Airplane air conditioning system and airplane comprising an airplane air conditioning system

Abstract

The present disclosure relates to an aircraft air conditioning system (100) and an aircraft comprising the same, wherein ambient air is cooled by a cooling system (200) having a first cooling circuit (210) and a second cooling circuit (220) which are thermally coupled to each other via a shared heat exchanger (205).

Description

Technical Field

[0001] This disclosure generally relates to an air conditioning system having a two-stage cooling circuit and an aircraft having such an air conditioning system. In particular, this disclosure relates to an aircraft air conditioning system and a corresponding aircraft, wherein ambient air is cooled by a cooling system having a first cooling circuit and a second cooling circuit thermally connected to each other via a common heat exchanger. Background Technology

[0002] Conventional aircraft air conditioning systems use bleed air from the aircraft engines, which is expanded, cooled, and regulated to supply the aircraft cabin. However, the goal is to provide an air conditioning system without bleed air to reduce fuel consumption.

[0003] For example, US 2017 / 275004 A1 and EP 3 168 154 A1 provide environmental control systems that regulate ambient air for cooling via an electric compressor and heat exchanger arranged in a ram air passage. EP 3 168 154 A1 also includes a refrigeration device comprising a refrigerant compressor driven by an electric motor, wherein the refrigerant is thermally coupled to the ambient air for additional cooling.

[0004] However, the aircraft's air conditioning system can still be improved, for example, in terms of its energy consumption. Summary of the Invention

[0005] Therefore, the purpose of this disclosure is to provide a more energy-efficient aircraft air conditioning system.

[0006] This objective is achieved by the invention as defined by the principal aspects of this disclosure. Preferred embodiments are defined by the dependent aspects of this disclosure.

[0007] According to a first aspect for better understanding of this disclosure, an aircraft air conditioning system includes an ambient air inlet configured to receive unpressurized ambient air, a cooling system configured to cool a refrigerant, and a heat exchanger for cooling the ambient air. Unpressurized ambient air should be understood as air drawn from the environment surrounding the air conditioning system, such as ambient air from the environment of the aircraft in which the air conditioning system is installed. The ambient air is received at an ambient pressure that depends only on the current altitude of the aircraft. By way of example only, the unpressurized ambient air may be received from an air inlet in the outer skin of the aircraft or from a ram air passage. The unpressurized ambient air is not from bleed air from the aircraft engines.

[0008] The cooling system includes a first cooling circuit configured to cool a first refrigerant, a second cooling circuit configured to cool a second refrigerant, and a common heat exchanger thermally connecting the first and second refrigerants. In other words, the cooling system comprises cascaded cooling circuits thermally connected to each other. Therefore, the cooling capacity of the first cooling circuit is used to cool the second refrigerant in the second cooling circuit, thus achieving a lower temperature (of the second refrigerant) compared to a single cooling circuit. Each of the first and second cooling circuits can operate with optimized energy consumption, which can be lower than the energy consumption of a single cooling circuit energized to provide the same cooling capacity.

[0009] A heat exchanger for cooling ambient air thermally connects a second refrigerant to the ambient air. Therefore, the cooler second refrigerant is used to cool the ambient air, for example, for further use in the aircraft's cabin. Thus, the air conditioning system allows for the provision of conditioned, cool ambient air to the aircraft without the need for bleed air. Due to the cascaded cooling loop, the entire system can operate more energy-efficiently.

[0010] By way of example only, the first cooling circuit and / or the second cooling circuit may be a vapor cycle. The first refrigerant and / or the second refrigerant may be a two-phase refrigerant that changes between a gaseous and a liquid state. For example, R134A (CH2F-CF3), R245fa (1,1,1,3,3-pentafluoropropane), hydrofluoroolefin (HFO) refrigerants, CO2, or natural gas may be used as refrigerants for the first cooling circuit and / or the second cooling circuit.

[0011] In a variant implementation, the first cooling circuit may include a first compressor configured to compress a first refrigerant, a first condenser configured to cool the compressed first refrigerant, and a first expansion valve located downstream of the first condenser and configured to expand the first refrigerant. Due to the expansion of the first refrigerant, the temperature of the first refrigerant is lower than the temperature after the first compressor. Therefore, the first refrigerant can be used as a radiator for the second cooling circuit.

[0012] In a variation of the implementation, the first cooling circuit may include a first compressor configured to compress a first refrigerant, a first condenser configured to cool the compressed first refrigerant, a first expansion valve located downstream of the first condenser and configured to expand the first refrigerant, and a first evaporator configured to thermally connect the expanded first refrigerant to ambient air. Specifically, taking into account the flow direction of the ambient air, the first evaporator is thermally connected to the ambient air upstream of the heat exchanger that thermally connects the second refrigerant to the ambient air. In other words, the first cooling circuit having the first evaporator can pre-cool the ambient air before it is cooled to a desired temperature at the heat exchanger that thermally connects the second refrigerant to the ambient air.

[0013] In a variation of the implementation, the first evaporator and the shared heat exchanger can be arranged in series in the first cooling circuit. For example, the first refrigerant leaving the first evaporator can then enter the shared heat exchanger. Alternatively, the first refrigerant leaving the shared heat exchanger can then enter the first evaporator. The order in which the first evaporator and the shared heat exchanger are connected in series depends on the intended primary cooling target, i.e., ambient air (via the first evaporator) or the second cooling circuit (via the shared heat exchanger).

[0014] In a variant implementation, the first evaporator and the shared heat exchanger can be arranged parallel to each other in the first cooling circuit. In other words, the first refrigerant leaving the expansion valve can be directly guided to the first evaporator and the shared heat exchanger. The corresponding refrigerant piping branches off after the expansion valve and reconnects downstream of the first evaporator and the shared heat exchanger.

[0015] In a variation of the implementation, the first cooling circuit may include one or more control valves configured to control the mass or volumetric flow rate of a first refrigerant toward one or more downstream components, such as a first evaporator and / or a shared heat exchanger. Therefore, such control valves may be implemented as shut-off valves or solenoid valves in (branch) piping lines, or as three-way valves (with three ports) at branch or reconnection points in the refrigerant piping lines.

[0016] In a variation of the implementation, the condenser can be configured to condense any gaseous refrigerant present upstream of the condenser in the first cooling circuit. Therefore, in the case of a two-phase refrigerant, the condenser ensures that only the liquid first refrigerant is directed to the expansion valve. As an example only, downstream of the expansion valve, the first refrigerant may evaporate, i.e., become gaseous. It should be understood that the change to gas can occur additionally or solely in the first evaporator.

[0017] In a variation of the implementation, the aircraft air conditioning system may also include a water extractor or water separator configured to extract water from ambient air downstream of the first evaporator. Due to the pre-cooling of the ambient air at / within the first evaporator, the ambient air can be dried / dehumidified in the water extractor before being further guided and processed. Because the refrigerant in the first cooling circuit is not cooled to the temperature required to cool the ambient air to its intended temperature—that is, because the first refrigerant is hotter—the risk of icing in the first evaporator is reduced, and therefore the risk of icing in the water extractor or separator is also reduced. The first cooling circuit can be configured such that the first evaporator does not reach a temperature below a threshold temperature value, such as 5°C or 1°C, i.e., above the freezing point of water in ambient air but below its dew point. For example, the compressor and / or expansion valve can be controlled to achieve this temperature of the first refrigerant in the first evaporator.

[0018] In a variation of the implementation, the water extractor can be integrated into the first evaporator. This allows for a very compact and energy-efficient air conditioning system that provides (pre)conditioning of the ambient air in the early stages of its treatment.

[0019] In a variant implementation, a shared heat exchanger can be positioned in the first cooling circuit downstream of the first evaporator and upstream of the first compressor. Therefore, the cooling process of the first refrigerant restarts after absorbing heat (energy) from the second cooling circuit, particularly at the first compressor.

[0020] In a variant of the implementation, the first condenser can be arranged in a ram air duct and configured to thermally connect the compressed first refrigerant with the ram air within the ram air duct. Therefore, effective cooling of the first refrigerant downstream of the first compressor can be achieved without requiring any fuel-consuming components of the aircraft, such as the aircraft engine.

[0021] In a variant implementation, the second cooling circuit may include a second compressor configured to compress a second refrigerant and a second expansion valve configured to expand the second refrigerant. A common heat exchanger is arranged in the second cooling circuit downstream of the second compressor and upstream of the second expansion valve, and is configured to function as a second condenser by cooling the compressed second refrigerant. The cooling is relative to the first refrigerant, i.e., the first refrigerant acts as a radiator for the second refrigerant.

[0022] In a variant implementation, the shared heat exchanger constituting the second condenser can condense any gaseous refrigerant. Therefore, it is possible to avoid directing the gaseous refrigerant to the expansion valve.

[0023] The second cooling circuit can be configured in the same manner as the first cooling circuit. Therefore, any details described regarding the first cooling circuit also apply to the second cooling circuit, and repetition of these details is omitted for the sake of brevity.

[0024] In a variant implementation, the aircraft air conditioning system may further include: an ambient air compressor, an ambient air compression mechanism that compresses unpressurized ambient air received from the ambient air inlet; and an electric motor that drives the ambient air compressor. Such an ambient air compressor may be specifically used if the pressure of the unpressurized ambient air (i.e., the ambient air pressure within the aircraft environment) is insufficient to regulate the aircraft, such as the aircraft cabin. This includes any accumulated pressure at the air inlet due to the aircraft's flight speed.

[0025] In a variation of the implementation, the aircraft air conditioning system may also include a nacelle exhaust duct and a nacelle exhaust turbine connected to the nacelle exhaust duct. The nacelle exhaust turbine may be driven by a pressure differential between exhaust pressure from the nacelle and any other area with lower pressure in which the nacelle exhaust duct terminates.

[0026] As an example only, the cabin exhaust line may terminate at / inside a ram air duct and / or at an opening in the aircraft skin. Therefore, since the aircraft cabin is periodically pressurized, a pressure differential will exist between the pressurized cabin and the aircraft environment, which can be used to recover energy.

[0027] In this implementation, the ambient air compressor and the nacelle exhaust turbine are arranged on a common shaft. Therefore, energy from the nacelle exhaust can be recovered to at least partially pressurize the ambient air conditioned by the air conditioning system.

[0028] In a variation of the implementation, the aircraft air conditioning system may further include an ambient air heat exchanger arranged in a ram air duct and configured to thermally connect the compressed ambient air with the ram air within the ram air duct. Therefore, the compressed ambient air, which is periodically heated during compression, can be cooled relative to the ambient air in the ram air duct.

[0029] In a variation of the implementation, the aircraft air conditioning system may further include: a cabin air recirculation line configured to guide cabin air; and a mixer unit configured to mix cooled ambient air with recirculated cabin air from the cabin air recirculation line. Therefore, the aircraft cabin can provide: conditioned air from the surrounding environment, i.e., fresh air used in the aircraft cabin; and recirculated air, i.e., reused air from the cabin.

[0030] In a variation of the implementation, the aircraft air conditioning system may further include cooling air lines configured to direct cabin air to electrical components requiring cooling. These cooling air lines lead to ram air ducts or terminate in openings within the aircraft's outer skin, particularly the outer skin. Therefore, since a pressure differential typically exists between the cabin and the ram air ducts, the cooling air directed through the cooling air lines may flow solely due to this pressure difference. This allows for effective cooling of the electrical components.

[0031] In a variant implementation, the cooling air lines can branch off from the cabin air recirculation lines. This allows for highly efficient piping throughout the entire air conditioning system.

[0032] According to the second aspect, in order to better understand this disclosure, an aircraft includes one or more variations of the aircraft air conditioning system of the first aspect or a variant thereof.

[0033] This disclosure is not limited to the aspects and variations in the forms and order described. In particular, the description of aspects and variations should not be construed as a specific restrictive grouping of features. It will be understood that this disclosure also covers combinations of aspects and variations. Thus, each variation or optional feature can be combined with any other aspect, variation, optional feature, or even combination thereof. Attached Figure Description

[0034] The present disclosure will be further described below with reference to exemplary implementations shown in the accompanying drawings, in which:

[0035] Figure 1 The diagram schematically illustrates the aircraft's air conditioning system;

[0036] Figure 2 An exemplary two-stage cooling system is schematically illustrated;

[0037] Figure 3 schematically illustrated Figure 2 Ts diagram of the cooling system;

[0038] Figure 4 An exemplary two-stage cooling system for an aircraft's air conditioning system is schematically illustrated.

[0039] Figure 5 schematically illustrated Figure 4 Ph diagram of the cooling system;

[0040] Figure 6 The details of an exemplary cooling circuit are schematically illustrated; and

[0041] Figure 7 The illustration schematically depicts an aircraft including an air conditioning system. Detailed Implementation

[0042] In the following description, specific details are set forth for purposes of explanation and not limitation, in order to provide a thorough understanding of this disclosure. It will be apparent to those skilled in the art that this disclosure may be practiced in other implementations that depart from these specific details.

[0043] Figure 1 The diagram schematically illustrates an aircraft air conditioning system 100 configured to supply conditioned air to the aircraft cabin 10. Air for the air conditioning system 100 may be received from an ambient air inlet 105, which is configured to receive air from the aircraft 1 (…). Figure 7 The ambient air inlet 105 is located on the outer skin of the aircraft 1 or a similar area, where it can receive ambient air at ambient pressure. It should be understood that ram pressure may accumulate at the ambient air inlet 105 during flight. However, the ambient air can be considered to be at ambient pressure because the ram pressure is still significantly lower than the pressure of the bleed air drawn from the aircraft engine (not shown).

[0044] Ambient air from ambient air inlet 105 is directed toward cooling system 200 via ambient air line 120. Cooling system 200 is configured to cool the refrigerant used to cool the ambient air. Specifically, air conditioning system 100 also includes heat exchanger 225, which cools the ambient air directed through ambient air line 120.

[0045] The cooling system 200 includes a first cooling circuit 210 and a second cooling circuit 220 respectively configured to cool a first refrigerant and a second refrigerant. The first cooling circuit 210 and the second cooling circuit 220 are thermally connected via a common heat exchanger 205. For example, the first cooling circuit 210 can be used as a radiator for the second cooling circuit located at the common heat exchanger 205.

[0046] The ambient air is then cooled in a heat exchanger 225, which thermally connects the ambient air and the second refrigerant.

[0047] More specifically, the first cooling circuit may include a first compressor 211 and a first condenser 212, the first compressor 211 being configured to compress a first refrigerant, and the first condenser 212 being configured to cool the compressed first refrigerant. The first condenser 212 may use any radiator. This is merely an example. Figure 1The diagram illustrates a first condenser 212, which is arranged in a ram air duct 20 such that the ram air (ambient air) is used as a radiator for the first refrigerant. Therefore, the first refrigerant is cooled in the condenser 212, where any gaseous refrigerant (of the first refrigerant) is condensed, i.e., changes from a gaseous state to a liquid state.

[0048] Downstream of condenser 212 may be a first expansion valve 213, which is configured to expand the first refrigerant that has been compressed and condensed. On one hand, the expanded first refrigerant may be directed to a common heat exchanger 205, where the expanded first refrigerant serves as a radiator for the second refrigerant in the second cooling circuit 220.

[0049] A portion of the shared heat exchanger 205 can be used as an evaporator. An alternative configuration of a portion of the first cooling circuit 210 is illustrated with reference to the diagram. Figure 6 The shared heat exchanger 205 can be directly fluidly connected to the first expansion valve 213.

[0050] On the other hand, the first cooling circuit 210 may also include a first evaporator 215 configured to thermally connect the expanding first refrigerant to the ambient air. The first evaporator may be arranged upstream of the heat exchanger 225, which thermally connects the second refrigerant to the ambient air, in the direction of ambient air flow. Therefore, the first evaporator 215 of the first cooling circuit 210 can be used to pre-cool the ambient air.

[0051] Reference Figure 1 and Figure 6 The first evaporator 215 can be directly fluidly connected to the first expansion valve 213. In other words, the expanding first refrigerant evaporates in the first evaporator 215. (As from...) Figure 1 From this, it can be concluded that the first evaporator 215 can be installed in series with the common heat exchanger 205, such that the expanding first refrigerant evaporates first in the first evaporator 215 before entering the common heat exchanger 205. (Refer to...) Figure 6 The first evaporator 215 can alternatively be installed in parallel with the common heat exchanger 205. Therefore, the first evaporator 215 and the common heat exchanger 205 can receive the expanding first refrigerant, making it compatible with... Figure 1 Compared to the tandem mounting shown, these two components can have a higher cooling capacity.

[0052] It should be understood that the shared heat exchanger 205 and the first evaporator 215 can also be installed in series, wherein the shared heat exchanger 205 serves as the first component, allowing the first refrigerant leaving the shared heat exchanger 205 to enter or be guided into the first evaporator 215.

[0053] It should also be understood that in a parallel arrangement, at least one valve (not shown) may be provided in one or both branch piping lines for the first refrigerant to control the amount (mass and / or volumetric flow rate) of the first refrigerant entering the common heat exchanger 205 and the first evaporator 215. Alternatively, each branch piping line may include an independent evaporator valve instead of the single evaporator valve 213 shown.

[0054] In any case, the aircraft air conditioning system 100 may also include a water extractor 218 configured to extract water from ambient air downstream of the first evaporator 215. Thus, the first cooling circuit 210 can be used to provide a radiator for the second cooling circuit 220 to pre-cool the ambient air and dry it in the water extractor 218. By way of example only, the water extractor 218 may be integrated into the first evaporator 215.

[0055] The second cooling circuit 220 may have a similar or identical structure to the first cooling circuit 210. For example, the second cooling circuit 220 may include a second compressor 221 configured to compress a second refrigerant and a second expansion valve 223 configured to expand the second refrigerant. A common heat exchanger 205 is arranged in the second cooling circuit 220 downstream of the second compressor 221 and upstream of the second expansion valve 223. This allows the common heat exchanger 205 to operate as a second condenser, which cools the compressed second refrigerant relative to the first refrigerant, which acts as a radiator. Similarly, any gaseous refrigerant can be condensed in the common heat exchanger 205.

[0056] It should be understood that one or both of the first and second refrigerants can be any type of refrigerant. By way of example only, the first and / or second refrigerant can be two-phase refrigerants that change between a gaseous and a liquid state, particularly in components referred to as evaporators 215, 225 and condensers 212, 205. For example, R134A (CH2F-CF3), CO2, or R245fa (1,1,1,3,3-pentafluoropropane) can be used as refrigerants in the first cooling circuit 210 and / or the second cooling circuit 220. Since the first cooling circuit operates at a higher temperature, the first refrigerant can also be water, etc.

[0057] The aircraft air conditioning system 100 may also include ambient air compressors 111 and 112, wherein the ambient air compressors 111 and 112 are in Figure 1 The example shown is a two-stage compressor with a first stage 111 and a second stage 112. The ambient air compressors 111 and 112 can be driven by an electric motor 110. Therefore, the air conditioning system 100 does not require bleed air and can be operated using only electrical components.

[0058] The ambient air compressors 111 and 112 can be supported by the nacelle exhaust turbine 119.

[0059] For example, the air conditioning system 100 may also include a cabin exhaust duct 150 for removing air from the aircraft cabin 10. The cabin exhaust duct 150 may terminate at a cabin air injector 155, which may inject cabin exhaust gas into the surrounding environment 2. By way of example only, the cabin air injector 105 may be arranged in a ram air duct 20.

[0060] Furthermore, the ram air duct 20 may have a ram air inlet 21 and a ram air outlet 22, enabling ram air flow between the ram air inlet 21 and the ram air outlet 22, particularly during the flight phase of the aircraft 1. A ram air fan 25 may also be provided in the ram air duct 20 to ensure sufficient airflow or movement of ram air through the ram air duct 20.

[0061] This ram airflow or flow can be used in conjunction with the cabin air jet 155, as it helps to draw cabin exhaust gases out of the jet 155. However, if there is a pressure difference between the aircraft cabin 10 and the surrounding environment 2 (e.g., during high-altitude flight), cabin exhaust gases in the cabin exhaust line 150 can be transported through that pressure difference.

[0062] The energy of the nacelle exhaust gas can be used to drive the nacelle exhaust turbine 119. The ambient air compressors 111 and 112 and the nacelle exhaust turbine 119 can be arranged on a common shaft.

[0063] In addition, the ram airflow or flow (ram air during flight or airflow delivered by ram air fan 25) helps to cool the condenser 212 of the first cooling circuit 210.

[0064] Furthermore, the aircraft air conditioning system 100 may also include an ambient air heat exchanger 122 disposed in the ram air duct 20. This ambient air heat exchanger 122 may be configured to thermally connect the compressed ambient air in the duct 120, and particularly the compressed ambient air in the ambient air branch 121, with the ram air (or airflow delivered by the fan 25) in the ram air duct 20. Ambient air downstream of the ambient air heat exchanger 122 may be guided to the first evaporator 215 and the water separator 218 via a corresponding ambient air duct 123.

[0065] Ambient air ducts 120, 121, and 123 may include one or more valves 125, 126, and 127. This allows control over the amount of ambient air cooled by the cooling system 200 or bypassed via valve 126. Back pressure valves 125 and 127 may be used to increase system pressure to facilitate the extraction of water from the water separator 218.

[0066] Additionally, another water separator 128 can be installed upstream of valve 127 in the ambient air duct 120. This additional water separator 128 can be used if the ambient air bypasses the cooling system 200. Alternatively, the additional water separator 128 can be located at, or integrated into, the heat exchanger 225 that thermally connects the second refrigerant to the ambient air.

[0067] Any separated water (from water extractor / water separator 218 and / or water extractor / water separator 128) can be directed to water injector 28, which can be configured to inject water into ram air duct 20. This water injector 28 can be arranged in ram air duct 20 upstream of condenser 212 and / or ambient air heat exchanger 122, where the injected water evaporates and thus cools the ram air before flowing through condenser 212 and / or ambient air heat exchanger 122.

[0068] Figure 1 Valves 129 and 151, located in ambient air duct 120 and cabin exhaust duct 150 respectively, are also shown. Both valves can be positioned at the boundary of the aircraft cabin 10, i.e., at the boundary between the pressurized area (cabin 10) and the unpressurized area (outside the aircraft cabin 10). Valve 129 can function as a check valve.

[0069] The aircraft air conditioning system 100 may further include a mixing unit 130, which receives ambient air (i.e., conditioned air) from ambient air duct 120 and / or cold ambient air duct 123, and recirculated air from cabin air recirculation line 131. Thus, fresh conditioned air can be mixed with reused cabin air. A recirculation fan 135 may be provided in cabin air recirculation line 131.

[0070] Figure 1 A cooling air line 170 is also shown in dashed lines. The cooling air line 170 is configured to direct cabin air to electrical components that require cooling. Such electrical components may be motors 110 that drive ambient air compressors 111, 112. The cooling air line 170 may also terminate in the ambient environment 2, for example, by terminating in ram air duct 20.

[0071] It should be understood that the cooling air line 170 can also be configured to direct cabin air to one or both of the first compressor 211 of the first cooling circuit 210 and the second compressor 221 of the second cooling circuit 220, although Figure 1 Not shown in the diagram. Since these compressors 211 and 221 can also be operated by electric motors, air cooling can be provided using cabin air via cooling air line 170.

[0072] Figure 2 An exemplary two-stage cooling system is schematically illustrated. This two-stage cooling system can be used with... Figure 1 The cooling system 200 is the same as that in the other system, except that the first evaporator 215 is omitted for the sake of simplicity. Figure 3 schematically illustrated Figure 2 The Ts diagram of the cooling system.

[0073] As from Figure 2 and Figure 3 It can be concluded that the first refrigerant in the first cooling circuit 210 and the second refrigerant in the second cooling circuit 220 will experience a temperature rise when they are compressed in the corresponding first compressor 211 and second compressor 221.

[0074] However, to achieve the same effect, the compressor work of both the first compressor 211 and the second compressor 221 is less than the hypothetical compressor work of a single compressor, as shown by the dashed line. Furthermore, due to the use of the two-stage cooling system 200, the temperature of the second refrigerant can be reduced, i.e., the cooling capacity can be increased, such as... Figure 3 The dashed line in the diagram further illustrates this. Therefore, the two-stage cooling system 200 allows for more energy-efficient operation and can even achieve lower temperatures for the (second) refrigerant.

[0075] Figure 4 and Figure 5 The diagrams illustrate, respectively, the following: Figure 1 An exemplary two-stage cooling system 200 is shown in the figure, along with a Ph diagram of such a cooling system 200.

[0076] As from Figure 5 It can be concluded that the first evaporator 215 can operate in a temperature range above the freezing point (see Figures 6 and 7), while the second evaporator 225 (see Figures 9 and 1) can reach even colder temperatures. Therefore, the first evaporator 215 and the water separator 218 can operate without the risk of icing, and the entire cooling system 200 achieves good air conditioning in an energy-efficient manner.

[0077] Figure 7 The illustration schematically shows the following, including about Figures 1 to 6 Aircraft 1 with an air conditioning system 100 described.

[0078] It should be believed that the advantages of the techniques presented herein will be fully appreciated through the foregoing description, and it will be apparent that various changes can be made to the form, construction, and arrangement of exemplary aspects of this disclosure without departing from the scope of this disclosure or sacrificing all its beneficial effects. Because the techniques presented herein can be varied in many ways, it will be understood that this disclosure should be limited only by the scope of the appended claims.

Claims

1. An aircraft air conditioning system (100), comprising: An ambient air inlet (105) is configured to receive unpressurized ambient air; A cooling system (200) configured to cool the refrigerant; as well as A heat exchanger (225) cools the ambient air. Its features are, The cooling system (200) includes: A first cooling circuit (210) is configured to cool a first refrigerant; A second cooling circuit (220), configured to cool a second refrigerant; and A shared heat exchanger (205) thermally connects the first refrigerant and the second refrigerant. The heat exchanger (225) that cools the ambient air connects the second refrigerant to the ambient air.

2. The aircraft air conditioning system (100) according to claim 1, wherein, The first cooling circuit (210) includes: A first compressor (211) is configured to compress the first refrigerant; A first condenser (212) is configured to cool the compressed first refrigerant and preferably to condense any gaseous refrigerant. A first expansion valve (213) is located downstream of the first condenser (212) and configured to expand the first refrigerant; and The first evaporator (215) is configured to thermally connect the expanded first refrigerant to the ambient air upstream of the heat exchanger (225) that thermally connects the second refrigerant to the ambient air in the flow of the ambient air.

3. The aircraft air conditioning system (100) according to claim 2 further includes: A water extractor (218) configured to extract water from the ambient air downstream of the first evaporator (215). Preferably, the water extractor (218) is integrated into the first evaporator (215).

4. The aircraft air conditioning system (100) according to claim 2 or 3, wherein, The shared heat exchanger (205) is arranged in the first cooling circuit (210) downstream of the first evaporator (215) and upstream of the first compressor (211), and / or The first condenser (212) is arranged in the ram air duct (20) and configured to thermally connect the compressed first refrigerant with the ram air in the ram air duct (20).

5. The aircraft air conditioning system (100) according to any one of claims 1 to 4, wherein, The second cooling circuit (220) includes: A second compressor (221), configured to compress the second refrigerant; and The second expansion valve (223) is configured to expand the second refrigerant. The common heat exchanger (205) is arranged in the second cooling circuit (220) downstream of the second compressor (221) and upstream of the second expansion valve (223), and is configured to function as a second condenser by cooling the compressed second refrigerant, and preferably to condense any gaseous refrigerant.

6. The aircraft air conditioning system (100) according to any one of claims 1 to 5, further comprising: An ambient air compressor (111, 112) is configured to compress unpressurized ambient air received from the ambient air inlet (105); as well as An electric motor (110) drives the ambient air compressor.

7. The aircraft air conditioning system (100) according to claim 6 further includes: Cabin exhaust pipe (150); as well as A nacelle exhaust turbine (119) is connected to the nacelle exhaust line (150). The ambient air compressor (111, 112) and the nacelle exhaust turbine (119) are arranged on a common shaft.

8. The aircraft air conditioning system (100) according to claim 6 or 7, further comprising: An ambient air heat exchanger (122) is arranged in a ram air duct (20) and configured to thermally connect the compressed ambient air with the ram air in the ram air duct (20).

9. The aircraft air conditioning system (100) according to any one of claims 1 to 8, further comprising: Cabin air recirculation line (131), the cabin air recirculation line (131) is configured to guide cabin air; as well as A mixer unit (130) is configured to mix the cooled ambient air with recirculated cabin air from the cabin air recirculation line (131).

10. The aircraft air conditioning system (100) according to claim 9 further comprises: Cooling air line (170) configured to direct cabin air to electrical components (110, 211, 221) that require cooling. The cooling air pipeline (170) leads to the ram air pipeline (20). Preferably, the cooling air line (170) branches off from the cabin air recirculation line (131).

11. An aircraft (1), comprising: The aircraft air conditioning system (100) according to any one of claims 1 to 10.

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