An air cycle refrigeration system, an aircraft and a method of controlling the same

Abstract

The application provides an air circulation refrigeration system, an aircraft and a control method thereof, the air source of the air circulation refrigeration system is from the engine exhaust of the aircraft, and the air circulation refrigeration system comprises a condenser, a water separator, a turbine, a mixing cavity and a first heat exchanger; the condenser is provided with a condensation hot pipe and a condensation cold pipe which are coupled together; the first heat exchanger comprises a first hot pipe and a first cold pipe which are coupled together; the engine exhaust flows through the condensation hot pipe, the first hot pipe, the water separator, the turbine and the condensation cold pipe in sequence; a cold path branch is arranged on the pipeline after the outlet of the condensation cold pipe, the cold path branch is communicated with the first cold pipe; and a cold path valve is arranged on the cold path branch, so that the technical problem that the water content in the air entering the turbine is relatively high in the prior art can be solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of aircraft, and particularly relates to an air cycle refrigeration system, an aircraft and a control method thereof. BACKGROUND

[0002] At present, many aircraft use a "three-wheel type" (three-wheel type refers to three coaxial rotating devices of turbine, compressor and fan) air cycle refrigeration to obtain cold air, the cold air is cooled into a mixing chamber and mixed with other air to adjust temperature and pressure, and the mixed air is input into a passenger cabin and a cockpit to provide a comfortable pressure and temperature environment for the passenger cabin and the cockpit. However, in the actual use process, due to the performance degradation of a water separator or a heat exchanger, the water separation capacity of the water separator is reduced, so that the air entering the turbine contains a large amount of water, and the outlet air temperature of the turbine is usually much lower than 0℃, and finally the turbine outlet and the condenser cold edge of the air cycle machine are prone to ice blocking.

[0003] How to reduce the water content in the air entering the turbine to reduce the occurrence of ice blocking is a technical problem to be solved at present. SUMMARY

[0004] Therefore, the present application provides an air cycle refrigeration system, an aircraft and a control method thereof, which can solve the technical problem of a large amount of water content in the air entering the turbine in the prior art.

[0005] The first aspect of the present application provides an air cycle refrigeration system applied to an aircraft, a gas source of the air cycle refrigeration system is from engine exhaust of the aircraft, and the air cycle refrigeration system comprises a condenser, a water separator, a turbine, a mixing chamber and a first heat exchanger, the condenser is provided with a condensation hot pipe and a condensation cold pipe which are thermally coupled together, and the first heat exchanger comprises a first hot pipe and a first cold pipe which are thermally coupled together.

[0006] The engine exhaust flows through the condensation hot pipe, the first hot pipe, the water separator, the turbine and the condensation cold pipe in sequence.

[0007] A cold path branch is arranged on a pipeline after an outlet of the condensation cold pipe, the cold path branch is communicated with the first cold pipe, and a cold path valve is arranged on the cold path branch.

[0008] In some embodiments, the air cycle refrigeration system further comprises a second heat exchanger.

[0009] The second heat exchanger comprises a second hot pipe and a second cold pipe which are thermally coupled together, and the second cold pipe is communicated with an outlet of the turbine and an inlet of the condensation cold pipe.

[0010] The aircraft also generates ram air, and the ram air enters the second hot pipe after heat exchange with the engine exhaust.

[0011] In some embodiments, the ram air enters the second heat pipe through a hot branch, and a hot valve is arranged on the hot branch.

[0012] In some embodiments, the air circulation refrigeration system further comprises an ice removal control device capable of detecting a pressure difference ΔP between an outlet of the turbine and an outlet of the condenser cold pipe.

[0013] In some embodiments, the ice removal control device is further capable of controlling the opening degree of the cold valve and the hot valve.

[0014] In a second aspect, the present application further provides an aircraft comprising the air circulation refrigeration system.

[0015] In a third aspect, the present application provides an aircraft control method, the aircraft being the aircraft described above, the air circulation refrigeration system being provided with an ice removal control device, a turbine, and a condenser cold pipe, the control method comprising an ice removal method, the ice removal method comprising:

[0016] obtaining a pressure difference ΔP between an outlet of the turbine and an outlet of the condenser cold pipe, when ΔP < y Kpa, controlling the cold valve to be closed; and when ΔP ≥ y Kpa, controlling the cold valve to be opened.

[0017] In some embodiments, during the opening of the cold valve, the opening degree of the cold valve increases with the increase of ΔP.

[0018] In some embodiments, when the hot valve is provided, the control method further comprises: when ΔP < y+z Kpa, controlling the hot valve to be closed; and when ΔP ≥ y+z Kpa, controlling the hot valve to be opened.

[0019] In some embodiments, during the opening of the hot valve, the opening degree of the hot valve increases with the increase of ΔP.

[0020] By arranging the first heat exchanger, the air discharged from the condenser cold pipe is dehumidified and dried again, so that the air entering the turbine is more dry, the ice formation speed in the turbine and the pipeline downstream of the turbine outlet is slowed down, and the more dry air flowing out of the turbine can also speed up the sublimation of ice, which is conducive to improving the ice removal speed by sublimation. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the description of the embodiments or the prior art. The drawings in the following description are only exemplary, and other drawings can be obtained by those skilled in the art without creative effort on the basis of the provided drawings.

[0022] Figure 1 is a schematic diagram of an air cycle refrigeration system according to an embodiment of the present application;

[0023] Figure 2 is a schematic diagram of an air cycle refrigeration system according to the prior art;

[0024] The reference signs are:

[0025] 1, primary heat exchanger; 2, secondary heat exchanger; 3, regenerator; 4, condenser; 401, condensation hot pipe; 402, condensation cold pipe; 501, first heat exchanger; 5011, first hot pipe; 5012, first cold pipe; 502, second heat exchanger; 5021, second hot pipe; 5022, second cold pipe; 6, water separator; 7, turbine; 8, fan assembly; 9, mixing chamber; 901, cold path branch; 902, cold path valve; 903, hot path branch; 904, hot path valve; 905, differential pressure transmitter; 906, controller; 907, compressor; 908, high temperature branch. DETAILED DESCRIPTION

[0026] The technical solutions 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 only a part of the embodiments of the present application, rather than all the embodiments of the present application. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the scope of protection of the present application.

[0027] In the description of the present application, it should be understood that the orientation words such as "front, back, up, down, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicate the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate and imply that the indicated device or element must have a particular orientation or be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the scope of protection of the present application; the orientation words "inner, outer" refer to the inner and outer relative to the contour of each component.

[0028] For purposes of the description hereinafter, spatial relative terms, such as "above", "below", "upper", "lower", and the like, can be used to describe the relative position of one element or feature to another element or feature as illustrated in the figures. It will be understood that the spatial relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "up" other elements or features would then be oriented "below" or "down" the other elements or features. Thus, the exemplary term "above" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatial relative descriptors used herein interpreted accordingly.

[0029] In addition, it should be noted that the use of "first", "second", and the like words of distinction do not connote any meaning of importance, but are used only to distinguish one element from another, and are used in the context of this patent application only and are not used to limit the scope of the present invention.

[0030] With reference to the accompanying drawings Figure 1 As shown in the drawings, the air circulation refrigeration system provided by the present application is applied to an airplane, the air source of the air circulation refrigeration system is from the engine exhaust of the airplane, and the air circulation refrigeration system comprises a condenser 4, a water separator 6, a turbine 7, a mixing chamber 9 and a first heat exchanger 501. The condenser 4 is provided with a condensation hot pipe 401 and a condensation cold pipe 402 which are coupled together. The first heat exchanger 501 comprises a first hot pipe 5011 and a first cold pipe 5012 which are coupled together.

[0031] The engine exhaust flows through the condensation hot pipe 401, the first hot pipe 5011, the water separator 6, the turbine 7 and the condensation cold pipe 402 in sequence.

[0032] A cold path branch 901 is arranged on the pipeline behind the outlet of the condensation cold pipe 402, the cold path branch 901 is communicated with the first cold pipe 5012, and a cold path valve 902 is arranged on the cold path branch 901.

[0033] Generally, the mixing chamber 9 is arranged behind the condensation cold pipe 402. When the temperature and pressure of the air discharged from the condensation cold pipe 402 are not suitable, the air is sent into the cabin after being adjusted in temperature and pressure in the mixing chamber 9. Specifically, the air entering the mixing chamber 9 from the condensation cold pipe 402 is mixed with the air entering the mixing chamber 9 from the cabin, and then the mixed air is sent into the cabin and the cockpit.

[0034] The air discharged from the condensing cold pipe 401 of the condenser 4 has low humidity, but still contains some moisture. After the air is further cooled in the turbine 7, it can freeze in the pipe behind the outlet of the turbine 7, affecting the flow of the air, so that the amount of low-temperature air entering the mixing chamber 9 is greatly reduced. At this time, by controlling the opening of the cold path valve 902, a part of the low-temperature air discharged from the condensing cold pipe 402 of the condenser 4 enters the first cold pipe 5012 of the first heat exchanger 501 through the cold path branch pipe to cool the air entering the first hot pipe 5011 from the condensing hot pipe 401 of the condenser 4, thereby reducing the saturated moisture content of the air (the lower the temperature, the lower the saturated humidity of the air, and the less the gaseous moisture contained in the air). That is, after the temperature is reduced, the moisture in the air will be separated as a liquid, the humidity of the air will be reduced, and the liquid will flow into the water separator 6 with the air. The liquid is separated in the water separator 6, thereby reducing the moisture contained in the air entering the turbine 7, slowing down the freezing speed of the pipe behind the outlet of the turbine 7, and avoiding further freezing of the pipe behind the outlet of the turbine 7. The more dry air discharged from the turbine 7 can sublimate the ice in the frozen area, thereby slowly subliming the ice in the pipe behind the outlet of the turbine 7 and reducing the ice. In addition, due to the high flow rate of the air at the outlet of the turbine 7, the accumulated ice can be washed away by the high-speed airflow. In this way, the pipe between the turbine 7 and the condenser 4 is smooth, and the phenomenon of ice blocking at the outlet of the turbine 7 is avoided.

[0035] The engine exhaust gas flows through the condensation heat pipe 401 in sequence, and the temperature is reduced. Part of the moisture in the air is condensed and separated out, improving the dryness of the air. The air and the liquid flow through the first heat pipe 5011, and then enter the water separator 6. The water is discharged from the water separator 6, and the dry air passes through the turbine 7, and the temperature of the air is greatly reduced. At this time, the temperature of the air can reach minus 10 to minus 50 degrees. The low-temperature air is cooled by the condensation heat pipe 402 to cool the air entering the condensation heat pipe 401. At this time, the temperature of the low-temperature air is increased, but the temperature is still relatively low, and cannot be directly used in the cabin. The low-temperature air discharged from the condenser 4 enters the mixing chamber 9 and mixes with other air (air in the cabin and / or the driver's cabin) in the mixing chamber 9. After being mixed, adjusted in temperature and pressure, the air is input into the cabin and the driver's cabin. The low-temperature air discharged from the turbine 7 may freeze in the pipeline (second cold pipe 5022 below) between the turbine 7 and the condenser 4, causing the turbine 7 to discharge air and reducing the amount of cold air entering the mixing chamber 9. At this time, the cold path valve 902 can be controlled to open, and the first heat exchanger 501 is used to further dehumidify the air before entering the water separator 6, further reducing the humidity of the air entering the turbine 7. The temperature of the air discharged from the first cold pipe 5012 is increased, and the air can flow into the mixing chamber 9. That is, the first heat exchanger 501 has two states, one is heat exchange, and the other is no heat exchange. When it is necessary to further dehumidify the air, the cold path valve 902 is opened. Although it will affect the temperature of the air entering the cabin, if the pipeline between the turbine 7 and the condenser 4 is not deiced, it will further affect the air circulation refrigeration system. When it is not necessary to further dehumidify the air, the cold path valve 902 is closed.

[0036] Preferably, as shown in the drawings, the air circulation refrigeration system further comprises a second heat exchanger 502; the second heat exchanger 502 comprises a second heat pipe 5021 and a second cold pipe 5022 which are coupled together, and the second cold pipe 5022 communicates the outlet of the turbine 7 with the inlet of the condensation cold pipe 402. Figure 1

[0037] The second heat pipe 5021 exchanges heat with the ram air, and the second cold pipe 5022 exchanges heat with the condensation cold pipe 402.

[0038] The work of the aircraft refers to the movement of the aircraft relying on its own power. It includes the movement of the aircraft on the ground and the flight of the aircraft in the air.

[0039] Specifically, when the aircraft is flying at high altitude (above the stratosphere), the ram air comes from natural suction caused by the internal and external pressure difference; when the aircraft is moving on the ground or flying below the stratosphere, the ram air mainly comes from the fan assembly working to suck air into the air circulation refrigeration system.

[0040] ​The ram air exchanges heat with the engine exhaust, reducing the temperature of the engine exhaust, and the temperature of the ram air is increased. The ram air with increased temperature enters the second heat pipe 5021 to heat the second cold pipe 5022, so that the ice in the second cold pipe 5022 can be thawed, ensuring smoothness between the turbine 7 outlet and the condensing cold pipe 402.

[0041] As shown in the prior art, Figure 2 The high-temperature air (200℃ or above) is directly introduced from the engine exhaust into the pipeline after the turbine 7 outlet through the high-temperature branch 908, and the high-temperature air mixes with the low-temperature air discharged from the turbine 7 to melt and remove the ice in the pipeline after the turbine 7 outlet. This results in a significant reduction in the cold quantity entering the mixing chamber 9. However, the present application utilizes the ram air exchanged with the engine exhaust to exchange heat with the second cold pipe 5022, without consuming engine exhaust, thereby ensuring the final refrigeration capacity and the refrigeration performance of the air cycle refrigeration system, ensuring that the temperature of the air entering the mixing chamber 9 meets the requirements, and heating the second cold pipe 5022.

[0042] Preferably, as shown in the Figure 1 The ram air enters the second heat pipe 5021 through the heat path branch 903, and the heat path branch 903 is provided with a heat path valve 904.

[0043] By setting the heat path branch 903 and the heat path valve 904, whether to heat the second cold pipe 5022 and the amount of heating can be controlled. When the second cold pipe 5022 is heated, the temperature of the air in the second cold pipe 5022 will increase to a certain extent, which will result in a decrease in the cold quantity entering the mixing chamber 9. Therefore, by controlling the heat path valve 904, whether to heat the second cold pipe 5022 can be controlled, and continuous and excessive heating of the second cold pipe 5022 to cause insufficient cold quantity of the air flowing out of the second cold pipe 5022 can be avoided.

[0044] Preferably, as shown in the Figure 1 The air cycle refrigeration system further comprises an ice removal control device, which can detect the pressure difference ΔP between the outlet of the turbine 7 and the outlet of the condensing cold pipe 402.

[0045] When the second cold pipe 5022 is iced, the pressure difference between the turbine 7 outlet and the condensing cold pipe 402 outlet will increase. By judging the pressure difference, the icing degree can be more accurately determined.

[0046] Specifically, the ice removal control device comprises a differential pressure transmitter 905, and the two measurement parts of the differential pressure transmitter 905 are respectively arranged at the turbine 7 outlet and the condensing cold pipe 402 outlet of the condenser 4 to detect the change of the pressure difference.

[0047] Preferably, the deicing control device is also capable of controlling the opening size of the cold path valve 902 and the hot path valve 904.

[0048] By controlling the opening and closing of the cold path valve 902 and the hot path valve 904, the opening size, and whether to deice, the deicing efficiency, the final goal is to realize the minimum influence on the cold quantity entering the mixing chamber 9 under the condition of deicing, and finally ensure the stable operation of the air cycle refrigeration system. The deicing control device also includes a controller 906, which controls the opening size of the cold path valve 902 and the hot path valve 904.

[0049] The minimum valve opening is valve closing.

[0050] The aircraft provided by the present application comprises the air cycle refrigeration system.

[0051] The aircraft adopting the air cycle refrigeration system described above can continuously and stably provide cold air for the internal space of the aircraft.

[0052] Specifically, as shown in the figure, Figure 1 The air cycle refrigeration system further comprises a primary heat exchanger 1, a secondary heat exchanger 2, a fan assembly 8, a compressor 907, and a regenerator 3. The engine exhaust gas sequentially flows through the primary heat exchanger 1, the compressor 907, the secondary heat exchanger 2, the regenerator 3, the condensing hot pipe 401, the first hot pipe 5011, the water separator 6, the regenerator 3, the turbine 7, the second cold pipe 5022, and the condensing cold pipe 402, and then enters the mixing chamber 9. The primary heat exchanger 1, the secondary heat exchanger 2, and the regenerator 3 are all heat exchangers used for cooling the engine exhaust gas. Among them, the engine exhaust gas is saturated in humidity after being cooled in the regenerator 3 and the condenser 4, and most of the water vapor condenses into liquid water, which enters the water separator 6 with the airflow for separation.

[0053] The compressor 907 is used to boost the engine exhaust gas, and the fan assembly 8 is used to draw air outside the aircraft into the aircraft. The ram air is high in temperature after passing through the primary heat exchanger 1 and the secondary heat exchanger 2, and can be used to input the second hot pipe 5021 to deice the second cold pipe 5022.

[0054] The present application also provides a control method for an aircraft, the aircraft being the aircraft described above, the air cycle refrigeration system being provided with a deicing control device, a turbine 7, and a condensing cold pipe 402. The control method comprises a deicing method, which comprises:

[0055] The pressure difference ΔP between the outlet of the turbine 7 and the outlet of the condensing cold pipe 402 is obtained, and when ΔP < yKpa, the cold path valve 902 is controlled to be closed; when ΔP ≥ yKpa, the cold path valve 902 is controlled to be opened.

[0056] The pressure difference ΔP between the outlet of the turbine 7 and the outlet of the condensing cold pipe 402 is obtained, and according to the size relation between ΔP and a preset value, it is judged whether deicing is needed, for example, the preset value is yKpa, when ΔP < yKpa, the pressure difference between the outlet of the turbine 7 and the outlet of the condensing cold pipe 402 is small, which indicates that there is less or no icing, only the normal pressure drop of the pipe, at this time, it is determined that the air circulation system does not need deicing, and the cold air discharged from the condensing cold pipe 402 enters the mixing chamber 9 and mixes with other air (such as heated ram air) to adjust the pressure, and then is sent into the cabin and the cab. When ΔP ≥ yKpa, the pressure difference between the outlet of the turbine 7 and the outlet of the condensing cold pipe 402 is large, and ΔP has been greater than the pressure drop due to the resistance of the pipe itself, it is determined that the air circulation system needs deicing, at this time, the cold path valve 902 is controlled to be opened, and part of the low-temperature air discharged from the condensing cold pipe 402 enters the first cold pipe 5012 to cool and dehumidify the air before entering the water separator 6, reduces the saturation humidity of the air, and precipitates more liquid water, the water and the air enter the water separator 6 together, the liquid water is discharged in the water separator 6, and the drier air enters the turbine 7 to expand and cool. The drier air discharged from the turbine 7 enters the pipe between the outlet of the turbine 7 and the condensing cold pipe 402, so that the ice in the pipe sublimates faster to achieve the purpose of deicing. y can be 5-9, and z can be 6-8.

[0057] Preferably, during the opening of the cold path valve 902, the opening degree of the cold path valve 902 increases with the increase of ΔP.

[0058] In the range of ΔP ≥ yKpa, the larger ΔP is, the more serious the icing is, at this time, the air entering the water separator 6 needs to be drier, so that the drier air flows out of the turbine 7 to accelerate the sublimation of ice.

[0059] The greater the opening of the cold path valve 902, the lower the temperature of the air discharged from the first heat pipe 5011, the lower the air saturation humidity, the more water separated (condensed), the greater the water separator 6 drainage, and the less ice in the pipeline after the turbine 7 outlet. Ultimately, the temperature of the air discharged from the condensing cold pipe 402 is lower. As shown in Table 1, the temperature change of the air entering the water separator 6 causes the drainage, ice, and air temperature change of the condensing cold pipe 402 to change. In Table 1, t is the base value of the temperature at the inlet of the water separator 6. As can be seen from the table, as the temperature of the air at the inlet of the water separator 6 gradually decreases, the drainage of the water separator 6 gradually increases (i.e., the water separated and condensed from the air increases), the ice in the pipeline (second cold pipe 5022) after the turbine 7 outlet gradually decreases, and the temperature at the outlet of the condenser 4 gradually decreases.

[0060]

[0061] Table 1

[0062] Preferably, when the hot path valve 904 is provided, the control method further comprises: when ΔP < (y+z) Kpa, controlling the hot path valve 904 to be closed, and when ΔP ≥ (y+z) Kpa, controlling the hot path valve 904 to be opened.

[0063] When ΔP < (y+z) Kpa, the ice in the pipeline between the turbine 7 outlet and the condensing cold pipe 402 is not serious, and only the cold path valve 902 needs to be opened to achieve ice removal. At this time, the hot path valve 904 is closed. When ΔP ≥ (y+z) Kpa, the ice in the pipeline between the turbine 7 outlet and the condensing cold pipe 402 is relatively serious, and only the cold path valve 902 is opened, which is slow in removing ice by sublimation. At this time, the hot path valve 904 is controlled to be opened, and the ram air after heat exchange with the engine exhaust enters the second heat pipe 5021 to heat the second cold pipe 5022 to directly melt the ice in the second cold pipe 5022, thereby achieving rapid ice removal.

[0064] Specifically, the ice in the second cold pipe 5022 (which is connected between the turbine 7 outlet and the inlet of the condensing cold pipe 402) gradually increases. When ΔP < y Kpa, the cold path valve 902 and the hot path valve 904 are both closed. As the ice gradually increases, ΔP gradually increases. When ΔP is greater than y Kpa but less than (y+z) Kpa, the cold path valve 902 is opened, and the hot path valve 904 is closed for ice removal. If the ice removal effect is poor, the ice amount continues to increase, and when the ice amount increases to ΔP ≥ (y+z) Kpa, the hot path valve 904 is opened for ice removal.

[0065] Preferably, during the opening of the heat path valve 904, the opening degree of the heat path valve 904 increases with the increase of △P.

[0066] In the range of △P≥(y+z)Kpa, the opening degree of the heat path valve 904 increases with the increase of △P, and is not directly opened to the maximum, which can avoid over-heating the second cold pipe 5022, so that the temperature of the air entering the condensing cold pipe 402 is not low enough, which affects the dehumidification of the air in the condensing heat pipe 401 at the condenser 4 and the cold capacity of the air entering the mixing chamber 9.

[0067] Those skilled in the art can easily understand that the advantageous technical features of the above-mentioned modes can be freely combined and superimposed without conflict.

[0068] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above description is only the preferred embodiment of the present application, and it should be pointed out that, for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, which should be regarded as the protection scope of the present application.

Claims

1. An air cycle refrigeration system for use on an aircraft, the air cycle refrigeration system having an air supply from the engine bleed air of the aircraft, characterised in that, The air cycle refrigeration system comprises a condenser (4), a water separator (6), a turbine (7), a mixing chamber (9) and a first heat exchanger (501), the condenser (4) is provided with a condensing hot pipe (401) and a condensing cold pipe (402) which are coupled together, and the first heat exchanger (501) comprises a first hot pipe (5011) and a first cold pipe (5012) which are coupled together; The engine exhaust gas flows through the condensing hot pipe (401), the first hot pipe (5011), the water separator (6), the turbine (7) and the condensing cold pipe (402) in sequence; A cold branch (901) is arranged on the pipeline after the outlet of the condensing cold pipe (402), the cold branch (901) is communicated with the first cold pipe (5012), and a cold valve (902) is arranged on the cold branch (901).

2. The air cycle refrigeration system of claim 1, wherein, The air cycle refrigeration system further comprises a second heat exchanger (502); The second heat exchanger (502) comprises a second hot pipe (5021) and a second cold pipe (5022) which are coupled together, and the second cold pipe (5022) is communicated with the outlet of the turbine (7) and the inlet of the condensing cold pipe (402); The aircraft operation also generates ram air, and the ram air enters the second hot pipe (5021) after heat exchange with the engine exhaust gas.

3. The air cycle refrigeration system of claim 2, wherein, The ram air enters the second hot pipe (5021) through a hot branch (903), and a hot valve (904) is arranged on the hot branch (903).

4. The air cycle refrigeration system of claim 3, wherein, The air cycle refrigeration system further comprises an ice removal control device which can detect the pressure difference ΔP between the outlet of the turbine (7) and the outlet of the condensing cold pipe (402).

5. The air cycle refrigeration system of claim 4, wherein, The ice removal control device can also control the opening degree of the cold valve (902) and the hot valve (904).

6. An aircraft, characterized in that The aircraft is the aircraft of claim 6, and the air cycle refrigeration system is provided with an ice removal control device, a turbine (7) and a condensing cold pipe (402).

7. An aircraft control method, characterized in that, The control method comprises an ice removal method, and the ice removal method comprises: Obtaining the pressure difference ΔP between the outlet of the turbine (7) and the outlet of the condensing cold pipe (402), when ΔP < y Kpa, controlling the cold valve (902) to be closed, and when ΔP ≥ y Kpa, controlling the cold valve (902) to be opened; y is a preset value.

8. The control method according to claim 7, characterized by During the opening process of the cold valve (902), the opening degree of the cold valve (902) increases with the increase of ΔP.

9. The control method according to claim 7, characterized by, When the hot valve (904) is arranged, the control method further comprises: when ΔP < (y+z) Kpa, controlling the hot valve (904) to be closed, and when ΔP ≥ (y+z) Kpa, controlling the hot valve (904) to be opened; z is a preset value.

10. The control method according to claim 9, characterized by During the opening process of the hot valve (904), the opening degree of the hot valve (904) increases with the increase of ΔP.

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