Cooling system for equipment in aircraft cabin

Abstract

The invention relates to a cooling system for equipment in an aircraft cabin. The cooling system comprises a coolant supply system, a measurement and control system and a ground environment simulation system, the coolant supply system and the measurement and control system realize interconnection and cooperation through a gas circuit and a signal circuit, and are jointly connected with the interior of the ground environment simulation system so as to complete sweating cooling and temperature regulation experiments under a controlled air pressure condition; the coolant supply system is used for monitoring coolant mass flow, the measurement and control system is used for realizing closed-loop control of the coolant supply system, and the ground environment simulation system is used for simulating air pressure environments in the cabin at different flight heights. The physical mechanism of phase change sweating cooling under the conditions of low air pressure and high heat flow is disclosed, the effectiveness of closed-loop flow regulation in the aspects of prolonging the cooling time, improving the temperature control precision and reducing the liquid consumption is verified, and an experimental basis and technical support are provided for optimal design of a thermal management system in a hypersonic aircraft cabin.

Description

Technical Field

[0001] This invention belongs to the field of aerospace thermal protection and temperature control systems, and specifically relates to a cooling system for equipment inside an aircraft cabin. Background Technology

[0002] With the evolution of near-space vehicle missions, the thermal barrier problem has shifted from instantaneous high heat flux density to a sustained thermal environment challenge characterized by long-term, high total heat accumulation. Under long-duration, wide-speed-range, and complex operating conditions, the vehicle's cabin walls are subjected to intense aerodynamic heating, and the near-vacuum environment inside the cabin renders traditional heat dissipation methods ineffective. This is particularly true for high-power electronic equipment, where heat cannot be effectively dissipated, seriously threatening system stability. Sweating cooling, which relies on coolant penetration to the surface of porous media to remove heat, offers advantages such as low mass burden, reusability, and high cooling efficiency, and is considered a highly promising thermal management method for hypersonic vehicles. Current research on sweating cooling focuses on the flow, heat transfer, and phase change processes within porous media, with most work concentrating on steady-state characteristic analysis under constant coolant flow conditions. However, hypersonic vehicles face significant time-varying heat flux in actual operation, and under complex internal and external disturbances, relying solely on constant flow cooling is insufficient to meet temperature control requirements. Therefore, a sweating cooling control system is needed to dynamically adjust the coolant flow rate through control algorithms, thereby significantly improving coolant utilization efficiency. However, dynamic experimental research on actual operating conditions under low-pressure environments and the introduction of flow control strategies is still relatively limited, making it difficult to fully support its engineering application in thermal protection within hypersonic vehicle cabins.

[0003] Therefore, there is an urgent need for a cooling system for aircraft cabin equipment that can reproduce flight conditions in a low-pressure environment on the ground and improve coolant utilization by dynamically adjusting the flow rate. This would solve the problems in existing research that cannot simultaneously address low-pressure environments, long cooling times, and closed-loop flow rate regulation, and achieve effective heat dissipation and temperature control for cabin electrical equipment. Summary of the Invention

[0004] This invention proposes a cooling system for in-cabin equipment to solve the heat dissipation problem of long-endurance hypersonic aircraft.

[0005] This invention relates to a cooling system for aircraft cabin equipment, comprising: a coolant supply system, a measurement and control system, and a ground environment simulation system; the coolant supply system and the measurement and control system are interconnected and coordinated through air paths and signal lines, and are jointly connected to the interior of the ground environment simulation system to complete sweating cooling and temperature regulation experiments under controlled air pressure conditions; the coolant supply system is used to monitor the mass flow rate of the coolant, the measurement and control system is used to achieve closed-loop control of the coolant supply system, and the ground environment simulation system is used to simulate the cabin air pressure environment at different flight altitudes.

[0006] Furthermore, the coolant supply system includes a storage tank, an injection pump, a solenoid valve, and a flow meter. The storage tank serves as the starting point of the coolant supply system and is connected to the inlet of the injection pump. The outlet of the injection pump is sequentially connected to the flow meter via the solenoid valve. The storage tank is used to store the coolant, the injection pump is used to adjust the coolant output rate, the solenoid valve dynamically adjusts the coolant injection flow rate by receiving signals from a microprocessor, and the flow meter is connected to the porous medium used in the experiment. The flow meter is used to dynamically monitor the liquid supply process in real time.

[0007] Furthermore, the cooling medium is water or a water-based medium.

[0008] Furthermore, the measurement and control system includes a digital acquisition module, a microprocessor, and a PC. The input end of the digital acquisition module is connected to the flow meter, the output end of the digital acquisition module is connected to the microprocessor, the other end of the microprocessor communicates with the PC, and the microprocessor outputs pulse signals to the solenoid valve to adjust the opening and closing state of the solenoid valve by connecting to the solenoid valve.

[0009] Furthermore, the microprocessor incorporates threshold-hysteresis closed-loop control logic to drive the solenoid valve.

[0010] The microprocessor drives the solenoid valve using pulse width modulation.

[0011] Furthermore, the PC is equipped with experimental process control and data management software to remotely send out thresholds, hysteresis, PWM duty cycle / cycle, vacuum target pressure, and electric heater power.

[0012] Furthermore, the ground environment simulation system includes a vacuum pump, a sealed vacuum chamber, a pressure sensor, an electric heater, and a K-type thermocouple. The vacuum pump is connected to the sealed vacuum chamber to form an internal pressure environment. The electric heater, the K-type thermocouple, and the porous medium are all housed within the sealed vacuum chamber. The sealed vacuum chamber is equipped with a pressure sensor and a pressure relief valve. The pressure sensor is connected to a digital acquisition module, which collects pressure signals from the pressure sensor. A microprocessor is connected to the digital acquisition module, and the microprocessor controls the vacuum pump to start, stop, or throttle based on the signals from the pressure sensor.

[0013] Furthermore, the electric heater is a PTC heating element, and the electric heater is arranged in contact with the bottom surface of the porous medium to provide a constant or set heat flux density; the sealed vacuum chamber is a stainless steel structure, with a built-in electrical aviation plug for the introduction of K-type thermocouples and electric heaters; the pump is a 2XZ-4 type rotary vane vacuum pump; the porous medium is metal foam or sintered porous body.

[0014] Furthermore, the K-type thermocouple is fixed to the measuring surface of the porous medium; the K-type thermocouple includes two types: upper surface measuring point thermocouple and lower surface measuring point thermocouple. The upper surface measuring point thermocouple is used for closed-loop temperature control feedback, and the lower surface measuring point thermocouple is used to monitor heating input and thermal conductivity response.

[0015] Furthermore, the aircraft cabin equipment cooling system includes two operating modes: a closed-loop temperature control mode and a constant flow mode. The closed-loop temperature control mode uses the surface temperature of the porous medium as feedback and controls the solenoid valve through a combination of threshold-hysteresis and PWM. The constant flow mode provides a constant mass flow rate through an injection pump, with the solenoid valve in a normally open state, and is used for benchmark comparison experiments.

[0016] Beneficial effects

[0017] This invention proposes a cooling system for in-cabin equipment of a spacecraft, reveals the physical mechanism of phase change sweating cooling under low pressure and high heat flux conditions, and verifies the effectiveness of closed-loop flow regulation in extending cooling time, improving temperature control accuracy and reducing liquid consumption. It provides experimental basis and technical support for the optimized design of thermal management system in hypersonic spacecraft cabins. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the aircraft cabin equipment cooling system of the present invention;

[0019] Figure 2 This is a timing diagram of the experimental process for the cooling system of the aircraft cabin equipment of the present invention;

[0020] Figure 3 This is a schematic diagram of the sweating cooling control process when the cabin air pressure is 0.1 MPa, provided in an embodiment of the present invention.

[0021] Figure 4 A schematic diagram of the sweating cooling control process when the cabin air pressure is 0.15 MPa, provided for an embodiment of the present invention;

[0022] Figure 5 A schematic diagram of the sweating cooling control process for a total of 15 ml of coolant in the aircraft cabin, provided in an embodiment of the present invention;

[0023] Figure 6 A schematic diagram of the sweating cooling control process for a total of 20 ml of coolant in the aircraft cabin, provided in an embodiment of the present invention;

[0024] Figure 7 A schematic diagram of the sweating cooling control process for a total of 25 ml of coolant in the aircraft cabin, provided in an embodiment of the present invention;

[0025] Figure 8This is a schematic diagram of the sweating cooling control process for a total of 30 ml of coolant in the aircraft cabin, as provided in an embodiment of the present invention. Detailed Implementation

[0026] The following combination Figures 1 to 8 This implementation method will be described in detail.

[0027] This invention constructs a closed-loop temperature-controlled active flow regulation system on a ground-based vacuum experimental platform. Using porous media as the research object, it conducts phase change perspiration cooling experiments under low-pressure conditions, achieving simulation and control mechanism research on the thermal protection conditions inside a hypersonic vehicle cabin. During the experiment, a sealed vacuum chamber is used to reproduce the low-pressure and high-temperature environment. The porous media acts as a cooling channel, facilitating the phase change permeation and evaporation of the coolant. A solenoid valve dynamically supplies coolant under closed-loop commands from a microprocessor. This system can monitor the surface temperature of the porous media in real time and dynamically adjust the coolant injection amount according to a set threshold, thereby maintaining stable operation of the cooling process.

[0028] This invention relates to a cooling system for aircraft cabin equipment, comprising: a coolant supply system, a measurement and control system, and a ground environment simulation system; the coolant supply system and the measurement and control system are interconnected and coordinated through air paths and signal lines, and are jointly connected to the interior of the ground environment simulation system to complete sweating cooling and temperature regulation experiments under controlled air pressure conditions; the coolant supply system is used to monitor the mass flow rate of the coolant, the measurement and control system is used to achieve closed-loop control of the coolant supply system, and the ground environment simulation system is used to simulate the cabin air pressure environment at different flight altitudes.

[0029] The coolant supply system includes a reservoir, a syringe pump, a solenoid valve, and a flow meter. The reservoir, serving as the starting point of the system, is connected to the inlet of the syringe pump. The outlet of the syringe pump is sequentially connected to the flow meter via the solenoid valve. The reservoir stores the coolant; water or a water-based coolant is used in the experiment. It is stored in a liquid state under normal pressure and room temperature conditions and delivered to the surface of the porous media via a polyethylene pipe. The syringe pump adjusts the coolant output rate. The solenoid valve dynamically regulates the coolant injection flow rate by receiving signals from a microprocessor. The flow meter is connected to the porous media used in the experiment and is used for dynamic real-time monitoring of the supply process.

[0030] The measurement and control system includes a digital acquisition module, a microprocessor, and a PC. The input end of the digital acquisition module is connected to the flow meter, and the output end of the digital acquisition module is connected to the microprocessor. The other end of the microprocessor communicates with the PC. The microprocessor outputs pulse signals to the solenoid valve through a connection to regulate the opening and closing state of the solenoid valve.

[0031] The microprocessor incorporates threshold-hysteresis closed-loop control logic. This logic drives the solenoid valve to open when the porous media surface temperature is greater than or equal to the upper threshold, and closes it when the temperature is less than or equal to the lower threshold. The upper and lower thresholds, as well as the hysteresis bandwidth, can be adjusted by parameters sent from the PC. The microprocessor drives the solenoid valve using pulse width modulation (PWM). The PWM duty cycle and period can be adaptively tuned according to temperature deviation and temperature change rate to balance cooling rate and liquid consumption.

[0032] The PC terminal is configured with constant temperature or constant heat flow mode and records power and temperature data. It is equipped with experimental process control and data management software, featuring parameter setting, real-time monitoring, anomaly alarms, data storage, and report generation functions. It also supports remote control of threshold values, hysteresis, PWM duty cycle / cycle, vacuum target pressure, and electric heater power.

[0033] The ground environment simulation system includes a vacuum pump, a sealed vacuum chamber, a pressure sensor, an electric heater, and a K-type thermocouple. The vacuum pump is connected to the sealed vacuum chamber to create an internal pressure environment. The electric heater, K-type thermocouple, and porous medium are all housed within the sealed vacuum chamber. The sealed vacuum chamber is equipped with a pressure sensor and a pressure relief valve. The pressure sensor is connected to a digital acquisition module, which collects pressure signals from the pressure sensor. A microprocessor is connected to the digital acquisition module, and the microprocessor controls the vacuum pump to start, stop, or throttle based on the pressure sensor signals.

[0034] The electric heater is a PTC heating element, which is arranged in contact with the bottom surface of the porous medium to provide a constant or set heat flux density, suitable for simulating steady-state heat sources in low-pressure environments.

[0035] The sealed vacuum chamber is made of stainless steel and has an internal electrical aviation plug for the introduction of K-type thermocouples and electric heaters.

[0036] The vacuum pump is a 2XZ-4 type rotary vane vacuum pump, which is used as a pumping device to simulate the low-pressure cabin flight environment.

[0037] The porous medium is a metal foam or a sintered porous body. The porous medium can be replaced and installed to adapt to cooling studies with different permeabilities and specific surface areas.

[0038] Type K thermocouples are fixed to the measuring surface of a porous medium. After being amplified and converted by the data acquisition module, the data is input to a microprocessor. Type K thermocouples include two types: upper surface measuring thermocouples and lower surface measuring thermocouples. Upper surface measuring thermocouples are used for closed-loop temperature control feedback, while lower surface measuring thermocouples are used to monitor heating input and thermal conductivity response.

[0039] The aircraft cabin equipment cooling system includes two operating modes: closed-loop temperature control mode and constant flow mode. The closed-loop temperature control mode uses the surface temperature of the porous medium sample as feedback and controls the solenoid valve through a combination of threshold-hysteresis and PWM. The constant flow mode provides a constant mass flow rate through an injection pump, with the solenoid valve in a normally open state, and is used for benchmark comparison experiments.

[0040] The operating procedure of the aircraft cabin equipment cooling system is as follows: Figure 2 As shown, the experiment is mainly divided into three stages: pretreatment, experimental execution, and post-processing. In the pretreatment stage, the connections of all components of the cooling system are confirmed to be secure, and the sealing of the piping system is thoroughly checked to prevent leakage under low-pressure conditions. Subsequently, the measurement and control system is calibrated to ensure high accuracy and repeatability of the data acquired during the experiment. Upon entering the experimental stage, the sealed vacuum chamber is closed, and the vacuum pump is activated to gradually reduce the pressure inside the chamber to a preset value, simulating a high-altitude, low-pressure environment. Then, the electric heater is activated to continuously heat the lower surface of the porous medium, while its upper surface temperature is monitored in real time. During the experiment, the microprocessor uses a K-type thermocouple feedback signal to achieve closed-loop control of the solenoid valve, thereby dynamically adjusting the coolant injection flow rate. Under the combined action of gravity and surface tension, the coolant enters the porous material through capillary permeation and rapidly vaporizes in the low-pressure environment, releasing latent heat and effectively reducing the surface temperature of the porous medium, maintaining it within a set threshold range. Throughout the process, the PC continuously records surface temperature and coolant mass flow rate data to evaluate the temperature control stability and thermal management performance of the cooling system. In the post-processing stage, the solenoid valve, electric heater, coolant supply system, and vacuum pump are shut down in a safe sequence. Subsequently, the measurement and control system is shut down, and the ground environment simulation system is inspected and maintained to ensure that the experimental system is in good condition and that the data recording is complete and reliable.

[0041] Principle of Aircraft Cabin Equipment Cooling System

[0042] The closed-loop control of the aircraft cabin equipment cooling system relies on the real-time coupling of temperature measurement and flow regulation. During the experiment, a K-type thermocouple was fixed to the surface of a porous medium to collect temperature signals in real time, which were then transmitted to a digital acquisition module. The collected temperature signals were analyzed by a microprocessor and compared with preset temperature thresholds. When the surface temperature exceeded the upper threshold, the microprocessor issued a command to open the solenoid valve, and the coolant, under the action of the injection pump, was delivered to the surface of the porous medium through a flow meter. The coolant seeped into the pores under capillary action and rapidly vaporized, carrying away latent heat and achieving cooling. When the surface temperature dropped below the lower threshold, the microprocessor controlled the solenoid valve to close, stopping the coolant supply. Through this threshold-hysteresis control mode, the coolant injection and surface temperature were dynamically linked, forming a closed-loop feedback regulation. This principle can effectively suppress temperature fluctuations, improve temperature control stability, reduce coolant consumption, and ensure the efficient operation of the cooling system during long-endurance missions.

[0043] The principle of simulating the low-pressure thermal environment at ground level

[0044] Within a sealed vacuum chamber, a pump continuously evacuates air, gradually reducing the chamber pressure. When the pressure inside the chamber falls below atmospheric pressure, the mean free path of the gas molecules increases, and the gas density decreases significantly, thus simulating the low-pressure environment inside a high-altitude aircraft cabin. Due to the reduced pressure, the saturation temperature of the coolant decreases accordingly, allowing the liquid to undergo phase change vaporization at a lower temperature, thereby accelerating the phase change heat dissipation process. Simultaneously, an electric heater, acting as a constant heat source, is installed on the lower surface of the porous medium, generating a stable heat flow input in the low-pressure environment. In this way, the low-pressure thermal environment inside an aircraft cabin can be simulated under ground conditions, reproducing the heat dissipation mechanism and coolant vaporization behavior under high-altitude conditions.

[0045] Example

[0046] A schematic diagram of the overall structure of the aircraft cabin equipment cooling system of this invention is shown below. Figure 1 As shown, water or a water-based working medium was used as the cooling medium in the experiment. It was stored in liquid form under normal pressure and room temperature conditions and delivered to the surface of the experimental sample through polyethylene pipes with an inner diameter of no more than 0.5 mm. To ensure the system's sealing and structural stability, the pipe interfaces were reinforced with heat fusion or sealing gaskets to adapt to low-pressure conditions. An injection pump was used to adjust the coolant output rate, and a solenoid valve dynamically adjusted the coolant injection flow rate by receiving signals from a microprocessor. A flow meter was connected to the porous medium used in the experiment; the flow meter was used for dynamic, real-time, and high-precision monitoring of the liquid supply process.

[0047] The flow meter uses an SLQ-QT500 flow sensor with a sampling frequency of 220Hz. The instantaneous mass flow rate output by the flow meter is recorded synchronously with the solenoid valve's on / off status. The microprocessor timestamps the two data and uploads them to the PC to calculate the total coolant consumption and the heat absorption efficiency per unit mass.

[0048] The solenoid valve is an SMC SX90 thin solenoid valve, which measures 38 mm × 10 mm × 10 mm, weighs only 10 g, has a flow coefficient of 0.25, and a maximum flow capacity of 2.7 g / s. It is suitable for intermittent liquid supply control.

[0049] The electric heater uses a PTC heating element with dimensions of 100 mm × 100 mm × 2 mm, a rated voltage of 24 V, a heating power of 0.45 W / cm², a temperature range of 213.15 K to 473.15 K, and a dry-burning temperature of approximately 423.15 K. It is arranged in surface contact with the bottom surface of the porous medium to provide a constant or settable heat flux density, suitable for simulating steady-state heat sources under low-pressure environments.

[0050] The K-type thermocouple is fixed to the measuring surface of a porous medium with insulating tape. The temperature measuring range is -73.15 K to 1623.15 K. The signal is amplified and converted by the data acquisition module and then input into the microprocessor.

[0051] The vacuum pump uses a 2XZ-4 type rotary vane vacuum pump, which can reduce the pressure in the sealed vacuum chamber to no higher than [the pressure is not specified in the original text].

[0052] The pressure is 0.010 MPa and is maintained stably within a preset range, serving as an air extraction device to simulate the low-pressure cabin flight environment.

[0053] The porous medium is a metal foam or sintered porous body with a porosity of 0.2 to 0.6 and an average pore size of 10 μm to 200 μm; the sample can be replaced and installed to adapt to cooling studies with different permeabilities and specific surface areas.

[0054] according to Figure 2 The experiment was conducted using the timing sequence shown, and the results were recorded on the PC. For example... Figure 3 As shown, when the gas pressure inside the sealed vacuum chamber is 0.1 MPa and the electric heating element is kept at a constant temperature of 400 K, the closed-loop temperature control mode of this invention is used for temperature control, and the K-type thermocouple measures the transient temperature curves of the upper and lower surfaces of the porous medium. Figure 4 As shown, when the air pressure inside the sealed vacuum chamber is 0.15MPa and the electric heating element is kept at a constant temperature of 400K, the temperature is controlled by the closed-loop temperature control mode in this invention, and the transient temperature curves of the upper and lower surfaces of the porous medium are measured by the K-type thermocouple.

[0055] like Figure 5, 6 As shown in Figures 7 and 8, with a gas pressure of 0.1 MPa and an electric heating element at a constant temperature of 400 K within a sealed vacuum chamber, the closed-loop temperature control mode of this invention was used for temperature control. The K-type thermocouple measured the transient temperature curves of the upper and lower surfaces of the porous medium. The switching temperatures of the solenoid valve were set by the microprocessor to 314.15 K and 324.15 K, and the flow meter output coolant consumption data in real time. By controlling the total coolant volume between 15 ml and 30 ml, and utilizing the in-chamber equipment cooling system of this invention in a coordinated connection, the study of the sweating cooling temperature control characteristics under limited cold source conditions was achieved.

[0056] in, Figure 5 The sweating cooling regulation process corresponds to a total coolant volume of 15ml in the aircraft cabin. Figure 6 The sweating cooling regulation process corresponds to a total coolant volume of 20ml in the aircraft cabin. Figure 7 The sweating cooling regulation process corresponds to a total coolant volume of 25ml in the aircraft cabin. Figure 8 The sweating cooling control process corresponds to a total coolant volume of 30ml in the aircraft cabin.

[0057] The above description of the present invention is only a preferred embodiment of the present invention and is not intended to limit the implementation of the present invention. Those skilled in the art can easily make corresponding modifications or alterations based on the main concept and spirit of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of protection claimed in the claims.

Claims

1. A cooling system for equipment inside an aircraft cabin, characterized in that, include: The system includes a coolant supply system, a telemetry and control system, and a ground environment simulation system. The coolant supply system and the telemetry and control system are interconnected and coordinated through air circuits and signal lines, and are jointly connected to the ground environment simulation system to complete sweating cooling and temperature regulation experiments under controlled air pressure conditions. The coolant supply system is used to monitor the mass flow rate of the coolant, the telemetry and control system is used to achieve closed-loop control of the coolant supply system, and the ground environment simulation system is used to simulate the cabin air pressure environment at different flight altitudes.

2. The aircraft cabin equipment cooling system according to claim 1, characterized in that, The coolant supply system includes a storage tank, an injection pump, a solenoid valve, and a flow meter. The storage tank serves as the starting point of the coolant supply system and is connected to the inlet of the injection pump. The outlet of the injection pump is sequentially connected to the flow meter via the solenoid valve. The storage tank is used to store the coolant, the injection pump is used to adjust the coolant output rate, the solenoid valve dynamically adjusts the coolant injection flow rate by receiving signals from a microprocessor, and the flow meter is connected to the porous medium used in the experiment. The flow meter is used to dynamically monitor the liquid supply process in real time.

3. The aircraft cabin equipment cooling system according to claim 2, characterized in that, The cooling medium is water or a water-based medium.

4. The aircraft cabin equipment cooling system according to claim 1, characterized in that, The measurement and control system includes a digital acquisition module, a microprocessor, and a PC. The input end of the digital acquisition module is connected to the flow meter, and the output end of the digital acquisition module is connected to the microprocessor. The other end of the microprocessor communicates with the PC. The microprocessor outputs pulse signals to the solenoid valve through a connection to the solenoid valve to adjust the opening and closing state of the solenoid valve.

5. The aircraft cabin equipment cooling system according to claim 4, characterized in that, The microprocessor has built-in threshold-hysteresis closed-loop control logic to drive the solenoid valve. The microprocessor drives the solenoid valve using pulse width modulation.

6. The aircraft cabin equipment cooling system according to claim 4, characterized in that, The PC is equipped with experimental process control and data management software to remotely send out thresholds, hysteresis, PWM duty cycle / cycle, vacuum target pressure and heater power.

7. The aircraft cabin equipment cooling system according to claim 2, characterized in that, The ground environment simulation system includes a vacuum pump, a sealed vacuum chamber, a pressure sensor, an electric heater, and a K-type thermocouple. The vacuum pump is connected to the sealed vacuum chamber to create an internal pressure environment. The electric heater, the K-type thermocouple, and the porous medium are all housed within the sealed vacuum chamber. The sealed vacuum chamber is equipped with a pressure sensor and a pressure relief valve. The pressure sensor is connected to a digital acquisition module, which collects pressure signals from the pressure sensor. A microprocessor is connected to the digital acquisition module, and the microprocessor controls the vacuum pump to start, stop, or throttle based on the pressure sensor signals.

8. The aircraft cabin equipment cooling system according to claim 7, characterized in that, The electric heater is a PTC heating element, which is arranged in contact with the bottom surface of the porous medium to provide a constant or set heat flux density; the sealed vacuum chamber is a stainless steel structure with an internal electrical aviation plug for the introduction of a K-type thermocouple and the electric heater; the pump is a 2XZ-4 type rotary vane vacuum pump; the porous medium is metal foam or sintered porous body.

9. The aircraft cabin equipment cooling system according to claim 7, characterized in that, The K-type thermocouple is fixed to the measuring surface of the porous medium. The K-type thermocouple includes two types: upper surface measuring point thermocouple and lower surface measuring point thermocouple. The upper surface measuring point thermocouple is used for closed-loop temperature control feedback, and the lower surface measuring point thermocouple is used to monitor heating input and thermal conductivity response.

10. The aircraft cabin equipment cooling system according to claim 1, characterized in that, The aircraft cabin equipment cooling system includes two operating modes: closed-loop temperature control mode and constant flow mode. The closed-loop temperature control mode uses the surface temperature of the porous medium as feedback and controls the solenoid valve through a combination of threshold-hysteresis and PWM. The constant flow mode provides a constant mass flow rate through an injection pump, with the solenoid valve in a normally open state, and is used for benchmark comparison experiments.

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