A kind of heat and mass transfer experimental platform of gas baking system of baffle

Abstract

The present application relates to the technical field of fusion device, and more particularly to a heat and mass transfer experiment platform of a gas baking system of a divertor. The technical scheme 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 regenerator, the regenerator is connected with an electric heater and a cooler respectively; the vacuum system comprises a vacuum tank and a vacuum assembly installed on the vacuum tank, and the electric heater is connected with an experimental piece inside the vacuum tank. The present application can establish a heat and mass transfer model, help to understand the heat and mass transfer law, optimize the design and operation of the device, reveal the influence mechanism of the baking temperature, the working medium pressure and the flow rate, ensure the baking safety and stability, test the influence of different gas working media on the baking characteristics, test the vacuum leakage characteristics, find and solve problems in time, and ensure the high vacuum environment, reliability and stability of the fusion device.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of fusion devices, in particular to a divertor gas baking system heat and mass transfer experiment platform. BACKGROUND

[0002] A high vacuum environment required for plasma discharge of a fusion device needs high-temperature baking of internal components of a vacuum chamber. During high-temperature baking, thermal stress caused by uneven temperature distribution of the vacuum chamber and the internal components may cause deformation or fracture of the vacuum chamber and the internal components; in order to study the conjugate heat transfer phenomenon between the divertor and nitrogen and the heat transfer balance characteristics of the baking system, the application provides a divertor gas baking system heat and mass transfer experiment platform. SUMMARY

[0003] The application aims to solve the problem of thermal stress caused by uneven temperature distribution of the vacuum chamber and the internal components during high-temperature baking in the background art, and provides a divertor gas baking system heat and mass transfer experiment platform.

[0004] The technical scheme of the application is a divertor gas baking system heat and mass transfer experiment platform, comprising:

[0005] A gas baking system, wherein the gas baking system comprises a Roots blower, the Roots blower is connected with a regenerator, the regenerator is respectively connected with an electric heater and a cooler;

[0006] A vacuum system, wherein 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 gas supply section inside the vacuum tank;

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

[0008] A data acquisition and control system connected with an aviation plug of the vacuum tank.

[0009] Optionally, one end of the Roots blower away from the regenerator is connected with a nitrogen tank, a pressure reducing valve, a needle valve, an electromagnetic valve one, a stop valve, a manual exhaust valve and a manual air supplement valve connected in sequence between the nitrogen tank and the Roots blower, the electromagnetic valve one is connected with the cooler.

[0010] Optionally, the stop valve is connected with a safety valve, and the manual exhaust valve is connected with an electromagnetic valve two.

[0011] Optionally, the vacuum assembly comprises a vacuum gauge and a vacuum pump connected with the vacuum tank.

[0012] Optionally, the secondary cooling system comprises a refrigeration unit capable of adjusting the outlet water 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, and the main circuit of the refrigeration unit comprises a bypass branch, and a ball valve is installed on the bypass branch.

[0013] Optionally, the regenerator is connected with the gas return section of the internal experimental component of the vacuum tank, a variable diameter one is installed between the electric heater and the gas supply section of the internal experimental component of the vacuum tank, and a variable diameter two and a flow meter are sequentially installed between the regenerator and the gas return section of the internal experimental component of the vacuum tank.

[0014] Optionally, the data acquisition and control system comprises a PLC control system, the PLC control system is connected with a computer in a wired mode, and the PLC control system is connected with the aviation plug of the vacuum tank.

[0015] Optionally, pressure transmitters one are installed at two ends of the Roots blower, temperature transmitters one are installed between the regenerator and the Roots blower, between the regenerator and the electric heater, and between the regenerator and the cooler, a pressure transmitter two is installed between the cooler and the electromagnetic valve one, pressure transmitters three and temperature transmitters two are installed between the variable diameter one and the vacuum tank and between the flow meter and the vacuum tank, and the electromagnetic valve one, the electromagnetic valve two, the pressure transmitter one, the temperature transmitter one, the pressure transmitter two, the temperature transmitter two and the pressure transmitter three are connected with the PLC control system.

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

[0017] The application can establish a heat and mass transfer model of a vacuum component in a fusion device under a gas baking mode, help to deeply understand the heat transfer and mass transfer rules of the fusion device in a high-temperature baking process, and provide a theoretical basis for optimizing the design and operation of the fusion device.

[0018] The application can reveal the influence mechanism between the baking temperature of the internal component, the working medium pressure and the flow rate. By accurately controlling and measuring these parameters, the mutual relationship between them is studied, so that the baking process is better mastered, the safety and stability of the vacuum chamber and the internal component during high-temperature baking are ensured, and the thermal stress caused by uneven temperature distribution is avoided to cause deformation or fracture of the vacuum chamber and the internal component.

[0019] The application can test the influence of different gas working media on the baking characteristics of the internal component of the fusion device. This has important significance for selecting appropriate gas working media to improve the baking efficiency, reduce energy consumption and optimize the baking effect, and provides more choices and reference basis for the actual operation of the fusion device.

[0020] This invention can test the vacuum leakage characteristics of internal components of a fusion device under gas baking conditions. This is crucial for ensuring the vacuum environment of the fusion device, as a high vacuum environment is a necessary condition for the fusion device to achieve plasma discharge. By testing the vacuum leakage characteristics, potential leakage problems can be detected and resolved in a timely manner, improving the reliability and stability of the fusion device.

[0021] This invention can establish a heat and mass transfer model, which helps 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 the safety and stability of baking, test the influence of different gaseous working fluids on baking characteristics, and provide a basis for selecting a suitable working fluid and improving efficiency; it can also test vacuum leakage characteristics, promptly detect and solve problems, and ensure the high vacuum environment, reliability and stability of the fusion device. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the heat and mass transfer experimental platform for a divertor gas baking system.

[0023] Figure 2 The figure shows the experimental stability test results of a heat and mass transfer experimental platform for a divertor gas baking system.

[0024] Figure 3 This is a distribution diagram of temperature measurement points on the surface of the experimental piece;

[0025] Figure 4 This is a partial image of the surface temperature data collected from the experimental specimen.

[0026] Attached reference 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. Shut-off valve; 15. Safety valve; 16. Manual exhaust valve; 17. Solenoid valve two; 18. Variable diameter valve one; 19. Variable diameter valve 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 Implementation

[0027] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0028] Example

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

[0030] In the embodiment, the gas baking system comprises a Roots blower 1, a regenerator 2 connected with the Roots blower 1, an electric heater 3 and a cooler 4 connected with the regenerator 2 respectively; one end of the Roots blower 1 away from the regenerator 2 is connected with a nitrogen tank 9, and the nitrogen tank 9 and the Roots blower 1 are sequentially connected with 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 supplement valve 13 connected with the solenoid valve 12 in parallel, the solenoid valve 12 is connected with the cooler 4, the stop valve 14 is connected with a safety valve 15, and the manual exhaust valve 16 is connected with a solenoid valve 17. The Roots blower 1 serves as a power source, with a maximum pressure boost of 50 kPa and a maximum flow of 72 Nm 3 / h, and a frequency converter is used to realize flow regulation. The regenerator 2 undertakes preheating and heat recovery functions, and uses the nitrogen gas at the outlet of the baking test piece to preheat the cold nitrogen gas at the outlet of the Roots blower 1. The electric heater 3 has a maximum outlet temperature of 300℃, and is used in cooperation with a data acquisition and control system to regulate the temperature of the nitrogen gas sent to the inlet of the test piece. The nitrogen gas at the outlet of the test piece is cooled to the required inlet temperature of the Roots blower 1 after recovering heat through the regenerator 2 and then through a cooler 4. An automatic air supplement and exhaust device is installed between the cooler 4 and the Roots blower 1, and the solenoid valve 12 is used in cooperation with the data acquisition and control system to regulate the system pressure. In addition, the safety valve 15 mechanically releases pressure when the baking system fails and the pressure is too high.

[0031] The vacuum system comprises a vacuum tank 5 and a vacuum assembly installed on the vacuum tank 5, the electric heater 3 is connected with a gas supply section of the test piece inside the vacuum tank 5, and the vacuum assembly comprises a vacuum gauge 7 and a vacuum pump 8 connected with the vacuum tank 5. The regenerator 2 is connected with a gas return section of the test piece inside the vacuum tank 5, a variable diameter 18 is installed between the electric heater 3 and the gas supply section of the test piece inside the vacuum tank 5, a variable diameter 19 and a flowmeter 20 are sequentially installed between the regenerator 2 and the gas return section of the test piece inside the vacuum tank 5, and the vacuum environment in the vacuum chamber during the baking process of the fusion device is simulated. The capacitive diaphragm vacuum gauge monitors the vacuum pressure in real time, and the lowest vacuum can be extracted to 3.6 Pa. The vacuum tank 5 has a double-walled structure, and the water inlet and outlet on the tank body are connected. During the experiment, the cooling water enters the interlayer through the lower two water inlets and is discharged through the upper two water outlets and connected to the secondary side cooling system. One side of the tank body of the vacuum tank 5 is provided with two nitrogen gas interfaces, and the gas baking system is connected with the test piece. The other side of the vacuum tank 5 is provided with four aviation plugs, and the sensors for collecting the surface temperature of the test piece and the inner surface temperature of the vacuum tank 5 are connected with the data acquisition and control system.

[0032] In addition, the secondary cooling system provides a cold source for cooler 4 and vacuum tank 5. The secondary cooling system includes a refrigeration unit 6 with adjustable outlet water pressure. Refrigeration unit 6 is a refrigeration machine, which is existing technology. A refrigeration machine is a mechanical device that uses a compressor to change the pressure of refrigerant gas to achieve low-temperature refrigeration. The refrigeration machine is one of the most important components of compression refrigeration equipment. Refrigeration machines consist of five main parts connected in series: compressor, condenser, evaporator, dryer filter, and expansion valve. An appropriate amount of refrigerant is injected into the refrigeration unit, and the compressor operation is controlled by electrical components according to environmental requirements to achieve refrigeration and heat transfer. The secondary side of cooler 4 and the jacket of vacuum tank 5 are connected in parallel to the main circuit of refrigeration unit 6. The main circuit of refrigeration unit 6 includes a bypass branch, on which a ball valve is installed to regulate 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. The PLC control system 21 is wired to a computer and connected to the aviation connector of the vacuum tank 5. Pressure transmitters 22 are installed at both ends of the Roots blower 1. Temperature transmitters 23 are 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 24 is installed between the cooler 4 and the solenoid valve 12. Pressure transmitter 26 and temperature transmitter 25 are installed between the reducer 18 and the vacuum tank 5, and between the flow meter 20 and the vacuum tank 5. Solenoid valve 12, solenoid valve 27, pressure transmitter 22, temperature transmitter 23, pressure transmitter 24, temperature transmitter 25, and pressure transmitter 26 are all connected to the PLC control system 21. The thermal-hydraulic parameters of characteristic points in the baking system are collected using pressure transmitter 22, temperature transmitter 23, pressure transmitter 24, temperature transmitter 25, pressure transmitter 26, and flow meter 20. Temperature parameters of the experimental piece and the inner surface of the vacuum tank 5 are collected using a PT100 resistance thermometer. The PLC control system 21 is a PLC control cabinet. The system airflow is adjusted via a frequency converter within the PLC control cabinet. The temperature at the heater outlet is controlled using a PID algorithm. Solenoid valves 12 and 17 are automatically opened and closed to perform replenishment and exhaust functions, thus regulating the system pressure. The PLC control system 21, in conjunction with a computer, enables real-time monitoring and storage of parameters, as well as remote control of system equipment and valves.

[0034] Experimental verification

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

[0036] Experimental steps:

[0037] 1. Before starting the experiment, 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 nitrogen tank 9 outlet and the pressure reducing valve 10, close the manual air supplement valve 13, open the automatic opening and closing function of the electromagnetic control valve 12 and the electromagnetic valve 17, and set the pressure range of automatic air supplement and exhaust;

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

[0040] 4. Start the heater 3, set the outlet temperature of the heater 3, input P, I values, and wait for the outlet temperature of the heater 3 to stabilize. Observe whether the actual temperature at the outlet of the heater 3 oscillates within the acceptable range of the set temperature value or remains stable. 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, adjust the P, I values and repeat the above operation;

[0041] 5. Start the refrigeration unit 6, set the outlet water temperature. After the system stabilizes, observe whether the water temperature of the temperature transmitter two 24 at the outlet of the cooler 4 is lower than 40℃. If the target value has not been reached, adjust the set water temperature of the refrigeration unit 6;

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

[0043] 6. Adjust the frequency of the Roots blower 1 and the outlet set temperature of the heater 3 to change the inlet parameters of the experimental piece, and repeat the operation 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 cools down to near room temperature, turn off the nitrogen tank 9 and the pressure reducing valve 10, turn off the Roots blower 1 and the refrigeration unit 6.

[0046] Experimental data

[0047] Table 1 Completion of monitoring points

[0048]

[0049] Experimental conclusion

[0050] After the stability test of the experimental platform, it is shown that the experimental platform can perform repeated experiments well, Figure 2 The key points of flow, pressure and temperature parameters of the system are stably output through the data acquisition and control system when the system is running stably. For example Figure 3 The temperature of the surface key points of the experimental piece is measured by PT100 thermistor, and the temperature data can be collected Figure 4The real-time temperature of each temperature feature point of the experimental piece in the baking process. After several rounds of experiments, the experimental platform can heat the inlet temperature of the experimental piece to above 150 DEG C under the design pressure of 1.1-1.3 bar(G), meeting the temperature requirements of fusion baking.

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

[0052] Through the platform, the influence mechanism of the internal component baking temperature and the working medium pressure and flow can be revealed. By precisely controlling and measuring these parameters, the mutual relationship between them is studied, so that the baking process is better mastered, the safety and stability of the vacuum chamber and internal components during high-temperature baking are ensured, and the thermal stress caused by uneven temperature distribution is avoided to cause deformation or fracture of the vacuum chamber and its internal components.

[0053] The platform can test the influence of different gas working media on the baking characteristics of the internal components of the fusion device. This is of great significance for selecting appropriate gas working media to improve the baking efficiency, reduce energy consumption and optimize the baking effect, and provides more choices and reference basis for the actual operation of the fusion device. For example, by comparing the baking effects of different gas working media such as nitrogen and helium on the internal components under the same conditions, including temperature distribution, thermal stress, etc., the most suitable gas working medium can be determined.

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

[0055] The above specific embodiments are only several optional embodiments of the present application, and based on the technical solutions of the present application and the related inspiration of the above embodiments, those skilled in the art can make various alternative improvements and combinations on the above specific embodiments.

Claims

1. A heat and mass transfer experimental platform for a gas-fired filter baking system, characterized in that, It comprises: A gas baking system, which comprises a Roots blower (1) connected with a regenerator (2), the regenerator (2) is connected with an electric heater (3) and a cooler (4) respectively; A vacuum system, which comprises a vacuum tank (5) and a vacuum assembly installed on the vacuum tank (5), the electric heater (3) is connected with the experiment piece gas supply section inside the vacuum tank (5); A secondary side cooling system for providing cold source for the cooler (4) and the vacuum tank (5); A data acquisition and control system connected with the aviation plug of the vacuum tank (5); The regenerator (2) is connected with the gas return section of the experiment piece inside the vacuum tank (5), the electric heater (3) is installed with a variable diameter one (18) between the gas supply section of the experiment piece inside the vacuum tank (5), the regenerator (2) and the gas return section of the experiment piece inside the vacuum tank (5) are installed with a variable diameter two (19) and a flowmeter (20) in sequence; The end of the Roots blower (1) away from the regenerator (2) is connected with a nitrogen tank (9), the nitrogen tank (9) and the Roots blower (1) are connected with a pressure reducing valve (10), a needle valve (11), an electromagnetic valve one (12), a stop valve (14), a manual exhaust valve (16) and a manual air supplement valve (13) connected with the electromagnetic valve one (12) in parallel in sequence, the electromagnetic valve one (12) is connected with the cooler (4); The stop valve (14) is connected with a safety valve (15), the manual exhaust valve (16) is connected with an electromagnetic valve two (17); The data acquisition and control system comprises a PLC control system (21), the PLC control system (21) is connected with a computer by wire, the PLC control system (21) is connected with the aviation plug of the vacuum tank (5); Both ends of the Roots blower (1) are installed with a pressure transmitter one (22), the regenerator (2) and the Roots blower (1), the regenerator (2) and the electric heater (3), the regenerator (2) and the cooler (4) are installed with a temperature transmitter one (23) in between, the cooler (4) and the electromagnetic valve one (12) are installed with a pressure transmitter two (24) in between, the variable diameter one (18) and the vacuum tank (5), the flowmeter (20) and the vacuum tank (5) are installed with a pressure transmitter three (26) and a temperature transmitter two (25) in between, the electromagnetic valve one (12), the electromagnetic valve two (17), the pressure transmitter one (22), the temperature transmitter one (23), the pressure transmitter two (24), the temperature transmitter two (25), the pressure transmitter three (26) are connected with the PLC control system (21).

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

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

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