Aircraft active cooling method and system based on heat sink gradient utilization

Abstract

The invention provides an aircraft active cooling method based on heat sink gradient utilization, and the method at least comprises the steps: introducing a cooling medium into a liquid cooling channel of a generator controller, and carrying out the heat exchange between the cooling medium and the generator controller; introducing the cooling medium which absorbs heat for the first time into an active cooling flow channel of a generator main body, wherein the cooling medium exchanges heat with the generator main body; when the temperature of the ram air exceeds the tolerable temperature of the power turbine, the cooling medium absorbing heat again is atomized and sprayed into the ram air leading to the power turbine, and the temperature of the ram air is reduced through evaporation heat absorption of the cooling medium; and outlet air generated after the power turbine expands to do work is selectively exhausted into the atmosphere or introduced into the aircraft force bearing structure to be actively cooled. The invention further provides an aircraft active cooling system based on heat sink gradient utilization. The method has the beneficial effect that the utilization efficiency of the limited heat sink on the aircraft can be greatly improved.

Description

Technical Field

[0001] This invention relates to the field of aircraft energy and thermal management technology, and particularly to an active cooling method and system for aircraft based on the cascade utilization of heat sinks, which is especially suitable for power turbine power generation systems and load-bearing structure cooling. Background Technology

[0002] With the rapid development of aerospace technology, aircraft are flying at increasingly higher speeds, leading to dramatic compression and significant temperature increases in ram air. This heated ram air makes it difficult to effectively control the heat generated in high-temperature components during high-speed flight. In other words, advanced aircraft operate in extremely harsh thermal environments due to their high speeds, rendering traditional methods for thermal control of aircraft systems and equipment, as well as cooling of high-temperature load-bearing structures, unusable and posing increasingly prominent thermal safety challenges.

[0003] To reduce the performance compensation loss of the thermal control and active cooling systems of aircraft systems and equipment, it is necessary to refine the design of heat insulation schemes based on the actual temperature control requirements of the thermally controlled objects, and to comprehensively utilize natural heat sinks such as structures and fuel, as well as consumable heat sinks on the aircraft's carrying system. In order to maximize the effective utilization efficiency of heat sinks, we must explore methods for online generation and cascade utilization of heat sinks.

[0004] For example, Chinese invention patent CN118442141A discloses a thermal management scheme for a high-enthalpy ram air turbine power generation system. The structure includes a turbine stator, turbine rotor, motor, water tank, and oil tank. The turbine stator employs a sweating cooling scheme, while the turbine rotor uses a fuel-fired cooling scheme. Cooling channels are set inside the turbine stator blades, rotor blades, and impeller. Water is used to cool the stator blades, and fuel is used to cool the rotor blades and impeller, reducing the turbine temperature to within the allowable range for stable and safe operation. This invention utilizes water to cool the stator blades while simultaneously leveraging the heat absorption capacity of water evaporation to further reduce the temperature of the airflow entering the rotor blades, decreasing the fuel flow required to cool the rotor blades and impeller. It uses clean ram air from a high-altitude environment, providing a better external environment for sweating cooling and solving the cooling problem of hot-end components in existing high-enthalpy ram air turbines. However, simultaneously using water and fuel to cool the turbine stator and rotor requires complex modifications to the air turbine design, and sweating cooling also necessitates the introduction of complex auxiliary systems.

[0005] Chinese invention patent CN119102788A discloses a turbine power generation system for staged cooling of high-enthalpy ram air. The system includes: a primary heat exchanger, a secondary heat exchanger, an oil-gas turbine, an air turbine, and a flow divider valve. The hot-side inlet of the primary heat exchanger is connected to a high-temperature, high-pressure air passage; the hot-side outlet of the primary heat exchanger is connected to the hot-side inlet of the secondary heat exchanger; the hot-side outlet of the secondary heat exchanger is connected to the inlet of the air turbine; the outlet of the air turbine is connected to the inlet of the flow divider valve; the outlet of the flow divider valve is connected to the cold-side inlet of the secondary heat exchanger; the inlet of the oil-gas turbine is connected to a cracked oil-gas pipeline; and the outlet of the oil-gas turbine is connected to the cold-side inlet of the primary heat exchanger. This invention cools the high-temperature, high-pressure air by sequentially utilizing the low-temperature cracked gas cooled by the expansion and cooling of the oil-gas turbine and the low-temperature, low-pressure air cooled by the expansion and cooling of the air turbine. However, this system also suffers from complexity.

[0006] Therefore, it is necessary to study an active cooling method and system for aircraft based on the utilization of heat sink cascades, in order to solve the above problems or mitigate their impact from the perspective of the overall aircraft platform. Summary of the Invention

[0007] This invention provides an active cooling method for aircraft based on the cascade utilization of heat sinks. The method uses a cooling medium to sequentially cool the generator controller, the generator body, and the ram air. The ram air expands within the power turbine to generate electricity and produce low-temperature air, which is then used to cool the load-bearing structure of the aircraft. This method enables the cascade utilization of the sensible and latent heat of the cooling medium, while also achieving the comprehensive utilization of the energy and cooling capacity of the ram air, thereby effectively solving the aforementioned problems or mitigating their impact.

[0008] The active cooling method for aircraft based on heat sink cascade utilization of the present invention includes at least the following steps: A cooling medium is introduced into the liquid cooling channel of the generator controller, and the cooling medium exchanges heat with the generator controller to complete the first heat absorption. The cooling medium, after its initial heat absorption, is introduced into the active cooling channel of the generator body, where it exchanges heat with the generator body to complete the heat absorption process again. When the temperature of the ram air exceeds the withstand temperature of the power turbine, the cooling medium, after absorbing heat again, is atomized and sprayed into the ram air leading to the power turbine. The temperature of the ram air is reduced by absorbing heat through the evaporation of the cooling medium. The exhaust air from the power turbine after it expands and does work is selectively discharged into the atmosphere or introduced into the load-bearing structure of the aircraft for active cooling.

[0009] In one embodiment, the temperature of the inlet air to the power turbine is controlled by adjusting the mass flow ratio of the atomized cooling medium to the ram air leading to the power turbine.

[0010] In one embodiment, the cooling medium is atomized into droplets of 5~30μm through an atomizing nozzle under the pressure of the medium storage tank and / or the pressurization of the liquid pump.

[0011] In one embodiment, when the temperature of the ram air is lower than the tolerance temperature of the power turbine, the cooling medium that has absorbed heat again is recovered through a bypass circuit.

[0012] In one embodiment, the outlet airflow direction of the power turbine is determined based on the flight operating parameters of the aircraft; The operating parameters of the aircraft include at least the aircraft's flight speed, the temperature of the aircraft's load-bearing structure, and the power generation capacity of the power turbine.

[0013] In one embodiment, the temperature control of the cooling medium is coordinated with the thermal control system of the aircraft, and the temperature of the cooling medium is actively adjusted by fuel or circulating coolant to maintain it within a preset temperature range.

[0014] In another aspect, the present invention provides an active cooling system for aircraft based on the utilization of heat sink cascades, wherein the active cooling system is applied to the active cooling method for aircraft based on the utilization of heat sink cascades as described above, comprising: A medium storage tank, wherein the medium storage tank is used to store cooling medium; A liquid cooling channel is provided on the generator controller, and the liquid cooling channel is connected to the medium storage tank through a first pipe. An active cooling channel is laid on the generator body, and the active cooling channel is connected to the liquid cooling channel through a second pipe. An atomizing nozzle is disposed in the air intake channel before the power turbine inlet, and the atomizing nozzle is connected to the active cooling channel through a third pipe.

[0015] In one embodiment, the active cooling system for the aircraft further includes a three-way valve, the inlet of which is connected to the active cooling channel, the first outlet of which is connected to the third pipe, and the second outlet of which is connected to the medium storage tank via a bypass circuit.

[0016] In one embodiment, a circulating cooling circuit is provided outside the medium storage tank, and fuel oil or circulating coolant flows through the circulating cooling circuit.

[0017] In one embodiment, a flow control valve is provided on the first pipeline, and temperature monitoring devices are provided in the medium storage tank, the generator controller, the generator body, and the gas intake channel.

[0018] The active cooling method for aircraft based on the utilization of heat sink cascade provided by this invention has at least the following advantages compared with the prior art: The active cooling method for aircraft based on the cascaded utilization of heat sinks of this invention sequentially cools the generator controller, generator body, and ram air using a cooling medium. The ram air expands within the power turbine to generate electricity and produces cryogenic air, which is then used to cool the load-bearing structure of the aircraft. This method achieves cascaded utilization of the sensible and latent heat of the cooling medium and comprehensive utilization of the energy and cooling capacity of the ram air. This active cooling method based on the cascaded utilization of heat sinks is simple and easy to implement. It ensures that the air turbine power generation system better adapts to actual working environments and loads, improves the performance and reliability of the air turbine power generation system, and significantly enhances the utilization efficiency of the limited heat sinks on the aircraft, reducing the weight, space, and energy costs associated with thermal management.

[0019] The present invention provides an active cooling system for aircraft based on the utilization of heat sink cascades. Since it is applied to the above-mentioned active cooling method for aircraft based on the utilization of heat sink cascades, it also has the above-mentioned beneficial effects. Attached Figure Description The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0020] Figure 1 This is a schematic flowchart of an active cooling method for an aircraft according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the active cooling system for an aircraft according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the active cooling system of the aircraft in an embodiment of the present invention when cooling ram air; Figure 4 This is a schematic diagram of the structure of the active cooling system of the aircraft during the recovery of the cooling medium in an embodiment of the present invention.

[0021] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale.

[0022] Figure label: 1-Medium storage tank, 2-Generator controller, 3-Generator body, 4-First pipe, 5-Liquid cooling channel, 6-Second pipe, 7-Active cooling channel, 8-Third pipe, 9-Atomizing nozzle, 10-Air intake channel, 11-Power turbine, 12-Atmospheric environment / Aircraft load-bearing structure, 121-Atmospheric environment, 122-Aircraft load-bearing structure, 13-Three-way valve, 14-Bypass circuit, 15-Circulating cooling circuit, 16-Flow control valve, 17-Engine air intake / Airframe windward surface. Detailed Implementation

[0023] The invention will now be further described with reference to the accompanying drawings.

[0024] Example 1 like Figures 1 to 4 As shown, the steps of the active cooling method for aircraft based on heat sink cascade utilization of the present invention include at least: Step S1: The cooling medium is introduced into the liquid cooling channel 5 of the generator controller 2, and the cooling medium exchanges heat with the generator controller 2 to complete the first heat absorption; Step S2: The cooling medium after the first heat absorption is introduced into the active cooling channel 7 of the generator body 3, and the cooling medium exchanges heat with the generator body 3 to complete the second heat absorption; Step S3: When the temperature of the ram air exceeds the withstand temperature of the power turbine 11, the cooling medium, after absorbing heat again, is atomized and sprayed into the ram air leading to the power turbine 11. The temperature of the ram air is reduced by absorbing heat through the evaporation of the cooling medium. Step S4: Selectively discharge the outlet air of the power turbine 11 after it expands and does work into the atmosphere or into the load-bearing structure 12 of the aircraft for active cooling.

[0025] Specifically, in step S1, the cooling medium flows out of the medium storage tank 1 and enters the liquid cooling channel 5, which is precisely designed into the generator controller 2. As the cooling medium flows through, it absorbs the Joule heat and switching loss heat generated by the generator controller 2 during operation through forced convection heat transfer, stabilizing its temperature within the applicable range. At the same time, the cooling medium itself increases in temperature due to heat absorption, completing the first heat absorption.

[0026] In this way, step S1 utilizes the sensible heat absorption capacity of the cooling medium to cool the generator controller 2, which is most sensitive to temperature and has a high heat flux density, ensuring the reliability of the core control circuit. At the same time, it preheats the cooling medium, increases its overall enthalpy value, prepares for subsequent latent heat utilization, and avoids the waste of cooling capacity that may be caused by the direct atomization of the low-temperature cooling medium.

[0027] In step S2, the cooling medium, after its initial heat absorption, enters the precisely designed active cooling channel 7 of the generator body 3 through a pipeline. As the cooling medium with sufficient heat capacity flows through, it exchanges heat with the high-temperature components of the generator body 3, carrying away the heat generated during operation and stabilizing the temperature of the generator body 3 within an applicable range. At the same time, the temperature of the cooling medium further increases significantly, completing the second heat absorption.

[0028] This step S2 further utilizes the sensible heat absorption capacity of the cooling medium to ensure that the generator's armature and bearings operate within the high-efficiency temperature range, preventing insulation aging and magnetic performance degradation. At the same time, it further preheats the cooling medium, bringing its temperature closer to the gas-liquid phase transition point, laying the foundation for subsequent high-efficiency atomization and evaporative heat absorption.

[0029] In step S3, when the aircraft is in high-speed cruise mode, the temperature of the ram air introduced into the power turbine 11 far exceeds the tolerance limit of the power turbine 11. At this time, the cooling medium, after absorbing heat again, is sent through a pipe to the atomizing nozzle 9 installed in the air intake channel 10 of the power turbine 11. At the atomizing nozzle 9, the cooling medium is broken into micron-sized droplets and sprayed into the incoming high-temperature ram air. Because the micro-droplets have a very large specific surface area, they undergo flash evaporation or rapid evaporation in the high-temperature ram air, requiring the absorption of a large amount of latent heat of vaporization, which is directly taken from the surrounding ram air, thereby causing the temperature of the ram air to drop sharply. In this way, the latent heat of the cooling medium is used to achieve efficient cooling, which can cool the incoming ram air with a total temperature of thousands of degrees Celsius to the temperature range where the power turbine 11 can operate safely. The tolerance limit of the power turbine 11 and the tolerance capacity of its structures, including the power turbine blades and seals, are also considered.

[0030] In step S4, the cooled ram air enters the power turbine 11, expands, and performs work to drive the generator to produce electricity. Simultaneously, the enthalpy and temperature of the ram air are further reduced. The outlet air of the power turbine 11 has a low temperature. Depending on real-time operating conditions, the system either directly discharges the outlet air to the atmospheric environment 121 or guides it into a pre-set cooling channel inside the aircraft's load-bearing structure 122 for active cooling. This allows the ram air to expand and generate electricity within the power turbine 11, while simultaneously producing a cryogenic air source. When the aircraft's load-bearing structure 122 requires cooling, convective heat transfer from the cryogenic outlet air can be used to lower its temperature, preventing heat accumulation; when the aircraft's load-bearing structure 122 does not require cooling, it can be directly discharged.

[0031] Overall, the active cooling method for aircraft sequentially cools the generator controller 2, generator body 3, and ram air using a cooling medium. The ram air expands within the power turbine 11 to generate electricity and produce cryogenic air, which is then used to cool the aircraft's load-bearing structure 122. This method achieves cascaded utilization of the sensible and latent heat of the cooling medium and comprehensive utilization of the energy and cooling capacity of the ram air. This active cooling method for aircraft based on cascaded utilization of heat sinks is simple and easy to implement. It ensures that the air turbine power generation system better adapts to the actual working environment, improves the performance and reliability of the air turbine power generation system, and significantly enhances the utilization efficiency of the limited heat sinks on the aircraft, reducing the weight, space, and energy costs associated with thermal management.

[0032] In one example, the cooling medium may be water, an aqueous solution of ethylene glycol, or other liquids with high latent heat.

[0033] Furthermore, water can be selected as the cooling medium, as it has the characteristics of high latent heat, no pollution, and low cost and availability.

[0034] In one example, in step S3, the temperature of the inlet air of the power turbine 11 is controlled by adjusting the mass flow ratio of the atomized cooling medium to the ram air leading to the power turbine 11.

[0035] Specifically, the temperature and flow rate of the ram air leading to the power turbine 11 are monitored, as are the temperature and flow rate of the cooling medium when it is atomized and injected. Based on the monitored temperature and flow rate data, the required flow rate of cooling medium to cool the corresponding flow rate of ram air is calculated, i.e., the mass flow rate ratio of the cooling medium to the ram air, thereby precisely controlling the temperature of the air entering the power turbine 11. Furthermore, when the temperature of the ram air increases, the mass flow rate ratio of the cooling medium to the ram air is correspondingly increased. This can control the increase of the liquid pump outlet pressure or the increase of the valve opening to the atomizing nozzle 9 to inject more cooling medium and enhance the cooling effect; conversely, it is reduced. This avoids overheating damage to the power turbine 11 due to insufficient cooling and also prevents waste of cooling medium due to overcooling. This allows the power turbine 11 to adapt to changes in flight speed and altitude, maintaining its power generation system within its optimal efficiency range.

[0036] In one example, in step S3, the cooling medium is atomized into droplets of 5~30μm through the atomizing nozzle 9 under the pressure of the medium storage tank 1 and / or the pressurization of the liquid pump.

[0037] Specifically, the internal pressure of the medium storage tank 1 and / or the liquid pump provide the pressure differential required for cooling medium atomization. The high-pressure liquid cooling medium is then torn into droplets with a particle size range of 5-30 μm through the atomizing nozzle 9. The atomized droplet size is designed to be 5-30 μm to prevent excessively large droplets from causing incomplete evaporation in the high-speed flowing ram air, which could lead to cavitation due to high-speed impacts on turbine blades. Conversely, excessively small droplets avoid increasing the energy consumption of the booster nozzle and losing limited latent heat. This ensures that the cooling medium completely evaporates within a very short airflow residence time, maximizing the utilization efficiency of the cooling medium's latent heat while avoiding negative impacts of the liquid medium on subsequent flow channels.

[0038] In one example, in step S3, when the temperature of the ram air is lower than the tolerance temperature of the power turbine 11, the cooling medium that has absorbed heat again is recovered through the bypass circuit 14.

[0039] Specifically, the outlet end of the active cooling channel 7 is equipped with a diversion device, such as a three-way valve 13. The inlet end of the three-way valve 13 receives the cooling medium after it has absorbed heat again from the active cooling channel 7, and its two outlet ends are respectively connected to the atomizing nozzle 9 and the bypass circuit 14. The bypass circuit 14 can guide the cooling medium back to the medium storage tank 1. When the aircraft is at low speed, the temperature of the ram air introduced into the power turbine 11 is lower than the withstand temperature of the power turbine 11, that is, it is determined that there is no need to inject atomized cooling medium into the ram air. The cooling medium can then be controlled by the three-way valve 13 to flow to the bypass circuit 14 to achieve the recycling of the cooling medium. This can save consumable cooling medium, extend the continuous working time of the system, simplify the system operation mode under low-speed conditions, and reduce power consumption.

[0040] It should be noted that the flow rate of the cooling medium flowing through the generator controller 2 and the generator body 3 is not less than the flow rate of the cooling medium leading to the air turbine inlet for cooling the ram air. When the flow rate of the cooling medium cooling the generator controller 2 and the generator body 3 is equivalent to the flow rate of the cooling medium required to cool the ram air, all the cooling medium after cooling the generator controller 2 and the generator body 3 can be introduced into the atomizing nozzle 9 to cool the incoming ram air. Figure 3 As shown; when the flow rate of the cooling medium for cooling the generator controller 2 and the generator body 3 is greater than the flow rate of the cooling medium required for cooling the ram air, the excess cooling medium is recovered through the bypass circuit 14; when the temperature of the ram air is lower than the withstand temperature of the power turbine 11, i.e., when the ram air does not need cooling, all the cooling medium is recovered through the bypass circuit 14, such as... Figure 4 As shown. In one example, in step S4, the outlet airflow direction of the power turbine 11 is determined based on the flight operating parameters of the aircraft; The operating parameters of the aircraft include at least the temperature of the load-bearing structure 122, the flight speed of the aircraft, and the power generation capacity of the power turbine 11.

[0041] Specifically, the temperature of the aircraft's load-bearing structure 122 can be obtained by temperature measurement points buried in key areas such as the leading edge of the wing and the fuselage anchorage. The temperature of the load-bearing structure 122 can be used to determine the direction of the outlet airflow of the power turbine 11. That is, when the temperature of the load-bearing structure 122 is higher than the preset safe temperature value, it is determined that the load-bearing structure 122 needs cooling, and the outlet air of the power turbine 11 flows towards the load-bearing structure 122; when the temperature of the load-bearing structure 122 is lower than the preset safe temperature value, it is determined that the load-bearing structure 122 does not need cooling, and the outlet air of the power turbine 11 is discharged into the atmospheric environment 121 to improve the work capacity of the power turbine 11.

[0042] Furthermore, the flight speed of the aircraft can be provided by the flight control system. The faster the flight speed, the higher the temperature of the aircraft's load-bearing structure 122 due to aerodynamic heating, and the more urgent the cooling requirement. When the actual flight speed of the aircraft is higher than the preset speed value, it can be determined that the aircraft's load-bearing structure 122 needs cooling, and the outlet air of the power turbine 11 flows to the aircraft's load-bearing structure 122; when the flight speed of the aircraft is lower than the preset speed value, it is determined that the aircraft's load-bearing structure 122 does not need cooling, and the outlet air of the power turbine 11 is discharged into the atmospheric environment 121.

[0043] In addition, the power generation capacity of the power turbine 11 can reflect the amount of work done by the power turbine 11 and its ability to absorb exhaust waste heat. The greater the power generation capacity of the power turbine 11, the greater the exhaust flow and cooling capacity, making it more suitable for cooling.

[0044] It should be noted that in practical applications, the operating conditions of the aircraft and the power turbine power generation system, such as the temperature of the aircraft's load-bearing structure 122, the aircraft's flight speed, and the power generation capacity of the power turbine 11, can also be comprehensively analyzed to determine the airflow direction at the outlet of the power turbine 11. For example, the operating condition parameters of the aircraft and the power generation system can be designed into a built-in logic algorithm for control.

[0045] In one example, the temperature control of the cooling medium is integrated with the aircraft's thermal management system, which actively regulates the temperature of the cooling medium using fuel or circulating coolant to maintain it within a preset temperature range.

[0046] Specifically, a heat exchange coil can be integrated into the outer wall or interior of the medium storage tank 1 to form a circulating cooling loop 15. The circulating cooling loop 15 is coupled to the existing fuel system or circulating coolant system on the aircraft. For example, if overheating occurs due to prolonged closed-loop recycling of preheated coolant, fuel can flow through this coil before being supplied to the engine, or a portion of the low-temperature circulating coolant used to cool avionics can be diverted here to utilize the lower-temperature fuel or coolant for cooling, ensuring the coolant remains within its optimal operating temperature window. The preset temperature range can be specifically set according to the actual temperature control requirements of the generator controller 2 and generator body 3, as well as the atomization effect requirements of the atomizing nozzle 9. This avoids the possibility of excessively high coolant temperature affecting pump cavitation performance or generating steam in the storage tank, while also preventing excessively low temperature from reducing the efficiency of subsequent evaporative cooling. This, in turn, improves the integration of the entire thermal management system.

[0047] Furthermore, reliable passive insulation measures can be adopted on the outer wall of the medium storage tank 1, such as adding an insulation layer.

[0048] Example 2 like Figures 2 to 4 As shown, the active cooling system for aircraft based on heat sink cascade utilization of the present invention is applied to the active cooling method for aircraft based on heat sink cascade utilization in Embodiment 1 above, including: Medium storage tank 1 is used to store cooling medium; Liquid cooling channel 5 is laid on generator controller 2, and liquid cooling channel 5 is connected to medium storage tank 1 through first pipe 4; Active cooling channel 7 is laid on generator body 3, and active cooling channel 7 is connected to liquid cooling channel 5 through second pipe 6. Atomizing nozzle 9 is located in the air intake channel 10 before the inlet of the power turbine 11. Atomizing nozzle 9 is connected to the active cooling channel 7 through a third pipe 8.

[0049] Specifically, the cooling medium is stored in a sealed medium tank 1. The liquid cooling channel 5 is tightly fitted to or embedded in the power devices, control chips, and auxiliary components within the generator controller 2. The active cooling channel 7 covers the stator windings, rotor, bearings, and power devices integrated within the generator body 3. The atomizing nozzle 9 is installed in the air intake channel 10 before the inlet of the power turbine 11. The liquid cooling channel 5 is connected to the medium tank 1 via the first pipe 4, the active cooling channel 7 is connected to the liquid cooling channel 5 via the second pipe 6, and the atomizing nozzle 9 is connected to the active cooling channel 7 via the third pipe 8, forming a series medium flow path. The cooling medium flows sequentially along this path, undergoing initial heat absorption, secondary heat absorption, and atomization in sequence. The power turbine 11 is installed downstream of the air intake channel 10, utilizing cooled ram air to perform work. The outlet pipe of the power turbine 11 is divided into two paths: one connects to the atmospheric environment 121, and the other connects to the cooling channel of the aircraft's load-bearing structure 122. The outflow direction can be selected by a valve. Thus, the active cooling system for aircraft can provide the hardware foundation for the implementation of the tiered cooling method, and its structure is simple and easy to implement.

[0050] In one example, the active cooling system for the aircraft also includes a three-way valve 13, the inlet of which is connected to the active cooling channel 7, the first outlet of which is connected to the third pipe 8, and the second outlet of which is connected to the medium storage tank 1 via a bypass circuit 14.

[0051] Specifically, a three-way valve 13 is connected to the end of the active cooling channel 7. The first outlet of the three-way valve 13 is connected to the third pipe 8, allowing the cooling medium to pass to the atomizing nozzle 9 for atomization and injection into the pressurized air. The second outlet of the three-way valve 13 is connected to the bypass circuit 14, allowing the cooling medium to pass to the medium storage tank 1 and mix with the cooling medium inside, thus achieving cooling and recovery. The three-way valve 13 can be a solenoid valve or a motor-driven valve, which can switch the flow path according to the control signal.

[0052] In one example, a circulating cooling circuit 15 is provided outside the medium storage tank 1, and fuel or circulating coolant flows through the circulating cooling circuit 15.

[0053] Specifically, coils or jackets are laid outside the medium storage tank 1 to form a circulating cooling circuit 15. The circuit is connected to the aircraft fuel line or the central circulating coolant line through inlet and outlet pipes, so that the fuel or coolant flows through the circulating cooling circuit 15 and exchanges heat with the cooling medium in the medium storage tank 1 to achieve cooling of the cooling medium.

[0054] Furthermore, an insulation layer can be added outside the medium storage tank 1 and the circulating cooling circuit 15, that is, a reliable passive insulation method is adopted to reduce the loss of cooling medium.

[0055] In one example, a flow control valve 16 is installed on the first pipeline 4, and temperature monitoring devices are installed in the medium storage tank 1, the generator controller 2, the generator body 3, and the gas intake channel 10.

[0056] Specifically, sensors are arranged at key nodes such as the medium storage tank 1, the generator controller 2 and the outlet of the liquid cooling channel 5, the generator body 3 and the outlet of the active cooling channel 7, and the air intake channel 10 to monitor the temperature of the cooling medium, ram air, and equipment. A flow control valve 16 is installed on the first pipeline 4 to adjust the initial flow rate from the medium storage tank 1 to the cooling path. All sensors and valves are electrically connected to the aircraft's integrated controller. Based on the collected temperature and flow signals, the controller uses algorithms to determine and control the flow control valve 16 and the three-way valve 13 to achieve precise control of the entire cooling process.

[0057] Furthermore, a liquid pump can be installed on the third pipe 8 to increase the pressure of the cooling medium flowing to the atomizing nozzle 9.

[0058] In one example, the inlet of the air intake passage 10 is connected to the engine intake passage or the windward side 17 of the engine block to introduce ram air into the power turbine 11, thereby reducing the complexity of the system layout and piping arrangement and minimizing the loss of system volume, weight and performance compensation.

[0059] In summary, the beneficial effects of this invention compared to the prior art include at least the following: This invention provides a cooling method and system suitable for the cascade utilization of heat sinks in full-speed-range aircraft. By using consumable cooling medium and expanded and cooled ram air for active cooling of the power turbine power generation system and the load-bearing structure of the aircraft, the air turbine power generation system can be better adapted to the actual working environment, improve the performance and reliability of the power generation system, and the solution is simple and easy to implement.

[0060] The present invention provides a method for the comprehensive utilization of sensible and latent heat of consumable cooling media, which enables the tiered utilization of the media according to the needs of the thermally controlled object. The present invention can fully utilize the heat sink potential of consumable cooling media and ram air in conjunction with the operating environment, maximizing the reduction of heat sink waste, minimizing the volume and weight of the thermal control system, and reducing performance compensation losses. The present invention also provides an active cooling method for the load-bearing structure of an aircraft, which introduces a small amount of relatively low-temperature air to create a temperature gradient in the thermal structure, avoiding excessively high structural equilibrium temperatures due to large amounts of heat accumulation and increasing structural design redundancy. The method of the present invention is applicable to the thermal control of ram air turbines in low-speed, wide-speed-range, and high-altitude aircraft, and has universality and scalability.

[0061] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An active cooling method for aircraft based on the cascade utilization of heat sinks, characterized in that, The steps include at least: A cooling medium is introduced into the liquid cooling channel of the generator controller, and the cooling medium exchanges heat with the generator controller to complete the first heat absorption. The cooling medium, after its initial heat absorption, is introduced into the active cooling channel of the generator body, where it exchanges heat with the generator body to complete the heat absorption process again. When the temperature of the ram air exceeds the withstand temperature of the power turbine, the cooling medium, after absorbing heat again, is atomized and sprayed into the ram air leading to the power turbine. The temperature of the ram air is reduced by absorbing heat through the evaporation of the cooling medium. The exhaust air from the power turbine after it expands and does work is selectively discharged into the atmosphere or introduced into the load-bearing structure of the aircraft for active cooling.

2. The active cooling method for aircraft based on heat sink cascade utilization according to claim 1, characterized in that, Temperature control of the inlet air of the power turbine is achieved by adjusting the mass flow ratio of the atomized cooling medium to the ram air leading to the power turbine.

3. The active cooling method for aircraft based on heat sink cascade utilization according to claim 1, characterized in that, The cooling medium is atomized into droplets of 5~30μm through an atomizing nozzle under the pressure of the medium storage tank and / or the pressurization of the liquid pump.

4. The active cooling method for aircraft based on heat sink cascade utilization according to claim 1, characterized in that, When the temperature of the ram air is lower than the tolerance temperature of the power turbine, the cooling medium that has absorbed heat again is recovered through a bypass circuit.

5. The active cooling method for aircraft based on heat sink cascade utilization according to claim 1, characterized in that, The outlet airflow direction of the power turbine is determined based on the flight operating parameters of the aircraft. The operating parameters of the aircraft include at least the aircraft's flight speed, the temperature of the aircraft's load-bearing structure, and the power generation capacity of the power turbine.

6. The active cooling method for aircraft based on heat sink cascade utilization according to claim 1, characterized in that, The temperature control of the cooling medium is coordinated with the thermal control system of the aircraft to actively regulate the temperature of the cooling medium through fuel or circulating coolant, so as to maintain it within a preset temperature range.

7. An active cooling system for aircraft based on the cascade utilization of heat sinks, characterized in that, The active cooling system for the aircraft is applied to the active cooling method for the aircraft based on the utilization of heat sink cascades as described in any one of claims 1 to 6, comprising: A medium storage tank, wherein the medium storage tank is used to store cooling medium; A liquid cooling channel is provided on the generator controller, and the liquid cooling channel is connected to the medium storage tank through a first pipe. An active cooling channel is laid on the generator body, and the active cooling channel is connected to the liquid cooling channel through a second pipe. An atomizing nozzle is disposed in the air intake channel before the power turbine inlet, and the atomizing nozzle is connected to the active cooling channel through a third pipe.

8. The active cooling system for aircraft based on heat sink cascade utilization according to claim 7, characterized in that, The active cooling system for the aircraft also includes a three-way valve, the inlet of which is connected to the active cooling channel, the first outlet of which is connected to the third pipe, and the second outlet of which is connected to the medium storage tank via a bypass circuit.

9. The active cooling system for aircraft based on heat sink cascade utilization according to claim 7, characterized in that, The medium storage tank is equipped with a circulating cooling circuit, in which fuel oil or circulating coolant flows.

10. The active cooling system for aircraft based on heat sink cascade utilization according to claim 7, characterized in that, The first pipeline is equipped with a flow control valve, and temperature monitoring devices are installed in the medium storage tank, the generator controller, the generator body, and the gas intake channel.

Images