CN-122009504-A - Aircraft fuel thermal management system, control method and aircraft

CN122009504ACN 122009504 ACN122009504 ACN 122009504ACN-122009504-A

Abstract

The application discloses an aircraft fuel oil thermal management system, a control method and an aircraft, wherein the thermal management system comprises an aircraft oil return branch, an engine oil return branch and an overlapping refrigerating system, the input end of the aircraft oil return branch is connected with the output end of an aircraft thermal management main way, the input end of the engine oil return branch is connected with the output end of the engine oil return main way, the output end of the aircraft oil return branch is connected with the output end of the engine oil return branch, the overlapping refrigerating system comprises a low-temperature refrigerating loop, a high-temperature refrigerating loop and an intermediate circulating loop, the first input end of the low-temperature refrigerating loop is connected with the common end of the aircraft oil return branch and the engine oil return branch, the first output end of the low-temperature refrigerating loop is used for being connected with the input end of the engine oil return main way, and the first output end of the high-temperature refrigerating loop is used for being connected with the input end of a combustion chamber. The scheme can effectively reduce the temperature of the fuel tank and improve the heat sink utilization rate of the fuel.

Inventors

LIN YUANFANG
YANG SHIYU
LIANG XINGANG

Assignees

清华大学

Dates

Publication Date: 20260512
Application Date: 20260325

Claims (10)

1. The aircraft fuel oil thermal management system is characterized by comprising an aircraft oil return branch, an engine oil return branch and an overlapping refrigerating system; The input end of the aircraft oil return branch is connected with the output end of the aircraft thermal management main road, the input end of the engine oil return branch is connected with the output end of the engine thermal management main road, and the output end of the aircraft oil return branch is connected with the output end of the engine oil return branch; The cascade refrigeration system comprises a low-temperature refrigeration loop, a high-temperature refrigeration loop and an intermediate circulation loop, wherein a first input end of the low-temperature refrigeration loop is connected with a public end of an aircraft oil return branch and an engine oil return branch, a first output end of the low-temperature refrigeration loop is used for being connected with an input end of a fuel oil return main, a first input end of the high-temperature refrigeration loop is used for being connected with an input end of the engine oil return branch, a first output end of the high-temperature refrigeration loop is used for being connected with an input end of a combustion chamber, a first input end of the intermediate circulation loop is connected with a second output end of the low-temperature refrigeration loop, a first output end of the intermediate circulation loop is connected with a second input end of the high-temperature refrigeration loop, and a second output end of the intermediate circulation loop is connected with a second input end of the high-temperature refrigeration loop.
2. The system of claim 1, wherein the low temperature refrigeration circuit comprises a first expansion valve, a first evaporative heat exchanger, and a first compressor, the high temperature refrigeration circuit comprises a first condensing heat exchanger, a second expansion valve, and a second compressor, and the intermediate circulation circuit comprises a second evaporative heat exchanger, a circulation pump, and a second condensing heat exchanger; The first end of the first evaporation heat exchanger is connected with the first end of the second condensation heat exchanger through the first compressor, the second end of the second condensation heat exchanger is connected with the second end of the first evaporation heat exchanger through the first expansion valve, the first end of the first condensation heat exchanger is connected with the first end of the second evaporation heat exchanger through the second expansion valve, the second end of the second evaporation heat exchanger is connected with the second end of the first condensation heat exchanger through the second compressor, the third end of the second evaporation heat exchanger is connected with the third end of the second condensation heat exchanger, and the fourth end of the second condensation heat exchanger is connected with the fourth end of the second evaporation heat exchanger through the circulating pump.
3. The system of claim 1, wherein the working medium of the low temperature refrigeration circuit is pentafluoropropane R245fa, the working medium of the high temperature refrigeration circuit is methanol, and the working medium of the intermediate circulation circuit is polyalphaolefin PAO.
4. The system of claim 3, wherein the aircraft thermal management bus comprises a numerical control system, a ring control system, a booster fuel pump and a hydraulic system, wherein the input end of the numerical control system is used for being connected with a fuel tank, the output end of the numerical control system is connected with the input end of the hydraulic system sequentially through the ring control system and the booster fuel pump, and the output end of the hydraulic system is used for being connected with the input end of the aircraft oil return branch; The engine thermal management main way comprises a main fuel pump and a fuel/lubricating oil heat exchanger, wherein the output end of the hydraulic system is used for being connected with the input end of the fuel/lubricating oil heat exchanger through the main fuel pump, and the output end of the fuel/lubricating oil heat exchanger is used for being connected with the input end of the engine oil return branch; The fuel return main path comprises a fuel/air heat exchanger, wherein the input end of the fuel/air heat exchanger is used for being connected with the first output end of the low-temperature refrigeration loop, and the output end of the fuel/air heat exchanger is used for being connected with the fuel tank.
5. The system of any one of claims 1 to 4, further comprising a controller; The controller is used for obtaining a first operation parameter according to the fuel temperature limit and the lubricating oil temperature limit, and obtaining a second operation parameter according to the superheat degree of a condensation outlet of the working medium, the superheat degree of an evaporation outlet of the working medium and the heat sink utilization rate of the fuel; And controlling the aircraft oil return branch and the engine oil return branch to operate under the first operating parameter, and controlling the cascade refrigeration system to operate under the second operating parameter.
6. The system of claim 5, wherein the controller for obtaining the first operating parameter and the second operating parameter comprises: The controller is used for obtaining the mass flow of the fuel flowing into the aircraft oil return branch and the mass flow of the fuel flowing into the engine oil return branch through an energy conservation equation and a mass conservation equation, and obtaining the condensing pressure of the working medium, the evaporating pressure of the working medium, the circulating flow of the working medium and the circulating maximum temperature through a thermodynamic state equation and the energy conservation equation.
7. The control method of the aircraft fuel oil thermal management system is characterized in that the system comprises an aircraft oil return branch, an engine oil return branch and an overlapping refrigerating system; The input end of the aircraft oil return branch is connected with the output end of the aircraft thermal management main road, the input end of the engine oil return branch is connected with the output end of the engine thermal management main road, and the output end of the aircraft oil return branch is connected with the output end of the engine oil return branch; The control method comprises the following steps: The method comprises the steps of obtaining a first operation parameter according to a fuel oil temperature limit and a lubricating oil temperature limit, obtaining a second operation parameter according to the superheat degree of a condensation outlet of a working medium, the superheat degree of an evaporation outlet of the working medium and the heat sink utilization rate of fuel oil; The cascade refrigeration system comprises a low-temperature refrigeration loop, a high-temperature refrigeration loop and an intermediate circulation loop, wherein a first input end of the low-temperature refrigeration loop is connected with a public end of an aircraft oil return branch and an engine oil return branch, a first output end of the low-temperature refrigeration loop is used for being connected with an input end of a fuel oil return main, a first input end of the high-temperature refrigeration loop is used for being connected with an input end of the engine oil return branch, a first output end of the high-temperature refrigeration loop is used for being connected with an input end of a combustion chamber, a first input end of the intermediate circulation loop is connected with a second output end of the low-temperature refrigeration loop, a first output end of the intermediate circulation loop is connected with a second input end of the high-temperature refrigeration loop, and a second output end of the intermediate circulation loop is connected with a second input end of the high-temperature refrigeration loop.
8. The control method of claim 7, wherein the obtaining the first operating parameter and the second operating parameter comprises: And obtaining the condensation pressure of the working medium, the evaporation pressure of the working medium, the circulation flow of the working medium and the circulation maximum temperature through a thermodynamic state equation and a thermal balance equation.
9. The control method of claim 7, wherein controlling the aircraft oil return branch and the engine oil return branch to operate at the first operating parameter and controlling the cascade refrigeration system to operate at the second operating parameter comprises: And controlling the aircraft oil return branch and the engine oil return branch to operate under the first operating parameter according to a proportional-integral-derivative algorithm, and controlling the cascade refrigeration system to operate under the second operating parameter.
10. An aircraft comprising the aircraft fuel thermal management system provided in any one of claims 1 to 6, further comprising: The system comprises an aircraft thermal management main way, an engine thermal management main way, a fuel return main way, a fuel tank and a combustion chamber.

Description

Aircraft fuel thermal management system, control method and aircraft Technical Field The application relates to the technical field of aviation, in particular to an aircraft fuel thermal management system, a control method and an aircraft. Background When the aircraft is operating properly, both the aircraft and the engines generate significant thermal loads. In the related art, the aircraft mainly uses fuel as a main heat sink, namely, the fuel in the fuel tank is utilized to cool the aircraft and the engine in turn, and the fuel more than the requirement of the combustion chamber is cooled by ram air and then returned to the fuel tank. However, in order to cool each subsystem of the aircraft sufficiently, a large amount of fuel is required for cooling. On the one hand, the temperature of the fuel flowing into the combustion chamber is lower, so that the waste of a fuel heat sink is caused, and on the other hand, the flow limit of the ram air can reduce the heat dissipation efficiency of the fuel, so that the temperature of the fuel tank is quickly increased, and the comprehensive heat management performance of the aircraft is poor. Disclosure of Invention In view of the above, the application provides an aircraft fuel thermal management system, a control method and an aircraft, which can effectively reduce the temperature of a fuel tank and improve the heat sink utilization rate of fuel. In order to solve the problems, the technical scheme provided by the application is as follows: in a first aspect of the application, an aircraft fuel thermal management system is provided, comprising an aircraft oil return branch, an engine oil return branch and an cascade refrigeration system; The input end of the aircraft oil return branch is connected with the output end of the aircraft thermal management main road, the input end of the engine oil return branch is connected with the output end of the engine thermal management main road, and the output end of the aircraft oil return branch is connected with the output end of the engine oil return branch; the cascade refrigeration system comprises a low-temperature refrigeration loop, a high-temperature refrigeration loop and an intermediate circulation loop, wherein a first input end of the low-temperature refrigeration loop is connected with a common end of an aircraft oil return branch and an engine oil return branch, a first output end of the low-temperature refrigeration loop is used for being connected with an input end of a fuel oil return main, a first input end of the high-temperature refrigeration loop is used for being connected with an input end of the engine oil return branch, a first output end of the high-temperature refrigeration loop is used for being connected with an input end of a combustion chamber, a first input end of the intermediate circulation loop is connected with a second output end of the low-temperature refrigeration loop, a first output end of the intermediate circulation loop is connected with a second input end of the low-temperature refrigeration loop, and a second input end of the intermediate circulation loop is connected with a second output end of the high-temperature refrigeration loop. In one possible implementation, the low-temperature refrigeration loop comprises a first expansion valve, a first evaporation heat exchanger and a first compressor, the high-temperature refrigeration loop comprises a first condensation heat exchanger, a second expansion valve and a second compressor, and the intermediate circulation loop comprises a second evaporation heat exchanger, a circulation pump and a second condensation heat exchanger; The first end of the first evaporation heat exchanger is connected with the first end of the second condensation heat exchanger through a first compressor, the second end of the second condensation heat exchanger is connected with the second end of the first evaporation heat exchanger through a first expansion valve, the first end of the first condensation heat exchanger is connected with the first end of the second evaporation heat exchanger through a second expansion valve, the second end of the second evaporation heat exchanger is connected with the second end of the first condensation heat exchanger through a second compressor, the third end of the second evaporation heat exchanger is connected with the third end of the second condensation heat exchanger, and the fourth end of the second condensation heat exchanger is connected with the fourth end of the second evaporation heat exchanger through a circulating pump. In one possible implementation, the working medium of the low-temperature refrigeration circuit is pentafluoropropane R245fa, the working medium of the high-temperature refrigeration circuit is methanol, and the working medium of the intermediate circulation circuit is polyalphaolefin PAO. In one possible implementation mode, the aircraft thermal management main way comprises a numerical contro