Aero liquid-gas hydrogen heat exchanger test device and method

Abstract

This specification discloses an experimental apparatus for an aviation liquid-gas hydrogen heat exchanger. The apparatus includes an aviation liquid-gas hydrogen heat exchanger, a hydrogen storage device, a hydrogen source, and an engine. The aviation liquid-gas hydrogen heat exchanger and the hydrogen storage device are connected via a first set of pipes. The hydrogen storage device and the hydrogen source are connected via a second set of pipes. A first set of valves is provided on the first set of pipes to control the flow of hydrogen medium between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger. A second set of valves is provided on the second set of pipes to control the flow of hydrogen medium between the hydrogen source and the hydrogen storage device. A first set of sensors is also provided on the first set of pipes to detect the temperature and / or pressure of a specific portion of the first set of pipes. The aviation liquid-gas hydrogen heat exchanger is located in a certain area near the exhaust system of the engine.

Description

Technical Field

[0001] This application relates to the field of hydrogen-powered aero-engine technology, and in particular to a test apparatus and method for an aero-liquid-gas hydrogen heat exchanger. Background Technology

[0002] Hydrogen fuel boasts advantages such as wide availability, high energy density, zero carbon emissions, and excellent combustibility, making it an ideal fuel for the aviation industry's move towards zero-carbon operation. Therefore, hydrogen power is poised to become one of the most promising power forms for future aviation. To improve the volumetric energy density of hydrogen fuel, it is typically stored as cryogenic, low-pressure liquid hydrogen (20-30K, 0.3-0.5MPa). The hydrogen supply temperature for hydrogen engines must be no lower than 150K to ensure the safe and efficient operation of the combustion chamber. Therefore, hydrogen-powered aircraft require liquid-to-gas hydrogen heat exchangers to convert liquid hydrogen into gaseous hydrogen at a suitable temperature by transferring heat energy to the cryogenic hydrogen medium.

[0003] The liquid-gas hydrogen heat exchanger coupled with the hydrogen aero-engine has unique characteristics. First, the liquid-gas hydrogen heat exchanger and hydrogen supply system are airborne systems with low ambient temperatures, so ground tests should closely simulate airborne operating conditions. Second, liquid hydrogen is a relatively expensive medium, so ground tests should maximize efficiency and minimize liquid hydrogen consumption.

[0004] Currently, there is no suitable test plan for aviation liquid-gas hydrogen heat exchangers. Summary of the Invention

[0005] This specification provides a test apparatus and method for an aviation liquid-gas hydrogen heat exchanger, which addresses the technical problem of how to conduct efficient and high-quality tests on aviation liquid-gas hydrogen heat exchangers.

[0006] To address the aforementioned technical problems, the embodiments in this specification provide the following technical solutions: This specification provides an aviation liquid-gas hydrogen heat exchanger test apparatus, the apparatus including an aviation liquid-gas hydrogen heat exchanger, a hydrogen storage device, a hydrogen source, and an engine; The aviation liquid-gas hydrogen heat exchanger and the hydrogen storage device are connected by a first pipeline group. The hydrogen storage device and the hydrogen source are connected by a second pipeline group; The first pipeline group is equipped with a first valve group, which is used to control the flow of hydrogen medium between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger. The second pipeline assembly is equipped with a second valve assembly, which is used to control the flow of hydrogen medium between the hydrogen source and the hydrogen storage device; The first pipeline assembly is also equipped with a first sensor assembly, which is used to detect the temperature and / or pressure of a specific part of the first pipeline assembly; The aviation liquid-gas hydrogen heat exchanger is located in a certain area near the exhaust device of the engine.

[0007] Preferably, the device further includes a temperature control device, and the aviation liquid-gas hydrogen heat exchanger is connected to the temperature control device via a third pipeline group.

[0008] Preferably, the third pipe assembly is provided with a third sensor assembly, which is used to detect the temperature and / or pressure of a specific part of the third pipe assembly.

[0009] Preferably, the device further includes a fourth sensor group for detecting the thrust and / or exhaust temperature of the engine.

[0010] Preferably, the device further includes a vent pipe, which is connected to the first pipe group via a fourth pipe group.

[0011] Preferably, the fourth pipeline group is provided with a fourth valve group, which is used to control the flow of hydrogen medium between the first pipeline group and the vent pipe.

[0012] Preferably, the system also includes a control terminal, which is used to control the first valve group, the second valve group, and the first sensor group.

[0013] The above-described at least one technical solution adopted in the embodiments of this specification can achieve the following beneficial effects: The aforementioned technical solution can meet the specific requirements of testing aircraft liquid-gas hydrogen heat exchangers. It can be applied to ground testing of liquid-gas hydrogen heat exchangers, a key component of liquid hydrogen aircraft propulsion systems. It can cover the entire process of preparation and testing for liquid-gas hydrogen heat exchange, and can be used for various tests on aircraft liquid-gas hydrogen heat exchangers, such as cold start performance and variable operating condition heat exchange performance tests. Simultaneously, it can investigate the impact of the heat exchanger on engine thrust and exhaust temperature, and simulate the airborne environment through pre-cooling and pressurization. This technical solution can effectively improve the testing results and efficiency of aircraft liquid-gas hydrogen heat exchangers.

[0014] This specification provides a test method for an aviation liquid-gas hydrogen heat exchanger, the method comprising: Liquid hydrogen is added to the hydrogen storage device, and the pipeline assembly between the hydrogen source and the hydrogen storage device is pre-cooled. Once the pressure of the hydrogen storage device meets the requirements, the pipeline group between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger is formally cooled. After the pipeline assembly between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger is cooled to the preset conditions, a cold start test, a heat exchange performance pre-test, and a heat exchange performance boundary test are performed respectively. The cold start test includes: The hydrogen storage device introduces hydrogen medium into the aviation liquid-gas hydrogen heat exchanger at a preset flow rate, and tests whether the heat exchange effect of the aviation liquid-gas hydrogen heat exchanger meets the engine starting conditions. The heat exchange performance pre-test includes: Adjust the hydrogen medium flow rate between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger, as well as the engine operating conditions, to determine the basic hydrogen flow rate for the heat exchange performance boundary test under each engine operating condition. The heat transfer performance boundary test includes: Under various engine operating conditions, the flow rate of the hydrogen medium between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger is controlled according to the hydrogen base flow rate until the hydrogen outlet temperature of the aviation liquid-gas hydrogen heat exchanger reaches the upper and lower limits of the allowable temperature, so as to determine the heat exchange performance boundary of the aviation liquid-gas hydrogen heat exchanger.

[0015] Preferably, adjusting the hydrogen medium flow rate between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger, as well as the engine operating conditions, to determine the basic hydrogen flow rate for the heat exchange performance boundary test includes: For any engine operating condition, the flow rate of the hydrogen medium from the hydrogen storage device to the aviation liquid-gas hydrogen heat exchanger is adjusted until the temperature of the hydrogen medium flowing out of the aviation liquid-gas hydrogen heat exchanger reaches a first condition. The flow rate of the hydrogen medium when the first condition is reached is taken as the basic hydrogen flow rate for the heat exchange performance boundary test under that engine operating condition.

[0016] Preferably, the heat transfer performance boundary test further includes: Under any engine operating condition, data monitoring operations are performed; wherein, the data monitoring operations include: during the process of the hydrogen outlet temperature of the aviation liquid-gas hydrogen heat exchanger changing between the upper and lower limits, acquiring the thrust and exhaust temperature data of the engine at preset temperature intervals; After completing the data monitoring operations under various engine operating conditions, the impact of the aviation liquid-gas hydrogen heat exchanger on the engine is determined.

[0017] The above-described at least one technical solution adopted in the embodiments of this specification can achieve the following beneficial effects: The above-mentioned technical solution can meet the special requirements of aviation liquid-gas hydrogen heat exchanger testing. It can be applied to ground testing of liquid-gas hydrogen heat exchangers, which are key components of liquid hydrogen aircraft power systems. It can cover the entire process of preparation and testing of liquid-gas hydrogen heat exchangers. It can be used for various tests on aviation liquid-gas hydrogen heat exchangers, such as cold start performance and variable operating condition heat exchange performance tests. At the same time, it can determine the influence of the heat exchanger on engine thrust and exhaust temperature, and simulate the airborne environment through pre-cooling and pressurization.

[0018] The above technical solution includes a preliminary heat exchange performance test, which provides a reference for subsequent heat exchange boundary assessment tests, improves test efficiency, and reduces the cost of using liquid hydrogen.

[0019] The above technical solutions can effectively improve the test results and efficiency of aviation liquid-gas hydrogen heat exchangers. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings used in the description of the embodiments of this specification or the prior art will be briefly described below. Obviously, the drawings used in some embodiments of this application are only described below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the architecture of the aviation liquid-gas hydrogen heat exchanger test device provided in the first embodiment of this specification.

[0022] Figure 2 This is a schematic diagram of the test process of the aviation liquid-gas hydrogen heat exchanger in the second embodiment of this specification.

[0023] Figure 3 This is a schematic diagram of the liquid hydrogen co-filling and precooling process in the second embodiment of this specification.

[0024] Figure 4 This is a schematic diagram of the pressurization process of the liquid hydrogen storage tank in the second embodiment of this specification.

[0025] Figure 5 This is a schematic diagram of the upstream precooling process of the aviation liquid-gas hydrogen heat exchanger in the second embodiment of this specification.

[0026] Figure 6 This is a schematic diagram of the cold start test process in the second embodiment of this specification.

[0027] Figure 7 This is a schematic diagram of the heat exchange performance pre-test process in the second embodiment of this specification.

[0028] Figure 8 This is a schematic diagram of the heat transfer performance boundary test process in the second embodiment of this specification.

[0029] Figure 9 This is a schematic diagram of the cold start test results in the second embodiment of this specification.

[0030] Figure 10 This is a schematic diagram of the heat transfer performance pre-test and heat transfer performance boundary test results in the second embodiment of this specification.

[0031] In the diagram: 1. High-pressure hydrogen source; 2. Liquid hydrogen main booster valve; 3. Liquid hydrogen supplementary booster valve; 4. Liquid hydrogen storage tank; 5. Emergency valve; 6. Main valve; 7. First temperature and pressure sensor group; 8. Pressure regulating valve; 9. Second temperature and pressure sensor group; 10. Inlet hose; 11. Liquid-gas hydrogen heat exchanger; 12. Outlet hose; 13. Third temperature and pressure sensor group; 14. Constant temperature water bath; 15. Flow sensor; 16. Flow regulating valve; 17. Pre-cooling valve; 18. Main pre-cooling valve; 19. Vent pipe; 20. Engine; 21. Thrust sensor; 22. Exhaust temperature sensor group. Detailed Implementation

[0032] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments involved in the specific implementation are only a part of the embodiments of this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in the specific implementation without creative effort should fall within the protection scope of this application.

[0033] The first embodiment of this specification (hereinafter referred to as "Embodiment 1") provides an aviation liquid-gas hydrogen heat exchanger test device, which includes an aviation liquid-gas hydrogen heat exchanger, a hydrogen storage device, a hydrogen source, and an engine; The aviation liquid-gas hydrogen heat exchanger and the hydrogen storage device are connected by a pipeline group (referred to as the first pipeline group); The hydrogen storage device and the hydrogen source are connected by a pipeline group (referred to as the second pipeline group); The first pipeline group is equipped with a first valve group, which is used to control the flow of hydrogen medium between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger. The second pipeline assembly is equipped with a second valve assembly, which is used to control the flow of hydrogen medium between the hydrogen source and the hydrogen storage device. The first pipeline group is also equipped with a first sensor group, which is used to detect the temperature and / or pressure of a specific part of the first pipeline group. The aviation liquid-gas hydrogen heat exchanger is located in a certain area near the engine's exhaust system.

[0034] Preferably, the test device for the aviation liquid-gas hydrogen heat exchanger also includes a temperature control device, and the aviation liquid-gas hydrogen heat exchanger and the temperature control device are connected by a pipeline group (referred to as the third pipeline group).

[0035] Preferably, a third sensor group is provided on the third pipe group, which is used to detect the temperature and / or pressure of a specific part of the third pipe group.

[0036] Preferably, the aircraft liquid-gas hydrogen heat exchanger test apparatus also includes a fourth sensor group for detecting engine thrust and / or exhaust temperature.

[0037] Preferably, the test device for the aviation liquid-gas hydrogen heat exchanger also includes a vent pipe, which is connected to the first pipe group via a pipe group (referred to as the fourth pipe group).

[0038] Preferably, a fourth valve group is provided on the fourth pipeline group, which is used to control the flow of hydrogen medium between the first pipeline group and the vent pipe.

[0039] Preferably, the test device for the aviation liquid-gas hydrogen heat exchanger also includes a fire-fighting module to prevent the hydrogen from being ignited.

[0040] The aforementioned pipe group can refer to a single pipe, or multiple pipes connected sequentially and / or multiple pipes connected in parallel, as is the case in Example 1.

[0041] The architecture of this aircraft liquid-gas hydrogen heat exchanger test device will be further illustrated below with a specific example: refer to Figure 1 The experimental setup for the aviation liquid-gas hydrogen heat exchanger includes: The aircraft includes an aviation liquid-gas hydrogen heat exchanger (hereinafter referred to as the heat exchanger or liquid-gas hydrogen heat exchanger) 11, a liquid hydrogen storage tank (i.e., hydrogen storage device) 4, a high-pressure hydrogen source (hereinafter referred to as the hydrogen source) 1, and an engine 20. The engine 20 may be a sample or a test piece.

[0042] The heat exchanger 11 is connected to the liquid hydrogen storage tank 4 via a first pipeline assembly. The portion of the first pipeline assembly closest to the heat exchanger 11 is a flexible hose 10.

[0043] The liquid hydrogen storage tank 4 and the high-pressure hydrogen source 1 are connected by a second pipeline group; The first pipeline group is equipped with a first valve group, which is used to control the flow of hydrogen medium between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger 11. The first valve group includes an emergency valve 5, a main valve 6, and a pressure regulating valve 8.

[0044] The second pipeline assembly is equipped with a second valve assembly, which is used to control the flow of hydrogen medium between the hydrogen source 1 and the hydrogen storage device. The second valve assembly includes a liquid hydrogen main pressurization valve 2 and a liquid hydrogen supplementary pressurization valve 3.

[0045] The first pipeline assembly is also equipped with a first sensor assembly, which is used to detect the temperature and / or pressure of a specific section within the first pipeline assembly. The first sensor assembly includes two temperature and pressure sensor assemblies: a first temperature and pressure sensor assembly 7 (or temperature and pressure sensor assembly 1) and a second temperature and pressure sensor assembly 9 (or temperature and pressure sensor assembly 2). The temperature and pressure sensor assembly may include temperature sensors and pressure sensors, or it may include sensors that simultaneously detect both temperature and pressure; the same applies hereinafter.

[0046] The heat exchanger 11 is located in a certain area near the exhaust device of the engine 20.

[0047] The test apparatus for the aviation liquid-gas hydrogen heat exchanger also includes a constant temperature water bath 14 (i.e., a constant temperature device), and the heat exchanger 11 is connected to the constant temperature water bath 14 via a third piping group. Among them, the part of the third piping group closest to the heat exchanger 11 uses an outlet hose 12.

[0048] The third pipeline is equipped with a third sensor group, which is used to detect the flow rate in a specific section of the third pipeline. The third sensor group includes a temperature and pressure sensor group 13 (referred to as the third temperature and pressure sensor group, or temperature and pressure sensor group 3).

[0049] The aircraft liquid-gas hydrogen heat exchanger test setup also includes another sensor group (referred to as the fourth sensor group), which is used to detect the thrust and / or exhaust temperature of engine 20. The fourth sensor group includes a thrust sensor 21 and an exhaust temperature sensor 22.

[0050] The test device for the aviation liquid-gas hydrogen heat exchanger also includes a vent pipe 19, which is connected to the first pipeline group via a fourth pipeline group.

[0051] A fourth valve group is installed on the fourth pipeline group, which is used to control the flow of hydrogen medium between the first pipeline group and the vent pipe 19. The fourth valve group includes a pre-cooling valve 17 and a main pre-cooling valve 18.

[0052] The vent pipe 19 is connected to the constant temperature water bath 14 via a fifth pipeline assembly. This fifth pipeline assembly includes a fifth valve assembly and a sensor assembly (referred to as the fifth sensor assembly). The fifth valve assembly controls the flow of hydrogen between the constant temperature water bath 14 and the vent pipe 19, while the fifth sensor assembly detects the flow rate in a specific section of the fifth pipeline. The fifth valve assembly includes a flow regulating valve 16, and the fifth sensor assembly includes a flow sensor 15.

[0053] The test device for the aviation liquid-gas hydrogen heat exchanger also includes a fire suppression module to prevent the hydrogen from being ignited.

[0054] The second embodiment of this specification (hereinafter referred to as "Embodiment 2") provides a test method for an aviation liquid-gas-hydrogen heat exchanger based on the aviation liquid-gas-hydrogen heat exchanger test device provided in Embodiment 1. That is, Embodiment 2 is a method for testing an aviation liquid-gas-hydrogen heat exchanger using the aviation liquid-gas-hydrogen heat exchanger test device provided in Embodiment 1.

[0055] refer to Figure 2 The test method for the aviation liquid-gas hydrogen heat exchanger provided in Example 2 includes: Liquid hydrogen is added to the hydrogen storage device, and the pipeline group (i.e., the second pipeline group) between the hydrogen source and the hydrogen storage device is pre-cooled; this process can be called "liquid hydrogen co-filling and pre-cooling". Once the hydrogen storage device reaches the required pressure, the pipeline assembly between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger is formally cooled; this process includes pressurizing the hydrogen storage device and pre-cooling upstream of the liquid-gas hydrogen heat exchanger.

[0056] After the pipeline assembly between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger is cooled to the preset conditions, a cold start-up test, a heat exchange performance pre-test (or heat exchange performance preliminary test), and a heat exchange performance boundary test (or heat exchange performance boundary preliminary test) are performed respectively. The cold start test includes: The hydrogen storage device introduces hydrogen medium into the aviation liquid-gas hydrogen heat exchanger at a preset flow rate, and tests whether the heat exchange effect of the aviation liquid-gas hydrogen heat exchanger meets the engine starting conditions. The heat exchange performance pre-test includes: Adjust the hydrogen medium flow rate between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger, as well as the engine operating conditions, to determine the basic hydrogen flow rate for the heat exchange performance boundary test under each engine operating condition. The heat transfer performance boundary test includes: Under various engine operating conditions, the flow rate of the hydrogen medium between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger is controlled according to the hydrogen base flow rate until the hydrogen outlet temperature of the aviation liquid-gas hydrogen heat exchanger reaches the upper and lower limits of the allowable temperature, so as to determine the heat exchange performance boundary of the aviation liquid-gas hydrogen heat exchanger.

[0057] Preferably, adjusting the hydrogen medium flow rate between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger, as well as the engine operating conditions, to determine the basic hydrogen flow rate for the heat exchange performance boundary test includes: For any engine operating condition, the flow rate of the hydrogen medium from the hydrogen storage device to the aviation liquid-gas hydrogen heat exchanger is adjusted until the temperature of the hydrogen medium flowing out of the aviation liquid-gas hydrogen heat exchanger reaches a first condition. The flow rate of the hydrogen medium when the first condition is reached is taken as the basic hydrogen flow rate for the heat exchange performance boundary test under that engine operating condition.

[0058] Preferably, the heat transfer performance boundary test further includes: Under any engine operating condition, data monitoring operations are performed; wherein, the data monitoring operations include: during the process of the hydrogen outlet temperature of the aviation liquid-gas hydrogen heat exchanger changing between the upper and lower limits, acquiring the thrust and exhaust temperature data of the engine at preset temperature intervals; After completing the data monitoring operations under various engine operating conditions, the impact of the aviation liquid-gas hydrogen heat exchanger on the engine is determined.

[0059] The following is for reference. Figure 1 and Figure 2 The following is a further illustrative description of Embodiment 2: In this example, the liquid hydrogen pipeline was pre-cooled and the liquid hydrogen storage tank 4 was pressurized before the test. Then, the cold start test, the heat exchange performance pre-test and the heat exchange performance boundary assessment test were carried out in sequence.

[0060] S1: In Example 2, liquid hydrogen can be added to the hydrogen storage device while simultaneously pre-cooling at a small flow rate before the test, until the hydrogen storage device is pressurized to the required pressure. This achieves the aforementioned coordinated liquid hydrogen addition and pre-cooling. To accelerate the cooling efficiency of the upstream pipeline of heat exchanger 11, cooling begins during low-pressure liquid hydrogen addition, with cooling occurring simultaneously at a small flow rate. At the same time, an ice-water mixture is added to the constant-temperature water bath 14 to protect the downstream equipment of the liquid-gas hydrogen heat exchanger 11. Figure 1 Taking the aircraft liquid-gas hydrogen heat exchanger test apparatus shown as an example, and referring to... Figure 2 and Figure 3 Specifically, this may include the following steps: s1.1 Confirm that emergency valve 5, main valve 6, and pre-cooling valve 17 are open, and pressure regulating valve 8 is closed; S1.2, begin liquid hydrogen refueling; s1.3, a small flow of liquid hydrogen flows out from the liquid hydrogen storage tank 4, flows through the emergency valve 5, the main valve 6, and the pre-cooling valve 17, and then flows out from the drain pipe. The temperature reading of the first temperature and pressure sensor group 7 should be monitored and gradually decreased. s1.4, Liquid hydrogen is added to the required level; S1.5, close emergency valve 5, main valve 6, and pre-cooling valve 17; s1.6, add ice-water mixture to constant temperature water bath 14.

[0061] S2: The hydrogen storage device is pressurized using a high-pressure gaseous hydrogen source until the pressure inside the device reaches the required or design pressure (e.g., P + 0.5 MPa) of the liquid-gas hydrogen heat exchanger 11, and pressure compensation is performed during the test based on the pressure drop within the storage device. Figure 1 Taking the aircraft liquid-gas hydrogen heat exchanger test apparatus shown as an example, and referring to... Figure 2and Figure 4 Specifically, this may include the following steps: S2.1, confirm that emergency valve 5 is closed; S2.2, Open the main liquid hydrogen booster valve 2; s2.3, waiting for the pressure in liquid hydrogen storage tank 4 to increase to P+0.5MPa; S2.4, Close the main liquid hydrogen booster valve 2; s2.5. In subsequent tests, the pressure inside the tank was monitored, and the pressure was compensated using liquid hydrogen booster valve 3.

[0062] S3: Since the pre-cooling in stage S1 may not have cooled the pipeline between pressure regulating valve 8 and heat exchanger 11, formal pre-cooling of the upstream pipeline of heat exchanger 11 is performed in stage S3. That is, after pressurization of liquid hydrogen storage tank 4, a short period of pre-cooling is continued on the inlet pipeline of heat exchanger 11 to ensure that heat exchanger 11 itself is not cooled (so that the upstream pipeline of the liquid-gas hydrogen heat exchanger is sufficiently cooled to facilitate cold start-up testing), until the pipeline cooling efficiency decreases and the inlet temperature measuring point of heat exchanger 11 approaches a preset value, such as 30K, at which point pre-cooling is considered complete. Figure 1 Taking the aircraft liquid-gas hydrogen heat exchanger test apparatus shown as an example, and referring to... Figure 2 and Figure 5 Specifically, this may include the following steps: s3.1 Confirm that emergency valve 5, main valve 6, and pre-cooling valve 17 are open, and flow regulating valve 16 and pre-cooling valve 17 are closed; s3.2, the opening degree of pressure regulating valve 8 is set to 5%; s3.3, a small flow of liquid hydrogen flows out from the liquid hydrogen storage tank 4, flows through the emergency valve 5, the main valve 6, the pressure regulating valve 8, and the pre-cooling valve 17, and then flows out from the drain pipe. The temperature readings of the first temperature and pressure sensor group 7 and the second temperature and pressure sensor group 9 should be monitored and gradually decreased. s3.4, the rate at which the temperature reading of the second temperature and pressure sensor group 9 decreases slows down, indicating that pre-cooling has ended; S3.5, close emergency valve 5, main valve 6, and pre-cooling valve 17.

[0063] S4: In the cold start test, a small flow rate (i.e., the preset flow rate) of liquid hydrogen is introduced into the heat exchanger 11 from the hydrogen storage device to test the liquid-gas hydrogen conversion effect that the liquid-gas hydrogen heat exchanger can achieve, and to verify whether the heat exchange effect of the liquid-gas hydrogen heat exchanger can support the start-up of the hydrogen engine, until the downstream temperature of the heat exchanger 11 (i.e. the hydrogen temperature flowing out of the heat exchanger 11) drops to the lower limit of the allowable temperature.

[0064] The cold start test is further explained as follows: Low-temperature liquid hydrogen needs to be heated by the high-temperature exhaust gas from the engine to be converted into gaseous hydrogen at the suitable temperature required by the hydrogen engine (this suitable temperature range is denoted as [Tmin, Tmax]), where Tmin is the lowest permissible temperature for the entire hydrogen engine system. Specifically, the hydrogen engine system includes not only the engine itself but also its own hydrogen regulation device. The main function of this device is to monitor the temperature of the hydrogen flowing into the engine and includes a regulating valve to reduce the hydrogen pressure to the permissible pressure in the combustion chamber and to regulate the hydrogen flow rate. Simultaneously, the device also includes several solenoid valves for controlling the flow of hydrogen. Tmin is primarily limited by these valves in the hydrogen regulation device. If the temperature falls below this limit, the valve sealing structure of the hydrogen regulation device will gradually fail, leading to hydrogen leakage.

[0065] However, hydrogen engines require a small flow of hydrogen into the combustion chamber to start and expel hot exhaust gas. Therefore, a small flow of hydrogen needs to be introduced into the engine before it is started to complete the starting process (called a cold start). Although the flow rate of this pre-introduced hydrogen is small, its temperature must still meet the engine's starting requirements (i.e., the appropriate temperature range mentioned above).

[0066] The principle of cold start testing: Although the engine cannot produce high-temperature exhaust before starting, the heat exchanger, as a metal with a normal-temperature heat capacity, can transfer heat to the small flow of hydrogen flowing into it (heat exchange). However, the heat capacity of the heat exchanger is limited. Even if the hydrogen flow rate is relatively small (1-2 g / s), the heat in the heat exchanger will be rapidly extracted, causing the temperature of the hydrogen flowing out of the heat exchanger to drop lower and lower until it reaches or even falls below the engine's allowable temperature limit.

[0067] The purpose of the cold start test: In the cold start test, a small flow rate of liquid hydrogen is introduced into the heat exchanger 11 to test its liquid-to-gas hydrogen conversion efficiency. This verifies the heat exchanger 11's ability to maintain the hydrogen medium exiting it within the aforementioned suitable temperature range, thus verifying its ability to support hydrogen engine startup. For example, after hydrogen continuously flows into the heat exchanger 11 at a flow rate of 1-2 g / s, the time from when hydrogen begins to exit the heat exchanger 11 (which, upon testing, shows the temperature meets the aforementioned suitable temperature range) to when the hydrogen temperature reaches the lower limit of that range (referred to as the first time) is compared with the required startup time of the hydrogen engine (referred to as the second time) to determine whether the heat exchanger's heat capacity meets the engine startup requirements. Specifically, if the first time is not less than the second time, the heat exchanger can support the cold start of the hydrogen engine. Therefore, the cold start test can verify whether the heat exchange effect of the aviation liquid-to-gas hydrogen heat exchanger meets the engine startup conditions.

[0068] by Figure 1 Taking the aircraft liquid-gas hydrogen heat exchanger test apparatus shown as an example, and referring to... Figure 2 and Figure 6 The cold start test may specifically include the following steps: S4.1 Confirm that emergency valve 5 is open and all other valves are closed; s4.2, the automatic pressurization setting for liquid hydrogen storage tank 4 is P+0.5MPa (the purpose is to ensure that the pressure of hydrogen upstream of the heat exchanger remains relatively constant, but the specific value is only an example). S4.3, main valve 6 is open, and the opening degree of pressure regulating valve 8 is set to 5%; s4.4, monitor the pressure reading of the second temperature and pressure sensor group 9 until it increases to 3MPa; S4.5, the opening degree of flow regulating valve 16 is set to 15%; s4.6, monitor the flow sensor reading 15 until it stabilizes at 1-2 g / s; s4.7, monitor the temperature reading of the third temperature and pressure sensor group 13 (representing the hydrogen temperature flowing out of heat exchanger 11) until it drops to Tmin, and record the duration from when the hydrogen flow rate stabilizes at 1-2 g / s until the temperature drops to Tmin; S4.8, the opening degree of pressure regulating valve 8 and flow regulating valve 16 is set to 0%.

[0069] In addition, since it is a cold start test, it is not necessary to actually start the engine. Figure 1 Engine 20 in the text does not necessarily have to be a hydrogen engine.

[0070] S5: In the preliminary heat exchange performance test, under each engine operating condition, the hydrogen medium flow rate between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger is adjusted to determine a basic hydrogen flow rate under that engine operating condition. This provides a control basis for the boundary assessment test of heat exchange performance under that engine operating condition and accelerates the test speed. Furthermore, the thrust sensor 21 and exhaust temperature sensor 22 are used to measure the thrust and exhaust temperature of the engine 20 to obtain a quantitative impact of the heat exchanger 11 on the engine 20.

[0071] The principle of preliminary heat exchange performance testing of heat exchanger test equipment: Based on the current technological state of hydrogen engines, the hydrogen temperature exiting the hydrogen heat exchanger needs to be controlled within the aforementioned suitable temperature range. To explore the heat exchanger's performance under various engine operating conditions (heat exchange performance can be expressed as: if the hydrogen flow rate into the heat exchanger is A, then the hydrogen temperature exiting the heat exchanger is what it is; or if the hydrogen temperature exiting the heat exchanger is B, then the hydrogen flow rate into the heat exchanger is what it is), the hydrogen flow rate needs to be adjusted in a stepped manner to explore the hydrogen outlet temperature (i.e., the hydrogen temperature exiting the heat exchanger) under these flow rates.

[0072] The so-called stepped regulation refers to starting from a certain hydrogen flow rate, increasing or decreasing the opening of the flow control valve by a fixed amount, such as 5%, each time changing the fixed opening until the hydrogen outlet temperature stabilizes. The criterion for stabilizing the hydrogen outlet temperature can be: the temperature change does not exceed 2K within 30 seconds.

[0073] However, directly adjusting the hydrogen flow rate in a stepped manner leads to low experimental efficiency. This is because it's difficult to find a suitable starting point for "stepped adjustment" at the beginning of the experiment. If the starting point is unsuitable, frequent adjustments to the hydrogen flow rate will result in prolonged experimental time. For example, if the starting flow rate is too high and performance testing is delayed until the hydrogen outlet temperature stabilizes (for at least 30 seconds), the hydrogen outlet temperature will become too low. This necessitates reducing the flow rate for a second performance test, and there's no guarantee that the hydrogen flow rate will be properly adjusted during the second test. Prolonged experimental time leads to high liquid hydrogen consumption and excessive engine operation under certain conditions, which is detrimental to maintaining the engine in optimal working condition.

[0074] Therefore, by conducting preliminary heat exchange performance tests and rapidly adjusting the flow rate, a suitable starting point for each engine operating condition can be quickly identified. This starting point serves as the baseline hydrogen flow rate for that engine condition and is used for boundary tests of heat exchange performance under that condition. In subsequent boundary tests of heat exchange performance, for each engine operating condition, the flow rate of the hydrogen medium between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger is controlled based on the baseline hydrogen flow rate for that engine condition to assess the heat exchanger's heat exchange performance. This ensures a high success rate for the first-time completion of the boundary test of heat exchange performance, avoiding repeated and blind adjustments to the flow rate.

[0075] by Figure 1 Taking the aircraft liquid-gas hydrogen heat exchanger test apparatus shown as an example, and referring to... Figure 2 and Figure 7 The preliminary test of heat exchange performance may specifically include the following steps: S5.1, confirm that emergency valve 5 is open and all other valves are closed; s5.2, the automatic pressurization setting for liquid hydrogen storage tank 4 is P+0.5MPa; S5.3, main valve 6 is open, and pressure regulating valve 8 is set to 15% opening; s5.4, monitor the pressure reading of the second temperature and pressure sensor group 9 until it increases to 3MPa; s5.5, the opening of pressure regulating valve 8 is increased to 40%, and the opening of flow regulating valve 16 is increased simultaneously; s5.6, monitor the reading of flow sensor 15 until it stabilizes at 2g / s (i.e. control the flow rate of hydrogen medium from the hydrogen storage device to the aviation liquid-gas hydrogen heat exchanger to the preset flow rate). s5.7, engine 20 starts to idle condition; S5.8, quickly adjust the opening of the flow regulating valve 16 until the temperature of the third temperature and pressure sensor group 13 is 10℃ (i.e., the first condition is met. 10℃ is only an example. The specific temperature value can be determined according to the above suitable temperature range. Preferably, the temperature value here is the middle temperature selected according to the above suitable temperature range). Simultaneously monitor the reading of the thrust sensor 21 and the reading of the exhaust temperature sensor group 22, and record the hydrogen flow rate at this time as the basic hydrogen flow rate under the current engine operating conditions. s5.9, adjust the operating conditions of engine 20; s5.10, adjust the opening of pressure regulating valve 8 and flow regulating valve 16 to maintain the pressure of temperature and pressure sensor group 2 at 3±0.3MPa and the temperature of temperature and pressure sensor group 3 at 10℃, and simultaneously monitor the readings of thrust sensor 21 and exhaust temperature sensor group 22. s5.11, repeat steps s5.9 and s5.10 until all engine conditions are completed.

[0076] As can be seen, the above steps involve adjusting the flow rate of hydrogen medium from the hydrogen storage device to the aviation liquid-gas hydrogen heat exchanger for any engine operating condition until the temperature of the hydrogen medium flowing out of the aviation liquid-gas hydrogen heat exchanger reaches the first condition. The flow rate of hydrogen medium when the first condition is reached is taken as the basic hydrogen flow rate for the heat exchange performance boundary test under that engine operating condition.

[0077] Furthermore, the specific number of engine operating conditions to adjust can be determined based on the aircraft's thrust requirements. For example, during takeoff, medium to high engine speeds (e.g., 40,000 rpm) are needed; during cruise, medium engine speeds (e.g., 31,000 rpm) are needed; and during descent, medium to low engine speeds (e.g., 25,000 rpm) are needed. The engine can then be adjusted to these operating conditions respectively.

[0078] In addition, as mentioned above, Figure 1 Engine 20 is not required to be a hydrogen engine, but since the tests are still designed for hydrogen-fueled engines, engine 20 needs to comply with the parameter limitations of hydrogen-fueled engines.

[0079] S6: In the heat exchange performance boundary assessment test, for each engine operating condition, the hydrogen flow rate is changed starting from the basic hydrogen flow rate under that engine operating condition until the hydrogen outlet temperature of the liquid-gas hydrogen heat exchanger reaches the upper and lower limits of the aforementioned suitable temperature range. This allows for the assessment of the boundary of the heat exchange performance of the liquid-gas hydrogen heat exchanger under that engine operating condition. Furthermore, the thrust sensor 21 and exhaust temperature sensor 22 are used to measure the thrust and exhaust temperature of the engine 20 to determine whether the thrust of the aircraft equipped with the liquid-gas hydrogen heat exchanger is less than that of the aircraft without the liquid-gas hydrogen heat exchanger, thus obtaining the impact of the liquid-gas hydrogen heat exchanger on the engine.

[0080] The main purpose of the heat transfer performance boundary assessment test is to accelerate the overall test efficiency and avoid multiple iterative adjustments to the hydrogen flow rate.

[0081] If boundary value tests reveal that the thrust of an engine (equipped with a heat exchanger, and hydrogen is absorbing heat from the engine exhaust) is less than the thrust of an engine without a heat exchanger (the engine's own thrust), it indicates that the heat exchanger is causing a thrust loss. This is something that should be avoided as much as possible in a power system. Therefore, it is necessary to iteratively design and manufacture the heat exchanger, and then conduct tests on the new heat exchanger.

[0082] In the boundary assessment test of heat exchange performance, the purpose of monitoring the exhaust temperature is to obtain the impact of low-temperature hydrogen power extraction (that is, the absorption of exhaust heat) on the overall engine performance (engine exhaust temperature is a key overall engine performance parameter), and then to obtain the impact of the heat exchanger on the overall engine performance.

[0083] by Figure 1 Taking the aircraft liquid-gas hydrogen heat exchanger test apparatus shown as an example, and referring to... Figure 2 and Figure 8 The heat transfer performance boundary assessment test may specifically include the following steps: s6.1, increase the opening of flow regulating valve 16, and simultaneously adjust the opening of pressure regulating valve 8; s6.2, monitor the temperature readings of the third temperature sensor group until they drop to Tmin, and record a stable operating condition every 10°C, while simultaneously monitoring the readings of the thrust sensor 21 (that is, during the process of the hydrogen outlet temperature of the aviation liquid-gas hydrogen heat exchanger changing between the upper and lower limits, obtain the engine thrust and exhaust temperature data at preset temperature intervals). s6.3, reduce the opening of flow regulating valve 16, and simultaneously adjust the opening of pressure regulating valve 8; s6.4, monitor the temperature readings of the third sensor group until it increases to Tmax, record a stable working condition every 10℃, and simultaneously monitor the readings of the thrust sensor 21 and the exhaust temperature sensor group 22; s6.5, Adjust the operating conditions of engine 20, repeat the above operation until all operating conditions of engine 20 are completed; S6.6, engine 20 stopped; s6.7, the opening degree of pressure regulating valve 8 and flow regulating valve 16 is set to 0%.

[0084] Then, it can be determined whether the thrust of an aircraft equipped with a liquid-gas hydrogen heat exchanger is less than the thrust of an engine without a liquid-gas hydrogen heat exchanger (the engine's own thrust).

[0085] In steps s4-s6, liquid hydrogen is heated to a gaseous state after flowing through the liquid-gas hydrogen heat exchanger 11. The hydrogen outlet temperature is affected by the engine operating conditions and the liquid hydrogen flow rate. If the engine operating conditions and the liquid hydrogen flow rate are mismatched, the liquid hydrogen may be overheated or underheated, potentially causing the hydrogen temperature to exceed the tolerance temperature of downstream equipment. Therefore, after flowing through the liquid-gas hydrogen heat exchanger 11, the liquid hydrogen first flows into a constant-temperature water bath 14 for temperature control. The medium in the constant-temperature water bath 14 is an ice-water mixture, which can control the temperature of the hydrogen medium after heat exchange at around 0°C, protecting downstream equipment and ensuring experimental safety.

[0086] The above describes the content of cold start-up test, heat transfer performance pre-test, and heat transfer performance boundary assessment test. The test data and results obtained from these tests are as follows: Figure 9 and Figure 10 As shown.

[0087] Figure 9 This is an example of cold start test results. For example... Figure 9 As shown, the hydrogen outlet temperature of the liquid-gas hydrogen heat exchanger gradually decreases as the hydrogen mass flow rate gradually increases. It can be seen that the duration from when the hydrogen flow rate becomes measurable until it drops to 0 (indicating that the pressure regulating valve 8 and flow regulating valve 16 are adjusted to 0) is 25 seconds. Therefore, the cold start time that the heat exchanger can support (i.e., the aforementioned first time) is successfully determined to be 25 seconds, which can support the start-up of a hydrogen engine with a start-up time of less than 25 seconds.

[0088] Figure 10 This is an example of the results of a boundary value assessment test for heat transfer performance. For example... Figure 10 As shown, under different engine operating conditions (speed = 15000, 38000, 40000 rpm), the hydrogen outlet temperature also changes with the hydrogen flow rate. Figure 10 In the middle, T max =50℃; T min =-75℃). As engine operating conditions increase (speed increases), it reaches T. max and T min The greater the flow rate, the greater the engine operating conditions, the more exhaust heat can be used to heat the cryogenic hydrogen, and the stronger the heating effect can be achieved.

[0089] The various values ​​involved in Example 2, such as temperature, pressure, flow rate, and opening degree, are all examples and can be set as needed. Example 2 is not limited.

[0090] In Examples 1 and 2, all valves (groups) and sensors (groups) can be connected to control devices (such as computers, mobile phones, or other devices with data processing capabilities) (including wired or wireless connections) and controlled by a control terminal. After relevant settings or configurations are made on the control terminal, the control terminal can control the various valves and sensors (groups) to automatically perform the above steps, including but not limited to controlling the automatic opening and closing and opening degree of various valves, controlling the sensors (groups) to automatically collect various data, and controlling the engine to automatically adjust its operating conditions. The control terminal can receive various data generated in the above steps (such as data collected by sensors (groups)) and automatically calculate the required information or test results based on the received data, including but not limited to the hydrogen outlet temperature in the cold start test, the hydrogen base flow rate in the first time and heat exchange performance pre-test, the hydrogen flow rate in the heat exchange performance boundary assessment test, and the hydrogen outlet temperature.

[0091] The following beneficial effects can be achieved with Example 1 or Example 2: Example 1 or Example 2 can be used for testing liquid-gas hydrogen heat exchangers in hydrogen-powered aircraft engines. It covers the entire process of preparation and testing liquid-gas hydrogen heat exchange, and can be used to test the cold-start performance and variable-condition heat exchange performance of the heat exchanger. It can also determine the heat exchanger's impact on engine thrust and exhaust temperature, and simulate the airborne environment through pre-cooling and pressurization, thus improving the comprehensiveness, accuracy, and efficiency of the test. Example 1 or Example 2 includes a preliminary heat exchange performance test, providing a reference for subsequent heat exchange boundary assessment tests, improving test efficiency, and reducing the cost of using liquid hydrogen.

[0092] In Example 1 or Example 2, a phased liquid hydrogen pipeline pre-cooling process and a phased liquid hydrogen storage tank pressurization and stabilization process are set up: the liquid hydrogen pipeline pre-cooling simulates the airborne cryogenic characteristics of the liquid hydrogen pipeline; the phased pressurization and pressure replenishment simulates the heat exchanger's requirement for stable inlet pressure; the above methods make the ground test more closely resemble airborne operating conditions and strongly support the performance verification of the heat exchanger.

[0093] In Example 1 or Example 2, a cold start test is set up, and the engine thrust and exhaust temperature parameters are monitored during the heat exchange performance pre-test and boundary trial: By monitoring the key engine parameters in the cold start test and heat exchange performance test, the influence of the heat exchanger on the engine thrust performance and exhaust temperature is obtained, providing a reference for the performance regulation of the engine after coupling the heat exchanger.

[0094] In Example 1 or Example 2, a preliminary heat transfer performance test is set up before the boundary assessment test: the basic hydrogen flow rate of each engine operating condition is obtained through the preliminary heat transfer performance test, which provides a reference for the subsequent boundary assessment test, improves test efficiency, reduces liquid hydrogen consumption, and thus reduces the cost of using liquid hydrogen.

[0095] Example 1 or Example 2 can be applied to ground tests of liquid-gas hydrogen heat exchangers, a key component of liquid hydrogen aircraft propulsion systems, effectively improving test results and efficiency.

[0096] The contents not described in detail in Embodiment 1 and Embodiment 2 can be referred to or cited in each other, and the above embodiments can be used in combination.

[0097] The above description is merely an embodiment of this specification and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A test apparatus for an aviation liquid-gas hydrogen heat exchanger, characterized in that, The device includes an aviation liquid-gas hydrogen heat exchanger, a hydrogen storage device, a hydrogen source, and an engine. The aviation liquid-gas hydrogen heat exchanger and the hydrogen storage device are connected by a first pipeline group. The hydrogen storage device and the hydrogen source are connected by a second pipeline group; The first pipeline group is equipped with a first valve group, which is used to control the flow of hydrogen medium between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger. The second pipeline assembly is equipped with a second valve assembly, which is used to control the flow of hydrogen medium between the hydrogen source and the hydrogen storage device; The first pipeline assembly is also equipped with a first sensor assembly, which is used to detect the temperature and / or pressure of a specific part of the first pipeline assembly; The aviation liquid-gas hydrogen heat exchanger is located in a certain area near the exhaust device of the engine.

2. The apparatus as claimed in claim 1, characterized in that, The device also includes a temperature control device, and the aviation liquid-gas hydrogen heat exchanger is connected to the temperature control device via a third pipeline group.

3. The apparatus as described in claim 2, characterized in that, The third pipeline assembly is equipped with a third sensor assembly, which is used to detect the temperature and / or pressure of a specific part of the third pipeline assembly.

4. The apparatus as claimed in claim 1, characterized in that, The device also includes a fourth sensor group for detecting the thrust and / or exhaust temperature of the engine.

5. The apparatus as claimed in claim 1, characterized in that, The device also includes a vent pipe, which is connected to the first pipe group via a fourth pipe group.

6. The apparatus as claimed in claim 5, characterized in that, The fourth pipeline group is equipped with a fourth valve group, which is used to control the flow of hydrogen medium between the first pipeline group and the vent pipe.

7. The apparatus as claimed in claim 1, characterized in that, It also includes a control terminal, which is used to control the first valve group, the second valve group, and the first sensor group.

8. A test method for an aviation liquid-gas hydrogen heat exchanger, characterized in that, The method includes: Liquid hydrogen is added to the hydrogen storage device, and the pipeline assembly between the hydrogen source and the hydrogen storage device is pre-cooled. Once the pressure of the hydrogen storage device meets the requirements, the pipeline group between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger is formally cooled. After the pipeline assembly between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger is cooled to the preset conditions, a cold start test, a heat exchange performance pre-test, and a heat exchange performance boundary test are performed respectively. The cold start test includes: Hydrogen medium is introduced into the aviation liquid-gas hydrogen heat exchanger by the hydrogen storage device at a preset flow rate, and the heat exchange effect of the aviation liquid-gas hydrogen heat exchanger is tested to see if it meets the engine starting conditions. The heat exchange performance pre-test includes: Adjust the hydrogen medium flow rate between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger, as well as the engine operating conditions, to determine the basic hydrogen flow rate for the heat exchange performance boundary test under each engine operating condition. The heat transfer performance boundary test includes: Under various engine operating conditions, the flow rate of the hydrogen medium between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger is controlled according to the hydrogen base flow rate until the hydrogen outlet temperature of the aviation liquid-gas hydrogen heat exchanger reaches the upper and lower limits of the allowable temperature, so as to determine the heat exchange performance boundary of the aviation liquid-gas hydrogen heat exchanger.

9. The method as described in claim 8, characterized in that, Adjusting the hydrogen medium flow rate between the hydrogen storage device and the aviation liquid-gas hydrogen heat exchanger, as well as the engine operating conditions, to determine the baseline hydrogen flow rate for the heat exchange performance boundary test includes: For any engine operating condition, the flow rate of the hydrogen medium from the hydrogen storage device to the aviation liquid-gas hydrogen heat exchanger is adjusted until the temperature of the hydrogen medium flowing out of the aviation liquid-gas hydrogen heat exchanger reaches a first condition. The flow rate of the hydrogen medium when the first condition is reached is taken as the basic hydrogen flow rate for the heat exchange performance boundary test under that engine operating condition.

10. The method as described in claim 8 or 9, characterized in that, The heat transfer performance boundary test also includes: Under any engine operating condition, data monitoring operations are performed; wherein, the data monitoring operations include: during the process of the hydrogen outlet temperature of the aviation liquid-gas hydrogen heat exchanger changing between the upper and lower limits, acquiring the thrust and exhaust temperature data of the engine at preset temperature intervals; After completing the data monitoring operations under various engine operating conditions, the impact of the aviation liquid-gas hydrogen heat exchanger on the engine is determined.

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