Experimental control device for researching injection system

Abstract

The invention provides an experiment control device for researching an ejection system. The experiment control device comprises a high-pressure power source pipeline, a multi-stage ejector pipeline and a control and data acquisition system, the high-pressure power source pipeline is used for providing high-pressure gas for the multi-stage ejector pipeline, so that each stage of ejector in the multi-stage ejector pipeline can work normally; the multi-stage ejector pipeline comprises a first-stage ejector pipeline to an nth-stage ejector pipeline, and all the stages of ejector pipelines are sequentially connected in a cascade form; and the control and data acquisition system is used for controlling the multi-stage ejector pipeline and acquiring data. According to the experimental control device for studying the injection system, the performance of various ejector systems can be studied, so that the ejector systems meet the design target and adapt to various variable working conditions, and the injection performance is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ejectors, and in particular to an experimental control device for studying ejector systems. Background Art

[0002] During the transportation of natural gas, leakage and exhaust may occur, resulting in energy waste. This leads to increased greenhouse gas emissions and has a negative impact on the environment. To solve this problem, it is necessary to recover and compress natural gas and reinject it into high-pressure pipelines for reuse. Currently, there are two main methods for gas recovery: compressors and ejectors. The compressor requires electricity to pressurize the gas to the target pressure, and this process is accompanied by an increase in temperature. In addition, a condenser is required to cool the compressed gas, which makes the system complicated and difficult to maintain. On the other hand, the ejector has many advantages in application. The ejector can convert pressure energy into energy for compressing low-pressure gas. It has a simple structure and no rotating parts, so it is small in size and does not require electricity. Due to its simple structure and high cost-effectiveness, the ejector is favored.

[0003] In the process of studying the ejector system, it is necessary to evaluate the amount of natural gas that can be recovered by the system (ejection coefficient) and the pressure that can be compressed (compression ratio) as the basis for the ejector structure design and the optimization of the ejector system control method. These performance evaluations require continuous experimental research on the ejector system to ensure that it can meet the standards and requirements. At present, most experimental devices related to ejectors only take the ejection coefficient as the main target, focus on the ejector body and regard its structural optimization as a means of improvement. It is believed that the ejector is a quasi-steady-state change and is not controlled. There is a lack of consideration of the compression ratio of the structure and the instantaneous dynamic change of the control from the perspective of the overall system. Therefore, it is necessary to develop an ejector system experimental device that can evaluate the performance from the perspective of structure and control. Summary of the invention

[0004] In view of the defects in the prior art, the purpose of the present invention is to provide an experimental control device for studying the ejector system. The present invention provides a pipeline design for the ejector system for construction, adopts an adjustable valve to create the actual environmental working condition and collects data through sensor transmitter detection, so as to study the performance of various ejector systems, enable the ejector system to meet the design goals, adapt to various variable working conditions, and improve the ejection performance.

[0005] To solve the above problems, the technical solution of the present invention is:

[0006] An experimental control device for studying an ejector system comprises a high-pressure power source pipeline, a multi-stage ejector pipeline and a control and data acquisition system; the high-pressure power source pipeline is used to provide high-pressure gas to the multi-stage ejector pipeline, so that each stage of the ejectors in the multi-stage ejector pipeline can work normally; the multi-stage ejector pipeline comprises a first-stage ejector pipeline to an n-th-stage ejector pipeline, and each stage of the ejector pipeline is connected in sequence in a cascade form; the control and data acquisition system is used to control the multi-stage ejector pipeline and collect data.

[0007] Preferably, the high-pressure power source pipeline includes a high-pressure gas cylinder group, a heat exchanger, and a high-pressure safety valve to provide high-pressure gas for the multi-stage ejector pipeline.

[0008] Preferably, the heat exchanger is connected in series with the pipeline coming out of the high-pressure gas cylinder group to adjust the temperature of the high-pressure gas; when the temperature of the high-pressure gas is higher than the designed working temperature of each stage of the ejector, a low-temperature fluid is introduced into the heat exchanger for heat exchange, so that the temperature of the high-pressure gas drops to the designed temperature; when the temperature of the low-pressure gas is lower than the designed working temperature of each stage of the ejector, a high-temperature fluid is introduced into the heat exchanger for heat exchange, so that the temperature of the high-pressure gas rises to the designed temperature; the high-pressure gas coming out of the heat exchanger is used as the power gas for each stage of the ejector to enable the ejectors at each stage to work normally.

[0009] Preferably, the high-pressure safety valve is installed in the high-pressure gas pipeline coming out of the heat exchanger, so that the internal pressure of the pipeline does not exceed the designed high pressure when the ejector is not working, thereby ensuring safety.

[0010] Preferably, each stage of the multi-stage ejector pipeline includes an ejector, a low-pressure flow transmitter, a low-pressure pressure transmitter, a low-pressure temperature transmitter, a high-pressure pneumatic pressure reducing valve, a high-pressure ball valve, a high-pressure flow transmitter, a high-pressure pressure transmitter, a high-pressure temperature transmitter, a medium-pressure pressure transmitter, a medium-pressure temperature transmitter, a medium-pressure ball valve, and a medium-pressure safety valve; the connection form is: the low-pressure flow transmitter, the low-pressure pressure transmitter, and the low-pressure temperature transmitter are all connected to the ejector low-pressure inlet pipeline for detecting the low-pressure gas state; the high-pressure pneumatic pressure reducing valve, the high-pressure ball valve, the high-pressure flow transmitter, the high-pressure pressure transmitter, and the high-pressure temperature transmitter are all connected to the ejector high-pressure inlet pipe The high-pressure pneumatic reducing valve and high-pressure ball valve are used to control the pressure and flow of high-pressure gas. The high-pressure flow transmitter, high-pressure pressure transmitter and high-pressure temperature transmitter are used to detect the state of high-pressure gas. The medium-pressure pressure transmitter, medium-pressure temperature transmitter, medium-pressure ball valve and medium-pressure safety valve are all connected to the medium-pressure outlet pipeline of the ejector. The medium-pressure pressure transmitter and medium-pressure temperature transmitter are used to detect the state of medium-pressure gas. The medium-pressure ball valve is connected in series at the last outlet of the pipeline to control the pressure of the medium-pressure gas at this level. The medium-pressure safety valve is connected before the medium-pressure ball valve and can be considered as a branch of the medium-pressure outlet pipeline of the ejector, so that the internal pressure of the pipeline does not exceed the designed medium pressure, so that the ejector does not flow back while ensuring the safety of the pipeline.

[0011] Preferably, the first-stage ejector pipeline of the multi-stage ejector pipeline is connected in series with a low-pressure pneumatic reducing valve and a low-pressure ball valve at the front inlet of the ejector low-pressure inlet pipeline to simulate the pressure and flow of the low-pressure recovered gas.

[0012] Preferably, the ejector medium-pressure outlet pipeline of the first stage to the n-1 stage ejector pipeline is directly connected to the ejector low-pressure inlet of the next stage to achieve the cumulative compression ratio of each stage; the ejector medium-pressure outlet pipeline of the nth stage ejector pipeline can be directly emptied when nitrogen is used.

[0013] Preferably, the control and data acquisition system is used to control the low-pressure pneumatic pressure reducing valve and the high-pressure pneumatic pressure reducing valve in the multi-stage ejector pipeline, and obtain experimental data through pressure, temperature and flow transmitters, which can be used to test the performance of the ejector system in this environment.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] 1. The present invention is applicable to experiments on various ejector structure designs, using pneumatic regulating valves and high-pressure ball valves to simulate variable working conditions of high-pressure and low-pressure gases, and using medium-pressure ball valves to adjust the outlet pressure of medium-pressure gases, so as to achieve better research on ejectors;

[0016] 2. The present invention provides a pipeline design for the ejector system for construction, uses an adjustable valve to create actual environmental conditions, and detects and collects data through sensor transmitters, so that the performance of various ejector systems can be studied, so that the system meets the design goals, adapts to various variable conditions, and improves the ejection performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0018] Figure 1 A detailed structural diagram of an experimental control device for studying an ejection system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0020] Specifically, the present invention provides an experimental control device for studying an ejector system, such as Figure 1 As shown, the device includes a high-pressure power source pipeline, a multi-stage ejector pipeline, and a control and data acquisition system 5.

[0021] The high-pressure power source pipeline provides high-pressure gas to the multi-stage ejector pipeline, so that the ejectors of each stage in the multi-stage ejector pipeline can work normally. The multi-stage ejector pipeline includes the first-stage ejector pipeline to the n-th-stage ejector pipeline, and the ejector pipelines of each stage are connected in series. The control and data acquisition system 5 can control the adjustable valve in the multi-stage ejector pipeline and collect data from each sensor transmitter and convert it into actual physical quantity.

[0022] The high-pressure power source pipeline includes a high-pressure gas cylinder group 1, a heat exchanger 101, and a high-pressure safety valve 102, which provide high-pressure gas for the multi-stage ejector pipeline so that each stage of the ejector in the multi-stage ejector pipeline can work normally; the high-pressure gas cylinder group 1, considering the safety of the experiment, uses nitrogen instead of natural gas for the experiment. As the most concise and convenient high-pressure power source for the experiment, it needs to have a high pressure greater than the starting and normal working pressure of each stage of the ejector. The heat exchanger 101 is connected in series with the pipeline coming out of the high-pressure gas cylinder group 1 to adjust the temperature of the high-pressure gas. Since the working temperature of the high-pressure gas is 35°C, and the gas temperature in the high-pressure gas cylinder group 1 of nitrogen is lower than 0°C, high-temperature water is introduced into the heat exchanger 101 for heat exchange, so that the temperature of the high-pressure gas rises to the design temperature. The high-pressure gas coming out of the heat exchanger 101 is used as the power gas for the ejectors at each level to make them work; the high-pressure safety valve 102 is installed in the high-pressure gas pipeline coming out of the heat exchanger 101, so that the internal pressure of the pipeline does not exceed the design high pressure when the ejector is not working, thereby ensuring safety, because it can be directly discharged when using nitrogen.

[0023] Specifically, in this embodiment, the multi-stage ejector pipeline is a three-stage ejector system, including a first-stage ejector pipeline, a second-stage ejector pipeline and a third-stage ejector pipeline.

[0024] The first-stage ejector pipeline includes a first-stage ejector 2, a first-stage low-pressure flow transmitter 203, a first-stage low-pressure pressure transmitter 204, a first-stage low-pressure temperature transmitter 205, a first-stage high-pressure pneumatic pressure reducing valve 206, a first-stage high-pressure ball valve 207, a first-stage high-pressure flow transmitter 208, a first-stage high-pressure pressure transmitter 209, a first-stage high-pressure temperature transmitter 210, a first-stage medium-pressure pressure transmitter 211, a first-stage medium-pressure temperature transmitter 212, a first-stage medium-pressure ball valve 213, and a first-stage medium-pressure safety valve. 214; the first-stage ejector 2 is an adjustable ejector with an adjustable cone structure, and its connection form is: the first-stage low-pressure flow transmitter 203, the first-stage low-pressure pressure transmitter 204, and the first-stage low-pressure temperature transmitter 205 are all in the low-pressure inlet pipeline of the first-stage ejector 2, which are used to detect the low-pressure gas state of this stage; the first-stage high-pressure pneumatic pressure reducing valve 206, the first-stage high-pressure ball valve 207, the first-stage high-pressure flow transmitter 208, the first-stage high-pressure pressure transmitter 209, and the first-stage high-pressure temperature transmitter 210 are all in the first The first-stage high-pressure inlet pipeline of the first-stage ejector 2, the first-stage high-pressure pneumatic pressure reducing valve 206, the first-stage high-pressure ball valve 207 are connected in series at the front entrance of the pipeline to control the pressure and flow of the high-pressure gas at this stage, the first-stage high-pressure flow transmitter 208, the first-stage high-pressure pressure transmitter 209, the first-stage high-pressure temperature transmitter 210 are used to detect the state of the high-pressure gas at this stage; the first-stage medium-pressure pressure transmitter 211, the first-stage medium-pressure temperature transmitter 212, the first-stage medium-pressure ball valve 213, the first-stage medium-pressure safety valve 214 are all in the first-stage ejector 2 The medium-pressure outlet pipeline, the first-stage medium-pressure pressure transmitter 211 and the first-stage medium-pressure temperature transmitter 212 are used to detect the state of the medium-pressure gas at this stage. The first-stage medium-pressure ball valve 213 is connected in series at the last outlet of the pipeline to control the pressure of the first-stage medium-pressure gas. The first-stage medium-pressure safety valve 214 before the first-stage medium-pressure ball valve 213 can be considered as a branch of the medium-pressure outlet pipeline of the first-stage ejector 2, so that the internal pressure of the pipeline does not exceed the designed medium pressure, thereby preventing the ejector from backflow and ensuring the safety of the pipeline. When nitrogen is used, it can be directly discharged.

[0025] The second-stage ejector pipeline includes a second-stage ejector 3, a second-stage low-pressure flow transmitter 301, a second-stage low-pressure pressure transmitter 302, a second-stage low-pressure temperature transmitter 303, a second-stage high-pressure pneumatic pressure reducing valve 304, a second-stage high-pressure ball valve 305, a second-stage high-pressure flow transmitter 306, a second-stage high-pressure pressure transmitter 307, a second-stage high-pressure temperature transmitter 308, a second-stage medium-pressure pressure transmitter 309, a second-stage medium-pressure temperature transmitter 310, a second-stage medium-pressure ball valve 311, and a second-stage medium-pressure safety valve. 312; the second-stage ejector 3 is an adjustable ejector with an adjustable cone structure, and its connection form is: the second-stage low-pressure flow transmitter 301, the second-stage low-pressure pressure transmitter 302, and the second-stage low-pressure temperature transmitter 303 are all in the low-pressure inlet pipeline of the second-stage ejector 3, which are used to detect the low-pressure gas state of this stage; the second-stage high-pressure pneumatic pressure reducing valve 304, the second-stage high-pressure ball valve 305, the second-stage high-pressure flow transmitter 306, the second-stage high-pressure pressure transmitter 307, and the second-stage high-pressure temperature transmitter 308 are all in the second The second stage high pressure inlet pipeline of the second stage ejector 3, the second stage high pressure pneumatic pressure reducing valve 304, the second stage high pressure ball valve 305 are connected in series at the front entrance of the pipeline to control the pressure and flow of the high pressure gas of this stage, the second stage high pressure flow transmitter 306, the second stage high pressure pressure transmitter 307, the second stage high pressure temperature transmitter 308 are used to detect the state of the high pressure gas of this stage; the second stage medium pressure pressure transmitter 309, the second stage medium pressure temperature transmitter 310, the second stage medium pressure ball valve 311, the second stage medium pressure safety valve 312 are all in the second stage ejector 3 The medium-pressure outlet pipeline, the second-stage medium-pressure pressure transmitter 309 and the second-stage medium-pressure temperature transmitter 310 are used to detect the state of the medium-pressure gas at this stage. The second-stage medium-pressure ball valve 311 is connected in series at the last outlet of the pipeline to control the pressure of the second-stage medium-pressure gas. The second-stage medium-pressure safety valve 312 before the second-stage medium-pressure ball valve 311 can be considered as a branch of the medium-pressure outlet pipeline of the second-stage ejector 3, so that the internal pressure of the pipeline does not exceed the designed medium pressure, thereby preventing the ejector from backflow and ensuring the safety of the pipeline. When nitrogen is used, it can be directly discharged.

[0026] The third-stage ejector pipeline includes a third-stage ejector 4, a third-stage low-pressure flow transmitter 401, a third-stage low-pressure pressure transmitter 402, a third-stage low-pressure temperature transmitter 403, a third-stage high-pressure pneumatic pressure reducing valve 404, a third-stage high-pressure ball valve 405, a third-stage high-pressure flow transmitter 406, a third-stage high-pressure pressure transmitter 407, a third-stage high-pressure temperature transmitter 408, a third-stage medium-pressure pressure transmitter 409, a third-stage medium-pressure temperature transmitter 410, a third-stage medium-pressure ball valve 411, and a third-stage medium-pressure safety valve. 412; the third-stage ejector 4 is an adjustable ejector with an adjustable cone structure, and its connection form is: the third-stage low-pressure flow transmitter 401, the third-stage low-pressure pressure transmitter 402, and the third-stage low-pressure temperature transmitter 403 are all in the low-pressure inlet pipeline of the third-stage ejector 4, which are used to detect the low-pressure gas state of this stage; the third-stage high-pressure pneumatic pressure reducing valve 404, the third-stage high-pressure ball valve 405, the third-stage high-pressure flow transmitter 406, the third-stage high-pressure pressure transmitter 407, and the third-stage high-pressure temperature transmitter 408 are all in the third The third-stage high-pressure inlet pipeline of the third-stage ejector 4, the third-stage high-pressure pneumatic pressure reducing valve 404, and the third-stage high-pressure ball valve 405 are connected in series at the front entrance of the pipeline to control the pressure and flow of the high-pressure gas at this stage, the third-stage high-pressure flow transmitter 406, the third-stage high-pressure pressure transmitter 407, and the third-stage high-pressure temperature transmitter 408 are used to detect the state of the high-pressure gas at this stage; the third-stage medium-pressure pressure transmitter 409, the third-stage medium-pressure temperature transmitter 410, the third-stage medium-pressure ball valve 411, and the third-stage medium-pressure safety valve 412 are all in the third-stage ejector 4. The medium-pressure outlet pipeline, the third-stage medium-pressure pressure transmitter 409 and the third-stage medium-pressure temperature transmitter 410 are used to detect the state of the medium-pressure gas at this stage. The third-stage medium-pressure ball valve 411 is connected in series at the last outlet of the pipeline to control the pressure of the third-stage medium-pressure gas. The third-stage medium-pressure safety valve 412 before the third-stage medium-pressure ball valve 411 can be considered as a branch of the medium-pressure outlet pipeline of the third-stage ejector 4, so that the internal pressure of the pipeline does not exceed the designed medium pressure, thereby preventing the ejector from backflow and ensuring the safety of the pipeline. When nitrogen is used, it can be directly discharged.

[0027] In this embodiment, the first-stage ejector pipeline also includes a first-stage low-pressure pneumatic pressure reducing valve 201 and a first-stage low-pressure ball valve 202, which are connected in series at the front of the low-pressure inlet pipeline of the first-stage ejector 2 to simulate the pressure and flow of the low-pressure recovered gas; the medium-pressure outlet pipeline of the first-stage ejector 2 is directly connected to the ejection low-pressure inlet of the second-stage ejector 3, and the medium-pressure outlet pipeline of the second-stage ejector 3 is directly connected to the ejection low-pressure inlet of the third-stage ejector 4 to achieve the cumulative compression ratio of each stage; the medium-pressure outlet pipeline of the third-stage ejector 4 can be directly emptied due to the use of nitrogen.

[0028] The control and data acquisition system 5 can control the first-stage low-pressure pneumatic pressure reducing valve 201, the first-stage high-pressure pneumatic pressure reducing valve 206, the second-stage high-pressure pneumatic pressure reducing valve 304, and the third-stage high-pressure pneumatic pressure reducing valve 404 in the multi-stage ejector pipeline. The control device can be used to simulate the complex variable operating conditions that the actual ejector system will face, mainly the step change in the pressure of the high-pressure gas during startup and the periodic change caused by the fluctuation during normal operation, as well as the periodic change in the flow rate of the low-pressure gas as the compressor unit is vented during operation. Experimental data can be obtained through pressure, temperature, and flow transmitters, which can be used to test the performance of the ejector system under this environment.

[0029] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. An experimental control device for studying an ejection system, characterized in that: The device includes a high-pressure power source pipeline, a multi-stage ejector pipeline, and a control and data acquisition system; the high-pressure power source pipeline is used to provide high-pressure gas to the multi-stage ejector pipeline, so that the ejectors of each stage in the multi-stage ejector pipeline can work normally; the multi-stage ejector pipeline includes a first-stage ejector pipeline to an n-th-stage ejector pipeline, and the ejector pipelines of each stage are connected in sequence in a cascade form; the control and data acquisition system is used to control the multi-stage ejector pipeline and collect data.

2. The experimental control device for studying the ejection system according to claim 1, characterized in that: The high-pressure power source pipeline includes a high-pressure gas cylinder group, a heat exchanger, and a high-pressure safety valve, which provide high-pressure gas for the multi-stage ejector pipeline.

3. The experimental control device for studying the ejection system according to claim 2, characterized in that: The heat exchanger is connected in series with the pipeline coming out of the high-pressure gas cylinder group to adjust the temperature of the high-pressure gas; when the temperature of the high-pressure gas is higher than the designed working temperature of each stage of the ejector, a low-temperature fluid is introduced into the heat exchanger for heat exchange, so that the temperature of the high-pressure gas drops to the designed temperature; when the temperature of the low-pressure gas is lower than the designed working temperature of each stage of the ejector, a high-temperature fluid is introduced into the heat exchanger for heat exchange, so that the temperature of the high-pressure gas rises to the designed temperature; the high-pressure gas coming out of the heat exchanger is used as the power gas for each stage of the ejector to enable the ejectors at each stage to work normally.

4. The experimental control device for studying the ejection system according to claim 2, characterized in that: The high-pressure safety valve is installed in the high-pressure gas pipeline coming out of the heat exchanger, so that the internal pressure of the pipeline does not exceed the designed high pressure when the ejector is not working, thereby ensuring safety.

5. The experimental control device for studying the ejection system according to claim 1, characterized in that: Each stage of the multi-stage ejector pipeline includes an ejector, a low-pressure flow transmitter, a low-pressure pressure transmitter, a low-pressure temperature transmitter, a high-pressure pneumatic pressure reducing valve, a high-pressure ball valve, a high-pressure flow transmitter, a high-pressure pressure transmitter, a high-pressure temperature transmitter, a medium-pressure pressure transmitter, a medium-pressure temperature transmitter, a medium-pressure ball valve, and a medium-pressure safety valve; the connection form is: the low-pressure flow transmitter, the low-pressure pressure transmitter, and the low-pressure temperature transmitter are all connected to the ejector low-pressure inlet pipeline for detecting the low-pressure gas state; the high-pressure pneumatic pressure reducing valve, the high-pressure ball valve, the high-pressure flow transmitter, the high-pressure pressure transmitter, and the high-pressure temperature transmitter are all connected to the ejector high-pressure inlet pipeline, High-pressure pneumatic reducing valve and high-pressure ball valve are used to control the pressure and flow of high-pressure gas. High-pressure flow transmitter, high-pressure pressure transmitter and high-pressure temperature transmitter are used to detect the status of high-pressure gas. Medium-pressure pressure transmitter, medium-pressure temperature transmitter, medium-pressure ball valve and medium-pressure safety valve are all connected to the medium-pressure outlet pipeline of the ejector. Medium-pressure pressure transmitter and medium-pressure temperature transmitter are used to detect the status of medium-pressure gas. Medium-pressure ball valve is connected in series at the last outlet of the pipeline to control the pressure of the medium-pressure gas at this level. The medium-pressure safety valve is connected before the medium-pressure ball valve and can be considered as a branch of the medium-pressure outlet pipeline of the ejector, so that the internal pressure of the pipeline does not exceed the designed medium pressure, thereby preventing the ejector from backflow and ensuring the safety of the pipeline.

6. The experimental control device for studying the ejection system according to claim 1, characterized in that: The first stage ejector pipeline of the multi-stage ejector pipeline is connected in series with a low-pressure pneumatic pressure reducing valve and a low-pressure ball valve at the front inlet of the ejector low-pressure inlet pipeline, so as to simulate the pressure and flow of the low-pressure recovered gas.

7. The experimental control device for studying the ejection system according to claim 1, characterized in that: The ejector medium-pressure outlet pipeline of the first stage to the n-1 stage ejector pipeline is directly connected to the ejector low-pressure inlet of the next stage, realizing the cumulative compression ratio of each stage; the ejector medium-pressure outlet pipeline of the nth stage ejector pipeline can be directly emptied when nitrogen is used.

8. The experimental control device for studying the ejection system according to claim 1, characterized in that: The control and data acquisition system is used to control the low-pressure pneumatic pressure reducing valve and the high-pressure pneumatic pressure reducing valve in the multi-stage ejector pipeline, and obtain experimental data through pressure, temperature and flow transmitters, which can be used to test the performance of the ejector system in this environment.

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