Phase change sweating cooling experiment device and method based on high-temperature premixed flame jet flow

Abstract

The invention discloses a phase change sweating cooling experimental device and method based on high-temperature premixed flame jet, and the device comprises a high-temperature heat source heating system, a cooling system and a measuring system. The high-temperature heat source heating system comprises a fuel gas cylinder, an oxidant gas cylinder, a first gas pressure reducing valve, a second gas pressure reducing valve, a first flow controller, a second flow controller, a premixing tank and a flame nozzle; the fuel gas cylinder is connected with the gas pressure reducing valve and the first flow controller, and the oxidant gas cylinder is connected with the second gas pressure reducing valve and the second flow controller. The experimental device can realize flexible adjustment of the heating intensity and the heating form of an experimental piece, can simulate the actual heat flow condition of an aircraft part, can change the heating and coolant supply conditions in real time, and realizes transient response research of phase change sweating cooling to external excitation. And data support is provided for related theoretical research of phase change sweating cooling.

Description

Technical Field

[0001] This invention relates to the field of experimental technology for active thermal protection sweating cooling, specifically to an experimental device and method for phase change sweating cooling based on a high-temperature premixed flame jet. Background Technology

[0002] Hypersonic vehicles, as advanced transport carriers, possess immense application value and have become a development target for various countries. From an external environmental perspective, hypersonic vehicles experience intense friction with the atmosphere during flight, resulting in severe aerodynamic heating. Within the engine combustion chamber, the combustion of high-calorific-value fuels such as hydrogen and hydrocarbons significantly heats the combustion chamber walls. Furthermore, the presence of supports and cavities within the combustion chamber creates complex shockwave systems from the supersonic airflow, further exacerbating the thermal environment. Under such conditions, the vehicle's structure is highly susceptible to ablation and damage, necessitating effective thermal protection measures.

[0003] Sweating cooling is one type of active thermal protection solution. The cooling medium passes through a porous medium and then coats the hot-end surface, forming a coolant film. On one hand, the coolant can undergo strong heat exchange with the solid framework inside the porous medium, carrying away heat; on the other hand, the film structure covering the heated wall increases the thermal resistance of the high-temperature mainstream heat transfer to the wall, thus providing thermal protection. Sweating cooling consumes little coolant, has high cooling efficiency, maintains its basic structure, and can be reused, making it considered one of the most promising thermal protection technologies for hypersonic propulsion systems. Summary of the Invention

[0004] To overcome the limitations of existing technologies where single radiant heating methods cannot reproduce the high-speed airflow scouring and aerodynamic-thermal coupling environment, this invention provides a phase change sweating cooling experimental device and method based on a high-temperature premixed flame jet. The technical solution adopted by this invention is as follows:

[0005] A phase change sweating cooling experimental device and method based on high-temperature premixed flame jet includes a high-temperature heat source heating system, a cooling system, and a measurement system.

[0006] Furthermore, the high-temperature heat source heating system includes a fuel cylinder 1, an oxidant cylinder 2, a first gas pressure reducing valve 31, a second gas pressure reducing valve 32, a first flow controller 41, a second flow controller 42, a premixing tank 5, and a flame nozzle 6. The fuel cylinder 1 is connected to the gas pressure reducing valve 31 and the first flow controller 41, the oxidant cylinder 2 is connected to the second gas pressure reducing valve 32 and the second flow controller 42, the first flow controller 41 and the second flow controller 42 are both connected to the premixing tank 5, and the premixing tank 5 is connected to the flame nozzle 6. The gases from the fuel cylinder 1 and the oxidant cylinder 2 are mixed in the premixing tank 5, and then heated to the porous medium experimental piece 7 by the flame nozzle 6.

[0007] Furthermore, the cooling system includes a water tank 8, a water pump 9, and a third flow controller 43; the water tank 8 is connected to the water pump 9, and then to the flow controller 4, through which cooling water is supplied to the porous medium experimental piece 7 for cooling.

[0008] Furthermore, the measurement system includes a temperature sensor 10, an infrared thermal imager 11, a pressure sensor 12, and a data acquisition system 13; the temperature sensor 10 is connected to the porous media experimental piece 7, and the pressure sensor 12 is connected to the branch supplying cooling water to the porous media experimental piece 7; the measurement data of the temperature sensor 10 and the pressure sensor 12 are displayed in real time in the data acquisition system 13; the infrared thermal imager 11 measures the temperature of the heated surface of the porous media experimental piece in a non-contact manner.

[0009] The present invention also relates to a method for using the above-mentioned phase change sweating cooling experimental device based on high-temperature premixed flame jet, comprising the following steps:

[0010] S1. Turn on water pump 9 to supply cooling water; turn on first gas pressure reducing valve 31 and second gas pressure reducing valve 32 in sequence, and adjust the gas volume flow rate through first flow controller 41 and second flow controller 42; turn on data acquisition system 13 to start recording experimental data.

[0011] S2, Ignite and start the experiment; continuously monitor the temperature shown by the temperature sensor (10) and observe the condition of the porous medium experimental piece 7. After the temperature stabilizes, use the infrared thermal imager 11 to take pictures and measure the surface temperature of the experimental piece.

[0012] S3. When stopping heating, first close the ethylene cylinder 1, then close the air cylinder 2. Combustion heating ends. After the porous media blunt-headed experimental piece 7 cools to room temperature, turn off the water pump 9. The experiment ends.

[0013] Beneficial effects

[0014] The present invention aims to provide an experimental device and method for phase change sweating cooling based on high-temperature premixed flame jet, which can observe macroscopic phenomena in the phase change sweating cooling process and obtain data such as wall temperature and coolant supply pressure, providing a technical basis and data support for revealing the intrinsic mechanism of phase change sweating cooling and the flow heat transfer characteristics in porous media.

[0015] The heat source of this invention uses a high-temperature premixed flame instead of the high-temperature air under conventional conditions, eliminating the need for air heating devices and procedures. Overall, the experimental device has a simpler structure, smaller size, and is easier to operate.

[0016] The flame nozzle of this invention can be flexibly adjusted to generate heating of different intensities and ranges on porous media experimental specimens, and can simulate the actual heating conditions of high heat flux components of aircraft, thus verifying the effectiveness of sweating cooling.

[0017] The premixed flame of this invention can adjust the heating mode of porous media experimental specimens and the supply flow rate of cooling water in real time, enabling experiments on transient phase change sweating cooling to obtain the response of coolant supply pressure and wall temperature to changes in external conditions. Attached Figure Description

[0018] Figure 1 This is an experimental system diagram of a phase change sweating cooling experimental device and method based on high-temperature premixed flame jet according to the present invention.

[0019] Figure 2 This is a schematic diagram showing the heat flux density calibration results under different oxygen-fuel ratios when ethylene / air is used as a high-temperature heat source in this invention.

[0020] Figure 3 This is a schematic diagram showing the dynamic changes in cooling water supply pressure and temperature during the phase change sweating cooling experiment of a blunt-nosed body according to the present invention.

[0021] Label Explanation

[0022] 1. Fuel cylinder; 2. Oxidant cylinder; 31. First gas pressure reducing valve; 32. Second gas pressure reducing valve; 33. Third gas pressure reducing valve; 41. First flow controller; 42. Second flow controller; 5. Premixed tank; 6. Flame nozzle; 7. Porous media experimental specimen; 8. Water tank; 9. Water pump; 10. Temperature sensor; 11. Infrared thermal imager; 12. Pressure sensor; 13. Data acquisition system Detailed Implementation

[0023] like Figure 1 As shown, the phase change sweating cooling experimental device based on high-temperature premixed flame jet in this embodiment includes a high-temperature heat source heating system, a cooling system, and a measurement system.

[0024] The high-temperature heat source heating system includes a fuel cylinder (1), an oxidant cylinder (2), a first gas pressure reducing valve (31), a second gas pressure reducing valve (32), a first flow controller (41), a second flow controller (42), a premixing tank (5), and a flame nozzle (6). The fuel cylinder (1) is connected to the gas pressure reducing valve (31) and the first flow controller (41), the oxidant cylinder (2) is connected to the second gas pressure reducing valve (32) and the second flow controller (42), the first flow controller (41) and the second flow controller (42) are both connected to the premixing tank (5), and the premixing tank (5) is connected to the flame nozzle (6). The gases from the fuel cylinder (1) and the oxidant cylinder (2) are mixed in the premixing tank (5), and then heated to the porous medium experimental specimen (7) through the flame nozzle (6). The flame after ignition blows directly onto the experimental specimen, achieving the heating effect.

[0025] The heating intensity of the premixed flame on the test specimen can be adjusted by selecting the fuel / oxidizer gas source, adjusting the oxygen-fuel ratio through a flow controller, and changing the distance between the flame nozzle and the test specimen. The heating range of the premixed flame on the test specimen can be adjusted by adjusting the diameter and type of the flame nozzle and changing the distance between the flame nozzle and the test specimen. To ensure safety while achieving precise control of the fuel / oxidizer gas flow rate, remote control is required.

[0026] The cooling system includes a water tank (8), a water pump (9), and a third flow controller (43); the water tank (8) is connected to the water pump (9), and then to the flow controller (4). The flow controller (4) supplies cooling water to the porous medium test piece (7) to cool it.

[0027] The measurement system includes a temperature sensor (10), an infrared thermal imager (11), a pressure sensor (12), and a data acquisition system (13). The temperature sensor (10) is connected to the porous medium experimental piece (7), and the pressure sensor (12) is connected to the branch supplying cooling water to the porous medium experimental piece (7). The measurement data of the temperature sensor (10) and the pressure sensor (12) are displayed in real time in the data acquisition system (13). The infrared thermal imager (11) measures the temperature of the heated surface of the porous medium experimental piece in a non-contact manner.

[0028] To achieve better premixing, a premixing tank is used to premix the gas. To prevent the flame from flowing back into the oxidant gas cylinder, a one-way valve is added to the oxidant gas side and connected through a pipeline.

[0029] To prevent particulate matter or impurities in the water from clogging the porous media test specimen, deionized water was used as the coolant. The cooling water supply pressure was measured using a pressure transmitter powered by a 24V power supply; temperature was measured by connecting the positive and negative terminals of a sheathed thermocouple to the measurement and control system; the overall surface temperature of the test specimen was captured by an infrared thermal imager.

[0030] Example 1: In this example, the fuel used in the high-temperature heat source heating system is ethylene gas, and the oxidant is air.

[0031] Example 2: In this example, the porous medium experimental piece 7 in the cooling system adopts a blunt-headed body structure, which is made of sintered stainless steel particles, and the porous medium has a pore size of 70 μm.

[0032] Example 3: In this example, the cooling water in the cooling system is supplied to the porous media experimental piece 7 at a volumetric flow rate of 4 mL / min through a flow controller.

[0033] Example 4: In this example, the experimental procedure for phase change sweating cooling of a blunt-nosed body based on a high-temperature premixed flame jet is as follows:

[0034] S1. Turn on the water pump (9) to supply cooling water; turn on the first gas pressure reducing valve (31) and the second gas pressure reducing valve (32) in sequence, and adjust the gas volume flow rate through the first flow controller (41) and the second flow controller (42); turn on the data acquisition system (13) to start recording experimental data.

[0035] S2, Ignite and start the experiment; continuously monitor the temperature shown by the temperature sensor (10) and observe the condition of the porous medium experimental piece (7). After the temperature stabilizes, use an infrared thermal imager (11) to take pictures and measure the surface temperature of the experimental piece.

[0036] S3. When stopping heating, first close the ethylene gas cylinder (1), then close the air gas cylinder (2), and the combustion heating ends; after the porous media blunt head body experimental piece (7) cools down to room temperature, turn off the water pump (9), and the experiment ends.

[0037] The above description is merely an embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still make changes and variations to the technical solutions of the foregoing embodiments, or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A phase change sweating cooling experimental device based on high-temperature premixed flame jet, characterized in that, It includes a high-temperature heat source heating system, a cooling system, and a measurement system.

2. The phase change sweating cooling experimental device based on high-temperature premixed flame jet according to claim 1, characterized in that, The high-temperature heat source heating system includes a fuel cylinder (1), an oxidant cylinder (2), a first gas pressure reducing valve (31), a second gas pressure reducing valve (32), a first flow controller (41), a second flow controller (42), a premix tank (5), and a flame nozzle (6). The fuel cylinder (1) is connected to the gas pressure reducing valve (31) and the first flow controller (41), the oxidant cylinder (2) is connected to the second gas pressure reducing valve (32) and the second flow controller (42), the first flow controller (41) and the second flow controller (42) are both connected to the premix tank (5), and the premix tank (5) is connected to the flame nozzle (6).

3. The experimental apparatus and method for phase change sweating cooling based on high-temperature premixed flame jet according to claim 1, characterized in that, The cooling system includes a water tank (8), a water pump (9), and a third flow controller (43); the water tank (8) is connected to the water pump (9), and then to the flow controller (4).

4. The phase change sweating cooling experimental device based on high-temperature premixed flame jet according to claim 1, characterized in that, The measurement system includes a temperature sensor (10), an infrared thermal imager (11), a pressure sensor (12), and a data acquisition system (13). The temperature sensor (10) is connected to the porous medium experimental piece (7), and the pressure sensor (12) is connected to the branch supplying cooling water to the porous medium experimental piece (7). The measurement data of the temperature sensor (10) and the pressure sensor (12) are displayed in real time in the data acquisition system (13). The infrared thermal imager (11) measures the temperature of the heated surface of the porous medium experimental piece in a non-contact manner.

5. A method for using the phase change sweating cooling experimental apparatus based on a high-temperature premixed flame jet as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. Turn on the water pump (9) to supply cooling water; turn on the first gas pressure reducing valve (31) and the second gas pressure reducing valve (32) in sequence, and adjust the gas volume flow rate through the first flow controller (41) and the second flow controller (42); turn on the data acquisition system (13) to start recording experimental data. S2, Ignite and start the experiment; continuously monitor the temperature shown by the temperature sensor (10) and observe the condition of the porous medium experimental piece (7). After the temperature stabilizes, use an infrared thermal imager (11) to take pictures and measure the surface temperature of the experimental piece. S3. When stopping heating, first close the ethylene gas cylinder (1), then close the air gas cylinder (2), and the combustion heating ends; after the porous media blunt head body experimental piece (7) cools down to room temperature, turn off the water pump (9), and the experiment ends.

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