Full-size low-temperature medium outflow test system and outflow test method

Abstract

The invention provides a full-size low-temperature medium outflow test system and an outflow test method. The system comprises a control system, an end socket, a storage tank, a conveying main pipeline, a pressure accumulator, a discharge pipeline, a filling pipeline, an air sealing pipeline, a pressurizing pipeline, a pressurizing tank, a liquid nitrogen filling tank car, a flow meter, a filling port, a regulating valve, a stop valve and an air sealing port. According to the system, a full-size test platform is built, low-temperature liquid nitrogen is used for replacing a low-temperature propellant, the working states of the pressurized conveying system under different flows and pressures are simulated, and the requirement that the system obtains the flowing performance closer to the real working condition through test examination under a low-temperature medium is met.

Description

Technical Field

[0001] The invention belongs to the field of rocket pressurization and transportation, and in particular relates to a full-scale cryogenic medium outflow test system and an outflow test method. Background Art

[0002] In the field of space launch, the biggest difference between liquid rockets and solid rockets lies in the power system. The power system of liquid rockets is mainly composed of the booster delivery system and the engine system, which is one of the most important subsystems of liquid rockets. Among them, the engine is called the "heart" of the liquid rocket, providing the original power for the rocket flight, and has a significant impact on the performance and flight reliability of the rocket; and the booster delivery system, as an important system to ensure the reliable operation of the liquid rocket engine, is also of great significance to the overall reliability and safety of the liquid rocket, and to a certain extent restricts the development of the aerospace industry.

[0003] The rapid development of modern aerospace technology and the technological progress of cryogenic propellants, especially the widespread application of high specific impulse hydrogen-oxygen engines, have brought higher challenges to the booster delivery system and put forward more stringent technical requirements. In order to ensure that the cryogenic engine can be restarted after the end of the glide phase, it is necessary to ensure that there is no problem with the supply of propellant. Therefore, it is very important to solve the problem of propellant management in low gravity or weightlessness. In addition, with the continuous complexity of aerospace missions, problems such as air inclusion in the delivery pipeline and cavitation of the turbo pump caused by the two-phase flow in the propellant tank will become non-negligible. More seriously, once the propellant is strongly vaporized at the pump inlet, it will cause the impeller to malfunction, causing the propellant flow at the combustion chamber inlet to deviate from the mixing ratio, resulting in unstable combustion. In severe cases, it may even cause damage to the pipeline structure and equipment, greatly increasing the failure rate of the booster delivery system.

[0004] Once a booster delivery system fails, the consequences are often serious and the losses are huge. Especially for manned spacecraft, the failure of the booster delivery system will pose a serious threat to the life safety of the crew. Therefore, it is very necessary and urgent to carry out research on the flow performance of the booster delivery system for the aerospace industry. At present, the flow performance of the booster delivery system is mainly studied by numerical simulation and normal temperature reduction test. It is impossible to accurately obtain data that is closer to the actual working conditions, which brings many limitations to the assessment of the flow stability of the system such as penetration, collapse, swirl, cavitation, etc. under low temperature conditions. Summary of the invention

[0005] The purpose of the present invention is to solve the above-mentioned problem that when obtaining the flow performance of the booster conveying system, it mainly relies on numerical simulation and normal temperature reduction test, and lacks full-scale low-temperature test means. A full-scale low-temperature medium outflow test system is provided. The system builds a full-scale test platform, uses low-temperature liquid nitrogen instead of cryogenic propellant, simulates the working state of the booster conveying system under different flow rates and pressures, and realizes the need for the system to obtain flow performance closer to the actual working conditions through test assessment under low-temperature medium.

[0006] The present invention provides a full-scale low-temperature medium outflow test system and an outflow test method applied to the system, wherein the system comprises a control system, a sealing head, a storage tank, a main conveying pipeline, a pressure accumulator, a discharge pipeline, a filling pipeline, a gas sealing pipeline, a boosting pipeline, a boosting tank, a liquid nitrogen filling tank truck, a flow meter, a filling port, a regulating valve, a stop valve, and a gas sealing port; the sealing head comprises a pressure measuring port, an exhaust port, a boosting port, a stop valve, and an energy dissipator.

[0007] The test bench is built according to the full-size pressurized conveying system, and the tank, conveying main line and accumulator are installed on the test bench. The test bench meets the load-bearing and stability requirements during the test and parking process;

[0008] Furthermore, the head is designed according to the tank size, system gasification volume and boosting requirements, the head is reserved with exhaust ports, boosting ports and pressure measuring ports, the energy dissipator is designed according to the boosting requirements, the energy dissipator is installed at the lower end of the boosting port, and the discharge port of the energy dissipator is avoided to be directly aligned with the liquid surface;

[0009] Furthermore, compensators are installed on the main delivery pipeline and the discharge pipeline to compensate for the cold deformation of the pipeline during the test;

[0010] Furthermore, the discharge pipeline is sequentially arranged with a flow meter, a filling port, a regulating valve, a stop valve and a gas sealing port;

[0011] Furthermore, a movable bracket is installed on the discharge pipeline to adapt to the bending deformation caused by the presence of liquid nitrogen in the lower part of the horizontal pipe section and the absence of liquid nitrogen in the upper part at the beginning of filling;

[0012] Furthermore, the booster tank is connected to the booster port of the head and the air seal port of the discharge pipeline respectively, so as to realize the air pillow pressure control during the test and the isolation of the system from the air during the parking process;

[0013] Furthermore, according to the amount of heat leakage in the system, insulation layers are added to the heads, storage tanks, pipelines, and accumulators to reduce the amount of heat exchange between the system and the outside world;

[0014] Furthermore, the air pillow pressure is monitored through the pressure measuring port of the head and fed back to the control system. The control system sets the air pillow pressure control target according to the test conditions and realizes real-time closed-loop control of the air pillow pressure through the boost port and the exhaust port.

[0015] Furthermore, the liquid nitrogen is added by direct filling with a tank truck, the filling port is connected to the liquid outlet of the tank truck, the liquid nitrogen is squeezed out by the pressure of the tank truck, and is sequentially transported to the discharge pipeline, the pressure accumulator, the main transportation pipeline, and the storage tank;

[0016] Furthermore, before adding liquid nitrogen, the system is precooled using low-temperature nitrogen generated by gasification of the tank truck, and system air replacement is achieved at the same time;

[0017] Furthermore, the outflow flow rate is controlled by the opening of the discharge pipeline regulating valve. The opening corresponding to different flow rates is obtained through preliminary tests. The opening of the regulating valve is adjusted to the desired position before the formal test. When the formal test starts, the stop valve is opened to realize the outflow test at the preset flow rate.

[0018] Further, the measured parameters include pressure, differential pressure, level, flow, temperature and vibration;

[0019] Furthermore, pressure measurement uses a low-temperature pressure sensor with a frequency response range of 0 to 100 Hz, and differential pressure measurement uses a normal temperature differential pressure sensor. The low-temperature liquid nitrogen is gasified into normal temperature nitrogen through a pressure-inducing pipe and connected to the normal temperature differential pressure sensor. Liquid level measurement is converted into liquid level height by the pressure difference between the bottom of the box and the air pillow. Flow measurement uses an orifice flowmeter, temperature measurement uses a platinum resistance temperature sensor, and vibration measurement uses a normal temperature vibration sensor. Temperature isolation is achieved through threaded connections between pipelines, bakelite blocks, and sensors.

[0020] The present invention also provides an outflow test method applied to a full-scale low-temperature medium outflow test system, comprising the following steps:

[0021] 1) First, prepare for the test, check the initial status of the valve and sensor, connect the liquid nitrogen tank truck to the filling port, and open the manual stop valve of the filling port;

[0022] 2) Start precooling the pipeline until the filling level is reached, while monitoring the tank pressure;

[0023] 3) Stop filling after the filling level is reached and set the opening of the regulating valve;

[0024] 4) Open the stop valve, set the air pillow pressure control target, and realize real-time closed-loop control of the air pillow pressure through the boost port and exhaust port;

[0025] 5) After the outflow stops, stop the test.

[0026] The beneficial effects of the present invention are as follows:

[0027] 1. The present invention adopts a head design to achieve pressure control. By designing the exhaust port, boost port, pressure measuring port and energy dissipator in the head, the pressure control of the system during the filling and outflow process can be achieved, and the flow performance of the propellant under different conditions can be obtained while ensuring safety;

[0028] 2. The present invention solves the cold deformation problem of the cryogenic system by installing compensators and movable brackets on the pipeline. The cryogenic pipeline will be deformed by expansion and contraction and bending after being cooled. The internal stress caused by expansion and contraction can be released by the compensator, and the internal stress caused by bending can be released by the movable bracket, thereby improving the safety of the system;

[0029] 3. The present invention adopts the whole system insulation method to suppress the "geyser" phenomenon. The "geyser" phenomenon of the low temperature system may damage the structure. By adding an insulation layer to the whole system, the heat exchange between the system and the outside world is reduced, thereby suppressing the occurrence of "geyser" to a certain extent and improving the safety and reliability of the system;

[0030] 4. The present invention realizes flow control through the combination of flow meter, regulating valve and stop valve. The opening of the regulating valve is pre-set, and the stop valve is opened quickly, which ensures the flow control accuracy and realizes the rapid establishment of flow, thus saving the consumption of low-temperature medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention:

[0032] Figure 1 1 is a schematic diagram of the composition of a full-scale low-temperature medium outflow test system according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the head design of an embodiment of the present invention;

[0034] Figure 3 is a schematic diagram of a main conveying line and a compensator according to an embodiment of the present invention;

[0035] Figure 4 is a schematic diagram of a discharge pipeline according to an embodiment of the present invention;

[0036] Figure 5 It is a flow chart of the outflow test of an embodiment of the present invention.

[0037] Among them: 1-head; 2-storage tank; 3-transmission main pipeline; 4-accumulator; 5-discharge pipeline; 6-filling pipeline; 7-gas sealing pipeline; 8-boosting pipeline; 9-boosting tank; 10-liquid nitrogen filling tank truck; 11-flow meter; 12-filling port; 13-regulating valve; 14-stop valve; 15-gas sealing port; 1-1-pressure measuring port; 1-2-exhaust port; 1-3-boosting port; 1-4-stop valve; 1-5-energy dissipator DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0039] The present embodiment provides a full-scale cryogenic medium outflow test system, including a control system, a head 1, a storage tank 2, a main delivery line 3, an accumulator 4, a discharge line 5, a filling line 6, a gas seal line 7, a boosting line 8, a boosting tank 9, a liquid nitrogen filling tank truck 10, a flow meter 11, a filling port 12, a regulating valve 13, a stop valve 14, and a gas seal port 15.

[0040] The end cap 1 includes a pressure measuring port 1-1, an exhaust port 1-2, a pressure boosting port 1-3, a stop valve 1-4, and an energy dissipator 1-5.

[0041] Specific implementation method:

[0042] 1) Design the head according to the tank size, system gasification volume and pressure requirements, and reserve exhaust ports, pressure ports and pressure measuring ports on the head;

[0043] 2) Design the energy dissipator according to the pressure increase requirements, install it at the lower end of the pressure increase port, and avoid the discharge port of the energy dissipator being directly aligned with the liquid surface;

[0044] 3) Build a test bench based on the full-size pressurized conveying system, and the test bench meets the load-bearing and stability requirements during the test and parking process;

[0045] 4) After the end cap is connected to the tank, install the tank, main conveying line and accumulator on the test bench;

[0046] 5) The discharge pipeline is connected to the accumulator through an elbow. The discharge pipeline is arranged with a flow meter, a filling port, a regulating valve, a stop valve, and a gas seal port in sequence.

[0047] 6) The discharge pipeline is equipped with a movable bracket, which can move up and down as the pipeline bends and deforms, and can bear the weight of the pipeline after the deformation is restored;

[0048] 7) Install compensators on the main pipeline and horizontal pipeline;

[0049] 8) Install insulation layers on the heads, storage tanks, pipelines and accumulators according to the heat leakage of the system;

[0050] 9) Install pressure, differential pressure, liquid level, flow, temperature, and vibration sensors at predetermined locations and connect them to the test system;

[0051] 10) Connect the booster tank to the booster port of the head and the gas seal port of the discharge pipeline;

[0052] 11) Connect the liquid nitrogen tank truck to the filling port;

[0053] 12) Carry out the test according to the outflow test process.

[0054] This embodiment also provides an outflow test method applied to a full-scale low-temperature medium outflow test system, comprising the following steps:

[0055] 1) First, prepare for the test, check the initial status of the valve and sensor, connect the liquid nitrogen tank truck to the filling port, and open the manual stop valve of the filling port;

[0056] 2) Start precooling the pipeline until the filling level is reached, while monitoring the tank pressure;

[0057] 3) Stop filling after the filling level is reached and set the opening of the regulating valve;

[0058] 4) Open the stop valve, set the air pillow pressure control target, and realize real-time closed-loop control of the air pillow pressure through the boost port and exhaust port;

[0059] 5) After the outflow stops, stop the test.

[0060] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A full-scale low-temperature medium outflow test system, characterized in that: The system includes control system, head, storage tank, main conveying pipeline, accumulator, discharge pipeline, filling pipeline, gas sealing pipeline, boosting pipeline, boosting tank, liquid nitrogen filling tank truck, flow meter, filling port, regulating valve, stop valve, gas sealing port; The sealing head includes a pressure measuring port, an exhaust port, a boost port, a stop valve, and an energy dissipator; the energy dissipator is installed at the lower end of the boost port, and the discharge port of the energy dissipator is prevented from being directly aligned with the liquid surface; Build a test bench based on the full-size pressurized delivery system, and install the storage tank, delivery main line, and accumulator on the test bench; The main delivery pipeline and the discharge pipeline are equipped with compensators to compensate for the cold deformation of the pipeline during the test; The discharge pipeline is sequentially provided with a flow meter, a filling port, a regulating valve, a stop valve and a gas sealing port; The booster tank is respectively connected to the booster port of the head and the gas seal port of the discharge pipeline; The air pillow pressure is monitored through the pressure measuring port of the head and fed back to the control system. The control system sets the air pillow pressure control target according to the test conditions and realizes real-time closed-loop control of the air pillow pressure through the boost port and the exhaust port.

2. A full-scale low-temperature medium outflow test system according to claim 1, characterized in that: According to the heat leakage of the system, install insulation layer on the head, storage tank, pipelines and accumulator.

3. A full-scale low-temperature medium outflow test system according to claim 2, characterized in that: Liquid nitrogen is added directly by tank truck. The filling port is connected to the liquid outlet of the tank truck. The liquid nitrogen is squeezed out by the pressure of the tank truck and transported to the discharge pipeline, accumulator, main transportation pipeline and storage tank in sequence.

4. A full-scale low-temperature medium outflow test system according to claim 3, characterized in that: Before adding liquid nitrogen, the system is precooled using low-temperature nitrogen generated by gasification in a tank truck, while also achieving system air replacement.

5. A full-scale low-temperature medium outflow test system according to claim 1, characterized in that: Measurement parameters include pressure, differential pressure, level, flow, temperature and vibration.

6. A full-scale low-temperature medium outflow test system according to claim 5, characterized in that: The pressure is measured using a low-temperature pressure sensor with a frequency response range of 0 to 100 Hz.

7. A full-scale low-temperature medium outflow test system according to claim 5, characterized in that: Use a normal temperature differential pressure sensor to measure the pressure difference, and use a pressure-inducing tube to gasify low-temperature liquid nitrogen into normal temperature nitrogen and connect it to the normal temperature differential pressure sensor.

8. A full-scale low-temperature medium outflow test system according to claim 5, characterized in that: The liquid level is measured by converting the pressure difference between the box bottom and the air pillow into liquid level height.

9. A full-scale low-temperature medium outflow test system according to claim 5, characterized in that: The flow rate was measured using an orifice flow meter.

10. A flow test method for a full-scale low-temperature medium flow test system according to any one of claims 1 to 9, characterized in that: The following steps are involved: 1) First, prepare for the test, check the initial status of the valve and sensor, and connect the liquid nitrogen tank truck to the filling port. Open the manual shut-off valve at the filling port; 2) Start precooling the pipeline until the filling level is reached, while monitoring the tank pressure; 3) Stop filling after the filling level is reached and set the opening of the regulating valve; 4) Open the stop valve, set the air pillow pressure control target, and realize real-time closed-loop control of the air pillow pressure through the boost port and the exhaust port; 5) After the outflow stops, stop the test.

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