Heat and mass transfer experiment platform for divertor gas baking system

Abstract

The invention relates to the technical field of fusion devices, in particular to a heat and mass transfer experimental platform for a divertor gas baking system. According to the technical scheme, the device comprises a gas baking system, a vacuum system, a secondary side cooling system and a data acquisition and control system, the gas baking system comprises a Roots blower, the Roots blower is connected with a heat regenerator, and the heat regenerator is connected with an electric heater and a cooler; the vacuum system comprises a vacuum tank and a vacuum assembly installed on the vacuum tank, and the electric heater is connected with an experiment piece in the vacuum tank. According to the invention, a heat and mass transfer model can be established, which is helpful for understanding a heat and mass transfer rule, optimizing device design and operation, revealing an influence mechanism of baking temperature, working medium pressure and flow, ensuring baking safety and stability, and testing the influence of different gas working media on baking characteristics; the vacuum leakage characteristic can be tested, problems can be found and solved in time, and the high vacuum environment, reliability and stability of the fusion device are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of fusion devices, and in particular to a heat and mass transfer experimental platform for a divertor gas baking system. Background Art

[0002] In order to obtain the high vacuum environment required for plasma discharge in the fusion device, the internal components of the vacuum chamber need to be baked at high temperature. During the high-temperature baking process, the thermal stress caused by the uneven temperature distribution of the vacuum chamber and its internal components may cause the vacuum chamber and its internal components to deform or break; in order to study the conjugate heat transfer phenomenon between the divertor and nitrogen and the heat transfer balance characteristics of the baking system. This application proposes a heat and mass transfer experimental platform for the divertor gas baking system. Summary of the invention

[0003] The purpose of the present invention is to propose a heat and mass transfer experimental platform for a divertor gas baking system to address the problem in the background technology that thermal stress caused by uneven temperature distribution of the vacuum chamber and its internal components during high-temperature baking may cause deformation or fracture of the vacuum chamber and its internal components.

[0004] The technical solution of the present invention is a heat and mass transfer experimental platform for a divertor gas baking system, comprising:

[0005] An air baking system, the air baking system comprising a Roots blower, the Roots blower is connected to a regenerator, and the regenerator is respectively connected to an electric heater and a cooler;

[0006] A vacuum system, wherein the vacuum system comprises a vacuum tank and a vacuum assembly mounted on the vacuum tank, wherein the electric heater is connected to an air supply section of the experimental piece inside the vacuum tank;

[0007] A secondary cooling system for providing a cooling source for the cooler and the vacuum tank;

[0008] Data acquisition and control system connected to the vacuum tank aviation plug.

[0009] Optionally, a nitrogen tank is connected to one end of the Roots blower away from the regenerator, and a pressure reducing valve, a needle valve, a solenoid valve 1, a stop valve, a manual exhaust valve and a manual air supply valve connected in parallel with the solenoid valve 1 are connected in sequence between the nitrogen tank and the Roots blower, and the solenoid valve 1 is connected to the cooler.

[0010] Optionally, the stop valve is connected to a safety valve, and the manual exhaust valve is connected to a second solenoid valve.

[0011] Optionally, the vacuum assembly includes a vacuum gauge and a vacuum pump connected to the vacuum tank.

[0012] Optionally, the secondary side cooling system includes a refrigeration unit with adjustable water outlet pressure, the secondary side of the cooler and the interlayer of the vacuum tank are connected in parallel to the main circuit of the refrigeration unit, the main circuit of the refrigeration unit includes a bypass branch, and a ball valve is installed on the bypass branch.

[0013] Optionally, the regenerator is connected to the air return section of the experimental piece inside the vacuum tank, a reducer 1 is installed between the electric heater and the air supply section of the experimental piece inside the vacuum tank, and a reducer 2 and a flow meter are installed in sequence between the regenerator and the air return section of the experimental piece inside the vacuum tank.

[0014] Optionally, the data acquisition and control system includes a PLC control system, the PLC control system is wired to a computer, and the PLC control system is connected to the vacuum tank aviation plug.

[0015] Optionally, pressure transmitter one is installed at both ends of the Roots blower, temperature transmitter one is installed between the regenerator and the Roots blower, between the regenerator and the electric heater, and between the regenerator and the cooler, pressure transmitter two is installed between the cooler and the solenoid valve one, pressure transmitter three and temperature transmitter two are installed between the reducer one and the vacuum tank, and between the flowmeter and the vacuum tank, and solenoid valve one, solenoid valve two, pressure transmitter one, temperature transmitter one, pressure transmitter two, temperature transmitter two, and pressure transmitter three are all connected to the PLC control system.

[0016] Compared with the prior art, the present invention has at least one of the following beneficial technical effects:

[0017] The present invention can establish a heat and mass transfer model under the gas baking mode of vacuum components in a fusion device, which helps to deeply understand the laws of heat transfer and material transfer of the fusion device during high-temperature baking, and provides a theoretical basis for optimizing the design and operation of the fusion device.

[0018] The present invention can reveal the influence mechanism between the baking temperature of internal components and the pressure and flow rate of the working fluid. By accurately controlling and measuring these parameters and studying the relationship between them, the baking process can be better mastered to ensure the safety and stability of the vacuum chamber and its internal components during high-temperature baking, and to avoid deformation or fracture of the vacuum chamber and its internal components caused by thermal stress generated by uneven temperature distribution.

[0019] The present invention can test the influence of different gas working fluids on the baking characteristics of internal components of fusion devices. This is of great significance for selecting suitable gas working fluids to improve baking efficiency, reduce energy consumption and optimize baking effects, and provides more options and references for the actual operation of fusion devices.

[0020] The present invention can test the vacuum leakage characteristics of the internal components of the fusion device under the gas baking condition. This is crucial to ensure the vacuum environment of the fusion device, because a high vacuum environment is a necessary condition for the fusion device to obtain plasma discharge. By testing the vacuum leakage characteristics, potential leakage problems can be discovered and solved in a timely manner, improving the reliability and stability of the fusion device.

[0021] The present invention can establish a heat and mass transfer model, which is helpful to understand the laws of heat and mass transfer, optimize the design and operation of the device, reveal the influence mechanism of baking temperature and working fluid pressure and flow rate, ensure safe and stable baking, and can test the influence of different gas working fluids on baking characteristics, providing a basis for selecting suitable working fluids and improving efficiency; it can test vacuum leakage characteristics, discover and solve problems in time, and ensure the high vacuum environment, reliability and stability of the fusion device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a heat and mass transfer experimental platform for a divertor gas baking system;

[0023] Figure 2 This is a diagram showing the experimental stability test results of a heat and mass transfer experimental platform for a divertor gas baking system;

[0024] Figure 3 The distribution diagram of temperature measurement points on the surface of the test piece;

[0025] Figure 4 Collect result graph for the surface temperature of the test piece.

[0026] Figure numerals: 1. Roots blower; 2. Regenerator; 3. Electric heater; 4. Cooler; 5. Vacuum tank; 6. Refrigeration unit; 7. Vacuum machine; 8. Vacuum pump; 9. Nitrogen tank; 10. Pressure reducing valve; 11. Needle valve; 12. Solenoid valve one; 13. Manual air supply valve; 14. Stop valve; 15. Safety valve; 16. Manual exhaust valve; 17. Solenoid valve two; 18. Reducer one; 19. Reducer two; 20. Flow meter; 21. PLC control system; 22. Pressure transmitter one; 23. Temperature transmitter one; 24. Pressure transmitter two; 25. Temperature transmitter two; 26. Pressure transmitter three. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0028] Example

[0029] like Figure 1 As shown, a heat and mass transfer experimental platform for a divertor gas baking system proposed in the present invention includes a gas baking system, a vacuum system, a secondary side cooling system and a data acquisition and control system. Each system is described in detail below.

[0030] In this embodiment, the gas baking system includes a Roots blower 1, which is connected to a regenerator 2, which is respectively connected to an electric heater 3 and a cooler 4; the end of the Roots blower 1 away from the regenerator 2 is connected to a nitrogen tank 9, and a pressure reducing valve 10, a needle valve 11, a solenoid valve 12, a stop valve 14, a manual exhaust valve 16, and a manual air supply valve 13 connected in parallel with the solenoid valve 12 are connected between the nitrogen tank 9 and the Roots blower 1 in sequence, the solenoid valve 12 is connected to the cooler 4, the stop valve 14 is connected to a safety valve 15, and the manual exhaust valve 16 is connected to the solenoid valve 2 17. The Roots blower 1 is used as a power source, with a maximum boost of 50kPa and a maximum flow of 72Nm 3 / h, and the frequency converter is used to adjust the flow rate. The regenerator 2 is used for preheating and heat recovery, and the nitrogen at the outlet of the baking test piece is used to preheat the cold nitrogen at the outlet of the Roots blower 1. The maximum outlet temperature of the electric heater 3 is 300°C, and the temperature delivered to the inlet of the test piece is adjusted in cooperation with the data acquisition and control system. After the nitrogen at the outlet of the test piece flows through the regenerator 2 to recover heat, it is cooled to the required inlet temperature of the Roots blower 1 through a cooler 4. An automatic air supply and exhaust device is installed between the cooler 4 and the Roots blower 1, and the system pressure is adjusted by using a solenoid valve 12 in cooperation with the data acquisition and control system. In addition, the safety valve 15 mechanically releases pressure when the baking system fails and the pressure is too high.

[0031] Among them, the vacuum system includes a vacuum tank 5 and a vacuum assembly installed on the vacuum tank 5, the electric heater 3 is connected to the experimental piece air supply section inside the vacuum tank 5, and the vacuum assembly includes a vacuum gauge 7 and a vacuum pump 8 connected to the vacuum tank 5. The regenerator 2 is connected to the experimental piece air return section inside the vacuum tank 5, and a reducer 18 is installed between the electric heater 3 and the experimental piece air supply section inside the vacuum tank 5. The regenerator 2 and the experimental piece air return section inside the vacuum tank 5 are successively installed with a reducer 19 and a flow meter 20 to simulate the vacuum environment in the vacuum chamber during the baking process of the fusion device. The capacitor film vacuum gauge monitors the vacuum pressure in real time, and the minimum vacuum can be evacuated to 3.6Pa. The vacuum tank 5 is a double-walled structure, connecting the upper and lower drain ports and water inlets of the tank body. During the experiment, the cooling water enters the interlayer from the two lower water inlets, is discharged through the two upper drain ports and is connected to the secondary cooling system. Two nitrogen interfaces are left on one side of the tank body of the vacuum tank 5 to connect the gas baking system with the experimental piece. Four aviation plugs are left on the other side of the vacuum tank 5 to connect the sensor for collecting the temperature of the surface of the test piece and the inner surface of the vacuum tank 5 to the data acquisition and control system.

[0032] In addition, the secondary cooling system is used to provide a cold source for the cooler 4 and the vacuum tank 5; the secondary cooling system includes a refrigeration unit 6 with adjustable water outlet pressure, and the refrigeration unit 6 is a refrigerator, which belongs to the prior art. The refrigerator refers to a mechanical device that uses a compressor to change the pressure change of the refrigerant gas to achieve low-temperature refrigeration. The refrigerator is one of the most important components of compression refrigeration equipment. The refrigerator is composed of five major parts connected in series: a compressor, a condenser, an evaporator, a drying filter, and an expansion throttle valve. An appropriate amount of refrigerant is injected into it, and the electrical appliance controls the operation of the compressor according to the needs of the environment to achieve the purpose of refrigeration and heat transfer. The secondary side of the cooler 4 and the interlayer of the vacuum tank 5 are connected in parallel to the main circuit of the refrigeration unit 6. The main circuit of the refrigeration unit 6 includes a bypass branch, and a ball valve is installed on the bypass branch. The ball valve is used to adjust the flow rate.

[0033] In this embodiment, the vacuum system is connected to the data acquisition and control system, which includes a PLC control system 21, which is wired to a computer, and the PLC control system 21 is connected to the aviation plug of the vacuum tank 5; wherein, pressure transmitter 1 22 is installed at both ends of the Roots blower 1, temperature transmitter 1 23 is installed between the regenerator 2 and the Roots blower 1, between the regenerator 2 and the electric heater 3, and between the regenerator 2 and the cooler 4, pressure transmitter 2 24 is installed between the cooler 4 and the solenoid valve 12, pressure transmitter 3 26 and temperature transmitter 2 25 are installed between the reducer 18 and the vacuum tank 5, and between the flowmeter 20 and the vacuum tank 5, and solenoid valve 12, solenoid valve 2 17, pressure transmitter 1 22, temperature transmitter 1 23, pressure transmitter 2 24, temperature transmitter 2 25, and pressure transmitter 3 26 are all connected to the PLC control system 21. The thermal hydraulic parameters of the characteristic points in the baking system are collected through pressure transmitter 1 22, temperature transmitter 1 23, pressure transmitter 2 24, temperature transmitter 2 25, pressure transmitter 3 26 and flow meter 20. The temperature parameters of the experimental piece and the inner surface of the vacuum tank 5 are collected through PT100 thermal resistor. The PLC control system 21 is a PLC control cabinet. The frequency converter in the PLC control cabinet adjusts the system air volume, controls the temperature of the heater outlet through the PID algorithm, controls the automatic opening and closing of the solenoid valve 1 12 and the solenoid valve 2 17 to complete the filling and exhaust functions, and adjusts the system pressure. The PLC control system 21 cooperates with the computer to realize the real-time monitoring and storage functions of the parameters, as well as the remote control functions of the system equipment and valves.

[0034] Experimental verification

[0035] The technical effect of the heat and mass transfer experimental platform of the divertor gas baking system of the present invention is verified.

[0036] Experimental steps:

[0037] 1. Before the experiment begins, start the vacuum pump 8, reduce the pressure in the vacuum tank 5 to 3.6 Pa and keep the vacuum pump 8 running;

[0038] 2. Open the outlet of the nitrogen tank 9 and the pressure reducing valve 10, close the manual air supply valve 13, turn on the automatic opening and closing functions of the electromagnetic control valve 12 and the electromagnetic valve 2 17, and set the pressure range of automatic air supply and exhaust;

[0039] 3. Start Roots blower 1 and set the operating frequency of Roots blower 1 to reach the system target flow;

[0040] 4. Start heater 3, set the outlet temperature of heater 3, input P and I values, wait for the outlet temperature of heater 3 to stabilize, and observe whether the actual outlet temperature of heater 3 oscillates or remains stable within the acceptable range of the set temperature value. If it is within the acceptable range, proceed to the next step of the experiment; if the actual temperature deviates too much from the set value, readjust the P and I values ​​and repeat the above operation;

[0041] 5. Start the refrigeration unit 6 and set the outlet water temperature. After the system is stable, observe whether the water temperature of the temperature transmitter 24 at the cooler 4 port is lower than 40°C. If it does not reach the target value, adjust the set water temperature of the refrigeration unit 6;

[0042] After all systems are stable, record the key hot liquid parameters and all PT100 parameters of the baking system;

[0043] 6. Adjust the frequency of Roots blower 1 / heater 3 outlet set temperature to change the inlet parameters of the test piece, and repeat steps 4 and 5;

[0044] 7. At the end of the experiment, turn off the heater 3 and the vacuum pump 8;

[0045] 8. After the temperature drops to near room temperature, close the nitrogen tank 9 and the pressure reducing valve 10, and turn off the Roots blower 1 and the refrigeration unit 6.

[0046] Experimental data

[0047] Table 1 Completion status of monitoring points

[0048]

[0049] Experimental conclusion

[0050] The stability test of the experimental platform shows that the experimental platform can perform repeatable experiments well. Figure 2 It shows that when the system is running stably, the flow, pressure and temperature parameters of the key points of the system are stably output through the data acquisition and control system. Figure 3 , the temperature of key points on the surface of the test piece is measured using PT100 thermal resistor, and the following data can be collected: Figure 4The real-time temperature of each temperature characteristic point of the experimental piece during the baking process is shown. After multiple rounds of experiments, the experimental platform can heat the inlet temperature of the experimental piece to above 150°C under the experimental design pressure of 1.1-1.3 bar (G), meeting the temperature requirements of fusion baking.

[0051] The platform of the present invention can establish a heat and mass transfer model under the gas baking mode of vacuum components in a fusion device, which helps to deeply understand the laws of heat transfer and material transfer of the fusion device during high-temperature baking, and provides a theoretical basis for optimizing the design and operation of the fusion device.

[0052] The platform can reveal the influence mechanism between the baking temperature of internal components and the working fluid pressure and flow rate. By precisely controlling and measuring these parameters and studying their interrelationships, we can better understand the baking process, ensure the safety and stability of the vacuum chamber and its internal components during high-temperature baking, and avoid deformation or fracture of the vacuum chamber and its internal components caused by thermal stress generated by uneven temperature distribution.

[0053] This platform can test the effects of different gas working fluids on the baking characteristics of the internal components of the fusion device. This is of great significance for selecting the appropriate gas working fluid to improve baking efficiency, reduce energy consumption, and optimize baking effects, and provides more options and references for the actual operation of the fusion device. For example, the baking effects of different gas working fluids such as nitrogen and helium on internal components under the same conditions can be compared experimentally, including differences in temperature distribution, thermal stress, etc., to determine the most suitable gas working fluid.

[0054] This platform can test the vacuum leakage characteristics of the internal components of the fusion device under the gas baking condition. This is crucial to ensure the vacuum environment of the fusion device, because a high vacuum environment is a necessary condition for the fusion device to obtain plasma discharge. By testing the vacuum leakage characteristics, potential leakage problems can be discovered and solved in a timely manner, improving the reliability and stability of the fusion device.

[0055] The above specific embodiments are only several optional embodiments of the present invention. Based on the technical solutions of the present invention and the relevant inspirations of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A heat and mass transfer experimental platform for divertor gas baking system, characterized in that: include: An air baking system, the air baking system comprising a Roots blower (1), the Roots blower (1) being connected to a regenerator (2), the regenerator (2) being respectively connected to an electric heater (3) and a cooler (4); A vacuum system, the vacuum system comprising a vacuum tank (5) and a vacuum assembly mounted on the vacuum tank (5), the electric heater (3) being connected to an air supply section of the experimental piece inside the vacuum tank (5); A secondary cooling system for providing a cooling source for the cooler (4) and the vacuum tank (5); A data acquisition and control system connected to the aviation plug of the vacuum tank (5).

2. A heat and mass transfer experimental platform for divertor gas baking system according to claim 1, characterized in that: The end of the Roots blower (1) away from the regenerator (2) is connected to a nitrogen tank (9), and a pressure reducing valve (10), a needle valve (11), a solenoid valve (12), a stop valve (14), a manual exhaust valve (16), and a manual air supply valve (13) connected in parallel with the solenoid valve (12) are sequentially connected between the nitrogen tank (9) and the Roots blower (1), and the solenoid valve (12) is connected to the cooler (4).

3. A heat and mass transfer experimental platform for divertor gas baking system according to claim 2, characterized in that: The stop valve (14) is connected to a safety valve (15), and the manual exhaust valve (16) is connected to a second solenoid valve (17).

4. The heat and mass transfer experimental platform of the divertor gas baking system according to claim 1, characterized in that: The vacuum assembly comprises a vacuum gauge (7) and a vacuum pump (8) connected to the vacuum tank (5).

5. The heat and mass transfer experimental platform of the divertor gas baking system according to claim 1, characterized in that: The secondary cooling system comprises a refrigerating unit (6) with adjustable water outlet pressure, the secondary side of the cooler (4) and the interlayer of the vacuum tank (5) are connected in parallel to the main circuit of the refrigerating unit (6), the main circuit of the refrigerating unit (6) comprises a bypass branch, and a ball valve is installed on the bypass branch.

6. The heat and mass transfer experimental platform of the divertor gas baking system according to claim 1, characterized in that: The regenerator (2) is connected to the air return section of the experimental piece inside the vacuum tank (5), a reducer (18) is installed between the electric heater (3) and the air supply section of the experimental piece inside the vacuum tank (5), and a reducer (19) and a flow meter (20) are installed in sequence between the regenerator (2) and the air return section of the experimental piece inside the vacuum tank (5).

7. The heat and mass transfer experimental platform of the divertor gas baking system according to claim 3, characterized in that: The data acquisition and control system comprises a PLC control system (21), the PLC control system (21) is wiredly connected to a computer, and the PLC control system (21) is connected to an aviation plug of a vacuum tank (5).

8. The heat and mass transfer experimental platform for divertor gas baking system according to claim 7, characterized in that: Pressure transmitter one (22) is installed at both ends of the Roots blower (1); temperature transmitter one (23) is installed between the regenerator (2) and the Roots blower (1), between the regenerator (2) and the electric heater (3), and between the regenerator (2) and the cooler (4); pressure transmitter two (24) is installed between the cooler (4) and the solenoid valve one (12); pressure transmitter three (26) and temperature transmitter two (25) are installed between the reducer one (18) and the vacuum tank (5), and between the flow meter (20) and the vacuum tank (5); the solenoid valve one (12), the solenoid valve two (17), the pressure transmitter one (22), the temperature transmitter one (23), the pressure transmitter two (24), the temperature transmitter two (25), and the pressure transmitter three (26) are all connected to the PLC control system (21).

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