A supercritical hydrocarbon fuel flow heat transfer mechanism experimental system

Abstract

The present invention discloses a supercritical hydrocarbon fuel flow heat exchange mechanism experimental system, including a vacuum insulation chamber, a sampling system, a condensation system, a power supply system and a back pressure valve; wherein the fuel tank is used to introduce hydrocarbon fuel into the experimental piece; the power supply system is used to energize and heat the experimental piece through two slide rails; the two slide rails are used to slide relatively on the rotating bracket to fix the experimental pieces of different lengths; the rotating bracket is used to rotate and fix about the rotating support shaft to achieve adjustable angle of the experimental piece; a plurality of exposed thermocouples are used to collect the wall temperature of the experimental piece; the back pressure valve is used to control the working pressure in the pipeline of the experimental system to be supercritical pressure. The system solves the problems that the existing experimental device cannot be applied to experimental pieces of various sizes, cannot deflect the angle of the experimental piece, is difficult to collect data, and cannot achieve modal conversion.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrocarbon fuel experimental devices, and in particular relates to a supercritical hydrocarbon fuel flow heat exchange mechanism experimental system. Background Art

[0002] Air-breathing ramjet engines, represented by rocket-based combined cycle engines, have obvious advantages such as high thrust-to-weight ratio and high specific impulse. Under the dual effects of aerodynamic heating and heat release from fuel combustion in the combustion chamber, ramjet engines face an extremely harsh thermal environment. Thermal protection technology has become a key factor restricting the development of hypersonic aircraft.

[0003] Regenerative cooling is considered to be the best cooling method for rocket-based combined cycle engines, but the flow and heat transfer of fuels under supercritical pressure involved are quite complex. On the one hand, due to the multi-modal and highly maneuverable working characteristics of rocket-based combined cycle engines, the heat load distribution on the regenerative cooling wall of the combustion chamber is uneven; on the other hand, due to the drastic changes in the physical properties of hydrocarbon fuels under supercritical pressure as the temperature rises, the heat transfer efficiency in the cooling channel is difficult to evaluate. In addition, at temperatures above 750K, hydrocarbon fuels will also undergo violent chemical reactions such as cracking, endothermic reaction, and coking, making the flow and heat transfer characteristics in the active regenerative cooling channel extremely complex, which poses a huge challenge to the design of the cooling system of rocket-based combined cycle engines.

[0004] Therefore, in order to improve the understanding of the flow and heat transfer characteristics of hydrocarbon fuels under supercritical pressure and obtain the active cooling laws under typical engine operating conditions, it is necessary to carry out a large number of experimental studies on the mechanism of hydrocarbon fuels, reveal the flow and heat transfer of hydrocarbon fuels and the release mechanism of chemical heat sink in the regenerative cooling channel, and ultimately support the establishment of efficient regenerative cooling structure design methods.

[0005] In the existing experimental system for studying the mechanism of hydrocarbon fuels, the length and angle of the experimental fixture are fixed and cannot be adjusted, which imposes certain constraints on the size of the experimental piece and the experimental conditions, making it impossible to simulate the influence of the buoyancy of the engine on the flow and heat transfer of hydrocarbon fuels under specific maneuvering conditions. In addition, the existing experimental system does not have a control terminal that can pre-design the experimental sequence, so it is impossible to implement some complex modal conversion processes. Summary of the invention

[0006] The purpose of the present invention is to provide a supercritical hydrocarbon fuel flow heat transfer mechanism experimental system to solve the problems that the existing experimental equipment cannot be applied to experimental pieces of various sizes, cannot deflect the angle of the experimental piece, has difficulty in data collection, and cannot achieve modal conversion.

[0007] The present invention adopts the following technical solution: a supercritical hydrocarbon fuel flow heat transfer mechanism experimental system, comprising:

[0008] A hollow vacuum insulation chamber, wherein the vacuum insulation chamber is specifically provided with:

[0009] A rotating support shaft is a column structure and is fixedly arranged vertically on the inner wall of the vacuum insulation chamber;

[0010] A rotating bracket is a rod-shaped structure, which is vertically mounted on the rotating support shaft and is used to rotate around the rotating support shaft;

[0011] Two slide rails are respectively installed at two ends of the rotating bracket;

[0012] A test piece, which is a hollow tube, with both ends mounted on two slide rails;

[0013] A plurality of exposed thermocouples are arranged at intervals on the outer wall of the test piece;

[0014] The experimental system also includes:

[0015] A sampling system having a fuel tank filled with hydrocarbon fuel; the fuel tank is connected to the inlet end of the test piece;

[0016] a condensation system having a condenser; the condenser is connected to the outlet end of the test piece;

[0017] a power supply system, the positive and negative electrodes of which are respectively connected to the two slide rails;

[0018] a back pressure valve connected to the outlet of the condenser;

[0019] Among them, the fuel tank is used to supply hydrocarbon fuel into the experimental piece; the power supply system is used to power and heat the experimental piece through two slide rails; the two slide rails are used to slide relative to each other on the rotating bracket to fix experimental pieces of different lengths; the rotating bracket is used to rotate and fix about the rotating support axis to achieve adjustable angle of the experimental piece; multiple exposed thermocouples are used to collect the wall temperature of the experimental piece; the back pressure valve is used to control the working pressure in the experimental system pipeline to supercritical pressure.

[0020] Furthermore, the inlet end of the experimental piece is connected to the fuel tank through an incoming metal hose, and the outlet end of the experimental piece is connected to the condenser through an outgoing metal hose.

[0021] Furthermore, a No. 1 armored thermocouple and a No. 1 pressure sensor are provided at the connection between the experimental piece and the access metal hose, and the No. 1 armored thermocouple and the No. 1 pressure sensor are used to collect the temperature and flow pressure of the hydrocarbon fuel at the inlet end of the experimental piece respectively;

[0022] A No. 2 armored thermocouple and a No. 2 pressure sensor are provided at the connection between the test piece and the metal hose. The No. 2 armored thermocouple and the No. 2 pressure sensor are used to collect the temperature and flow pressure of the hydrocarbon fuel at the outlet of the test piece, respectively.

[0023] Furthermore, the experimental system also includes a communication module, and the data lines of each exposed thermocouple, No. 1 armored thermocouple, No. 1 pressure sensor, No. 2 armored thermocouple and No. 2 pressure sensor are all aggregated to the communication module, and the communication module inputs the collected data into the display device for real-time display.

[0024] Furthermore, the fuel tank is connected to the inlet end of the experimental piece through a filter, a constant flow metering pump, a one-way valve, a flow meter and an inlet switch valve in sequence, and a No. 1 pressure gauge is also provided at the outlet of the inlet switch valve.

[0025] Furthermore, the constant flow metering pump is in communication connection with a control terminal via the communication module, and the control terminal is used to adjust the flow rate of the hydrocarbon fuel by controlling the mass flow rate of the constant flow metering pump.

[0026] Furthermore, the power supply system includes a programmable DC power supply, on which a first electrode as a positive electrode and a second electrode as a negative electrode are provided, and the first electrode and the second electrode are electrically connected to the two slide rails respectively;

[0027] The programmable DC power supply is also connected to the control terminal through the communication module; the control terminal is used to control the current change of the power supply system.

[0028] Furthermore, the experimental system also includes a nitrogen bottle, the outlet of the nitrogen bottle passes through a nitrogen switch valve and merges with the outlet of the flow meter, and then is connected to the inlet of the inlet switch valve.

[0029] Furthermore, a No. 3 armored thermocouple and a No. 2 pressure gauge are connected in sequence between the outlet of the condenser and the back pressure valve, and a waste liquid recovery barrel is connected to the outlet of the back pressure valve.

[0030] Furthermore, the experimental system also includes a thermal imager, the lens of which is arranged toward the experimental piece, and is used to obtain a temperature cloud map of the surface of the experimental piece, and input the temperature cloud map to a display device for display through a communication module.

[0031] The beneficial effects of the present invention are:

[0032] (1) The two slide rails designed in the present invention can slide relative to each other on the rotating bracket, and the distance between the two slide rails can be changed to match and fix test pieces of different lengths. After conducting different experiments or changing the length of the test piece, there is no need to redesign a set of fixed structures to cope with the changes;

[0033] (2) In traditional experimental devices, the experimental pieces are placed in a heat-insulating chamber with heat-insulating cotton. However, the vacuum heat-insulating chamber designed in the present invention is made of transparent materials and does not require heat-insulating cotton. In addition, the transparent vacuum heat-insulating chamber provides the possibility of applying many advanced data collection technologies, and can obtain more comprehensive and richer experimental data for scientific research.

[0034] (3) The rotating bracket designed in the present invention can be rotated and fixed about the rotating support axis to achieve adjustable angle of the experimental piece, which is convenient for studying the influence of buoyancy on the flow and heat transfer of the experimental piece placed at different angles, and can provide a clearer understanding of the influence law of buoyancy;

[0035] (4) The experimental device of the present invention can summarize and display various data collected by all sensors in real time. The control modules of the programmable DC power supply and the constant current metering pump are managed by the control terminal. According to the actual experimental requirements, the experimental timing is pre-designed in the control terminal, and the experimental working conditions can be automatically converted during the experiment, conveniently realizing the complex modal conversion process. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural schematic diagram of a supercritical hydrocarbon fuel flow heat transfer mechanism experimental system of the present invention;

[0037] Figure 2 for Figure 1 Schematic diagram of the internal structure of the vacuum insulation chamber;

[0038] Figure 3 It is the experimental temperature data trend diagram of the embodiment.

[0039] Among them, 1. Fuel tank, 2. Filter, 3. Constant flow metering pump, 4. Check valve, 5. Mass flow meter, 6. Nitrogen switch valve, 7. Nitrogen bottle, 8. Inlet switch valve, 9. No. 1 pressure gauge, 10. Vacuum insulation chamber, 11. Access metal hose, 12. No. 1 armored thermocouple, 13. No. 1 pressure sensor, 14. Rotating bracket, 15. Rotating support shaft, 16. Slide rail, 17. Experimental piece, 18. No. 2 armored thermocouple, 19. No. 2 pressure sensor, 20. Access metal hose, 21. No. 1 electrode, 22. Programmable DC power supply, 23. No. 2 electrode, 24. Condenser, 25. No. 3 armored thermocouple, 26. No. 2 pressure gauge, 27. Back pressure valve, 28. Waste liquid recovery barrel, 29. Exposed thermocouple, 30. Thermal imager, 31. Communication module, 32. Control terminal, 33. Exhaust pipe, 34. Sensor line outlet, 35. Cable line outlet. DETAILED DESCRIPTION

[0040] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] The present invention provides a supercritical hydrocarbon fuel flow heat transfer mechanism experimental system, such as Figure 1 As shown, it includes a vacuum insulation chamber 10, a sampling system, a condensation system, a power supply system and a back pressure valve 27.

[0042] Among them, Figure 2As shown, the vacuum insulation chamber 10 is a hollow box structure, the vacuum insulation chamber 10 has an openable chamber door, and a vacuum exhaust pipe 33 for evacuating the vacuum insulation chamber 10 is connected to the vacuum insulation chamber 10. A rotating support shaft 15, a rotating bracket 14, two slide rails 16, a test piece 17 and a plurality of exposed thermocouples 29 are arranged in the vacuum insulation chamber 10.

[0043] The rotating support shaft 15 is a columnar structure, which is fixedly arranged vertically on the inner wall of the vacuum insulation chamber 10. The rotating bracket 14 is a rod-shaped structure, which is vertically mounted on the rotating support shaft 15 and is used to rotate around the rotating support shaft 15. After the rotating bracket 14 is mounted on the rotating support shaft 15, the angle of the rotating bracket 14 is adjusted according to the needs of the experimental conditions, and then a sleeve is threadedly connected to the end of the rotating support shaft 15, and the rotating bracket 14 is fixed at any angle by tightening the sleeve. Two slide rails 16 are respectively installed at both ends of the rotating bracket 14. The experimental piece 17 is a hollow tube, and its two ends are detachably mounted on the two slide rails 16. A plurality of exposed thermocouples 29 are arranged at intervals on the outer wall of the experimental piece 17.

[0044] The sampling system has a fuel tank 1 filled with hydrocarbon fuel, and the fuel tank 1 is connected to the inlet end of the experimental piece 17. The condensation system has a condenser 24, and the condenser 24 is connected to the outlet end of the experimental piece 17. The positive and negative poles of the power supply system are respectively connected to the two slide rails 16. A cable outlet 35 is provided on the outer wall of the vacuum insulation chamber 10, and the wires of the power supply system enter the vacuum insulation chamber 10 through the cable outlet 35 and are connected to the two slide rails 16. The back pressure valve 27 is connected to the outlet of the condenser 24. By screwing the back pressure valve 27, the working pressure in the pipeline of the experimental system can be manually controlled to be supercritical pressure and kept constant.

[0045] The fuel tank 1 is used to pass hydrocarbon fuel into the test piece 17. The power supply system is used to energize and heat the test piece 17 through the two slide rails 16. Since the contact part between the slide rail 16 and the rotating bracket 14 is a high temperature resistant insulating pad after power is turned on, the slide rail 16 is insulated from the rotating bracket 14; the outside of the slide rail 16 is a conductive material, so the slide rail 16 and the test piece 17 are conductive, and the test piece 17 is heated.

[0046] The two slide rails 16 are used to slide relative to each other on the rotating bracket 14 to fix the experimental pieces 17 of different lengths; the rotating bracket 14 is used to rotate and fix about the rotating support shaft 15 to achieve adjustable angle of the experimental piece 17; and multiple exposed thermocouples 29 are used to collect the wall temperature of the experimental piece 17.

[0047] In some embodiments, the inlet end of the test piece 17 is connected to the fuel tank 1 through the incoming metal hose 11, and the outlet end of the test piece 17 is connected to the condenser 24 through the outgoing metal hose 20. The lengths of the incoming metal hose 11 and the outgoing metal hose 20 are adjustable so that they can be stretched along with the rotation of the test piece 17, so as to facilitate the cooperation to achieve the angle change of the test piece 17.

[0048] In some embodiments, a No. 1 armored thermocouple 12 and a No. 1 pressure sensor 13 are connected to the connection between the experimental piece 17 and the access metal hose 11 through a four-way connector. The No. 1 armored thermocouple 12 and the No. 1 pressure sensor 13 are respectively used to collect the temperature and flow pressure of the hydrocarbon fuel at the inlet end of the experimental piece 17.

[0049] A No. 2 armored thermocouple 18 and a No. 2 pressure sensor 19 are connected to the connection between the test piece 17 and the outlet metal hose 20 through a four-way connector. The No. 2 armored thermocouple 18 and the No. 2 pressure sensor 19 are used to collect the hydrocarbon fuel temperature and flow pressure at the outlet end of the test piece 17 respectively.

[0050] In some embodiments, the experimental system further includes a communication module 31, which is located outside the vacuum insulation chamber 10. At least one sensor line outlet 34 is provided on the side wall of the vacuum insulation chamber 10, and the data lines of each exposed thermocouple 29, No. 1 armored thermocouple 12, No. 1 pressure sensor 13, No. 2 armored thermocouple 18 and No. 2 pressure sensor 19 are all led out through the sensor line outlet 34 and aggregated to the communication module 31. The communication module 31 is connected to a display device, and the collected data can be input into the display device for real-time display.

[0051] In some embodiments, the fuel tank 1 is connected to the inlet end of the experimental piece 17 through the filter 2, the constant flow metering pump 3, the one-way valve 4, the flow meter 5 and the inlet switch valve 8 in sequence, and a No. 1 pressure gauge 9 is also provided at the outlet of the inlet switch valve 8. The constant flow metering pump 3 is used to introduce hydrocarbon fuel into the pipeline of the experimental system in the working state. The filter 2 is used to filter out solid impurities in the hydrocarbon fuel to prevent the constant flow metering pump 3 from being blocked. The one-way valve 4 is used to avoid damage to the constant flow metering pump 3 due to the backflow of the hydrocarbon fuel. The data of the flow meter 5 can be input to the display device through the communication module 31 for real-time display.

[0052] In some embodiments, the constant current metering pump 3 is connected to a control terminal 32 through a communication module 31, and the control terminal 32 is used to adjust the flow rate of hydrocarbon fuel by controlling the mass flow rate of the constant current metering pump 3. The control terminal 32 manages the control modules of multiple devices such as the programmable DC power supply 22 and the constant current metering pump 3. According to the experimental requirements of multi-modal conversion in the working process of the rocket-based combined cycle engine, the experimental sequence is pre-designed, and the flow rate of hydrocarbon fuel can be regulated, and the current change of the power supply system can be regulated, thereby realizing the multi-modal conversion process of automatically converting the experimental working conditions.

[0053] In some embodiments, the power supply system includes a programmable DC power supply 22, on which a first electrode 21 as a positive electrode and a second electrode 23 as a negative electrode are provided, and the first electrode 21 and the second electrode 23 are electrically connected to the two slide rails 16 respectively;

[0054] The programmable DC power supply 22 is also connected to the control terminal 32 through the communication module 31; the control terminal 32 is used to control the current change of the power supply system to achieve different working conditions.

[0055] In some embodiments, the experimental system further includes a nitrogen bottle 7, the outlet of the nitrogen bottle 7 passes through the nitrogen switch valve 6 and merges with the outlet of the flow meter 5, and then is connected to the inlet of the inlet switch valve 8. The nitrogen bottle 7 and the nitrogen switch valve 6 form a branch, and are connected to the experimental system through a three-way connector, which is used to remove impurities and waste in the experimental pipeline before and after the experiment.

[0056] In some embodiments, a No. 3 armored thermocouple 25 and a No. 2 pressure gauge 26 are connected in sequence between the outlet of the condenser 24 and the back pressure valve 27 , and a waste liquid recovery barrel 28 is also connected to the outlet of the back pressure valve 27 .

[0057] The outlet of the condenser 24 is connected in sequence with a No. 3 armored thermocouple 25, a No. 2 pressure gauge 26, a back pressure valve 27 and a waste liquid recovery barrel 28. The hydrocarbon fuel after the reaction is cooled by the condenser 24 and flows into the waste liquid recovery barrel 28 for collection. By screwing the back pressure valve 27, the working pressure in the pipeline of the experimental system can be manually controlled to be supercritical pressure and kept constant. The data collected by the No. 3 armored thermocouple 25 can be input to the display device through the communication module 31 for real-time display.

[0058] In some embodiments, the experimental system further includes a thermal imager 30 , the lens of which is arranged toward the experimental piece 17 , and is used to obtain a temperature cloud map on the surface of the experimental piece 17 , and input the temperature cloud map to a display device for display via a communication module 31 .

[0059] Embodiment: The unsteady-state flow heat transfer characteristics of supercritical pressure hydrocarbon fuel in a vertical regenerative cooling channel were studied using a supercritical hydrocarbon fuel flow heat transfer mechanism experimental system of the present invention. The experimental piece 17 is used to simulate the regenerative cooling channel, and the experimental piece 17 is set in a vertical state.

[0060] In the experiment, the heating heat flow of the experimental piece 17 can be changed by changing the current of the programmable DC power supply 22. For example, the phenomenon of a short-term sudden change in the heat flow of the cooling channel wall can be simulated by causing a sudden increase in the heating heat flow of the experimental piece 17. The change in the flow rate of the hydrocarbon fuel delivered by the constant flow metering pump 3 can be used to simulate the change in the flow rate of the hydrocarbon fuel during the engine mode transition.

[0061] The experimental process of this embodiment is as follows:

[0062] S1. Fix both ends of the test piece 17 on the slide rail 16, fix the slide rail 16 on the rotating bracket 14, rotate the rotating bracket 14 to a vertical position and fix it, and connect the incoming metal pipe 11 and the outgoing metal pipe 20 to the inlet and outlet of the test piece 17 respectively through a four-way connector;

[0063] S2, using an electric welder to weld eight exposed thermocouples 29 evenly and at intervals on the outer wall of the experimental piece 17; the first electrode 21 connects the positive pole of the programmable DC power supply 22 to the slide rail 16 near the entrance end of the experimental piece 17, and the second electrode 23 connects the negative pole of the programmable DC power supply 22 to the slide rail 16 near the exit end of the experimental piece 17;

[0064] S3, close the door of the vacuum insulation chamber 10 and lock it, evacuate the vacuum insulation chamber 10 to make the vacuum insulation chamber 10 reach a vacuum state; then open the nitrogen switch valve 6, blow air into the pipeline where it is located, and after blowing for a period of time, close the nitrogen switch valve 6;

[0065] S4, open the one-way valve 4 and the inlet switch valve 8, then screw the back pressure valve 27 to manually control the working pressure in the pipeline to 5MPa; then turn on the constant flow metering pump 3, start filling the pipeline with hydrocarbon fuel, and the pressure in the pipeline gradually increases; observe the pressure values ​​of the No. 1 pressure gauge 9, the No. 1 pressure sensor 13 and the No. 2 pressure sensor 19, and when the pressure values ​​all reach 5MPa and stabilize, control the constant flow metering pump 3 to stop working;

[0066] S5. Set the experimental sequence in the control terminal 32 according to the contents of Table 1, then start the condensation system, and then start the experimental sequence through the control terminal 32; during the experimental sequence, the mass flow meter 5, the thermal imager 30, the No. 1 armored thermocouple 12, the No. 2 armored thermocouple 18, all exposed thermocouples 29, the No. 1 pressure sensor 13 and the No. 2 pressure sensor 19 can monitor and record multi-modal temperature, pressure, flow and pressure difference signals; the experimental sequence designed in this embodiment is shown in Table 1;

[0067] S6. After sequence 4 ends, the control terminal 32 turns off the power supply system, and at the same time observes the temperature values ​​collected by the exposed thermocouple 29, the first armored thermocouple 12, and the second armored thermocouple 18. When these three temperatures drop to room temperature, manually turn off the constant flow metering pump 3, open the nitrogen switch valve 6, and use nitrogen to blow out the residual fuel and reaction impurities in the pipeline. After blowing nitrogen for three minutes, close the one-way valve 4 and the inlet switch valve 8, and the experiment ends. In the experiment, the high-temperature hydrocarbon fuel after the reaction is cooled by the condenser 24 and flows into the waste liquid recovery barrel 28 for collection.

[0068] Table 1 Timing parameters

[0069]

[0070] After the experiment is completed, the experimental data such as the pressure drop at the inlet and outlet of the experimental piece 17, the distribution of the wall temperature, and the temperature of the hydrocarbon fuel at the inlet and outlet are extracted from the control terminal 32. The experimental temperature data trend is constructed through these experimental data. Figure 3 .

[0071] 1. If Figure 3 As shown, in order to ensure the safety of the experimenters, at the beginning of the experiment, in the timing 1 stage, only the constant current metering pump 3 is turned on, and its fuel flow rate is 1g / s, and the programmable DC power supply 22 is not working.

[0072] 2. If Figure 3 As shown, in the timing 2 stage, the fuel flow rate of the constant current metering pump 3 is maintained at 1g / s, the current value of the programmable DC power supply 22 reaches 50A, the tube wall temperature value rises sharply, and then enters a long-term stable stage, and the outlet temperature of the experimental piece 17 rises slowly and tends to be stable. Among them, at 31s, due to the influence of the current on the data acquisition process of the exposed thermocouple 29, the tube wall temperature value will have a short-term surge, and then return to normal value.

[0073] 3. If Figure 3As shown, in the timing stage 3, the opening of the one-way valve 4 and the inlet switch valve 8 is maintained, the current value of the programmable DC power supply 22 is controlled to increase to 80A, the fuel flow rate of the constant current metering pump 3 is increased to 1.5g / s, the tube wall temperature changes sharply in a short time, and then enters a long-term stable stage, and the outlet temperature of the experimental piece 17 rises slowly and tends to stabilize.

[0074] 4. If Figure 3 As shown, in the timing stage 4, the programmable DC power supply 22 is turned off, the fuel flow rate of the constant current metering pump 3 is increased to 3g / s, the tube wall temperature drops rapidly, and the outlet temperature of the test piece 17 slowly decreases and tends to be stable.

[0075] 5. If Figure 3 As shown, in the four time sequences in this experiment, the outlet temperature of the condenser 24 and the inlet temperature of the test piece 17 are both kept at room temperature.

[0076] In summary, when a supercritical hydrocarbon fuel flow heat transfer mechanism experimental system of the present invention is used to conduct a non-steady-state flow heat transfer characteristics experiment in a regenerative cooling channel, data such as the pressure drop at the inlet and outlet of the experimental piece 17, the wall temperature distribution, and the inlet and outlet fuel temperature can be obtained, which can be compared and verified with the numerical simulation results, and then the convective heat transfer characteristics of the hydrocarbon fuel under the supercritical pressure state can be analyzed, revealing the influence mechanism of buoyancy on the flow heat transfer process of the hydrocarbon fuel in the experimental piece under the supercritical pressure state, and obtaining the heat transfer change law of the hydrocarbon fuel in the non-steady-state process under the supercritical pressure state.

Claims

1. A supercritical hydrocarbon fuel flow heat transfer mechanism experimental system, characterized in that: include: A hollow vacuum insulation chamber (10), wherein the vacuum insulation chamber (10) is specifically provided with: a rotating support shaft (15) having a columnar structure and fixedly disposed perpendicularly to the inner wall of the vacuum insulation chamber (10); a rotating bracket (14) which is a rod-shaped structure and is vertically mounted on the rotating support shaft (15) and is used to rotate around the rotating support shaft (15); Two slide rails (16) are respectively mounted on two ends of the rotating bracket (14); A test piece (17), which is a hollow tube, with both ends mounted on the two slide rails (16); A plurality of exposed thermocouples (29) arranged at intervals on the outer wall of the experimental piece (17); The experimental system also includes: A sampling system comprising a fuel tank (1) filled with hydrocarbon fuel; the fuel tank (1) is connected to the inlet end of the test piece (17); A condensation system having a condenser (24); the condenser (24) is connected to the outlet end of the test piece (17); a power supply system, the positive and negative electrodes of which are respectively connected to the two slide rails (16); a back pressure valve (27) connected to the outlet of the condenser (24); The fuel tank (1) is used to supply hydrocarbon fuel to the experimental piece (17); the power supply system is used to electrically heat the experimental piece (17) through the two slide rails (16); the two slide rails (16) are used to slide relative to each other on the rotating bracket (14) to fix the experimental pieces (17) of different lengths; the rotating bracket (14) is used to rotate and fix about the rotating support shaft (15) to achieve adjustable angle of the experimental piece (17); the plurality of exposed thermocouples (29) are used to collect the wall temperature of the experimental piece (17); and the back pressure valve (27) is used to control the working pressure in the pipeline of the experimental system to be a supercritical pressure.

2. A supercritical hydrocarbon fuel flow heat transfer mechanism experimental system as claimed in claim 1, characterized in that: The inlet end of the test piece (17) is connected to the fuel tank (1) via an incoming metal hose (11), and the outlet end of the test piece (17) is connected to a condenser (24) via an outgoing metal hose (20).

3. A supercritical hydrocarbon fuel flow heat transfer mechanism experimental system as claimed in claim 2, characterized in that: A No. 1 armored thermocouple (12) and a No. 1 pressure sensor (13) are provided at the connection between the experimental piece (17) and the access metal hose (11), and the No. 1 armored thermocouple (12) and the No. 1 pressure sensor (13) are used to collect the temperature and flow pressure of the hydrocarbon fuel at the inlet end of the experimental piece (17), respectively; A No. 2 armored thermocouple (18) and a No. 2 pressure sensor (19) are provided at the connection between the experimental piece (17) and the outlet metal hose (20). The No. 2 armored thermocouple (18) and the No. 2 pressure sensor (19) are used to collect the temperature and flow pressure of the hydrocarbon fuel at the outlet end of the experimental piece (17), respectively.

4. A supercritical hydrocarbon fuel flow heat transfer mechanism experimental system as claimed in claim 3, characterized in that: The experimental system further comprises a communication module (31), and data lines of each of the exposed thermocouple (29), the No. 1 armored thermocouple (12), the No. 1 pressure sensor (13), the No. 2 armored thermocouple (18) and the No. 2 pressure sensor (19) are all aggregated to the communication module (31), and the communication module (31) inputs the collected data into a display device for real-time display.

5. A supercritical hydrocarbon fuel flow heat transfer mechanism experimental system as claimed in claim 4, characterized in that: The fuel tank (1) is connected to the inlet end of the test piece (17) via a filter (2), a constant flow metering pump (3), a one-way valve (4), a flow meter (5) and an inlet switch valve (8) in sequence, and a No. 1 pressure gauge (9) is also provided at the outlet of the inlet switch valve (8).

6. A supercritical hydrocarbon fuel flow heat transfer mechanism experimental system as claimed in claim 5, characterized in that: The constant flow metering pump (3) is communicatively connected to a control terminal (32) via the communication module (31), and the control terminal (32) is used to adjust the flow rate of the hydrocarbon fuel by controlling the mass flow rate of the constant flow metering pump (3).

7. A supercritical hydrocarbon fuel flow heat transfer mechanism experimental system as claimed in claim 6, characterized in that: The power supply system comprises a programmable DC power supply (22), the programmable DC power supply (22) being provided with a first electrode (21) as a positive electrode and a second electrode (23) as a negative electrode, the first electrode (21) and the second electrode (23) being electrically connected to the two slide rails (16) respectively; The programmable DC power supply (22) is also communicatively connected to the control terminal (32) via the communication module (31); the control terminal (32) is used to control current changes in the power supply system.

8. The supercritical hydrocarbon fuel flow heat transfer mechanism experimental system according to claim 5, characterized in that: The experimental system further comprises a nitrogen bottle (7), the outlet of the nitrogen bottle (7) passing through a nitrogen switch valve (6) and merging with the outlet of the flow meter (5), and then connected to the inlet of an inlet switch valve (8).

9. A supercritical hydrocarbon fuel flow heat transfer mechanism experimental system as claimed in claim 1 or 2, characterized in that: A No. 3 armored thermocouple (25) and a No. 2 pressure gauge (26) are connected in sequence between the outlet of the condenser (24) and the back pressure valve (27), and a waste liquid recovery bucket (28) is connected to the outlet of the back pressure valve (27).

10. The supercritical hydrocarbon fuel flow heat transfer mechanism experimental system according to claim 4, characterized in that: The experimental system further comprises a thermal imager (30), the lens of the thermal imager (30) being arranged toward the experimental piece (17), and being used to obtain a temperature cloud map of the surface of the experimental piece (17), and inputting the temperature cloud map to a display device for display via the communication module (31).

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