A detection device for a nuclear class temperature switch

Abstract

The present application belongs to the technical field of temperature switch detection, and particularly relates to a detection device for a nuclear-grade temperature switch, comprising a detection box and a control cabinet arranged on the side wall of the detection box, the rear side of the detection box being provided with a hot air blower and a cold air blower, further comprising a U-shaped support plate fixed in the interior of the detection box, the side wall of the U-shaped support plate being fixed with a plurality of detection tubes, the end of each detection tube being fixed with a flange plate for mounting a temperature switch to be detected, the upper and lower surfaces of the U-shaped support plate each being fixed with a plurality of gas boxes, the gas boxes on the same side being in common communication with a gas supply mechanism, and the output ends of the hot air blower and the cold air blower each being in communication with a corresponding gas supply mechanism. The present application can simulate the high-frequency and large-temperature-difference temperature fluctuation of a nuclear-grade temperature switch, detect the response and timeliness of the nuclear-grade temperature switch and the sealing reliability, and effectively improve the problems of single detection working condition and poor adhesion of traditional slow temperature rising and falling detection.

Description

Technical Field

[0001] This invention belongs to the field of temperature switch detection technology, and in particular relates to a detection device for nuclear-grade temperature switches. Background Technology

[0002] Nuclear-grade temperature switches are widely deployed in critical systems and equipment of nuclear power plants, such as containment systems, residual heat removal systems, and emergency power systems. They are used to monitor the temperature of the medium and output safety interlock signals. They are important instrumentation and control components that ensure the stable operation of the unit. These switches need to undergo performance testing during both the factory and overhaul stages to verify their accuracy under long-term service and extreme operating conditions.

[0003] Local nuclear-grade temperature switch (reference) Figure 10 Routine testing mainly relies on temperature control equipment such as constant temperature oil baths and dry block furnaces to complete performance calibration. During testing, the temperature measuring end of the switch is placed in a constant temperature medium, and the response speed of the temperature switch is tested by a low-speed gradient heating and cooling method. However, facilities within nuclear power plants, such as waste heat removal systems, emergency diesel generator sets, and equipment cooling pipelines, experience significant temperature fluctuations during long-term operation. Frequent rapid temperature changes occur during equipment start-up, shutdown, and load adjustment. Detection methods that rely solely on slow, uniform heating or cooling cannot simulate the alternating temperature stress that temperature switches endure over extended periods. Minor defects in the internal seals and transmission structures of temperature switches caused by frequent temperature fluctuations are not easily detected. The measured parameters, such as operating temperature and hysteresis, can only reflect performance under steady-state conditions, which is not conducive to demonstrating the accuracy and stability of nuclear-grade temperature switches during long-term service. Summary of the Invention

[0004] The purpose of this invention is to address the above-mentioned problems by providing a testing device for nuclear-grade temperature switches that can simulate the frequent temperature-temperature alternation working environment during actual service and detect the working stability of temperature switches under frequent temperature fluctuations.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a detection device for a nuclear-grade temperature switch, comprising a detection box and a control cabinet disposed on the side wall of the detection box, wherein a hot air blower and a cold air blower are disposed on the rear side of the detection box, and further comprising: A U-shaped support plate is fixed inside the detection box. Multiple detection tubes are fixed on the side wall of the U-shaped support plate. A flange for installing the temperature switch to be measured is fixed at the end of the detection tube. Multiple air boxes are fixed on both the upper and lower surfaces of the U-shaped support plate. Multiple air boxes on the same side are connected to an air supply mechanism. The output ends of the hot air blower and the cold air blower are connected to the corresponding air supply mechanism. Multiple calibration temperature sensors are all fixedly inserted into the wall of the corresponding detection tube; A pressurization detection unit is connected to the air box, and the pressurization detection unit is used to pressurize and discharge the air inside the air box; A sealing detection unit is installed at the end of the detection tube.

[0006] In the aforementioned detection device for a nuclear-grade temperature switch, the gas supply mechanism includes a hot gas inlet pipe and a cold gas inlet pipe fixedly inserted into the back of the detection box. The hot gas inlet pipe is connected to the output end of a hot air blower, and the cold gas inlet pipe is connected to the output end of a cold air blower. Both the hot gas inlet pipe and the cold gas inlet pipe are connected to a horizontal pipe sealed at both ends. Multiple diversion pipes connected to the gas boxes on the same side are fixedly inserted into the wall of the horizontal pipe. Each gas box located on the upper side of the U-shaped support plate is fixedly inserted with a hot gas supply pipe. The outlet end of the hot gas supply pipe is fixedly connected to a hot switching valve, and the outlet end of the hot switching valve is connected to the detection tube. Each gas box located on the lower side of the U-shaped support plate is fixedly inserted with a cold gas supply pipe. The outlet end of the cold gas supply pipe is fixedly connected to a cold switching valve, and the outlet end of the cold switching valve is connected to the detection tube. Both the hot switching valve and the cold switching valve are electrically connected to the control cabinet. The outlet end of the detection tube is provided with a return mechanism.

[0007] In the aforementioned detection device for a nuclear-grade temperature switch, the reflux mechanism includes an upper reflux pipe and a lower reflux pipe fixed inside the detection chamber. Both ends of the upper and lower reflux pipes are sealed. Multiple hot gas reflux valves are fixedly inserted into the bottom of the upper reflux pipe, and the hot gas reflux valves are connected to the corresponding detection pipes. A cold gas reflux valve is fixedly inserted into the top of the lower reflux pipe, and the cold gas reflux valve is connected to the corresponding detection pipe. One end of both the upper and lower reflux pipes extends to the outside of the detection chamber. An upper connecting pipe is fixedly inserted into the side wall of the upper reflux pipe, and the upper connecting pipe is connected to the suction end of a hot air blower. A lower connecting pipe is fixedly inserted into the side wall of the lower reflux pipe, and the lower connecting pipe is connected to the suction end of a cold air blower. Both the hot gas reflux valve and the cold gas reflux valve are electrically connected to the control cabinet.

[0008] In the aforementioned detection device for a nuclear-grade temperature switch, a hot gas inlet pipe is fixedly connected to a hot gas return three-way valve at the end furthest from the hot air blower, and a cold gas inlet pipe is fixedly connected to a cold gas return three-way valve at the end furthest from the air conditioner. One outlet of the hot gas return three-way valve is fixedly connected to a hot gas return pipe, and the other outlet of the hot gas return three-way valve is connected to a horizontal pipe on the same side. The hot gas return pipe is connected to an upper connecting pipe. One outlet of the cold gas return three-way valve is fixedly connected to a cold gas return pipe, and the other outlet of the cold gas return three-way valve is connected to a horizontal pipe on the same side. The cold gas return pipe is connected to a lower connecting pipe. Both the hot gas return three-way valve and the cold gas return three-way valve are electrically connected to the control cabinet.

[0009] In the aforementioned detection device for a nuclear-grade temperature switch, the pressurization detection unit includes a cylinder that is fixedly inserted into a gas box. A piston is slidably connected inside the cylinder, and a push rod is fixed to the end of the piston. An upper lifting plate is provided above the U-shaped support plate, and a lower lifting plate is provided below the U-shaped support plate. Both the upper and lower lifting plates are fixedly connected to multiple push rods on the same side. A drive assembly is installed on both the upper and lower lifting plates.

[0010] In the aforementioned detection device for nuclear-grade temperature switches, the drive assembly includes multiple connecting columns fixed between the upper and lower lifting plates. The connecting columns slide through the U-shaped support plate. A set of synchronous hydraulic cylinders is fixedly inserted into the top of the detection box, and the upper lifting plate is fixed to the movable end of the synchronous hydraulic cylinders. The synchronous hydraulic cylinders are electrically connected to the control cabinet.

[0011] In the aforementioned detection device for a nuclear-grade temperature switch, the sealing detection unit includes an internally threaded ring fixedly sleeved on the outside of the detection tube. The internally threaded ring is threadedly connected to a sealing pressure ring, which abuts against the flange sidewall of the temperature switch to be tested. An exhaust pipe is fixedly inserted into the internally threaded ring at the position between the sealing pressure ring and the detection tube, and a pressure detection component is installed at the outlet end of the exhaust pipe.

[0012] In the aforementioned detection device for a nuclear-grade temperature switch, the pressure detection assembly includes a detection box fixedly inserted into the exhaust end of an exhaust pipe. Inside the detection box is a pressure switch electrically connected to a control cabinet. A plug is installed at the detection end of the pressure switch, and the plug abuts against the end of the exhaust pipe. An exhaust hole is provided on the side wall of the detection box.

[0013] Compared with existing technologies, the present invention has the following advantages: 1. This invention, through the setting of a detection box, a hot air blower, a cold air blower, a U-shaped support plate, a detection tube, and an air supply mechanism, can output hot air and cold air at a set temperature respectively through the hot air blower and the cold air blower. Furthermore, through the air boxes on the upper and lower sides and the air supply mechanism, it can alternately deliver high-temperature hot air and low-temperature cold air into the detection tube. By using the rapid airflow switching method, it simulates the working environment of frequent hot and cold alternation during the actual service of the temperature switch, so that the temperature measuring end of the temperature switch is subjected to rapid temperature change stress. In this way, it can detect the working stability of the temperature switch under frequent temperature fluctuations, effectively improving the problems of the traditional slow heating and cooling detection method, such as single working conditions and poor fit.

[0014] 2. The present invention, through the set reflux mechanism, can return hot air and cold air to the intake end of the hot air blower and the cold air blower, reducing energy consumption and improving temperature stability. At the same time, with the set hot air reflux three-way valve, cold air reflux three-way valve, hot air reflux pipe and cold air reflux pipe, when hot air or cold air is delivered into the detection tube, the hot air or cold air continuously output by the hot air blower and the cold air blower can be returned and reused, without the need for frequent start and stop of the hot air blower or the cold air blower.

[0015] 3. The present invention, through the setting of a pressurization detection unit, can temporarily store hot and cold air during the alternating delivery of hot and cold air, and pressurize and discharge the temporarily stored hot or cold air during output. Using the discharged high-pressure gas, in conjunction with the setting of a sealing detection unit, the sealing performance of the temperature switch flange connection can be detected. In conjunction with the high and low temperature switching detection, the thermal expansion and contraction effect of high and low temperatures on the flange connection can be detected to determine the sealing reliability of the temperature switch flange connection. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural schematic diagram of a detection device for a nuclear-grade temperature switch provided by the present invention; Figure 2 This is a schematic diagram of the back structure of the testing box provided by the present invention; Figure 3 This is a schematic diagram of the connection structure between the testing box and the hot air blower and the cold air blower provided by the present invention; Figure 4 This is an installation diagram of the temperature switch to be measured provided by the present invention; Figure 5 This is a schematic diagram of the internal structure of the testing box provided by the present invention; Figure 6 This is a schematic diagram of the connection structure between the temperature switch to be measured and the detection tube provided by the present invention; Figure 7 This is a schematic diagram of the internal structure of the cylinder and air box provided by the present invention; Figure 8 This is a schematic diagram of the back structure of the reflux mechanism provided by the present invention; Figure 9 This is a schematic diagram of the connection structure between a single detection tube and two gas boxes provided by the present invention; Figure 10 This is a three-dimensional structural diagram of the temperature switch to be measured provided by the present invention.

[0017] In the diagram: 1. Detection box; 2. Control cabinet; 3. Hot air blower; 4. Air cooler; 5. U-shaped support plate; 6. Detection tube; 7. Temperature switch to be measured; 8. Flange; 9. Gas box; 10. Gas supply mechanism; 101. Hot gas inlet pipe; 102. Cold gas inlet pipe; 103. Horizontal pipe; 104. Diverter pipe; 105. Hot gas supply pipe; 106. Hot switching valve; 107. Cold gas supply pipe; 108. Cold switching valve; 11. Calibration temperature sensor; 12. Pressurization detection unit; 121. Cylinder; 122. Piston; 123. Push rod; 124. Upper lifting plate; 125. Lower lifting plate; 13. Sealing... 131. Sealing detection unit; 132. Internal threaded ring; 133. Sealing pressure ring; 134. Exhaust pipe; 15. Return mechanism; 16. Upper return pipe; 17. Lower return pipe; 18. Hot gas return valve; 19. Cold gas return valve; 10. Upper connecting pipe; 11. Lower connecting pipe; 12. Hot gas return three-way valve; 13. Cold gas return three-way valve; 14. Hot gas return pipe; 15. Cold gas return pipe; 16. Cold gas return pipe; 17. Drive assembly; 19. Connecting column; 19. Synchronous hydraulic cylinder; 20. Pressure detection assembly; 201. Detection box; 202. Pressure switch; 203. Plug; 204. Exhaust port. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0019] like Figures 1-6 As shown, a detection device for nuclear-grade temperature switches includes a detection chamber 1 and a control cabinet 2 installed on the side wall of the detection chamber 1. A hot air blower 3 and a cold air blower 4 are located at the rear of the detection chamber 1. The hot air blower 3 has a built-in electric heating core and can output continuously adjustable hot air from 25 to 270°C, achieving uniform hot air delivery via an internal axial flow fan. The cold air blower 4 employs a jet enthalpy-increasing refrigeration structure, stably outputting low-temperature cold air from -40 to 30°C, with cold air delivery completed via a built-in circulating fan. The device also includes a U-shaped support plate 5 and multiple... The temperature sensor 11 is calibrated. The U-shaped support plate 5 is fixed inside the detection box 1. Multiple detection tubes 6 are fixed on the side wall of the U-shaped support plate 5. The end of the detection tube 6 is fixed with a flange 8 for installing the temperature switch 7 to be measured. Multiple air boxes 9 are fixed on both the upper and lower surfaces of the U-shaped support plate 5. Multiple air boxes 9 on the same side are connected to the air supply mechanism 10. The output ends of the hot air blower 3 and the cold air blower 4 are connected to the corresponding air supply mechanism 10. The temperature sensor 11 is calibrated and fixedly inserted into the tube wall of the corresponding detection tube 6.

[0020] In actual testing, this embodiment takes the local nuclear-grade temperature switch 7 as an example. The hot air temperature output by the hot air blower 3 is 240℃, and the cold air temperature output by the cold air blower 4 is -35℃. The main purpose is to test its working stability under the rapid high and low temperature alternation environment caused by the long-term start-up and shutdown of the cooling auxiliary equipment in the nuclear power plant and the frequent load fluctuations. The hot air output by the hot air blower 3 enters the detection tube 6 through the air supply mechanism 10, which can simulate the high temperature environment of the temperature switch 7. The cold air output by the cold air blower 4 enters the detection tube 6 through the air supply mechanism 10, which can simulate the low temperature environment of the temperature switch 7. By alternately supplying high and low temperature airflows into the detection tube 6, the working environment of frequent hot and cold alternation during the actual service of the temperature switch 7 can be simulated, so that the temperature measuring end of the temperature switch 7 can withstand rapid temperature change. By verifying the real-time output temperature signal of the temperature sensor 11, the response speed of the temperature switch 7 under test can be calculated, and the timeliness of the response of the temperature switch 7 under high-frequency temperature fluctuation conditions can be observed. When the temperature sensor 11 detects that the airflow temperature in the detection tube 6 reaches the nominal operating temperature value of the temperature switch 7 under test, the timing module in the control cabinet 2 starts timing (the nominal operating temperature value can be set according to different models of the temperature switch 7 under test). If the response time of the contact output action signal of the temperature switch 7 under test is greater than the preset qualified threshold, it indicates that the dynamic response performance of the temperature switch 7 under rapid temperature change conditions is insufficient, and it cannot output the safety interlock control signal in time, making it difficult to meet the temperature monitoring and protection requirements of nuclear power plant field equipment load rapid fluctuation scenarios.

[0021] like Figures 1-5 ,as well as Figure 8 As shown, further, in this embodiment, the gas supply mechanism 10 includes a hot air inlet pipe 101 and a cold air inlet pipe 102 fixedly inserted into the back of the detection box 1. The hot air inlet pipe 101 is connected to the output end of the hot air blower 3, and the cold air inlet pipe 102 is connected to the output end of the air conditioner 4. Both the hot air inlet pipe 101 and the cold air inlet pipe 102 are connected to a horizontal pipe 103 with sealed ends. Multiple diversion pipes 104 connected to the air box 9 on the same side are fixedly inserted into the wall of the horizontal pipe 103. The air box 9 located on the upper side of the U-shaped support plate 5 is fixedly inserted with a hot air supply pipe 105. The hot air supply pipe 105 outlet... A heat switching valve 106 is fixedly connected to the end of the device, and the outlet end of the heat switching valve 106 is connected to the detection tube 6. The air boxes 9 located on the lower side of the U-shaped support plate 5 are all fixedly connected to cold air supply pipes 107. The outlet end of the cold air supply pipe 107 is fixedly connected to a cold switching valve 108, and the outlet end of the cold switching valve 108 is connected to the detection tube 6. Both the heat switching valve 106 and the cold switching valve 108 are electrically connected to the control cabinet 2. The outlet end of the detection tube 6 is equipped with a return mechanism 14. Both the heat switching valve 106 and the cold switching valve 108 are high-temperature resistant electrically driven butterfly valves with a switching speed of less than 1 second and a switching time of once every 30 seconds.

[0022] During actual testing, the hot air output from the hot air blower 3 enters the corresponding air box 9 through the hot air inlet pipe 101, the horizontal pipe 103, and the diversion pipe 104. The cold air output from the cool air blower 4 enters the corresponding air box 9 through the cold air inlet pipe 102, the horizontal pipe 103, and the diversion pipe 104. When the heat switching valve 106 is open, the cold switching valve 108 remains closed, and the hot air enters the detection tube 6 through the hot air supply pipe 105. When the heat switching valve 106 is closed, the cold switching valve 108 remains open, and the cold air enters the detection tube 6 through the cold air supply pipe 107. By alternately opening and closing the heat switching valve 106 and the cold switching valve 108, high-temperature hot air and low-temperature cold air can be alternately supplied to the detection tube 6, thereby simulating the working condition of frequent temperature fluctuations of the temperature switch 7 under test.

[0023] like Figures 1-5 ,as well as Figure 8 As shown, further, in this embodiment, the reflux mechanism 14 includes an upper reflux pipe 141 and a lower reflux pipe 142 fixed inside the detection box 1. Both ends of the upper reflux pipe 141 and the lower reflux pipe 142 are sealed. A plurality of hot gas reflux valves 143 are fixedly inserted into the bottom of the upper reflux pipe 141, and the hot gas reflux valves 143 are connected to the corresponding detection pipes 6. A cold gas reflux valve 144 is fixedly inserted into the top of the lower reflux pipe 142, and the cold gas reflux valve 144 is connected to the corresponding detection pipes 6. The upper reflux pipe 141 and the lower reflux pipe 142 are sealed. One end of each return pipe 142 extends to the outside of the detection box 1. An upper connecting pipe 145 is fixedly inserted into the side wall of the upper return pipe 141, and the upper connecting pipe 145 is connected to the suction end of the hot air blower 3. A lower connecting pipe 146 is fixedly inserted into the side wall of the lower return pipe 142, and the lower connecting pipe 146 is connected to the suction end of the air cooler 4. The hot air return valve 143 and the cold air return valve 144 are both electrically connected to the control cabinet 2. Both the hot air return valve 143 and the cold air return valve 144 are high-temperature resistant electrically driven butterfly valves with a switching speed of less than 1 second.

[0024] In actual testing, when the heat switching valve 106 is opened, the cold air return valve 144 opens 5 seconds in advance and closes 1 second later. Similarly, when the cold switching valve 108 is opened, the heat return valve 143 opens 5 seconds in advance and closes 1 second later. The early opening of the cold air return valve 144 or the heat return valve 143 can guide the hot or cold air in the detection tube 6 into the upper return pipe 141 or the lower return pipe 142. The hot air entering the upper return pipe 141 flows back to the suction end of the hot air blower 3 through the upper connecting pipe 145, while the cold air entering the lower return pipe 142 flows back to the suction end of the air cooler 4 through the lower connecting pipe 146. By recycling the hot and cold air, energy consumption can be reduced and the stability of the air temperature at the suction end of the hot air blower 3 and the air cooler 4 can be improved. By delaying the closure of the cold air return valve 144 or the hot air return valve 143 by 1 second, the cold or hot air in the detection tube 6 can be returned to the lower return pipe 142 or the upper return pipe 141 as much as possible, reducing the mixing of hot and cold air. This not only helps to improve the fluctuation range of the temperature environment around the simulated temperature switch 7, but also helps to avoid the cold air returning to the hot air blower 3 or the hot air returning to the air cooler 4, thus improving the working stability of the hot air blower 3 or the air cooler 4.

[0025] like Figures 1-5 ,as well as Figure 8 As shown, further, in this embodiment, the end of the hot air inlet pipe 101 away from the hot air blower 3 is fixedly connected to a hot air return three-way valve 15, and the end of the cold air inlet pipe 102 away from the air conditioner 4 is fixedly connected to a cold air return three-way valve 16. One of the outlets of the hot air return three-way valve 15 is fixedly connected to a hot air return pipe 17, and the other outlet of the hot air return three-way valve 15 is connected to the horizontal pipe 103 on the same side. The hot air return pipe 17 is connected to the upper connecting pipe 145. One of the outlets of the cold air return three-way valve 16 is fixedly connected to a cold air return pipe 18, and the other outlet of the cold air return three-way valve 16 is connected to the horizontal pipe 103 on the same side. The cold air return pipe 18 is connected to the lower connecting pipe 146. Both the hot air return three-way valve 15 and the cold air return three-way valve 16 are electrically connected to the control cabinet 2.

[0026] During actual testing, when hot or cold air is supplied to the air box 9, the hot air return three-way valve 15 and the cold air return three-way valve 16 remain connected to the corresponding horizontal pipe 103. However, when hot or cold air from inside the air box 9 is supplied to the detection tube 6, to prevent backflow, the connecting pipe between the corresponding hot air return three-way valve 15 or cold air return three-way valve 16 and the horizontal pipe 103 is closed. At this time, the hot air output from the hot air blower 3 enters the hot air inlet pipe 101. The air returns to the three-way valve 15 and then flows back to the upper connecting pipe 145 through the hot air return pipe 17, and finally back to the suction end of the hot air blower 3. The cold air output by the air conditioner 4 enters the cold air return three-way valve 16 through the cold air inlet pipe 102, and then flows back to the lower connecting pipe 146 through the cold air return pipe 18, and finally back to the suction end of the air conditioner 4. When delivering hot air or cold air to the detection pipe 6, it is not necessary to shut down the hot air blower 3 or the air conditioner 4.

[0027] like Figure 5 , Figures 7-9As shown, in this embodiment, the device further includes a pressure detection unit 12, which is connected to the air box 9. The pressure detection unit 12 is used to pressurize and discharge the air inside the air box 9. The pressure detection unit 12 includes a cylinder 121 that is fixedly inserted into the air box 9. A piston 122 is slidably connected inside the cylinder 121, and a push rod 123 is fixed to the end of the piston 122. An upper lifting plate 124 is provided above the U-shaped support plate 5, and a lower lifting plate 125 is provided below the U-shaped support plate 5. The upper lifting plate 124 and the lower lifting plate 125 are both fixedly connected to multiple push rods 123 on the same side. The upper lifting plate 124 and the lower lifting plate 125 are jointly equipped with a drive assembly 19. The drive assembly 19 includes multiple connecting columns 191 fixed between the upper lifting plate 124 and the lower lifting plate 125. The connecting columns 191 slide through the U-shaped support plate 5. A set of synchronous hydraulic cylinders 192 is fixedly inserted into the top of the detection box 1, and the upper lifting plate 124 is fixed to the movable end of the synchronous hydraulic cylinders 192. The synchronous hydraulic cylinders 192 are electrically connected to the control cabinet 2. The synchronous hydraulic cylinders 192 drive the upper lifting plate 124 to drive the lower lifting plate 125 through the connecting columns 191. The time required for a single upward or downward stroke is 10 seconds.

[0028] During actual testing, the synchronous hydraulic cylinder 192 begins to drive the upper lifting plate 124 to move downward 5 seconds before the hot switching valve 106 opens, and begins to drive the upper lifting plate 124 to rise 5 seconds before the cold switching valve 108 opens. When the upper lifting plate 124 moves, it drives the lower lifting plate 125 to move synchronously through the connecting column 191. When the upper lifting plate 124 and the lower lifting plate 125 rise, the two pistons 122 rise synchronously through the push rod 123. At this time, the air capacity space between the cylinder 121 on the upper side of the U-shaped support plate 5 and the air box 9 on the same side increases, allowing more air to be accommodated. Hot air is released, and the air space between the lower cylinder 121 and the air box 9 on the same side decreases. At this time, since the cold switching valve 108 is not open, the cold air pressure in the air box 9 on this side increases. After pressurization, the airflow pressure can reach 0.3 to 0.5 MPa. After the cold switching valve 108 is opened, the high-pressure cold air will quickly enter the detection tube 6, so that the sealing performance of the connection between the temperature switch under test 7 and the flange 8 of the detection tube 6 can be subjected to high-pressure impact. This facilitates the testing of the sealing reliability of the temperature switch under test 7 under long-term high and low temperature switching environment and pulsed high-pressure airflow impact.

[0029] like Figure 6 , Figure 9As shown, in this embodiment, the device further includes a sealing detection unit 13, which is installed at the end of the detection tube 6. The sealing detection unit 13 includes an internally threaded ring 131 fixedly sleeved on the outside of the detection tube 6. The internally threaded ring 131 is threadedly connected to a sealing pressure ring 132. The sealing pressure ring 132 abuts against the flange sidewall of the temperature switch 7 to be tested. An exhaust pipe 133 is fixedly inserted into the internally threaded ring 131 at the position between the sealing pressure ring 132 and the detection tube 6. A pressure detection component 20 is installed at the outlet end of the exhaust pipe 133. The sidewall of the sealing pressure ring 132 is provided with two sealing gaskets, which can improve the sealing performance of the sealing pressure ring 132 after it abuts against the flange of the temperature switch 7 to be tested, as well as the sealing performance of the sealing pressure ring 132 after it abuts against the end of the internally threaded ring 131.

[0030] During actual testing, after the flange 8 of the temperature switch 7 and the detection tube 6 are installed, the sealing ring 132 is screwed into the internal thread ring 131 so that the end face of the sealing ring 132 abuts against the flange of the temperature switch 7 and maintains a seal. When a leak occurs at the connection between the flange of the temperature switch 7 and the flange 8 of the detection tube 6, gas will enter the internal thread ring 131. At this time, the leaked gas will be discharged through the exhaust pipe 133. At this time, the exhaust pressure at the exhaust end of the exhaust pipe 133 increases. By detecting the exhaust pressure through the pressure detection component 20, it can be determined that a leak has occurred at the connection between the flange of the temperature switch 7 and the flange 8 of the detection tube 6.

[0031] like Figure 6 As shown, further, in this embodiment, the pressure detection component 20 includes a detection box 201 fixedly inserted into the exhaust end of the exhaust pipe 133. Inside the detection box 201, a pressure switch 202 electrically connected to the control cabinet 2 is fixed. A blocking block 203 is installed on the detection end of the pressure switch 202, and the blocking block 203 abuts against the end of the exhaust pipe 133. An exhaust hole 204 is opened on the side wall of the detection box 201.

[0032] During actual testing, when the air pressure inside the exhaust pipe 133 increases, the block 203 moves downward under the action of air pressure. At this time, the pressure switch 202 detects the exhaust pressure and immediately sends an electrical signal to the control cabinet 2. The control cabinet 2 then issues a voice prompt through its own alarm module.

[0033] The operation process of this invention is as follows: Open the door of the testing chamber 1, and connect each temperature switch 7 to be tested to the corresponding flange 8 in sequence (refer to...). Figure 4 , Figure 4 The dashed arrow in the middle indicates the installation direction of the temperature switch 7 to be measured. Then, screw in each sealing ring 132 in sequence, close the cabinet door, and then start the control cabinet 2. After control cabinet 2 starts, it connects the cold air return three-way valve 16 to the cold air return pipe 18 and the hot air return three-way valve 15 to the hot air return pipe 17, so that the hot air blower 3 and the air conditioner 4 output hot and cold air at stable temperatures. After 5 minutes, control cabinet 2 first controls the synchronous hydraulic cylinder 192 to drive the piston 122 upward 5 seconds in advance, and then synchronously controls the hot air return three-way valve 15 to connect to the corresponding horizontal pipe 103, and cuts off the connection circuit with the hot air return pipe 17. At this time, the hot air flows through the hot air return three-way valve 15 and the horizontal pipe 103 into the corresponding air box 9. As the piston 122 at the gas box 9 on this side moves upward, the gas capacity of the gas box 9 increases, and the hot gas flow can be temporarily stored in the gas box 9. At the same time, the gas inside the gas box 9 on the lower side of the U-shaped support plate 5 is compressed by the piston 122 and the pressure increases. After the synchronous hydraulic cylinder 192 works for 5 seconds, the control cabinet 2 controls the cold switching valve 108 to open. At this time, the high pressure gas in the gas box 9 on this side will quickly enter the detection tube 6 through the cold gas supply pipe 107. After the synchronous hydraulic cylinder 192 finishes working, the control cabinet 2 re-controls the hot gas return three-way valve 15 to connect with the hot gas return pipe 17. The cold switching valve 108 closes 25 seconds after opening, and the control cabinet 2 controls the hot switching valve 106 to open 5 seconds later. When the cold switching valve 108 closes, the control cabinet 2 controls the cold air return valve 144 to open synchronously, and closes 1 second after the hot switching valve 106 opens. At this time, the hot air stored in the air box 9 on the upper side of the U-shaped support plate 5 will enter the detection tube 6 through the hot air supply pipe 105. Under the action of the high temperature hot air, the contact of the temperature switch 7 to be tested will perform the trigger action. At the same time, the calibration temperature sensor 11 will detect the temperature rise. By detecting the temperature rise through the calibration temperature sensor 11, the response speed of the temperature switch 7 to be tested can be determined. Since the cold air return valve 144 opens earlier and closes later than the hot switching valve 106, the high pressure cold air in the detection tube 6 can be returned to the suction end of the air conditioner 4 through the lower return pipe 142 and the lower connecting pipe 146 as much as possible. Simultaneously, when the cold switching valve 108 is closed, the synchronous hydraulic cylinder 192 drives the piston 122 to move down and synchronously controls the cold air return three-way valve 16 to connect with the horizontal pipe 103 on the same side. At this time, the cold air will enter the air box 9 on this side through the cold air return three-way valve 16, the horizontal pipe 103 and the diversion pipe 104, while the hot air in the air box 9 on the upper side of the U-shaped support plate 5 is compressed until the hot switching valve 106 is opened. The high temperature and high pressure airflow will enter the detection tube 6. Through the alternating switching of the hot switching valve 106, the cold switching valve 108, the hot air return three-way valve 15, the cold air return three-way valve 16, the hot air return valve 143 and the cold air return valve 144, as well as the intermittent extension and retraction drive of the synchronous hydraulic cylinder 192, high and low temperature airflows can be alternately delivered to the detection tube 6. By using the rapid switching of high and low temperature airflows, the working condition of frequent temperature fluctuations of the temperature switch 7 under test can be simulated, and the temperature sensor 11 can be checked to detect its response speed. In this process, regardless of whether the airflow is high-temperature or low-temperature, it is first compressed by the piston 122 on the same side before entering the detection tube 6. Therefore, the airflow entering the detection tube 6 is all high-pressure airflow. Under the impact of the high-pressure airflow and the switching between high and low temperatures, the sealing of the connection between the temperature switch 7 and the flange 8 will be affected by the high-pressure impact of the airflow and the thermal expansion and contraction caused by temperature switching. If the sealing reliability of the connection between the temperature switch 7 and the flange 8 is unreliable, the airflow will leak from the connection. The leaked air will enter the internal threaded ring 131 and eventually be discharged through the exhaust pipe 133. Under the pressure of the discharged airflow, the moving contact of the pressure switch 202 will close and send an electrical signal to the control cabinet 2. The control cabinet 2 will then immediately issue an alarm message such as a voice prompt. The total duration of a single test can last up to 24 hours and can be set according to the testing requirements. All components of the entire device, such as the pipeline and the air box 9, need to be insulated or have an insulated structure to prevent the exchange of hot and cold temperatures from affecting the testing effect.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. 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 detection device for a nuclear-grade temperature switch, comprising a detection box (1) and a control cabinet (2) disposed on the side wall of the detection box (1), wherein a hot air blower (3) and a cold air blower (4) are provided on the rear side of the detection box (1), characterized in that, Also includes: U-shaped support plate (5) is fixed inside the detection box (1). Multiple detection tubes (6) are fixed on the side wall of the U-shaped support plate (5). A flange (8) for installing the temperature switch (7) to be measured is fixed at the end of the detection tube (6). Multiple air boxes (9) are fixed on both the upper and lower surfaces of the U-shaped support plate (5). Multiple air boxes (9) on the same side are connected to the air supply mechanism (10). The output ends of the hot air blower (3) and the cold air blower (4) are connected to the corresponding air supply mechanism (10). Multiple calibration temperature sensors (11) are fixedly inserted into the wall of the corresponding detection tube (6); The pressurization detection unit (12) is connected to the air box (9) and is used to pressurize and discharge the air inside the air box (9); A sealing detection unit (13) is installed at the end of the detection tube (6); The sealing detection unit (13) includes an internal threaded ring (131) fixedly sleeved on the outside of the detection tube (6). The internal threaded ring (131) is threadedly connected to a sealing pressure ring (132). The sealing pressure ring (132) abuts against the flange sidewall of the temperature switch (7) to be tested. An exhaust pipe (133) is fixedly inserted into the internal threaded ring (131) at the position between the sealing pressure ring (132) and the detection tube (6). A pressure detection component (20) is installed at the outlet end of the exhaust pipe (133). The pressure detection assembly (20) includes a detection box (201) fixedly inserted into the exhaust end of the exhaust pipe (133). Inside the detection box (201) is a pressure switch (202) electrically connected to the control cabinet (2). A plug (203) is installed on the detection end of the pressure switch (202), and the plug (203) abuts against the end of the exhaust pipe (133). An exhaust hole (204) is opened on the side wall of the detection box (201).

2. The detection device for a nuclear-grade temperature switch according to claim 1, characterized in that, The gas supply mechanism (10) includes a hot air inlet pipe (101) and a cold air inlet pipe (102) fixedly inserted into the back of the detection box (1). The hot air inlet pipe (101) is connected to the output end of the hot air blower (3), and the cold air inlet pipe (102) is connected to the output end of the air conditioner (4). Both the hot air inlet pipe (101) and the cold air inlet pipe (102) are connected to a horizontal pipe (103) sealed at both ends. The wall of the horizontal pipe (103) is fixedly inserted with multiple diversion pipes (104) connected to the air box (9) on the same side. The air box (9) located on the upper side of the U-shaped support plate (5) is fixedly inserted with a hot air supply pipe. The gas pipe (105) has a fixed connection to a heat switching valve (106) at its outlet end, and the outlet end of the heat switching valve (106) is connected to the detection pipe (6). The gas boxes (9) located on the lower side of the U-shaped support plate (5) are all fixedly connected to cold gas pipes (107). The outlet end of the cold gas pipe (107) is fixedly connected to a cold switching valve (108), and the outlet end of the cold switching valve (108) is connected to the detection pipe (6). The heat switching valve (106) and the cold switching valve (108) are both electrically connected to the control cabinet (2). The outlet end of the detection pipe (6) is provided with a return mechanism (14).

3. The detection device for a nuclear-grade temperature switch according to claim 2, characterized in that, The reflux mechanism (14) includes an upper reflux pipe (141) and a lower reflux pipe (142) fixed inside the detection box (1). Both ends of the upper reflux pipe (141) and the lower reflux pipe (142) are sealed. Multiple hot air reflux valves (143) are fixedly inserted into the bottom of the upper reflux pipe (141), and the hot air reflux valves (143) are connected to the corresponding detection pipes (6). A cold air reflux valve (144) is fixedly inserted into the top of the lower reflux pipe (142), and the cold air reflux valve (144) is connected to the corresponding detection pipes (6). The upper return pipe (141) and the lower return pipe (142) are both extended to the outside of the detection box (1). The upper return pipe (141) is fixedly connected to the side wall of the upper return pipe (141), and the upper connection pipe (145) is connected to the suction end of the hot air blower (3). The lower return pipe (142) is fixedly connected to the side wall of the lower connection pipe (142), and the lower connection pipe (146) is connected to the suction end of the air conditioner (4). The hot air return valve (143) and the cold air return valve (144) are both electrically connected to the control cabinet (2).

4. The detection device for a nuclear-grade temperature switch according to claim 3, characterized in that, The end of the hot air inlet pipe (101) away from the hot air blower (3) is fixedly connected to a hot air return three-way valve (15), and the end of the cold air inlet pipe (102) away from the air conditioner (4) is fixedly connected to a cold air return three-way valve (16). One of the outlets of the hot air return three-way valve (15) is fixedly connected to a hot air return pipe (17), and the other outlet of the hot air return three-way valve (15) is connected to a horizontal pipe (103) on the same side. The return pipe (17) is connected to the upper connecting pipe (145). One of the outlets of the cold air return three-way valve (16) is fixedly connected to the cold air return pipe (18), and the other outlet of the cold air return three-way valve (16) is connected to the horizontal pipe (103) on the same side. The cold air return pipe (18) is connected to the lower connecting pipe (146). The hot air return three-way valve (15) and the cold air return three-way valve (16) are both electrically connected to the control cabinet (2).

5. The detection device for a nuclear-grade temperature switch according to claim 1, characterized in that, The pressurization detection unit (12) includes a cylinder (121) fixedly inserted into the air box (9). A piston (122) is slidably connected inside the cylinder (121), and a push rod (123) is fixed at the end of the piston (122). An upper lifting plate (124) is provided above the U-shaped support plate (5), and a lower lifting plate (125) is provided below the U-shaped support plate (5). The upper lifting plate (124) and the lower lifting plate (125) are both fixedly connected to multiple push rods (123) on the same side. The upper lifting plate (124) and the lower lifting plate (125) are jointly equipped with a drive assembly (19).

6. The detection device for a nuclear-grade temperature switch according to claim 5, characterized in that, The drive assembly (19) includes multiple connecting columns (191) fixed between the upper lifting plate (124) and the lower lifting plate (125). The connecting columns (191) slide through the U-shaped support plate (5). A set of synchronous hydraulic cylinders (192) is fixedly inserted into the top of the detection box (1), and the upper lifting plate (124) is fixed to the movable end of the synchronous hydraulic cylinder (192). The synchronous hydraulic cylinder (192) is electrically connected to the control cabinet (2).

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