An airborne environmental control system with defrosting function and a defrosting method thereof

Abstract

The present application relates to a kind of onboard environmental control system with defrosting function and its defrosting method.The system includes three parts of main flow path, switching defrosting path and flow path switching valve assembly.Main flow path is made of high-temperature high-pressure gas cooler, condensing-reheating heat exchanger, high-pressure water separator, booster-refrigeration integrated machine and indirect pipeline and valve between each component.The switching defrosting path is made of auxiliary defrosting heat exchanger and connecting pipeline.The flow path switching valve assembly is made of pressure reducing valve and reversing valve group.The present application can realize efficient defrosting while running refrigeration function by increasing auxiliary defrosting heat exchanger and adjusting system airflow direction, ensure uninterrupted operation of environmental control system;Make full use of system cold, convert all the ice remaining in the system into system cooling, ensure that the supply air temperature of environmental control system meets the requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to an airborne environmental control system with defrosting function and a defrosting method thereof. BACKGROUND

[0002] The airborne environmental control system and the like generally utilize the tail gas residual energy of the aircraft with high temperature and pressure energy through conversion to realize the refrigeration or heating function. During the operation of the environmental control system, the engine tail gas is gradually cooled in the heat exchanger, and the water vapor in the gas will gradually condense and freeze into ice in the heat exchanger.

[0003] The current common airborne environmental control system process utilizing high-pressure tail gas residual energy is generally a high-pressure water removal system. Due to the low efficiency of the high-pressure water removal of the environmental control system, when it is rainy or the air is relatively humid, the water vapor contained in the tail gas is relatively large, and after condensation, it cannot be completely removed in the high-pressure water separator, and a large amount of water will enter the expansion refrigeration system. In addition, due to the high circulating condensation temperature of the high-pressure water removal, when the air is relatively dry, the water in the air cannot be removed, and the air entering the expansion refrigeration system is saturated wet air with high moisture content. After the expansion of the gas in the expansion refrigeration system, the temperature of the gas is greatly reduced, and a large amount of water is precipitated and frozen into ice at the outlet of the expansion refrigeration system, which is accumulated in the heat exchanger and causes ice blocking. Due to the fact that the bleed air of the environmental control system usually contains a large amount of water, ice blocking will occur in a short time after the environmental control system is started. After the ice blocking of the environmental control system, a large amount of cold energy is lost, which causes the performance of the entire environmental control system to be greatly reduced or unable to be normally used in a short time, which will cause the temperature in the cabin of the helicopter working in some extremely harsh environments for several hours or even longer to be unable to be neutralized by the heat generated by the high-power electronic equipment and the crew, causing the instruments in the cabin to overheat and be damaged or the crew to have symptoms such as heat stroke. Therefore, efficient utilization of the cold energy of the environmental control system and avoidance of ice blocking can ensure that the environmental control system can be normally operated in the started state. SUMMARY

[0004] In order to overcome the problems in the prior art, the present application provides an airborne environmental control system with defrosting function, which realizes efficient defrosting while realizing refrigeration function by increasing an auxiliary defrosting heat exchanger and adjusting the airflow direction, ensures uninterrupted operation of the environmental control system, and fully utilizes the cold energy of the system to convert all the ice remaining in the system into system cooling to ensure that the supply air temperature of the environmental control system meets the requirements.

[0005] The technical scheme for solving the above problems of the present application is an airborne environmental control system with defrosting function, which is characterized in that:

[0006] The system comprises a high-temperature and high-pressure gas cooler, a condensation-recovery heat exchanger, a booster-refrigeration integrated machine, and an auxiliary defrosting heat exchanger.

[0007] The upper outlet of the fourth reversing valve is connected with the upper outlet of the first reversing valve, the right inlet of the third reversing valve and the first inlet of the high-temperature high-pressure gas cooler respectively, the first outlet of the high-temperature high-pressure gas cooler is connected with the left inlet of the first reversing valve, the right outlet of the first reversing valve is connected with the first inlet of the condensing-reheating heat exchanger, the lower outlet of the first reversing valve is connected with the first inlet of the auxiliary defrosting heat exchanger, the upper outlet of the first reversing valve is connected with the right inlet of the third reversing valve, the upper inlet of the second reversing valve is connected with the first outlet of the condensing-reheating heat exchanger, the left inlet of the second reversing valve is connected with the first outlet of the auxiliary defrosting heat exchanger, the lower outlet of the second reversing valve is connected with the inlet of the high-pressure water separator, the lower outlet of the high-pressure water separator is connected with the lower inlet of the pressure reducing valve, the right outlet of the high-pressure water separator is connected with the first inlet of the booster-refrigeration integrated machine, the first outlet of the booster-refrigeration integrated machine is connected with the lower inlet of the third reversing valve, the upper outlet of the third reversing valve is connected with the second inlet of the condensing-reheating heat exchanger, the left outlet of the third reversing valve is connected with the second inlet of the auxiliary defrosting heat exchanger, the second outlet of the condensing-reheating heat exchanger is connected with the right inlet of the fifth reversing valve, the second outlet of the auxiliary defrosting heat exchanger is connected with the lower inlet of the fifth reversing valve, the upper outlet of the fifth reversing valve is connected with the system air outlet, the left outlet of the fifth reversing valve is connected with the right inlet of the pressure reducing valve, the left outlet of the pressure reducing valve is connected with the second inlet of the high-temperature high-pressure gas cooler, and the second outlet of the booster-refrigeration integrated machine is connected with the left outlet of the pressure reducing valve and the second inlet of the high-temperature high-pressure gas cooler.

[0008] In addition, the present application also provides a defrosting method based on the airborne environmental control system with defrosting function, and the special features are as follows:

[0009] The defrosting method comprises two working conditions, i.e., a conventional defrosting mode and a rapid defrosting mode.

[0010] When the air humidity is relatively small and the outlet pressure of the booster-refrigeration integrated machine can be kept stable or gently increased for a period of time, the conventional defrosting mode is started.

[0011] When the air humidity is relatively large and the outlet pressure of the booster-refrigeration integrated machine of the environmental control system changes sharply in a short time, the rapid defrosting mode is started.

[0012] Further, the conventional defrosting mode comprises a condensing-reheating heat exchanger defrosting stage and an auxiliary defrosting heat exchanger defrosting stage, and the rapid defrosting mode comprises a condensing-reheating heat exchanger defrosting stage and an auxiliary defrosting heat exchanger defrosting stage.

[0013] Further, in the condensing-reheating heat exchanger defrosting stage in the conventional defrosting mode:

[0014] The first switching valve closes the condensing-recovering heat exchanger side pipeline, opens the auxiliary defrosting heat exchanger side pipeline and the defrosting side pipeline, and the gas stream preliminarily cooled by the high-temperature high-pressure gas cooler enters the auxiliary defrosting heat exchanger for heat exchange. At this time, the second switching valve closes the condensing-recovering heat exchanger side pipeline, opens the pipeline between the auxiliary defrosting heat exchanger and the high-pressure water separator side, and the gas stream heat-exchanged by the auxiliary defrosting heat exchanger enters the high-pressure water separator through the second switching valve.

[0015] The defrosting gas stream enters the third switching valve from the first switching valve, the third switching valve sends the defrosting gas stream into the condensing-recovering heat exchanger and the inlet pipeline for condensing-recovering heat exchanger defrosting, simultaneously opens the pipeline between the booster-refrigeration integrated machine outlet and the auxiliary defrosting heat exchanger, the booster-refrigeration integrated machine outlet gas stream enters the auxiliary defrosting heat exchanger for heat exchange through the third switching valve, and the gas stream entering the auxiliary defrosting heat exchanger is discharged from the system air supply through the fifth switching valve; the defrosting gas stream enters the condensing-recovering heat exchanger through the frost accumulation pipeline after the third switching valve.

[0016] Further, after the condensing-recovering heat exchanger defrosting stage in the conventional defrosting mode is completed, the auxiliary defrosting heat exchanger defrosting stage is switched to:

[0017] The gas stream enters the third switching valve from the first switching valve after being cooled by the high-temperature high-pressure gas cooler, enters the auxiliary defrosting heat exchanger and the pipeline through the third switching valve for defrosting treatment, and the defrosting gas stream entering the auxiliary defrosting heat exchanger is mixed with the air supply sent by the booster fan through the pressure reducing valve after defrosting is completed, and then enters the high-temperature high-pressure gas cooler.

[0018] Further, the condensing-recovering heat exchanger defrosting stage and the auxiliary defrosting heat exchanger defrosting stage in the conventional defrosting mode are alternately run in the above-mentioned environmental control system running process.

[0019] Further, in the condensing-recovering heat exchanger defrosting stage in the fast defrosting mode:

[0020] The first switching valve is opened, the gas stream preliminarily cooled by the high-temperature high-pressure gas cooler enters the auxiliary defrosting heat exchanger for heat exchange, and the gas stream entering the auxiliary defrosting heat exchanger is mixed with the air supply sent by the booster fan through the pressure reducing valve after heat exchange is completed, and then enters the high-temperature high-pressure gas cooler.

[0021] At the same time, the fourth reversing valve is opened, and the high-temperature and high-pressure gas cooler front part gas flow is taken as the defrosting gas flow, passes through the third reversing valve, enters the condensing-reheating heat exchanger to carry out condensing-reheating heat exchanger defrosting, and after the defrosting gas flow passes through the third reversing valve and then passes through the frost accumulation pipeline, enters the condensing-reheating heat exchanger; after the defrosting gas flow exchanges heat with the frost layer, the temperature is reduced, passes through the fifth reversing valve, enters the pressure reducing valve, is mixed with the gas sent by the booster fan into the cold end of the high-temperature and high-pressure gas cooler, and then enters the high-temperature and high-pressure gas cooler to cool the gas.

[0022] Further, when the condensing-reheating heat exchanger defrosting stage in the rapid defrosting mode is completed, the auxiliary defrosting heat exchanger defrosting stage is switched to:

[0023] After the gas flow passes through the high-temperature and high-pressure gas cooler, the first reversing valve closes the auxiliary defrosting heat exchanger valve, the main gas flow enters the condensing-reheating heat exchanger to exchange heat, and the defrosting gas passes through the fourth reversing valve, enters the third reversing valve, and then enters the auxiliary defrosting heat exchanger and the pipeline to carry out defrosting treatment; after the defrosting gas flow entering the auxiliary defrosting heat exchanger completes defrosting, the defrosting gas flow is mixed with the air sent by the booster fan through the pressure reducing valve and then enters the high-temperature and high-pressure gas cooler.

[0024] Further, in the process of running the environmental control system, the condensing-reheating heat exchanger defrosting in the rapid defrosting mode and the auxiliary defrosting heat exchanger defrosting are alternately run to ensure the normal running of the environmental control system.

[0025] Advantages of the present application:

[0026] 1. The airborne environmental control system with defrosting function provided by the present application can keep the environmental control system stable during running, and defrost in time according to the system pressure change before the ice blockage affects the normal running of the system.

[0027] 2. The airborne environmental control system with defrosting function provided by the present application can fully utilize the cold energy in the environmental control system, utilize the water produced by the defrosting of the environmental control system to cool the system, and improve the performance of the system. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The structure schematic diagram of the airborne environmental control system with defrosting function provided by the present application;

[0029] Figure 2 The main flow path schematic diagram of the condensing-reheating heat exchanger defrosting stage of the present application;

[0030] Figure 3 The main flow path schematic diagram of the auxiliary defrosting heat exchanger defrosting stage of the present application;

[0031] Figure 4 The condensing-reheating heat exchanger defrosting gas flow path schematic diagram of the present application in the conventional defrosting mode;

[0032] Figure 5 The auxiliary defrosting heat exchanger defrosting gas flow path schematic diagram in the conventional defrosting mode of the present application;

[0033] Figure 6 The condensing re-warming device defrosting gas flow path schematic diagram in the rapid defrosting mode of the present application;

[0034] Figure 7 The auxiliary defrosting device defrosting gas flow path schematic diagram in the rapid defrosting mode of the present application.

[0035] As shown in the figure: 1, the first reversing valve, 2, the second reversing valve, 3, the third reversing valve, 4, the fourth reversing valve, 5, the fifth reversing valve. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application.

[0037] The present application provides an airborne environmental control system with defrosting function, comprising a main flow path, a switching defrosting path and a flow path switching valve assembly, according to the pressure change of the booster-refrigeration integrated machine, adjusting the opening and closing of each valve in the environmental control system, realizing the switching between heat exchangers, and fully utilizing the cold energy in the defrosting gas flow for cooling the high-temperature high-pressure gas cooler, realizing the maximum utilization of system cold energy, the main flow path is composed of a high-temperature high-pressure gas cooler, a condensing-re-warming heat exchanger, a high-pressure water separator, a booster-refrigeration integrated machine and indirect pipelines and valves between each component; the switching defrosting path is composed of an auxiliary defrosting heat exchanger and a connecting pipeline; the flow path switching valve assembly is composed of a pressure reducing valve and a reversing valve.

[0038] Specifically, the above-mentioned device is like Figure 1As shown, the upper outlet of the fourth reversing valve is connected with the upper outlet of the first reversing valve, the right inlet of the third reversing valve and the first inlet of the high-temperature high-pressure gas cooler respectively, the first outlet of the high-temperature high-pressure gas cooler is connected with the left inlet of the first reversing valve, the right outlet of the first reversing valve is connected with the first inlet of the condensation-reheating heat exchanger, the lower outlet of the first reversing valve is connected with the first inlet of the auxiliary defrosting heat exchanger, the upper outlet of the first reversing valve is connected with the right inlet of the third reversing valve, the upper inlet of the second reversing valve is connected with the first outlet of the condensation-reheating heat exchanger, the left inlet of the second reversing valve is connected with the first outlet of the auxiliary defrosting heat exchanger, the lower outlet of the second reversing valve is connected with the inlet of the high-pressure water separator, the lower outlet of the high-pressure water separator is connected with the lower inlet of the pressure reducing valve, the right outlet of the high-pressure water separator is connected with the first inlet of the pressure- refrigeration integrated machine, the first outlet of the pressure- refrigeration integrated machine is connected with the lower inlet of the third reversing valve, the upper outlet of the third reversing valve is connected with the second inlet of the condensation-reheating heat exchanger, the left outlet of the third reversing valve is connected with the second inlet of the auxiliary defrosting heat exchanger, the second outlet of the condensation-reheating heat exchanger is connected with the right inlet of the fifth reversing valve, the second outlet of the auxiliary defrosting heat exchanger is connected with the lower inlet of the fifth reversing valve, the upper outlet of the fifth reversing valve is connected with the system air outlet, the left outlet of the fifth reversing valve is connected with the right inlet of the pressure reducing valve, the left outlet of the pressure reducing valve is connected with the second inlet of the high-temperature high-pressure gas cooler, and the second outlet of the pressure- refrigeration integrated machine is connected with the left outlet of the pressure reducing valve and the second inlet of the high-temperature high-pressure gas cooler.

[0039] When the onboard environmental control system with the defrosting function is running, the outlet pressure of the pressure- refrigeration integrated machine is monitored to determine whether ice blockage occurs in the environmental control system, and the quick defrosting mode or the regular defrosting mode can be switched according to the pressure change speed.

[0040] When the air humidity is relatively small, the outlet pressure of the pressure- refrigeration integrated machine can be kept stable or gently increased for a period of time, and the regular defrosting mode is started.

[0041] When the air humidity is relatively large, the outlet pressure of the pressure- refrigeration integrated machine changes sharply in a short time, and the quick defrosting mode is started.

[0042] As a preferred embodiment of the present application, the regular defrosting mode includes a condensation-reheating heat exchanger defrosting stage and an auxiliary defrosting heat exchanger defrosting stage, and the quick defrosting mode includes a condensation-reheating heat exchanger defrosting stage and an auxiliary defrosting heat exchanger defrosting stage.

[0043] Specifically,

[0044] (1) when the system is in the condensation-reheating heat exchanger defrosting stage in the regular defrosting mode:

[0045] Referring to Figure 2, the first reversing valve 1 closes the condensing-recovering heat exchanger side pipeline, opens the auxiliary defrosting heat exchanger side pipeline and the defrosting side pipeline, and most of the gas flow preliminarily cooled by the high-temperature high-pressure gas cooler enters the auxiliary defrosting heat exchanger for heat exchange, and part of the gas flow enters the third reversing valve 3 for condensing-recovering heat exchanger defrosting. The gas flow entering the auxiliary defrosting heat exchanger enters the main pipeline through the second reversing valve 2, and the main gas flow flow path is as shown in Figure 2 . At this time, the second reversing valve 2 closes the condensing-recovering heat exchanger side pipeline, opens the pipeline between the auxiliary defrosting heat exchanger and the high-pressure water separator side, and the gas flow passing through the auxiliary defrosting heat exchanger enters the high-pressure water separator through the second reversing valve 2.

[0046] Referring to Figure 4 , the defrosting gas flow enters the third reversing valve 3 through the first reversing valve 1, and the third reversing valve 3 sends the defrosting gas flow into the condensing-recovering heat exchanger and the inlet pipeline for condensing-recovering heat exchanger defrosting. At the same time, referring to Figure 2 , the pipeline between the booster-refrigeration integrated machine outlet and the auxiliary defrosting heat exchanger is opened, the booster-refrigeration integrated machine outlet gas flow enters the auxiliary defrosting heat exchanger through the third reversing valve 3 for heat exchange, and the gas flow entering the auxiliary defrosting heat exchanger is discharged from the system through the fifth reversing valve 5.

[0047] The defrosting gas flow enters the condensing-recovering heat exchanger through the frost accumulation pipeline. Because the defrosting gas flow has a high temperature, the frost layer at the pipeline and the heat exchanger inlet can be completely melted in a short time. Referring to Figure 4 , after the defrosting gas flow exchanges heat with the frost layer, it enters the pressure reducing valve after passing through the fifth reversing valve 5, mixes with the gas sent by the booster fan into the cold end of the high-temperature high-pressure gas cooler, and then enters the high-temperature high-pressure gas cooler to cool the gas. Because the defrosting gas flow carries more water droplets into the high-temperature high-pressure gas cooler, it can better cool the hot fluid in the high-temperature high-pressure gas cooler, improve the efficiency of the heat exchanger, reduce the outlet temperature of the high-temperature high-pressure gas cooler, and thus improve the overall efficiency and energy utilization rate of the system.

[0048] When the condensing-recovering heat exchanger defrosting stage in the conventional defrosting mode is completed, the auxiliary defrosting heat exchanger defrosting stage is switched to:

[0049] After the gas flow passes through the high-temperature high-pressure gas cooler, the first reversing valve 1 closes the auxiliary defrosting heat exchanger valve, the main gas flow enters the condensing-recovering heat exchanger for heat exchange, and the main pipeline returns to the initial operating state, as shown in Figure 3 . At the same time, referring to Figure 5 , the defrosting gas flow enters the third reversing valve 3 through the first reversing valve 1, enters the auxiliary defrosting heat exchanger and the pipeline through the third reversing valve 3 for defrosting treatment, and the defrosting gas flow entering the auxiliary defrosting heat exchanger completes defrosting and then enters the high-temperature high-pressure gas cooler after mixing with the gas sent by the booster fan through the pressure reducing valve and the fifth reversing valve 5.

[0050] In the process of operation of the environmental control system, the condensing-recovering heat exchanger defrosting stage and the auxiliary defrosting heat exchanger defrosting stage in the conventional defrosting mode are alternately operated to ensure the normal operation of the environmental control system.

[0051] (2) In the condensing-recovering heat exchanger defrosting stage in the fast defrosting mode:

[0052] Referring to Figure 2 , the first reversing valve 1 is opened, and the gas stream preliminarily cooled by the high-temperature high-pressure gas cooler enters the auxiliary defrosting heat exchanger for heat exchange. After the heat exchange in the auxiliary defrosting heat exchanger, the gas stream enters the second reversing valve 2, and then enters the booster-refrigeration integrated machine through the high-pressure water separator. The gas at the outlet of the booster-refrigeration integrated machine enters the auxiliary defrosting heat exchanger through the third reversing valve 3 for heat exchange, and then is discharged from the system through the fifth reversing valve 5 to supply air.

[0053] Referring to Figure 6 , the fourth reversing valve 4 is opened, and the part of the gas stream before the high-temperature high-pressure gas cooler as the defrosting gas stream enters the condensing-recovering heat exchanger through the third reversing valve 3 for condensing-recovering heat exchanger defrosting. The defrosting gas stream enters the condensing-recovering heat exchanger through the third reversing valve 3 and the frost accumulation pipeline. Since the gas stream is not cooled by the high-temperature high-pressure gas cooler in the fast defrosting mode, the frost layer at the inlet of the pipeline and the heat exchanger can be completely melted in a very short time with a very small flow rate.

[0054] After the defrosting gas stream exchanges heat with the frost layer and the temperature is reduced, the defrosting gas stream enters the pressure reducing valve through the fifth reversing valve 5, is mixed with the gas sent into the cold end of the high-temperature high-pressure gas cooler by the booster fan, and then enters the high-temperature high-pressure gas cooler to cool the gas.

[0055] When the condensing-recovering heat exchanger defrosting stage in the fast defrosting mode is completed, the auxiliary defrosting heat exchanger defrosting stage is switched to:

[0056] Referring to Figure 3 , after the gas stream passes through the high-temperature high-pressure gas cooler, the first reversing valve 1 closes the auxiliary defrosting heat exchanger valve, and the main gas stream enters the condensing-recovering heat exchanger for heat exchange. At the same time, referring to Figure 7 , the defrosting gas passes through the fourth reversing valve 4, enters the third reversing valve 3, and then enters the auxiliary defrosting heat exchanger and the pipeline for defrosting treatment. After the defrosting gas stream entering the auxiliary defrosting heat exchanger is defrosted, the defrosting gas stream enters the high-temperature high-pressure gas cooler through the fifth reversing valve 5, the pressure reducing valve and the booster fan.

[0057] In the process of operation of the environmental control system, the condensing-recovering heat exchanger defrosting and the auxiliary defrosting heat exchanger defrosting in the fast defrosting mode are alternately operated to ensure the normal operation of the environmental control system.

[0058] The airborne environmental control system with defrosting function can ensure full utilization of cold energy of the environmental control system through cooperation and switching between the heat exchanger and the defrosting airflow; through switching between the valves, the flow direction and distribution of the high-temperature airflow in the control system are controlled, part of the high-temperature airflow is used as the defrosting airflow to melt the condensed frost in the environmental control system and then is used to cool the main airflow, cold energy is maximally utilized, and the system efficiency is improved; the working state of the heat exchanger is controlled through switching of the main airflow flow path, the heat exchanger is switched to operate before ice blockage occurs to affect the operation of the environmental control system, the uninterrupted operation of the environmental control system can be ensured, and the environmental control system cannot work normally due to frost formation is avoided.

[0059] The above merely describes the embodiments of the present application, and does not limit the protection scope of the present application, and any equivalent structure or equivalent flow transformation made by using the content of the specification and drawings, or direct or indirect application in other related system fields, are also included in the protection scope of the present application.

Claims

1. An airborne environmental control system with defrosting function, characterized in that: it comprises a high-temperature and high-pressure gas cooler, a condensation-recovery heat exchanger, an auxiliary defrosting heat exchanger, a high-pressure water separator, a pressure-boosting and refrigeration integrated machine, and four reversing valves; high-temperature and high-pressure gas is introduced into the left inlet of the fourth reversing valve (4), the upper outlet of the fourth reversing valve (4) is connected with the right inlet of the third reversing valve (3) and the first inlet of the high-temperature and high-pressure gas cooler, the first outlet of the high-temperature and high-pressure gas cooler is connected with the left inlet of the first reversing valve (1), the right outlet of the first reversing valve (1) is connected with the first inlet of the condensation-recovery heat exchanger, the lower outlet of the first reversing valve (1) is connected with the first inlet of the auxiliary defrosting heat exchanger, the upper outlet of the first reversing valve (1) is connected with the right inlet of the third reversing valve (3), the upper inlet of the second reversing valve (2) is connected with the first outlet of the condensation-recovery heat exchanger, the left inlet of the second reversing valve (2) is connected with the first outlet of the auxiliary defrosting heat exchanger, the lower outlet of the second reversing valve (2) is connected with the inlet of the high-pressure water separator, the lower outlet of the high-pressure water separator is connected with the lower inlet of the pressure-reducing valve, the right outlet of the high-pressure water separator is connected with the first inlet of the pressure-boosting and refrigeration integrated machine, the first outlet of the pressure-boosting and refrigeration integrated machine is connected with the lower inlet of the third reversing valve (3), the upper outlet of the third reversing valve (3) is connected with the second inlet of the condensation-recovery heat exchanger, the left outlet of the third reversing valve (3) is connected with the second inlet of the auxiliary defrosting heat exchanger, the second outlet of the condensation-recovery heat exchanger is connected with the right inlet of the fifth reversing valve (5), the second outlet of the auxiliary defrosting heat exchanger is connected with the lower inlet of the fifth reversing valve (5), the upper outlet of the fifth reversing valve (5) is connected with the system air outlet, the left outlet of the fifth reversing valve (5) is connected with the right inlet of the pressure-reducing valve, the left outlet of the pressure-reducing valve is connected with the second inlet of the high-temperature and high-pressure gas cooler, and the second outlet of the pressure-boosting and refrigeration integrated machine is connected with the left outlet of the pressure-reducing valve and the second inlet of the high-temperature and high-pressure gas cooler.

2. A defrosting method based on the airborne environmental control system with defrosting function according to claim 1, characterized in that: it comprises two working conditions, i.e., a regular defrosting mode and a rapid defrosting mode; the regular defrosting mode is started when the air humidity is relatively small and the outlet pressure of the pressure-boosting and refrigeration integrated machine can be kept stable or gently increased for a period of time; the rapid defrosting mode is started when the air humidity is relatively large and the outlet pressure of the pressure-boosting and refrigeration integrated machine changes dramatically in a short time; the regular defrosting mode comprises a condensation-recovery heat exchanger defrosting stage and an auxiliary defrosting heat exchanger defrosting stage; and the rapid defrosting mode comprises a condensation-recovery heat exchanger defrosting stage and an auxiliary defrosting heat exchanger defrosting stage.

3. The defrosting method according to claim 2, characterized in that: in the condensation-recovery heat exchanger defrosting stage in the regular defrosting mode, ​ ​ ​ ​ ​ ​ ​ ​ The first reversing valve (1) closes the condensing-temperature recovery heat exchanger side pipeline, and connects the auxiliary defrosting heat exchanger side pipeline. The gas flow preliminarily cooled by the high-temperature and high-pressure gas cooler enters the auxiliary defrosting heat exchanger for heat exchange. At this time, the second reversing valve (2) closes the condensing-temperature recovery heat exchanger side pipeline, and opens the pipeline between the auxiliary defrosting heat exchanger and the high-pressure water separator side. The gas flow heat-exchanged by the auxiliary defrosting heat exchanger enters the high-pressure water separator through the second reversing valve (2); The defrosting gas flow enters the third reversing valve (3) from the first reversing valve (1). The third reversing valve (3) sends the defrosting gas flow into the condensing-temperature recovery heat exchanger and the inlet pipeline for condensing-temperature recovery heat exchanger defrosting. Meanwhile, the pipeline between the booster-refrigeration integrated machine outlet and the auxiliary defrosting heat exchanger is opened. The booster-refrigeration integrated machine outlet gas flow enters the auxiliary defrosting heat exchanger for heat exchange through the third reversing valve (3). The gas flow entering the auxiliary defrosting heat exchanger is discharged from the system air supply through the fifth reversing valve (5). The defrosting gas flow enters the condensing-temperature recovery heat exchanger through the frost accumulation pipeline after the third reversing valve (3). After heat exchange with the frost layer, the defrosting gas flow enters the high-temperature and high-pressure gas cooler for cooling after passing through the fifth reversing valve (5) and the pressure reducing valve.

4. The defrosting method according to claim 3, characterized in that: When the condensing-temperature recovery heat exchanger defrosting stage in the conventional defrosting mode is completed, the auxiliary defrosting heat exchanger defrosting stage is switched to: After the gas flow passes through the high-temperature and high-pressure gas cooler, the first reversing valve (1) closes the valve connected with the auxiliary defrosting heat exchanger. The main gas flow enters the condensing-temperature recovery heat exchanger for heat exchange. Meanwhile, the defrosting gas flow enters the third reversing valve (3) through the first reversing valve (1). After passing through the third reversing valve (3), the defrosting gas flow enters the auxiliary defrosting heat exchanger for defrosting treatment. After the defrosting gas flow entering the auxiliary defrosting heat exchanger is defrosted, the defrosted gas flow is mixed with the air supply of the booster fan and then enters the high-temperature and high-pressure gas cooler through the fifth reversing valve (5) and the pressure reducing valve.

5. The defrosting method according to claim 4, characterized in that: During the operation of the environmental control system, the condensing-temperature recovery heat exchanger defrosting stage and the auxiliary defrosting heat exchanger defrosting stage in the conventional defrosting mode are alternately operated.

6. The defrosting method according to claim 5, characterized in that: During the condensing-temperature recovery heat exchanger defrosting stage in the fast defrosting mode: The first reversing valve (1) is opened. A part of the high-temperature and high-pressure gas flow preliminarily cooled by the high-temperature and high-pressure gas cooler enters the auxiliary defrosting heat exchanger for heat exchange. After the heat exchange in the auxiliary defrosting heat exchanger, the gas flow enters the second reversing valve (2), and then enters the booster-refrigeration integrated machine through the high-pressure water separator. The gas flow at the booster-refrigeration integrated machine outlet enters the auxiliary defrosting heat exchanger for heat exchange through the third reversing valve (3), and then is discharged from the system air supply through the fifth reversing valve (5). The fourth reversing valve (4) is opened, the upper outlet of the fourth reversing valve (4) is communicated with the right inlet of the third reversing valve (3), and the other part of the high-temperature and high-pressure gas flows through the fourth reversing valve (4) and the third reversing valve (3) and then enters the condensing-temperature recovery heat exchanger to perform condensing-temperature recovery heat exchanger defrosting; the defrosting gas flow passes through the third reversing valve (3) and then passes through the frost accumulation pipeline and then enters the condensing-temperature recovery heat exchanger; the defrosting gas flow is cooled after heat exchange with the frost layer, enters the pressure reducing valve after passing through the fifth reversing valve (5), is mixed with the gas sent by the booster fan to the cold end of the high-temperature and high-pressure gas cooler, and then enters the high-temperature and high-pressure gas cooler to cool the gas.

7. The defrosting method according to claim 6, characterized in that: When the condensing-temperature recovery heat exchanger defrosting stage in the fast defrosting mode is completed, the auxiliary defrosting heat exchanger defrosting stage is switched to: After the gas flow passes through the high-temperature and high-pressure gas cooler, the first reversing valve (1) closes the auxiliary defrosting heat exchanger valve, the main gas flow enters the condensing-temperature recovery heat exchanger for heat exchange, and the defrosting gas passes through the fourth reversing valve (4) and then enters the third reversing valve (3), and then enters the auxiliary defrosting heat exchanger and the pipeline for defrosting treatment; the defrosting gas flow entering the auxiliary defrosting heat exchanger is defrosted, is mixed with the air sent by the booster fan through the pressure reducing valve and the fifth reversing valve (5), and then enters the high-temperature and high-pressure gas cooler.

8. The defrosting method according to claim 7, characterized in that: During the operation of the environmental control system, the condensing-temperature recovery heat exchanger defrosting stage and the auxiliary defrosting heat exchanger defrosting stage in the fast defrosting mode are alternately operated.

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