An active sweat cooling structure based on gas-liquid injection mixed supply

Abstract

An active sweating cooling structure based on gas-liquid ejector mixing supply includes a microwave-transparent sweating thermal protection structure component, a mixing working fluid pipeline, ejector I, one-way valve I, ejector II, one-way valve II, gas path solenoid valve I, gas path solenoid valve II, gas pipeline, pressurizing gas valve, high-pressure gas cylinder, liquid pipeline I, liquid pipeline II, working fluid storage tank, and controller. After the pressurizing gas valve opens, high-pressure gas flows through the gas pipeline into the parallel ejectors I and II, ejecting the liquid working fluid from the storage tank and mixing it with the gas before flowing into the microwave-transparent sweating thermal protection component. Utilizing the sweating cooling principle, the working fluid permeates through the microwave-transparent porous layer to the surface of the structure component, achieving heat reduction and cooling of the microwave-transparent sweating thermal protection component. This invention achieves effective thermal protection and temperature control of the microwave-transparent component under high-speed flow conditions. The low water content of the working fluid ensures the transmittance of the microwave-transparent window structure under controllable cooling, solving the problem of feasible and efficient cooling of the microwave-transparent structure of high-speed aircraft.

Description

Technical Field

[0001] This invention belongs to the field of active thermal protection, specifically relating to an active sweating cooling structure based on gas-liquid ejection mixing supply. Background Technology

[0002] High-speed aircraft are equipped with communication antennas, radar seekers, and other communication and detection equipment. Therefore, it is necessary to design wave-transparent structures in localized areas of the aircraft to meet the wave-transparency requirements for communication and detection during high-speed flight. With increasing flight speed and duration, traditional wave-transparent materials are insufficient to meet the heat protection and insulation requirements under high-speed flight conditions. Active sweating measures for wave-transparent windows are a feasible thermal protection technology solution.

[0003] Common working fluids for sweating cooling include gases and liquids. Gases have weak cooling capacity; under high heat flux conditions, gas cooling systems require large fluid flow rates, resulting in low system efficiency and large system size. These space and weight limitations restrict the application of active gas sweating cooling solutions in high-speed aircraft. Among liquid working fluids, water phase change sweating cooling has the highest efficiency and a compact system structure, making it the most promising sweating cooling medium for high-speed aircraft. However, water has a relatively high dielectric constant, around 78 at room temperature. Materials with high dielectric constants absorb electromagnetic waves more strongly, weakening the penetration ability of radar waves or radio signals and reducing the material's wave transmission performance. Therefore, when using liquid water to cool wave-transparent window structures, the challenge of reducing electromagnetic wave penetration must be addressed. Summary of the Invention

[0004] To address the need for both high-speed aircraft to achieve both high wave transmittance and efficient cooling, this invention proposes an active sweating cooling structure based on a gas-liquid ejector mixed supply. In the gaseous cooling medium of the active sweating cooling system, a certain proportion of liquid water is introduced using an ejector, which ensures both the wave transmittance of the wave-transmitting window structure and achieves efficient cooling of the structure.

[0005] An active sweating cooling structure based on gas-liquid ejector mixing supply includes a wave-transparent sweating heat protection structure component, a mixing working fluid pipeline, ejector one, ejector two, solenoid valve one, solenoid valve two, a gas pipeline, a pressurizing gas valve, a high-pressure gas cylinder, liquid pipeline one, liquid pipeline two, a working fluid tank, and a controller; the mixing working fluid pipeline connects the wave-transparent sweating heat protection structure component to ejector one and ejector two connected in parallel; the outlets of ejector one and ejector two are connected in parallel and merge into the mixing working fluid pipeline; the liquid inlet of ejector one is connected to check valve one and passes through liquid pipeline one. The system is connected to the working fluid storage tank; the high-pressure gas inlet of ejector one is connected to gas path solenoid valve one, and then to the booster gas valve via a gas pipeline; the liquid inlet of ejector two is connected to check valve two, and then to the working fluid storage tank via liquid pipeline two; the high-pressure gas inlet of ejector two is connected to gas path solenoid valve two, and then to the booster gas valve via a gas pipeline; the booster gas valve is connected to the high-pressure gas cylinder; the controller is connected to the temperature measuring point on the wave-transparent sweating heat protection structure component, gas path solenoid valve one, gas path solenoid valve two, and booster gas valve via control cables respectively; After the pressurized gas valve is opened, the high-pressure gas flows through the gas pipeline into the parallel ejector one and ejector two, which inject and mix the working fluid in the working fluid storage tank into the microwave-transparent sweating heat protection structure component. The working fluid then permeates through the microwave-transparent porous layer of the microwave-transparent sweating heat protection structure component to the surface of the component. By utilizing the sweating cooling principle, the heat of the microwave-transparent sweating heat protection component is reduced and the temperature is controlled.

[0006] Through the parallel connection of ejector one and ejector two, the controller sends a control signal to control the opening and closing of the ejector gas pipeline, realizing three flow regulation modes: low water content working fluid supply, high water content working fluid supply, and maximum flow working fluid supply. In the low water content working fluid supply mode, gas path solenoid valve one is open and gas path solenoid valve two is closed, and the branch where ejector one is located is working. In this working mode, the water content in the cooling working fluid is low, which is suitable for flight modes where the external aerodynamic heating of the component is not high, but the wave transmission performance is high. In the high water content working fluid supply mode, solenoid valve one is closed and solenoid valve two is open, and the branch where ejector two is located is working. In this working mode, the water content in the cooling working fluid is high, and the sweating cooling effect is excellent, which is suitable for the component under high external aerodynamic heating conditions. In the maximum flow working fluid supply mode, solenoid valve one and solenoid valve two are open at the same time, the cooling working fluid supply flow is the maximum, the sweating cooling effect is the best, and it is suitable for the highest aerodynamic heating flight mode.

[0007] The high-pressure gas is high-pressure nitrogen with a pressure of 2 MPa, and the liquid working fluid is pure water.

[0008] Furthermore, the flow rate of ejector one is 4 g / s, with a liquid-to-gas ratio of 5:95; the flow rate of ejector two is 2 g / s, with a liquid-to-gas ratio of 3:7.

[0009] The wave-transparent sweating heat protection structure component adopts a three-layer structure, which includes a wave-transparent porous layer, a flow channel layer, and a wave-transparent load-bearing layer from the outside to the inside.

[0010] Furthermore, temperature measuring points are arranged on the wave-transparent bearing layer to detect the temperature of the wave-transparent bearing layer in real time. When the temperature measuring point data is higher than the withstand temperature value of the wave-transparent bearing layer, the controller issues a control command, solenoid valve one and solenoid valve two are fully opened to increase the working fluid supply flow and quickly reduce the temperature of the wave-transparent bearing layer to a safe temperature. When the temperature measuring point temperature is lower than the withstand temperature value, the controller controls the opening and closing of solenoid valve one and solenoid valve two based on the algorithm logic predicted by the aircraft's flight mode.

[0011] Furthermore, the thickness of the flow channel layer is no greater than 0.5 mm.

[0012] Furthermore, the thickness of the wave-transparent porous layer is greater than 10 mm, and the material is a porous rigid ceramic tile material or a porous quartz / quartz composite material.

[0013] The beneficial effects of this invention are as follows: (1) A gas-liquid mixture is used as the cooling medium for the sweating cooling system, which ensures the wave transmittance of the wave-transmitting window while meeting the window's heat protection and cooling requirements. (2) The gas-liquid working fluid is mixed by an ejector device to form a mixed cooling working fluid, which is then transported to the wave-transparent sweating heat protection structure component. The sweating cooling principle is used to achieve heat reduction and cooling of the structure component. (3) Two ejector devices are connected in parallel, and the controller controls the opening and closing of the ejector gas pipeline to achieve three types of flow regulation; (4) The wave-transmitting and sweating heat protection structure component adopts a three-layer structure with different layer thicknesses to meet the wave transmission and cooling requirements of the wave-transmitting window structure under different flight profiles. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of an active sweating cooling structure based on gas-liquid ejection mixing supply; Figure 2 This is a schematic diagram of a wave-transmitting, sweat-absorbing heat protection structure component. Detailed Implementation

[0015] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection claimed by the present invention.

[0016] A gas-liquid mixture is used as the cooling medium in the active sweating cooling system. This reduces the amount of liquid medium used, thus minimizing its attenuation of radar waves or wireless signals and maintaining the penetration of electromagnetic waves through the wave-transparent structural components. Simultaneously, it fully utilizes the efficient sweating cooling capacity of water's phase change. An active sweating cooling structure based on a gas-liquid mixture is shown below. Figure 1 As shown, it consists of a heat protection structure component that transmits light through sweating, temperature measuring points, a mixed working fluid pipeline, ejector one, one-way valve one, ejector two, one-way valve two, gas solenoid valve one, gas solenoid valve two, gas pipeline, pressurizing gas valve, high-pressure gas cylinder, liquid pipeline one, liquid pipeline two, working fluid storage tank and controller.

[0017] The connections of each component are as follows: the mixed working fluid pipeline connects to the translucent sweating heat protection structure assembly and ejector one and ejector two connected in parallel; the outlets of ejector one and ejector two are connected in parallel and merge into the mixed working fluid pipeline; the liquid inlet of ejector one is connected to check valve one, and is connected to the working fluid storage tank through liquid pipeline one; the high-pressure gas inlet of ejector one is connected to gas path solenoid valve one, and is connected to the booster gas valve through a gas pipeline; the liquid inlet of ejector two is connected to check valve two, and is connected to the working fluid storage tank through liquid pipeline two; the high-pressure gas inlet of ejector two is connected to gas path solenoid valve two, and is connected to the booster gas valve through a gas pipeline; the booster gas valve is connected to the high-pressure gas cylinder; the controller is connected to the temperature measuring point on the translucent sweating heat protection structure assembly, gas path solenoid valve one, gas path solenoid valve two, and booster gas valve through a control cable.

[0018] The principle is as follows: After the pressurization gas valve is opened, the high-pressure gas flows through the gas pipeline into ejector one and ejector two, mixes the working fluid in the working fluid tank, and then enters the interior of the microwave-transparent sweating heat protection structure component through the mixed working fluid pipeline. It then permeates to the surface of the component through the microwave-transparent porous layer. By utilizing the sweating cooling principle, the heat of the microwave-transparent sweating heat protection component is reduced and the temperature is controlled.

[0019] Two ejector devices are connected in parallel, and a controller sends a control signal to control the opening and closing of the ejector gas pipeline. By combining them, three flow control modes can be achieved: low water content working medium supply, high water content working medium supply, and maximum flow working medium supply. In the low-moisture-content working fluid supply mode, solenoid valve one is open and solenoid valve two is closed, with ejector one operating in the branch. In this mode, the low water content in the cooling fluid effectively reduces the attenuation of electromagnetic wave propagation, ensuring high wave transmission of the transmissive component. This mode is suitable for flight modes where external aerodynamic heating of the component is not high, but wave transmission performance is required. In the high-moisture-content working fluid supply mode, solenoid valve one is closed and solenoid valve two is open, with ejector two operating in the branch. In this mode, the high water content in the cooling fluid results in excellent transpiration cooling, suitable for component exteriors under high aerodynamic heating conditions to prevent outermost layer ablation and ensure the temperature of the transmissive load-bearing structure is within the operating range. In the maximum flow working fluid supply mode, solenoid valves one and two are open simultaneously, resulting in the maximum cooling fluid supply flow and optimal transpiration cooling effect. This mode is suitable for flight modes with the highest aerodynamic heating to prevent outermost layer ablation of the component.

[0020] The function of check valve one and check valve two is to ensure that the working fluid does not flow back in the branches where ejector one and ejector two are located, that is, the working fluid in the mixing pipeline will not flow back into the working fluid storage tank through ejector one and ejector two.

[0021] By rationally designing the parameters of the ejector nozzle diameter, water intake chamber, mixing chamber, and diffuser chamber, two ejector functions can be achieved. In a typical scheme, high-pressure nitrogen gas is used at a pressure of 2 MPa, and pure water is used as the liquid working fluid. For a 200mm x 200mm wave-transparent, sweating-inducing thermal protection structural component, ejector one is designed with a flow rate of 4 g / s, with a liquid-to-gas ratio of 5:95, ensuring high wave transmittance in the main wavelength bands while providing good sweating cooling. Ejector two is designed with a flow rate of 2 g / s, with a liquid-to-gas ratio of 3:7 and a high liquid working fluid content, providing excellent sweating cooling. By combining these two flow rates, the thermal protection, cooling, temperature control, and wave transmittance requirements of the wave-transparent, sweating-inducing thermal protection structural component during high-speed flight of the aircraft can be met.

[0022] like Figure 2As shown, the wave-transparent, sweat-inducing heat protection structure component adopts a three-layer structure. All three layers are made of materials with excellent wave-transparent properties, namely a wave-transparent load-bearing layer, a flow channel layer, and a wave-transparent porous layer. The wave-transparent porous layer is located on the outermost side of the structure component, forming the outermost layer of the aircraft. It needs to withstand the aerodynamic heating of the high-speed airflow during high-speed flight, while simultaneously transferring aerodynamic forces to the interior of the aircraft and maintaining its aerodynamic shape. The flow channel layer is located between the wave-transparent porous layer and the wave-transparent load-bearing layer, serving as a channel for the working fluid flow and transferring aerodynamic forces to the wave-transparent load-bearing layer. The wave-transparent load-bearing layer needs to possess sufficient strength to maintain the structural integrity of the entire component. Temperature measuring points are arranged on the side of the wave-transparent load-bearing layer for real-time monitoring of its structural temperature. When the temperature measurement data at the measuring point is higher than the withstand temperature value of the wave-transparent bearing layer, the controller issues a control command, and solenoid valve one and solenoid valve two are fully opened to quickly reduce the wave-transparent bearing layer to a safe temperature by using the maximum working fluid supply flow mode tool. When the temperature at the measuring point is lower than the withstand temperature value, the controller controls the opening and closing of solenoid valve one and solenoid valve two based on the algorithm logic predicted by the aircraft's flight mode.

[0023] The cooling medium enters the flow channel layer through the mixed working medium pipeline. Because the pressure of the cooling medium is higher than that of the high-speed airflow outside the structural component, the cooling medium flows through the porous layer under pressure and seeps to the outside of the structural component, forming a liquid film or gas film of a certain thickness on the surface of the porous layer. This film blocks the aerodynamic heating heat flow of the high-speed airflow and cools the porous layer during its flow in the flow channel layer and the porous layer, keeping the temperature of the porous layer within the tolerance range.

[0024] The thickness of the flow channel layer affects the wave transmission performance of the component. Simulation analysis shows that the thicker the flow channel layer, the greater the electromagnetic wave attenuation. Designing different layer thicknesses can meet the wave transmission and cooling requirements of the window structure for different flight profiles. Under typical operating conditions, the flow channel layer thickness is recommended to be no greater than 0.5 mm to reduce the thickness of the working fluid in the flow channel layer and minimize its impact on electromagnetic wave propagation. The porous wave-transmitting layer needs to have heat protection and insulation functions and a thickness greater than 10 mm, such as porous rigid ceramic tile materials or porous quartz / quartz composite materials. It should be able to block external heat input under surface temperatures up to 1100℃, extending the time for the wave-transmitting load-bearing layer to reach the withstand temperature, so that the wave-transmitting component can provide the high wave transmission environment required for short-term antenna operation even when no working fluid is supplied.

[0025] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An active sweating cooling structure based on gas-liquid ejection mixing supply, characterized in that, The system includes a microwave-transparent, sweat-inducing heat protection structure assembly, a mixed working fluid pipeline, ejector one, ejector two, solenoid valve one, solenoid valve two, a gas pipeline, a pressurizing gas valve, a high-pressure gas cylinder, liquid pipeline one, liquid pipeline two, a working fluid storage tank, and a controller. The mixed working fluid pipeline connects the microwave-transparent, sweat-inducing heat protection structure assembly to ejector one and ejector two connected in parallel. The outlets of ejector one and ejector two are connected in parallel and merge into the mixed working fluid pipeline. The liquid inlet of ejector one is connected to check valve one and is connected to the working fluid storage tank through liquid pipeline one. The high-pressure gas inlet of ejector one is connected to gas path solenoid valve one, and then to pressurization gas valve through a gas pipeline; the liquid inlet of ejector two is connected to check valve two, and then to working fluid storage tank through liquid pipeline two; the high-pressure gas inlet of ejector two is connected to gas path solenoid valve two, and then to pressurization gas valve through a gas pipeline; the pressurization gas valve is connected to high-pressure gas cylinder; the controller is connected to the temperature measuring point on the wave-transparent sweating heat protection structure component, gas path solenoid valve one, gas path solenoid valve two, and pressurization gas valve through control cables respectively; After the pressurized gas valve is opened, the high-pressure gas flows through the gas pipeline into the parallel ejector one and ejector two, which inject and mix the working fluid in the working fluid storage tank into the microwave-transparent sweating heat protection structure component. The working fluid then permeates through the microwave-transparent porous layer of the microwave-transparent sweating heat protection structure component to the surface of the component. By utilizing the sweating cooling principle, the heat of the microwave-transparent sweating heat protection component is reduced and the temperature is controlled.

2. The active sweating cooling structure based on gas-liquid ejection mixing supply according to claim 1, characterized in that, Through the parallel connection of ejector one and ejector two, the controller sends a control signal to control the opening and closing of the ejector gas pipeline, realizing three flow regulation modes: low water content working fluid supply, high water content working fluid supply, and maximum flow working fluid supply. In the low water content working fluid supply mode, gas path solenoid valve one is open and gas path solenoid valve two is closed, and the branch where ejector one is located is working. In this working mode, the water content in the cooling working fluid is low, which is suitable for flight modes where the external aerodynamic heating of the component is not high, but the wave transmission performance is high. In the high water content working fluid supply mode, solenoid valve one is closed and solenoid valve two is open, and the branch where ejector two is located is working. In this working mode, the water content in the cooling working fluid is high, and the sweating cooling effect is excellent, which is suitable for the component under high external aerodynamic heating conditions. In the maximum flow working fluid supply mode, solenoid valve one and solenoid valve two are open at the same time, the cooling working fluid supply flow is the maximum, the sweating cooling effect is the best, and it is suitable for the highest aerodynamic heating flight mode.

3. The active sweating cooling structure based on gas-liquid ejection mixing supply according to claim 1, characterized in that, The high-pressure gas is high-pressure nitrogen with a pressure of 2 MPa, and the liquid working fluid is pure water.

4. The active sweating cooling structure based on gas-liquid ejection mixing supply according to claim 2, characterized in that, The flow rate of ejector one is 4 g / s, with a liquid-to-gas ratio of 5:95; the flow rate of ejector two is 2 g / s, with a liquid-to-gas ratio of 3:

7.

5. The active sweating cooling structure based on gas-liquid ejection mixing supply according to claim 1, characterized in that, The wave-transparent sweating heat protection structure component adopts a three-layer structure, which includes a wave-transparent porous layer, a flow channel layer, and a wave-transparent load-bearing layer from the outside to the inside.

6. The active sweating cooling structure based on gas-liquid ejection mixing supply according to claim 5 is characterized in that, Temperature measuring points are arranged on the wave-transparent bearing layer to detect the temperature of the wave-transparent bearing layer in real time. When the temperature measurement data of the measuring point is higher than the withstand temperature value of the wave-transparent bearing layer, the controller issues a control command, solenoid valve one and solenoid valve two are fully opened, the working fluid supply flow is increased, and the wave-transparent bearing layer is quickly reduced to a safe temperature. When the temperature of the measuring point is lower than the withstand temperature value, the controller controls the opening and closing of solenoid valve one and solenoid valve two based on the algorithm logic indicated by the flight mode of the aircraft.

7. The active sweating cooling structure based on gas-liquid ejection mixing supply according to claim 5, characterized in that, The thickness of the flow channel layer is no more than 0.5 mm.

8. The active sweating cooling structure based on gas-liquid ejection mixing supply according to claim 5, characterized in that, The thickness of the porous translucent layer is greater than 10 mm, and the material is a porous rigid ceramic tile material or a porous quartz / quartz composite material.

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