a fuel chamber. Set several temperature check points on the heat transfer model and set the actual allowable temperature range for each temperature check point. In the heat transfer software, set the corresponding material properties and contact relationship properties, and set the kerosene pump chamber bearings, sealing rings, and other sealing components or other key parts of concern as the main temperature check points.

[0052] Step 7: Based on the qh table obtained in Step 5, set the boundary conditions for the heat transfer model;

[0053] Step 7.1: Set the inner surface of the oxidant chamber to convective heat transfer conditions or isothermal conditions according to the flow rate of the oxidant during the pre-cooling process, and set the outer surface of the oxidant chamber to adiabatic conditions.

[0054] Step 7.2: Set the inner surface of the fuel chamber to convective heat transfer conditions or isothermal conditions according to the fuel flow rate. The heat transfer coefficient h4 of the inner surface of the fuel chamber is calculated according to the DB formula, and the heat transfer temperature Th4 of the inner surface of the fuel chamber is the fuel temperature. Set the outer surface of the fuel chamber to natural convection heat transfer conditions. The heat transfer coefficient h1 of the outer surface of the fuel chamber is estimated according to the natural convection heat transfer formula, and the heat transfer temperature Th1 of the outer surface of the fuel chamber is the ambient temperature during the test.

[0055] Step 7.3: Set the inner surface of the isolation chamber to convective heat transfer conditions. The heat transfer coefficient h2 of the inner surface of the isolation chamber is set according to the qh table obtained in Step 5, and the heat transfer temperature Th2 of the inner surface of the isolation chamber is set according to the temperature of the purge gas in the purge chamber. Set the outer surface of the isolation chamber to natural convection heat transfer conditions. The heat transfer coefficient h3 of the outer surface of the isolation chamber is estimated according to the natural convection heat transfer formula, and the heat transfer temperature Th3 of the outer surface of the isolation chamber is the ambient temperature during the test.

[0056] Step 8: According to the boundary conditions of the heat transfer model, if the precooling and exhaust conditions of the turbopump do not change with time, the thermal state of the turbopump heat transfer model is obtained by steady-state analysis; if at least one of the precooling and exhaust conditions of the turbopump changes with time, the thermal state of the turbopump heat transfer model is obtained by transient analysis.

[0057] Step 9: Based on the thermal state of the turbopump heat transfer model, determine whether the temperature at each temperature check point is within the actual allowable temperature range. If the temperature at each temperature check point is within its corresponding actual allowable temperature range, the boundary conditions of the heat transfer model meet the requirements, and the thermal state analysis of the turbopump isolation chamber is completed. If at least one temperature check point is outside its corresponding actual allowable temperature range, return to Step 7 to modify the boundary conditions of the heat transfer model. The modification method is as follows: if the temperature check point that does not meet the conditions is inside the isolation chamber, then reselect a set of qh values ​​in the qh table that are different from the previously selected qh values. If the temperature check point that does not meet the conditions is inside the fuel chamber, then adjust the heat transfer coefficient h4 and the heat transfer temperature Th4 of the inner surface of the fuel chamber.

[0058] This embodiment can conveniently test the heat transfer coefficient and simulate the actual working conditions of the turbine pump isolation chamber, providing a basis for the thermal state analysis of the turbine pump isolation chamber.

Claims

1. A device for testing heat transfer coefficient of a turbine pump isolation cavity, characterized in that: comprising a fuel cavity simulation part (2), an isolation cavity simulation part (4) and an oxidant cavity simulation part (8) connected coaxially in sequence; the fuel cavity simulation part (2) is a first circular ring cavity, and the oxidant cavity simulation part (8) is a third circular ring cavity; the isolation cavity simulation part (4) comprises a hollow circular truncated cone and a second circular ring cavity, one end of the circular truncated cone is connected with one end of the second circular ring cavity, the other end of the circular truncated cone is connected with one end of the first circular ring cavity, and the other end of the second circular ring cavity is connected with one end of the third circular ring cavity; the other end of the first circular ring cavity is provided with a first circular ring plate, and the other end of the third circular ring cavity is provided with a third circular ring plate; isolation circular ring plates are arranged between the first circular ring cavity and the circular truncated cone and between the second circular ring cavity and the third circular ring cavity; the first circular ring plate is provided with a fuel inlet pipe (1) and a fuel outlet pipe (10); and the third circular ring plate is provided with an oxidant inlet pipe (9) and an oxidant outlet pipe (11); a plurality of connectors (3) are arranged on the side wall of the second circular ring cavity and / or the circular truncated cone, and the total number of the connectors (3) is at least three, at least two of which are respectively used for simulating inflow and outflow of purge gas during purging, and at least one of which is used for monitoring the internal temperature and pressure of the isolation cavity simulation part (4). 2.The device for testing heat transfer coefficient of a turbine pump isolation cavity according to claim 1, characterized in that: temperature sensors and pressure sensors are arranged in the fuel inlet pipe (1) and the oxidant inlet pipe (9); and temperature sensors are arranged in the fuel outlet pipe (10) and the oxidant outlet pipe (11). 3.The device for testing heat transfer coefficient of a turbine pump isolation cavity according to claim 2, characterized in that: the number of the connectors (3) is eight, four of which are arranged on the side wall of the circular truncated cone in a circumferential manner, and the other four of which are arranged on the side wall of the second circular ring cavity in a circumferential manner; the connectors (3) used for simulating inflow and outflow of purge gas during purging are pipe connectors, and the connectors (3) used for measuring temperature and pressure are aviation connectors; and the temperature sensors are thermocouples. 4.The device for testing heat transfer coefficient of a turbine pump isolation cavity according to claim 3, characterized in that: the second circular ring cavity and the third circular ring cavity are connected through connecting flanges (6), and sealing rings (5) are arranged between the two connecting flanges (6); and the inner diameters of the first circular ring plate, the third circular ring plate, the isolation circular ring plates, the first circular ring cavity, the second circular ring cavity, the third circular ring cavity and the circular truncated cone are equal. 5.The device for testing heat transfer coefficient of a turbine pump isolation cavity according to claim 4, characterized in that: the outer walls of the oxidant inlet pipe (9), the oxidant outlet pipe (11) and the oxidant cavity simulation part (8) are coated with a heat insulation material, and the heat insulation material comprises one or more of high-silica glass fiber cloth, Kevlar cloth and silicone rubber cloth. 6.The device for testing heat transfer coefficient of a turbine pump isolation cavity according to claim 5, characterized in that: ​ ​ ​ ​ ​ ​ ​ ​ The fuel inlet pipe (1) and the fuel outlet pipe (10) are symmetrically arranged about the axis of the first circular plate, and the oxidant inlet pipe (9) and the oxidant outlet pipe (11) are symmetrically arranged about the axis of the third circular plate.

7. A method for analyzing the thermal state of a turbine pump isolation cavity, using a turbine pump isolation cavity heat transfer coefficient testing device according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: Step 1, install the turbine pump isolation cavity heat exchange coefficient testing device to a preset position; Step 2, start filling the oxidant cavity simulation piece (8) with oxidant from the oxidant inlet pipe (9), when the oxidant cavity simulation piece (8) is filled, the oxidant automatically flows out from the oxidant outlet pipe (11), at the same time, the temperature T1 and the pressure P1 of the oxidant inlet pipe (9) and the temperature T2 of the oxidant outlet pipe (11) are monitored until T2 reaches a preset value, and the state is maintained for a time t1; Step 3, start filling the fuel cavity simulation piece (2) with fuel from the fuel inlet pipe (1), when the fuel cavity simulation piece (2) is filled, the fuel automatically flows out from the fuel outlet pipe (10), at the same time, the temperature T3 and the pressure P2 of the fuel inlet pipe (1) and the temperature T4 of the fuel outlet pipe (10) are monitored until T4 reaches a preset value, and the state is maintained for a time t2; Step 4, start blowing the isolation cavity simulation piece (4) with purge gas from at least one joint (3), when the isolation cavity simulation piece (4) is filled, the purge gas automatically flows out from another joint (3), at the same time, the temperature T5 and the pressure P3 of the joint (3) through which the purge gas is blown, the outer wall surface temperature T6, the inner wall surface temperature T7, the internal space temperature T8 and the internal space pressure P4 of the isolation cavity simulation piece (4) are monitored until T6, T7, T8 and P4 all reach a preset steady state range, the state is maintained for a time t3, and then the values of T6, T7, T8 and P4 at this time are recorded; Step 5, change the temperature and pressure of the purge gas, then return to step 4, obtain and record the values of T6, T7, T8 and P4 in another preset steady state range, until N corresponding values of T5 and P3 and T6, T7, T8 and P4 in the preset steady state range are obtained, and after being sorted, a flow-heat exchange coefficient table at different temperatures of the inner surface of the isolation cavity, i.e. a q-h table, is obtained; Step 6, establish a heat transfer model of an actual turbine pump, the heat transfer model comprising an oxidant cavity, an isolation cavity and a fuel cavity, a plurality of temperature check points are set on the heat transfer model, and an actual allowable temperature range is set for each temperature check point; Step 7, set the boundary conditions of the heat transfer model according to the q-h table obtained in step 5; Step 8, according to the boundary conditions of the heat transfer model, if neither the pre-cooling nor the discharge condition of the turbine pump changes with time, a steady state analysis method is used to obtain the thermal state of the heat transfer model of the turbine pump, and if at least one of the pre-cooling and the discharge condition of the turbine pump changes with time, a transient analysis method is used to obtain the thermal state of the heat transfer model of the turbine pump; Step 9, according to the heat state of the turbine pump heat transfer model, judge whether the temperature of each temperature check point is within the actual allowable temperature range, if the temperature of each temperature check point is within the corresponding actual allowable temperature range, the boundary condition of the heat transfer model meets the requirements, the thermal state analysis of the turbine pump isolation cavity is completed; if there is at least one temperature check point whose temperature is not within the corresponding actual allowable temperature range, return to step 7 to modify the boundary condition of the heat transfer model.

8. A method of thermal state analysis of a turbopump isolation chamber according to claim 7, wherein, Step 7 is specifically: Step 7.1, the inner surface of the oxidant cavity is set to convective heat transfer condition or constant temperature condition according to the flow of oxidant in the precooling process, and the outer surface of the oxidant cavity is set to adiabatic condition; Step 7.2, the inner surface of the fuel cavity is set to convective heat transfer condition or constant temperature condition according to the fuel flow, the heat transfer coefficient h4 of the fuel cavity inner surface is calculated according to the D-B formula, and the heat transfer temperature Th4 of the fuel cavity inner surface is the fuel temperature; the outer surface of the fuel cavity is set to natural convection heat transfer condition, the heat transfer coefficient h1 of the fuel cavity outer surface is estimated according to the natural convection heat transfer formula, and the heat transfer temperature Th1 of the fuel cavity outer surface is the environmental temperature during the test; Step 7.3, the inner surface of the isolation cavity is set to convective heat transfer condition, the heat transfer coefficient h2 of the isolation cavity inner surface is set according to the q-h table obtained in step 5, and the heat transfer temperature Th2 of the isolation cavity inner surface is set according to the temperature of the blowing cavity blowing gas; the outer surface of the isolation cavity is set to natural convection heat transfer condition, the heat transfer coefficient h3 of the isolation cavity outer surface is estimated according to the natural convection heat transfer formula, and the heat transfer temperature Th3 of the isolation cavity outer surface is the environmental temperature during the test.

9. The turbine pump isolation cavity thermal state analysis method according to claim 8, wherein: Step 9 of modifying the boundary condition of the heat transfer model is specifically: If the temperature check point that does not meet the condition is in the isolation cavity, a set of q-h values that are different from the selected q-h values are selected in the q-h table; if the temperature check point that does not meet the condition is in the fuel cavity, the heat transfer coefficient h4 of the fuel cavity inner surface and the heat transfer temperature Th4 of the fuel cavity inner surface are adjusted.

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