Gas generator ignition test device simulating ignition state of whole machine and working condition design method thereof

Abstract

The application provides a gas generator ignition test device simulating ignition state of a whole machine and a working condition design method thereof. The ignition test device comprises a gas generator, an igniter and a gas process nozzle. The gas generator is connected with a fuel supply system through a fuel supply pipeline. The volume of a cavity between a cut-off valve and the gas generator and the length of a pipeline, the throat area of a cavitation venturi, the inlet pressure of the cut-off valve and the like are designed, and a turbine is not used, so that the real working condition when the engine is ignited can be accurately simulated, and problems such as complex test device configuration, unclear simulation criteria of working condition design, non-coverage or over-coverage of working condition and the like during the thermal test of the full-size gas generator of the high-performance staged combustion cycle engine are solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of ignition test of gas generator, and particularly relates to a gas generator ignition test device simulating ignition state of an entire machine and a working condition design method thereof. BACKGROUND

[0002] A gas generator is contained in a high-performance staged combustion cycle liquid rocket engine, and a gas generator of a large-thrust engine is large in size and scale, so a reduced-scale unit is often used for test in the early stage of development to verify the feasibility of the injector scheme. For non-self-igniting propellants, an external energy ignition scheme such as chemical ignition or torch ignition needs to be used. When chemical ignition is used, the igniter is injected into the combustion chamber through each injector, and a reduced-scale unit of the generator can be used to fully evaluate the ignition scheme. When torch ignition is used, the combustion region spreads from the center to the periphery, and the success of ignition of a reduced-scale unit of the generator cannot fully indicate that the full-size generator can also be successfully ignited. Therefore, it is necessary to carry out full-size gas generator extrusion ignition test during the development process of a large-thrust staged combustion cycle engine.

[0003] The purpose of full-size oxygen-rich gas generator extrusion ignition test is to verify the ignition process of the generator when the engine starts, and if the test device is configured to simulate the state of the entire machine, there may be a problem of too complex configuration. Since the supply scheme cannot be completely consistent with the state of the entire machine, the simulation criteria are not clear during the design of the test working condition, and the working condition is not covered or over-evaluated. For the development of a large-thrust engine, the full-size gas generator is large in thermal test scale and high in cost, and a reasonable test device configuration should be used to meet the evaluation requirements. SUMMARY

[0004] In order to overcome the deficiencies in the prior art, the present application provides a gas generator ignition test device simulating ignition state of an entire machine and a working condition design method thereof, which solves the problems of complex test device configuration, unclear simulation criteria, non-covered or over-evaluated working condition during the thermal test of the full-size gas generator of a high-performance staged combustion cycle engine.

[0005] The technical scheme provided by the present application is as follows:

[0006] In a first aspect, a gas generator ignition test device simulating ignition state of an entire machine includes a gas generator, an igniter, a gas process nozzle, a cavitation venturi I, a cavitation venturi II, a stop valve I and a stop valve II.

[0007] The gas generator is connected to a fuel supply system through a fuel supply pipeline, the cavitation venturi I is installed on the fuel supply pipeline, and the stop valve I is installed downstream of the cavitation venturi I.

[0008] The gas generator is connected with the oxidant supply system through an oxidant supply pipeline, a cavitation venturi II is installed on the oxidant supply pipeline, and a stop valve II is installed downstream of the cavitation venturi II;

[0009] The cavitation venturi I and the cavitation venturi II are respectively used for controlling the fuel and oxidant supply flow rate into the gas generator during the ignition process; the stop valve I and the stop valve II are respectively used for controlling the on-off of the fuel supply pipeline and the oxidant supply pipeline, and adjusting the time sequence of the fuel and oxidant into the gas generator;

[0010] The fuel and oxidant in the gas generator are ignited by the ignition device, and the generated gas is directly discharged into the gas process nozzle; the throat equivalent flow area of the gas process nozzle is equal to the turbine stator flow area of the engine, the volume between the throat of the gas process nozzle and the gas generator is equal to the volume between the gas generator and the turbine of the engine, and the cavity volume, the pipeline length between the stop valve I, the stop valve II and the gas generator are consistent with the actual pipeline state of the engine.

[0011] In the second aspect, a gas generator ignition test device for simulating the ignition state of an entire machine includes a gas generator, an igniter, a gas process nozzle, a throttle I, a throttle II, a stop valve I and a stop valve II;

[0012] The gas generator is connected with the fuel supply system through a fuel supply pipeline, a stop valve I is installed on the fuel supply pipeline, and a throttle I is installed downstream of the stop valve I; the gas generator is connected with the oxidant supply system through an oxidant supply pipeline, a stop valve II is installed on the oxidant supply pipeline, and a throttle II is installed downstream of the stop valve II;

[0013] The stop valve I and the stop valve II are respectively used for controlling the on-off of the fuel supply pipeline and the oxidant supply pipeline, and adjusting the time sequence of the fuel and oxidant into the gas generator;

[0014] The throttle I and the throttle II are respectively used for simulating the flow resistance between the engine stop valve and the head cavity of the gas generator on the fuel supply pipeline and the oxidant supply pipeline;

[0015] The fuel and oxidant in the gas generator are ignited by the ignition device, and the generated gas is directly discharged into the gas process nozzle; the throat equivalent flow area of the gas process nozzle is equal to the turbine stator flow area of the engine, the volume between the throat of the gas process nozzle and the gas generator is equal to the volume between the gas generator and the turbine of the engine, and the cavity volume, the pipeline length between the stop valve I, the stop valve II and the gas generator are consistent with the actual pipeline state of the engine.

[0016] In a third aspect, a method for designing a working condition of a gas generator ignition test simulating an ignition state of an entire machine, the method comprising the following steps:

[0017]

[0018]

[0019]

[0020]

[0021] In a fourth aspect, a method for designing a working condition of a gas generator ignition test simulating an ignition state of an entire machine, the method comprising the following steps:

[0022]

[0023]

[0024] The gas generator ignition test device and the method for designing a working condition of the gas generator ignition test device provided by the present application have the following beneficial effects:

[0025] The gas generator ignition test device and the method for designing a working condition of the gas generator ignition test device provided by the present application can accurately simulate the real working condition of the engine ignition, and solve the problems of complex test device configuration, unclear simulation criteria, incomplete working condition coverage, and excessive test in the hot test of the full-size gas generator of the high-performance reburning cycle engine. BRIEF DESCRIPTION OF DRAWINGS

[0026] ​​​​​​Figure 1 System diagram of the gas generator ignition test device simulating the ignition state of the whole machine in one embodiment of the present application;

[0027] Figure 2 System diagram of the gas generator ignition test device simulating the ignition state of the whole machine in another embodiment of the present application;

[0028] Figure 3 Schematic diagram for calculating the flow of oxidizer when the gas generator is ignited. DETAILED DESCRIPTION

[0029] The features and advantages of the present application will become more apparent from the detailed description in conjunction with the accompanying drawings.

[0030] The term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0031] The present application provides a gas generator ignition test device simulating the ignition state of the whole machine, which is suitable for high pressure (generally 5-30 MPa) extrusion hot test and low inlet pressure (generally 0.4-2 MPa) hot test. When the high pressure extrusion hot test is implemented, as shown in the figure, the gas generator ignition test device comprises a gas generator, an igniter, a gas process nozzle, a cavitation venturi I, a cavitation venturi II, a stop valve I and a stop valve II. Figure 1

[0032] The gas generator is connected to a fuel supply system through a fuel supply pipeline, the cavitation venturi I is installed on the fuel supply pipeline, and the stop valve I is installed downstream of the cavitation venturi I.

[0033] The gas generator is connected to an oxidizer supply system through an oxidizer supply pipeline, the cavitation venturi II is installed on the oxidizer supply pipeline, and the stop valve II is installed downstream of the cavitation venturi II.

[0034] The cavitation venturi I and the cavitation venturi II are respectively used to control the supply flow of fuel and oxidizer into the gas generator during ignition; the stop valve I and the stop valve II are respectively used to control the on-off of the fuel supply pipeline and the oxidizer supply pipeline, and to adjust the timing of fuel and oxidizer into the gas generator; the cavitation venturi is configured to perform high pressure extrusion hot test, and the propellant supply flow of the gas generator during ignition can be controlled.

[0035] The fuel and oxidizer in the gas generator are ignited by the ignition device, and the generated gas is directly discharged into the gas process nozzle.

[0036] ​Since the test device omits the turbine, the gas directly enters the gas process nozzle, in order to accurately simulate the real working condition when the engine is ignited, the equivalent flow area of the throat of the gas process nozzle is used to simulate the flow area of the turbine stator of the engine (the equivalent flow area of the throat of the gas process nozzle = the flow area of the turbine stator of the engine), and the volume between the throat of the gas process nozzle and the gas generator simulates the volume between the upper gas generator and the turbine of the engine (the volume between the throat of the gas process nozzle and the gas generator = the volume between the upper gas generator and the turbine of the engine); the actual stator assembly can be used instead of the gas process nozzle to check the stator ablation resistance during ignition. The volume of the cavity between the stop valve I and the gas generator and the length of the pipeline are consistent with the actual pipeline state of the engine, and the process of filling the low-temperature propellant in the pipeline after the opening of the stop valve I and the head cavity of the gas generator is simulated.

[0037] In a preferred embodiment of the present application, a throttle I is installed downstream of the cavitation venturi I on the fuel supply pipeline, and the throttle I simulates the flow resistance between the engine stop valve and the head cavity of the gas generator on the fuel supply pipeline.

[0038] In a preferred embodiment of the present application, the pipeline downstream of the cavitation venturi I on the fuel supply pipeline is divided into a fuel supply branch pipeline and a fuel pre-cooling discharge branch, a stop valve I is installed on the fuel supply branch pipeline, and a stop valve III is installed on the fuel pre-cooling discharge branch.

[0039] The pipeline downstream of the cavitation venturi II on the oxidant supply pipeline is divided into an oxidant supply branch pipeline and an oxidant pre-cooling discharge branch, a stop valve II is installed on the oxidant supply branch pipeline, and a stop valve IV is installed on the oxidant pre-cooling discharge branch.

[0040] In the hot test at low inlet pressure (0.4-2 MPa), as shown in the figure, no cavitation venturi I is installed on the fuel supply pipeline in the gas generator ignition test device, a throttle I is installed downstream of the stop valve I, and the throttle I simulates the flow resistance between the engine stop valve I and the head cavity of the gas generator on the fuel supply pipeline. Figure 2 No cavitation venturi II is installed on the oxidant supply pipeline, a throttle II is installed downstream of the stop valve II, and the throttle II simulates the flow resistance between the engine stop valve II and the head cavity of the gas generator on the oxidant supply pipeline.

[0041]

[0042] ​In a preferred embodiment of the present application, the fuel supply pipeline is connected with a fuel supply branch pipeline and a fuel pre-cooling discharge branch, a stop valve I is installed on the fuel supply branch pipeline, and a stop valve III is installed on the fuel pre-cooling discharge branch; the oxidant supply pipeline is connected with an oxidant supply branch pipeline and an oxidant pre-cooling discharge branch, a stop valve II is installed on the oxidant supply branch pipeline, and a stop valve IV is installed on the oxidant pre-cooling discharge branch.

[0043] Since the actual flow rate flowing into the gas generator during engine starting process is gradually increased from 0. For low-temperature propellant, there also exists a state of gasification into two phases in the pipeline cavity behind the stop valves I and II. In the design of the test device, the cavity volume behind the stop valves I and II in the test device, the volume between the throat of the gas process nozzle and the gas generator, and the equivalent flow area of the throat of the gas process nozzle are simulated to be consistent with the engine, at this time, the flow rate at the stop valves I and II can be simulated to be consistent with the ignition process of the whole machine, that is, the state of the propellant actually flowing into the gas generator during ignition process can be ensured to be similar to that of the whole machine.

[0044] In the implementation of high-pressure extrusion heat test, the working condition design method of the gas generator ignition test simulating the ignition state of the whole machine is designed as follows:

[0045] (1) The engine starting process is simulated and analyzed to determine the oxidant flow rate and the fuel flow rate during the ignition of the gas generator. Since the flow rate value is constantly changing, the average value in the relatively stable interval during the ignition process is taken, as shown in Figure 3 .

[0046] (2) The gas pressure p i of the gas generator entering the steady state is determined according to the gas flow rate q m and in combination with the equivalent flow area of the throat of the gas process nozzle and other parameters.

[0047]

[0048] Wherein, q m is the total flow rate of the oxidant and the fuel, μ is the flow coefficient of the throat of the gas process nozzle, generally taken as 0.99; A is the equivalent flow area of the throat of the gas process nozzle; p i is the gas pressure before the throat of the gas process nozzle; R i is the gas constant; T i is the gas temperature; and k is the adiabatic index of the gas.

[0049] (3) The outlet pressure of the cavitation venturi is determined according to the steady-state working pressure p i of the gas generator, the pressure drop dP pz of the injector of the gas generator, and the pressure drop dP jlq of the supply pipeline throttle.

[0050] P eqsg = P i + dP pz + dP jlq .

[0051] Wherein, P eqsg is the outlet pressure of the cavitation venturi, dP pz is the pressure drop of the gas generator injector, dP jlq is the pressure drop of the supply orifice.

[0052] (4) According to the outlet pressure P eqsg of the cavitation venturi, the appropriate inlet pressure P iqsg of the cavitation venturi is selected, which generally needs to ensure that P iqsg is greater than 1.3 times P eqsg , to ensure that the cavitation venturi is in a cavitation state, and further to calculate the throat area A qsg of the cavitation venturi by using the following formula.

[0053]

[0054] In the formula, μ is the cavitation tube flow coefficient, generally taken as 0.9; P s is the saturated vapor pressure of the fuel or oxidizer; and ρ is the density of the fuel or oxidizer. The suffix o in the formula represents the oxidizer side, and the suffix f represents the fuel side.

[0055] When a large flow is tested by using the existing cavitation tube, the cavitation tube may be in a non-cavitation state under a steady state condition. At this time, the cavitation tube is ensured to be in a cavitation state when the gas generator is not ignited and pressurized, so that the ignition test can be tested. After the gas generator is ignited and pressurized, the flow of the cavitation tube in a non-cavitation state is reduced, but the change in the gas temperature caused by the deviation of the mixture ratio should still be within the material tolerance range. The flow coefficient of the cavitation tube in a non-cavitation state should be obtained in advance by carrying out liquid flow tests under corresponding conditions.

[0056] (5) A cold test needs to be carried out before the test, the filling degree of the head cavity and the flow of the propellant entering the generator are determined by the pressure measurement point climbing process of the head cavity, so as to determine the ignition timing of the generator. By controlling the opening time of the oxidizer valve and the fuel valve, the purpose of adjusting the ignition timing is achieved.

[0057] (6) By adjusting the inlet pressure of the test device, the mixture ratio and the ignition flow at the time of ignition of the generator can be adjusted.

[0058] If a low-inlet-pressure test scheme without a cavitation venturi is adopted, the above steps (2), (3), and (4) are modified as the following step (2):

[0059] (2) The inlet pressure of the stop valve during the ignition process is obtained by the whole engine starting simulation, which is generally the pump outlet pressure of the fuel / oxidizer supply system and is relatively stable during the ignition process. The pressure is taken as the inlet pressure condition of the subsequent hot test. Since the throttle ring is used to simulate the flow resistance between the engine stop valve and the head cavity of the gas generator, the propellant flow during the ignition process can also be simulated.

[0060] The present application is described in detail above in conjunction with the specific embodiments and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that the technical solutions and embodiments of the present application can be variously replaced, modified or improved without departing from the spirit and scope of the present application, and these all fall within the scope of the present application. The protection scope of the present application is subject to the appended claims.

[0061] The contents not described in detail in the specification of the present application are the known technology of those skilled in the art.

Claims

1. A gas generator ignition test device simulating the ignition state of a complete unit, characterized in that, This includes a gas generator, igniter, gas process nozzle, cavitation venturi tube I, cavitation venturi tube II, shut-off valve I, and shut-off valve II; The gas generator is connected to the fuel supply system through a fuel supply pipeline. A cavitation venturi tube I is installed on the fuel supply pipeline, and a shut-off valve I is installed downstream of the cavitation venturi tube I. The gas generator is connected to the oxidant supply system through an oxidant supply pipeline. A cavitation venturi tube II is installed on the oxidant supply pipeline, and a shut-off valve II is installed downstream of the cavitation venturi tube II. Cavitation Venturi tube I and cavitation Venturi tube II are used to control the flow rate of fuel and oxidant supplied to the gas generator during the ignition process, respectively; shut-off valve I and shut-off valve II are used to control the opening and closing of the fuel supply line and the oxidant supply line, respectively, and to adjust the timing of fuel and oxidant being supplied to the gas generator. The fuel and oxidant in the gas generator are ignited by an ignition device, and the generated gas is directly discharged into the gas process nozzle. The equivalent flow area of ​​the gas process nozzle throat is equal to the flow area of ​​the engine turbine stator, the volume between the gas process nozzle throat and the gas generator is equal to the volume between the engine gas generator and the turbine, and the volume of the cavity between the shut-off valve I, shut-off valve II and the gas generator, as well as the pipeline length, are consistent with the actual pipeline state of the engine.

2. The gas generator ignition test device for simulating the ignition state of the whole machine according to claim 1, characterized in that, A throttling coil I is installed downstream of the cavitation venturi tube I on the fuel supply line. The throttling coil I simulates the flow resistance between the engine shut-off valve and the gas generator head chamber on the fuel supply line. A throttling coil II is installed downstream of the cavitation venturi tube II on the oxidant supply line. The throttling coil II simulates the flow resistance between the engine shut-off valve and the gas generator head chamber on the oxidant supply line.

3. The gas generator ignition test device for simulating the ignition state of a complete machine according to claim 1, characterized in that, The downstream pipeline of the cavitation venturi tube I on the fuel supply pipeline is divided into a fuel supply branch pipeline and a fuel pre-cooling discharge branch pipeline. A shut-off valve I is installed on the fuel supply branch pipeline, and a shut-off valve III is installed on the fuel pre-cooling discharge branch pipeline. The downstream pipeline of the cavitation venturi tube II on the oxidant supply pipeline is divided into an oxidant supply branch pipeline and an oxidant pre-cooling discharge branch pipeline. A shut-off valve II is installed on the oxidant supply branch pipeline, and a shut-off valve IV is installed on the oxidant pre-cooling discharge branch pipeline.

4. The gas generator ignition test apparatus for simulating the ignition state of a complete machine according to claim 1 or 2, characterized in that, The gas generator ignition test device does not install a cavitation venturi tube I on the fuel supply line, but installs a throttling ring I downstream of the shut-off valve I. The throttling ring I simulates the flow resistance between the engine shut-off valve I and the gas generator head chamber on the fuel supply line. The oxidant supply line does not have a cavitation venturi tube II installed. Instead, a throttling ring II is installed downstream of the shut-off valve II. The throttling ring II simulates the flow resistance between the engine shut-off valve II and the gas generator head chamber on the oxidant supply line.

5. The gas generator ignition test device for simulating the ignition state of the whole machine according to claim 4, characterized in that, The fuel supply pipeline is followed by a fuel supply branch pipeline and a fuel precooling discharge branch pipeline. A shut-off valve I is installed on the fuel supply branch pipeline, and a shut-off valve III is installed on the fuel precooling discharge branch pipeline. The oxidant supply pipeline is followed by an oxidant supply branch pipeline and an oxidant precooling discharge branch pipeline. A shut-off valve II is installed on the oxidant supply branch pipeline, and a shut-off valve IV is installed on the oxidant precooling discharge branch pipeline.

6. A method for designing operating conditions for a gas generator ignition test simulating the ignition state of the entire unit, characterized in that, The operating condition design method using the gas generator ignition test apparatus simulating the ignition state of the whole machine as described in any one of claims 1 to 3 includes the following steps: The engine starting process is simulated and analyzed to determine the oxidant flow rate and fuel flow rate when the gas generator is ignited. The total flow rate of the two is the gas flow rate. Based on the gas flow rate and the equivalent flow area at the process throat, determine the gas pressure when the gas generator enters steady state. The outlet pressure of the cavitation venturi tube is determined based on the steady-state operating pressure of the gas generator, the pressure drop of the gas generator injector, and the pressure drop of the supply circuit throttling coil. Based on the outlet pressure of the cavitation venturi tube, select the inlet pressure of the cavitation venturi tube to ensure that the cavitation venturi tube is in a cavitation state. Then, based on the inlet pressure of the cavitation venturi tube, obtain the throat area of ​​the cavitation venturi tube.

7. The operating condition design method for simulating the ignition state of a gas generator according to claim 6, characterized in that, In the step of determining the pressure of the gas generator when it enters steady state based on the total flow rate of oxidant and fuel, combined with the equivalent flow area of ​​the process throat, the pressure of the gas generator when it enters steady state is determined by the following formula: Where, q m The gas flow rate is equal to the total flow rate of the oxidizer and fuel; μ is the flow coefficient at the throat of the gas process nozzle; A is the equivalent flow area at the throat of the gas process nozzle; p i R is the gas pressure before the throat of the gas process nozzle; i T is the gas constant of the fuel gas; i is the gas temperature; k is the gas adiabatic index.

8. The operating condition design method for simulating the ignition state of a gas generator according to claim 7, characterized in that, The step of determining the cavitation venturi outlet pressure based on the steady-state operating pressure of the gas generator, the pressure drop of the gas generator injector, and the pressure drop of the supply line throttling coil includes: P eqsg =P i +dP pz +dP jlq Among them, P eqsg dP is the outlet pressure of the cavitation venturi tube. pz For the pressure drop of the gas generator injector, dP jlq To reduce the pressure drop of the supply road throttling coil.

9. The operating condition design method for simulating the ignition state of a gas generator according to claim 8, characterized in that, The steps of selecting the inlet pressure of the cavitation venturi tube based on the outlet pressure to ensure it is in a cavitation state, and then obtaining the throat area of ​​the cavitation venturi tube based on the inlet pressure, include: Among them, A qsg P represents the area of ​​the cavitation venturi throat; iqsg P is the inlet pressure of the cavitation venturi tube. iqsg ≥1.3P eqsg μ is the cavitation pipe flow coefficient; P s ρ is the saturated vapor pressure of the fuel or oxidant; ρ is the density of the fuel or oxidant; the suffix 'o' in the formula represents the oxygen side, and 'f' represents the fuel side.

10. A method for designing operating conditions for a gas generator ignition test simulating the ignition state of the entire unit, characterized in that, The operating condition design method using the gas generator ignition test apparatus for simulating the ignition state of the whole machine as described in claim 4 or 5 includes the following steps: The engine starting process is simulated and analyzed to determine the oxidant flow rate and fuel flow rate when the gas generator is ignited. The total flow rate of the two is the gas flow rate. The inlet pressure of the shut-off valve during the ignition process is obtained through whole-machine start-up simulation. This pressure is then used as the inlet pressure condition for hot testing to carry out subsequent hot testing work.

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