An integrated refrigeration system for a more electric aircraft and its operating method

Abstract

This invention discloses an integrated refrigeration system and its operating method for multi-electric aircraft, including a vapor cycle refrigeration system for the cockpit and a reverse boost recirculation refrigeration cycle system for the electronics bay. Ambient air is compressed into a high-pressure gas source by a compressor, and the condenser exchanges heat with fuel. Cockpit exhaust has a large flow rate and low temperature; after filtration, it is compressed into a high-pressure gas source by a compressor, cooled in a recirculation cooler, and further cooled by turbine expansion before entering the air conditioning area to bear the heat load. After being reheated in the recirculation cooler, it is drawn in and pressurized by a compressor before being discharged outside the cabin. This invention eliminates engine bleed air, uses fuel as the condenser's cold source, fully utilizes cockpit exhaust, effectively reduces the need for external environmental bleed air, and is suitable for operating environments where ram air is no longer suitable as a cold source during hypersonic flight. It has advantages such as reducing engine complexity and cost, maintaining engine performance, high refrigeration efficiency, and large cooling capacity.

Description

Technical Field

[0001] This invention belongs to the field of aviation refrigeration systems and relates to an integrated refrigeration system for the cockpit and electronic equipment bay of multi-electric aircraft. Background Technology

[0002] Aircraft cockpits and electronics bays both require air conditioning to ensure the safety and comfort of passengers and the stable operation of electronic equipment. More-electric aircraft technology is a revolutionary advancement in aviation science, transforming traditional aircraft design concepts. In more-electric aircraft, electricity becomes the sole secondary energy source, significantly improving reliability, maintainability, and ground support capabilities.

[0003] With the rapid development of modern aircraft, the heat generated by the avionics of modern high-performance fighter jets has increased dramatically compared to previous models. Simultaneously, the high demands for hypersonic cruise capabilities make traditional air heat sinks insufficient for cooling needs. Therefore, the adoption of vapor compression refrigeration cycle systems has become one of the main development directions for airborne environmental control systems. However, this system still has shortcomings: 1. During hypersonic flight, ram air is no longer suitable as a cooling source. 2. When using engine compressor bleed air, the bleed air may be contaminated by fuel combustion products and lubricating oil system leaks, affecting engine performance. Furthermore, changes in supply air pressure are significantly affected by engine operating conditions. The reverse boost recirculation cooling system is simple in structure and economically efficient; however, the excessively high temperature of the ram air generated during hypersonic flight makes this system unsuitable for this type of aircraft.

[0004] Therefore, given the increasing demand for cooling capacity in aircraft and the need for high-performance engine maintenance, it is necessary to develop efficient and economical integrated cooling systems based on the characteristics of existing technologies and the current research status. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the deficiencies mentioned in the background art by providing an integrated refrigeration system based on the energy characteristics of multi-electric aircraft. This system eliminates engine bleed air and adds a first compressor to directly draw air from the external environment. It also adds a second compressor to use cabin exhaust to supply air to the refrigeration system of the electronic equipment bay. This system enables the application of the reverse boost system to hypersonic aircraft and is unaffected by fuel pollution and changes in air supply pressure.

[0006] An integrated refrigeration system for multi-electric aircraft includes a main refrigeration path, a recirculation path, and a refrigeration cycle path.

[0007] The main refrigeration path, in order of airflow direction, includes the first compressor, evaporator, and cabin.

[0008] The recirculation passage is located downstream of the exhaust outlet of the cabin and is used to cool the exhaust gas from the cabin. It includes a second compressor, a recirculation cooler and a cooling turbine in sequence according to the direction of cold air flow. The cooling turbine exchanges heat with the cold plate of the electronic equipment compartment and returns to the recirculation cooler. After being drawn in and pressurized by the third compressor, it is discharged outside the cabin.

[0009] The refrigeration cycle path has its inlet and outlet connected to the refrigeration inlet and refrigerant outlet of the evaporator, respectively. In order of refrigeration direction, it includes a compressor, condenser, intercooler, and dryer filter.

[0010] Preferably, a primary throttling valve is provided between the condenser and the intercooler, and a secondary throttling valve is provided between the dryer filter and the evaporator.

[0011] Preferably, a filter and an adsorber are installed sequentially between the exhaust outlet of the cabin and the second compressor to treat the exhaust.

[0012] Preferably, the intercooler includes a refrigerant inlet, a gaseous refrigerant outlet, and a liquid refrigerant outlet. The compressor outlet is connected to the hot-side inlet of the condenser via a pipe. Fuel enters the cold-side inlet of the condenser via a pipe and is sent to the fuel chamber from the cold-side outlet via a pipe.

[0013] As a preferred option, the refrigeration system uses an electrically driven compressor to draw air directly from the environment through the fuselage air inlet, compress it to a certain pressure, and then fully cool it through the evaporator before it enters the cabin for refrigeration.

[0014] Preferably, the refrigerant is condensed in the condenser by using fuel oil as a cold source for heat dissipation.

[0015] Preferably, the cabin exhaust passes through a filter and an adsorber to remove exhaust smoke and dust, and is then compressed to a certain pressure by an electrically driven compressor to serve as the air source for the reverse booster refrigeration system.

[0016] A method for operating a multi-electric aircraft integrated refrigeration system includes the following steps: Step 1, supplying air based on the main refrigeration path: acquiring the ambient air temperature and pressure, controlling the operating state of the first compressor based on the ambient air temperature and pressure, and controlling the first compressor to output air at a preset pressure to enter the evaporator for refrigeration; Step 2, supplying air based on the refrigeration cycle path: acquiring the evaporator inlet air temperature, controlling the refrigerant flow rate based on the air temperature to ensure that the air entering the cabin from the evaporator outlet reaches a preset temperature; acquiring the condenser inlet refrigerant temperature, and controlling the cold-end fuel flow rate based on the refrigerant temperature to fully cool the refrigerant; Step 3, supplying air based on the return cooling path: acquiring the cabin exhaust outlet pressure, controlling the operating state of the second compressor based on the cabin exhaust outlet pressure, and controlling the second compressor to output air at a preset pressure to enter the refrigeration cycle path to ensure a suitable and stable air supply pressure.

[0017] Preferably, the high-temperature, high-pressure subcooled liquid generated during the operation of the evaporator is throttled to an intermediate pressure gas-liquid two-phase state through a first-stage throttling valve and enters the intercooler. The gas phase enters the refrigeration compressor and mixes with the initially compressed refrigerant for cooling, thereby reducing the compressor's exhaust temperature. After compression, it enters the hot side of the condenser, where it exchanges heat with the fuel on the cold side of the condenser and then condenses. The liquid phase passes through a dryer filter and enters the second-stage throttling valve for isenthalpic depressurization refrigeration to obtain a low-temperature, low-pressure gas-liquid two-phase refrigerant. This low-temperature, low-pressure gas-liquid two-phase refrigerant is then sent to the evaporator to exchange heat with the air and evaporate. Finally, it enters the suction pipe of the refrigeration compressor for a new cycle.

[0018] Preferably, ambient air enters the first compressor for compression, then enters the evaporator for filtration and heat dissipation before being circulated into the cabin for cooling. The cabin exhaust is treated and then enters the recooler for cooling. It then enters the cooling turbine for adiabatic expansion and cooling, and outputs shaft power to drive the third compressor. The exhaust is sent to the electronics compartment for heat exchange with the cold plates of the electronics compartment to bear the heat load. It then enters the recooler to absorb heat, and is discharged outside the cabin after being drawn in and pressurized by the compressor.

[0019] The beneficial effects of this invention are:

[0020] 1. This invention uses an electrically driven compressor to directly draw air from the external environment through the air inlet on the fuselage, eliminating the need for engine bleed air. This solves the problem of engine bleed air being contaminated by fuel combustion products and oil system leaks. At the same time, it reduces the number of engine components, lowers complexity and cost, and increases reliability. The design of the engine power generation system is optimized, and the power generation efficiency is improved. Because bleed air is eliminated, the amount of air in the engine combustor is more complete, improving combustion efficiency and engine thrust.

[0021] 2. This invention uses fuel as the condenser cold source and is suitable for high Mach number aircraft.

[0022] 3. This invention makes full use of the cabin exhaust gas, which has a low temperature and a large flow rate. After treatment, the exhaust gas enters the reverse booster cooling system, effectively reducing the amount of external ambient air intake. The inlet gas temperature of the cooler is low, which effectively reduces the turbine inlet temperature and increases the system's cooling capacity to meet the increased cooling demand of the electronic equipment bay.

[0023] 4. This invention adopts an integrated cooling system for the cockpit electronic equipment compartment, which solves the problem of aircraft cooling source during hypersonic flight. It has a simple and efficient structure and improves the stability and reliability of system operation. Attached Figure Description

[0024] The accompanying drawings, which are provided to further illustrate the invention and form part of this application, are used to explain the invention and do not constitute an undue limitation thereof.

[0025] Figure 1This is a schematic diagram of an integrated refrigeration system based on a multi-electric aircraft.

[0026] Figure label:

[0027] 1-First compressor, 2-Evaporator, 3-Compressor, 4-Condenser, 5-First stage throttle valve, 6-Intercooler, 7-Dryer filter, 8-Second stage throttle valve, 9-Filter, 10-Adsorber, 11-Second compressor, 12-Recooler, 13-Third compressor, 14-Cooling turbine. Detailed Implementation

[0028] The present invention will be further described below with reference to embodiments. The following description represents only a portion of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0029] like Figure 1 As shown, an integrated refrigeration system based on a multi-electric aircraft according to the present invention includes a first compressor 1, an evaporator 2, a compressor 3, a condenser 4, a first-stage throttle valve 5, an intercooler 6, a dryer filter 7, a second-stage throttle valve 8, a filter 9, an adsorber 10, a second compressor 11, a recooler 12, a third compressor 13, and a cooling turbine 14.

[0030] Compressor 1 includes a gas inlet and a gas outlet;

[0031] Evaporator 2 includes a gas inlet, a gas outlet, a refrigerant inlet, and a refrigerant outlet;

[0032] The compressor 3 outlet is connected to the hot side inlet of the condenser 4 via a pipe. Fuel enters the cold side inlet of the condenser 4 via a pipe and is sent to the fuel chamber from the cold side outlet via a pipe.

[0033] Intercooler 6 includes a refrigerant inlet, a gaseous refrigerant outlet, and a liquid refrigerant outlet;

[0034] The second compressor 11 is connected to the cabin exhaust inlet, and a filter 9 and an adsorber 10 are installed in between to treat the exhaust.

[0035] The recirculating cooler 12 includes a cabin exhaust inlet, a cabin exhaust outlet, a return air inlet, and a return air outlet;

[0036] The inlet of cooling turbine 14 is connected to the cabin exhaust inlet of recooler 12, and the outlet is connected to the return air inlet of recooler 12.

[0037] The compressor 13 is connected to the return air outlet of the cooler 12, which pressurizes the gas and discharges it outside the cabin.

[0038] The integrated refrigeration system is divided into three branches: the main refrigeration path, the recirculation path, and the refrigeration cycle path.

[0039] The main refrigeration passage connects to the ambient air inlet and includes, in sequence, the first compressor 1, the evaporator 2, and the cabin, according to the direction of cold air flow.

[0040] The recirculation passage is located downstream of the exhaust outlet of the cabin and is used to cool the exhaust gas from the cabin. It includes a second compressor 11, a recirculation cooler 12 and a cooling turbine 14 in sequence according to the direction of cold air flow. The cooling turbine 14 exchanges heat with the cold plate of the electronic equipment compartment and then returns to the recirculation cooler 12. After being drawn in and pressurized by the third compressor 13, it is discharged outside the cabin.

[0041] The refrigeration cycle path connects to the refrigerant inlet and outlet of the evaporator 2, respectively. Following the refrigeration direction, it includes a compressor 3, a condenser 4, an intercooler 6, and a filter dryer 7. A primary throttling valve 5 connects the condenser 4 and the intercooler 6, while a secondary throttling valve 8 connects the filter dryer 7 and the evaporator 2. The intercooler 6 includes a refrigerant inlet, a gaseous refrigerant outlet, and a liquid refrigerant outlet. The compressor 3 outlet is connected to the hot-side inlet of the condenser 4 via a pipe. Fuel enters the cold-side inlet of the condenser 4 via a pipe and is then piped from the cold-side outlet to the fuel chamber.

[0042] The refrigeration system uses an electrically driven compressor to draw air directly from the environment through the fuselage air inlet. After being compressed to a certain pressure, the air is fully cooled by the evaporator 2 before entering the cabin for refrigeration. Between the cabin exhaust outlet and the second compressor 11, a filter 9 and an adsorber 10 are installed in sequence to remove exhaust smoke and dust. The exhaust gas is then compressed to a certain pressure by the second compressor 11 and used as the air source for the reverse boost refrigeration system.

[0043] This invention also provides a method for operating a multi-electric aircraft integrated refrigeration system.

[0044] Step 1, supplying air based on the main refrigeration path: obtain the ambient air temperature and pressure, control the operating state of the first compressor 1 according to the ambient air temperature and pressure, and control the first compressor 1 to output air at a preset pressure to enter the evaporator for refrigeration;

[0045] Step 2, based on the refrigeration cycle path: obtain the air temperature at the inlet of evaporator 2, and control the refrigerant flow rate according to the air temperature to ensure that the air entering the cabin from the outlet of evaporator 2 reaches the preset temperature for refrigeration.

[0046] Obtain the refrigerant temperature at the inlet of condenser 4, and control the fuel flow rate at the cold end based on the refrigerant temperature to fully cool the refrigerant;

[0047] Step 3, supplying air based on the cooling circuit: Obtain the cabin exhaust outlet pressure, and control the operation of the second compressor 11 according to the cabin exhaust outlet pressure to output preset pressure air into the cooling cycle circuit to ensure a suitable and stable air supply pressure.

[0048] like Figure 1 As shown, ambient air is compressed by compressor 1, enters evaporator 2 for filtration and heat dissipation, and then enters the cabin for cooling. Cabin exhaust is treated by filter 9 and adsorber 10 before entering cooler 12 for cooling, and then enters cooling turbine 14 for adiabatic expansion and cooling. The output shaft power drives compressor 13, which sends the exhaust to the electronics compartment for heat exchange with the cold plates of the electronics compartment to bear the heat load. It then enters cooler 12 to absorb heat, and is then drawn in and pressurized by compressor 13 before being discharged outside the cabin.

[0049] The high-temperature, high-pressure subcooled liquid is throttled to an intermediate pressure gas-liquid two-phase state through the first-stage throttling valve 5 and enters the intercooler 6. The gas phase enters the refrigeration compressor 3 and mixes with the initially compressed refrigerant for cooling, thereby reducing the discharge temperature of the compressor 3. After compression, it enters the hot side of the condenser 4 and condenses after exchanging heat with the fuel on the cold side of the condenser 4. The liquid phase passes through the dryer filter 7 and enters the second-stage throttling valve 8 for isenthalpic depressurization refrigeration. The resulting low-temperature, low-pressure gas-liquid two-phase refrigerant is then sent to the evaporator to exchange heat with the air and evaporate. It then enters the suction pipe of the refrigeration compressor to start a new cycle.

[0050] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0051] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An integrated refrigeration system for multi-electric aircraft, characterized in that, It includes the main refrigeration path, the return refrigeration path, and the refrigeration cycle path. The main refrigeration passage, in order of the direction of cold air flow, includes the first compressor (1), the evaporator (2) and the cabin; The cooling passage is located downstream of the exhaust outlet of the cabin and is used to cool the exhaust gas from the cabin. It includes a second compressor (11), a cooler (12) and a cooling turbine (14) in sequence according to the direction of cold air flow. The cooling turbine (14) exchanges heat with the cold plate of the electronic equipment compartment and returns to the cooler (12). It is then drawn in and pressurized by the third compressor (13) and discharged outside the cabin. The refrigeration cycle path is connected to the refrigerant inlet and refrigerant outlet of the evaporator (2) respectively. According to the refrigeration direction, it includes the compressor (3), condenser (4), intercooler (6), and dryer filter (7).

2. The integrated refrigeration system for multi-electric aircraft according to claim 1, characterized in that, A primary throttling valve (5) is provided between the condenser (4) and the intercooler (6), and a secondary throttling valve (8) is provided between the dryer filter (7) and the evaporator (2).

3. The integrated refrigeration system for multi-electric aircraft according to claim 1, characterized in that, A filter (9) and an adsorber (10) are sequentially installed between the exhaust outlet of the cabin and the second compressor (11) to treat the exhaust.

4. The integrated refrigeration system for multi-electric aircraft according to claim 1, characterized in that, The intercooler (6) includes a refrigerant inlet, a gaseous refrigerant outlet, and a liquid refrigerant outlet. The compressor (3) outlet is connected to the hot side inlet of the condenser (4) through a pipe. Fuel enters the cold side inlet of the condenser (4) through a pipe and is sent to the fuel chamber from the cold side outlet through a pipe.

5. The integrated refrigeration system for multi-electric aircraft according to claim 1, characterized in that, The refrigeration system is powered by an electric compressor that draws air directly from the environment through the fuselage air inlet. After being compressed to a certain pressure, the air is fully cooled by the evaporator (2) and then enters the cabin for refrigeration.

6. The integrated refrigeration system for multi-electric aircraft according to claim 1, characterized in that, The refrigerant is condensed in the condenser (4) by the fuel oil as a cold source.

7. The integrated refrigeration system for multi-electric aircraft according to claim 1, characterized in that, The cabin exhaust passes through a filter (9) and an adsorber (10) in sequence to remove exhaust smoke and dust. After being compressed to a certain pressure by the second compressor (11), it is used as the air source for the reverse pressure refrigeration system.

8. A method for operating a multi-electric aircraft integrated refrigeration system, characterized in that, The integrated refrigeration system for multi-electric aircraft as described in claim 1 includes the following steps: Step 1, supplying air based on the main refrigeration path: obtain the ambient air temperature and pressure, control the operation status of the first compressor (1) according to the ambient air temperature and pressure, and control the first compressor (1) to output preset pressure air to enter the evaporator for refrigeration; Step 2, based on the refrigeration cycle path: obtain the inlet air temperature of the evaporator (2), and control the refrigerant flow rate according to the air temperature to ensure that the air supplied to the cabin for refrigeration from the outlet of the evaporator (2) reaches the preset temperature; Obtain the refrigerant temperature at the inlet of the condenser (4), and control the cold end fuel flow rate according to the refrigerant temperature to fully cool the refrigerant; Step 3, supplying air based on the cooling circuit: obtain the cabin exhaust outlet pressure, and control the operation of the second compressor (11) according to the exhaust outlet pressure to control the second compressor (11) to output preset pressure air into the cooling cycle circuit to ensure a suitable and stable air supply pressure.

9. The operating method of the integrated refrigeration system for multi-electric aircraft according to claim 8, characterized in that, The high-temperature, high-pressure subcooled liquid formed by the operation of the evaporator (2) is throttled to the intermediate pressure gas-liquid two-phase state through the first-stage throttle valve (5) and enters the intercooler (6). The gas phase enters the refrigeration compressor (3) and mixes with the initially compressed refrigerant to cool it down, thereby reducing the exhaust temperature of the compressor (3). After compression, it enters the hot side of the condenser (4) and condenses after exchanging heat with the fuel on the cold side of the condenser (4). The liquid phase passes through the dryer filter (7) and enters the second-stage throttle valve (8) for isenthalpy-reduced pressure refrigeration to obtain a low-temperature, low-pressure gas-liquid two-phase refrigerant. The low-temperature, low-pressure gas-liquid two-phase refrigerant is sent into the evaporator (2) to exchange heat with the air and evaporate. Then it enters the suction pipe of the refrigeration compressor (3) for a new cycle.

10. The method of operating the integrated refrigeration system for multi-electric aircraft according to claim 8 or 9, characterized in that, After being treated, the cabin exhaust enters the recooler (12) to be cooled, and then enters the cooling turbine (14) for adiabatic expansion and cooling. The output shaft power drives the third compressor (13), which is sent to the electronic equipment compartment to exchange heat with the cold plate of the electronic equipment compartment to bear the heat load. Then it enters the recooler to absorb heat, and after being drawn in and pressurized by the compressor, it is discharged outside the cabin.

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