A refrigerant leakage rapid pre-detection device for heat pump production

Abstract

A kind of refrigerant leakage quick pre-checking device for heat pump production, including PLC operating system, infrared halogen detection system, its detection box is the open bottom cuboid empty box, and is located just above the detection station of production line.When the measured machine is located in the detection station of production line, detection box completely covers it, forms sealed cavity with detection station, and extracts vacuum from this cavity, so that the measured machine is in an environment without other gaseous interference, low pressure, no light, then use the infrared halogen detection probe inlayed in detection box to detect the refrigerant leakage of measured machine, if there is leakage, then transfer to accurate leak detection station to find leakage point, if not, then flow into next process.The refrigerant leakage quick pre-checking device for heat pump production has the characteristics of fast detection speed, stable environment and pure data when detecting the refrigerant leakage of heat pump unit.

Description

Technical Field

[0001] This application relates to the technical field of heat pump production testing equipment, specifically a rapid pre-detection device for refrigerant leaks in heat pump production. Background Technology

[0002] Heat pump systems must undergo rigorous leak testing to ensure their efficient, stable, and environmentally friendly operation. The refrigerant gas used in a heat pump system plays a crucial role in the heating process. However, once this refrigerant is released into the air, it not only has a serious impact on the environment, but some flammable refrigerant gases may also pose a threat to personnel and property safety. Simultaneously, refrigerant loss reduces heating efficiency and increases energy consumption. Therefore, accurate leak testing during the production, installation, and operation of heat pumps is particularly important. This not only effectively reduces costs for manufacturers and end-users but also ensures the safe, stable, and efficient operation of the heat pump system.

[0003] Traditional leak detection methods face accuracy challenges. During manufacturing, a typical leak rate is usually set at 1 to 3 grams per year to ensure the calculated lifespan of the heat pump. After all components of the heat pump system are connected or welded, the system is filled with refrigerant. At this point, leak testing of the final welded joints or filler ports is an essential step. To ensure that all potential leaks are detected and repaired before the system is put into operation, each weld point needs to be manually checked point by point using a highly sensitive leak detector. This results in inefficiency in multi-welded systems. Furthermore, now that standardized production has been implemented, over 95% of units are leak-free, with only a very small number having leaks. This leads to reduced production efficiency due to ineffective leak detection. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a rapid pre-detection device for refrigerant leaks in heat pump production, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A rapid pre-detection device for refrigerant leaks in heat pump production includes a PLC operating system, an infrared halogen detection system, and a detection box that is an empty rectangular box with an open bottom, positioned directly above the detection station on the production line. The detection box is slidably connected to a sliding frame and a support frame. Vacuum solenoid valves and check valves are symmetrically arranged on both sides of the detection box, namely a first solenoid valve, a first check valve, a second solenoid valve, and a second check valve. The inlets of the first and second check valves are respectively connected to the side walls of the detection box, and their outlets are respectively connected to the inlets of the first and second solenoid valves. The outlets of the first and second solenoid valves are respectively connected to the inlet of a vacuum pump via PVC steel wire hoses. The detection box has four... A first, second, third, and fourth detector head are respectively installed through the side wall, all of which are electrically connected to the infrared halogen detection system integrated in the operation box; a pressure relief solenoid valve is installed through the top of the detection box, and the outlet of the pressure relief solenoid valve is connected to the inlet of the air filter; a vacuum pressure transmitter is installed on one side of the detection box; the first solenoid valve, the second solenoid valve, the pressure relief solenoid valve, and the vacuum pressure transmitter are all electrically connected to the PLC control system integrated in the operation box; a rubber sealing gasket is installed on the bottom edge of the detection box; the operation box and the operation box bracket are hinged at one end, and the other end of the operation box bracket is fixedly connected to a column of the support frame; the vacuum pump is installed on the ground on the side of the support frame.

[0007] A first hydraulic cylinder and a second hydraulic cylinder are installed on the bottom frames on both sides of the support frame, and the output ends of the first hydraulic cylinder and the second hydraulic cylinder are connected to the sliding frame.

[0008] A pull rod type linear displacement sensor is installed on the bottom frame on both sides of the support frame, parallel to the first hydraulic cylinder and the second hydraulic cylinder. The pull rod type linear displacement sensor is electrically connected to the PLC control system integrated in the operation box.

[0009] Compared with existing technologies, this utility model has the following beneficial effects:

[0010] 1. This utility model can quickly screen out qualified and unqualified products with refrigerant leaks when detecting refrigerant leaks in heat pump units, thereby accelerating production efficiency and reducing manufacturing costs.

[0011] 2. This utility model utilizes an infrared halogen detector based on the principle of infrared halogen detection. Infrared halogen detectors are active detection devices, relying on their own emitted infrared light source for detection. This characteristic makes them particularly suitable for locating halogen gas leaks in light-free environments. This device ensures that the device under test is in a sealed, light-free environment during detection, eliminating ambient light interference and preventing stray light from affecting the detector's accuracy. Furthermore, the detector only receives the infrared light signal emitted by the instrument itself, resulting in purer data. Simultaneously, the sealed environment prevents external air from interfering with the detection, making the detection more accurate and rigorous.

[0012] 3. This invention employs a vacuuming method to detect refrigerant leaks, placing the tested unit in a low-pressure environment. At room temperature and low pressure, the refrigerant (R410a) exists in a gaseous state, with molecules undergoing thermal motion and diffusing throughout the container to achieve uniform distribution. Due to the lower pressure, the mean free path of the molecules is longer, the collision frequency is lower, and diffusion is faster. Attached Figure Description

[0013] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0014] Figure 2 This is a top view of the testing box of this utility model;

[0015] Figure 3 This is a control principle diagram of the lifting mechanism of this utility model;

[0016] Reference numerals: 1. Support frame; 2. Sliding frame; 3. Sliding wheel; 4. Testing box; 5. Test machine; 6. Testing station; 7. First hydraulic cylinder; 8. Second hydraulic cylinder; 9. Rod-type linear displacement sensor; 10. Operation box bracket; 11. Operation box; 12. Vacuum pump; 401. First solenoid valve; 402. First check valve; 403. Second solenoid valve; 404. Second check valve; 405. First probe; 406. Second probe; 407. Third probe; 408. Fourth probe; 409. Vacuum pressure sensor; 410. Rubber sealing gasket; 411. Pressure relief solenoid valve; 412. Air filter. Detailed Implementation

[0017] The technical solutions in the embodiments of this application will be described in a comprehensive, detailed and clear manner below with reference to the accompanying drawings.

[0018] See appendix Figure 1-3As shown, a rapid pre-inspection device for refrigerant leakage in heat pump production includes a PLC operating system and an infrared halogen detection system. The detection box 4 is an empty cuboid box with an open bottom and is placed directly above the detection station 6 on the production line. The detection box 4 is slidably connected to the support frame 1 via a sliding frame 2. Specifically, the sliding frame 2 is welded to the outer side of the detection box 4, and the sliding frame 2 is installed in the slide rail on the support frame 1 via sliding wheels 3. The detection chamber 4 is symmetrically equipped with vacuum solenoid valves and one-way valves on both sides, namely a first solenoid valve 401, a first one-way valve 402, a second solenoid valve 403, and a second one-way valve 404. The inlets of the first one-way valve 402 and the second one-way valve 404 are respectively connected to the side wall of the detection chamber 4, and their outlets are respectively connected to the inlets of the first solenoid valve 401 and the second solenoid valve 403. The outlets of the first solenoid valve 401 and the second solenoid valve 403 are respectively connected to the inlet of the vacuum pump 12 through PVC steel wire hoses. A first probe 405, a second probe 406, a third probe 407, and a fourth probe 408 are respectively installed through the four side walls of the detection chamber 4. All of these are electrically connected to the infrared halogen detection system integrated in the operation box 11; a pressure relief solenoid valve 411 is installed through the top of the detection box 4, and the outlet of the pressure relief solenoid valve 411 is connected to the inlet of the air filter 412; a vacuum pressure transmitter 409 is installed on one side of the detection box 4; the first solenoid valve 401, the second solenoid valve 403, the pressure relief solenoid valve 411, and the vacuum pressure transmitter 409 are all electrically connected to the PLC control system integrated in the operation box 11; a rubber sealing gasket 410 is installed on the bottom edge of the detection box 4, and the design of the rubber sealing gasket 410 makes the fit between the detection box 4 and the detection station 6 more tight and plays a role in buffering and shock absorption. The operation box 11 and the operation box support 10 are hinged at one end, and the hinged connection allows the operation box 11 to rotate horizontally around the operation box support 10, which is convenient for the operator to operate. The other end of the operation box support 10 is welded to a column of the support frame 1; the vacuum pump 12 is installed on the ground on the side of the support frame 1.

[0019] The PLC operating system and infrared halogen detection system both adopt existing technologies.

[0020] The support frame 1 has a first hydraulic cylinder 7 and a second hydraulic cylinder 8 installed on its two bottom frames respectively. The output ends of the first hydraulic cylinder 7 and the second hydraulic cylinder 8 are connected to the sliding frame 2 to complete the lifting and lowering of the test box 4. The lifting and lowering function of the first hydraulic cylinder 7 and the second hydraulic cylinder 8 adopts the system principle of synchronous control of dual hydraulic motors, which makes the operation of the two hydraulic cylinders more synchronized.

[0021] A pull-rod type linear displacement sensor 9 is installed parallel to the first hydraulic cylinder 7 and the second hydraulic cylinder 8 on both sides of the bottom frame of the support frame 1. This pull-rod type linear displacement sensor 9 is electrically connected to the PLC control system integrated in the control box 11, in conjunction with the hydraulic equipment. The cooperation between the pull-rod type linear displacement sensor 9 and the PLC control system enables intelligent and precise lifting and lowering of the detection box 4.

[0022] The working process of this utility model:

[0023] When the tested machine 5, after being charged with refrigerant, is located at the testing station 6 on the production line, the PLC control system in the control box 11 controls the hydraulic equipment to make the first hydraulic cylinder 7 and the second hydraulic cylinder 8 descend synchronously at the distance set by the pull rod type linear displacement sensor 9. This causes the sliding frame 2 to drive the testing box 4 and, with the assistance of the sliding wheels 3, descend within the support frame 1, ultimately allowing the testing box 4 to completely cover the tested machine 5. Together with the rubber sealing gasket 410, it forms a sealed cavity with the testing station 6. Then, the PLC control system in the control box 11 controls the vacuum pump 12 to run and opens the first solenoid valve 401 and the second solenoid valve 403. The air inside the sealed cavity of the detection chamber 4 is drawn out through the first one-way valve 402, the first solenoid valve 401, the second one-way valve 404, and the second solenoid valve 403, creating a low-pressure environment within the sealed cavity. At this time, the vacuum pressure transmitter 409 installed on the side of the detection chamber 4 transmits the real-time pressure value inside the sealed cavity to the control system. When the control system detects that the pressure value inside the sealed cavity of the detection chamber 4 reaches a set value, such as 10 kPa, it closes the first solenoid valve 401 and the second solenoid valve 403, placing the tested unit 5 in a low-pressure, light-free environment free from other gaseous interference. Then, the infrared halogen detection system inside the operation box 11 is activated, and the four infrared halogen detection probes embedded in the detection chamber 4 are used to detect refrigerant leakage in the tested unit 5 (for example, the leakage alarm value is set to 1 g / a; when the detected value is greater than or equal to this value, the system displays the value on the screen and sounds an alarm; if the value is less than this value, no alarm is triggered). If an alarm is triggered, it indicates a suspected leak. At this point, the PLC control system within the control box 11 opens the pressure relief solenoid valve 411, allowing outside air to pass through the air filter 412 and the pressure relief solenoid valve 411 before entering the detection chamber 4 to balance the internal and external pressures. When the vacuum pressure transmitter 409 transmits a real-time pressure value of one atmosphere to the control system within the detection chamber 4, it indicates there is no pressure difference between the inside and outside of the detection chamber 4, meaning the pressure relief is complete. The PLC control system within the control box 11 then controls the hydraulic equipment to raise the first hydraulic cylinder 7 and the second hydraulic cylinder 8 synchronously at the distance set by the lever-type linear displacement sensor 9, causing the detection chamber 4 to move upwards and open. The suspected leaking unit 5 is then transferred to the precision leak detection station to locate the leak point. If no alarm is triggered, it indicates that the tested unit 5 has no leak or is within the acceptable range. In this case, the qualified tested unit 5 can be allowed to proceed to the next process for continued production, following the same upward movement and opening procedure of the detection chamber 4. This method quickly screens qualified and unqualified products for refrigerant leaks, accelerating production efficiency and reducing manufacturing costs.

[0024] The above description is merely a preferred embodiment of this application and is not intended to limit the application in any other way. Any person skilled in the art may make changes or modifications to the disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this application without departing from the scope of this application shall still fall within the protection scope of this application.

Claims

1. A rapid pre-detection device for refrigerant leakage in heat pump production, comprising a PLC operating system and an infrared halogen detection system, characterized in that: The testing box (4) is an empty rectangular box with an open bottom, and is placed directly above the testing station (6) on the production line. The testing box (4) is slidably connected by a sliding frame (2) and a support frame (1). Vacuum solenoid valves and check valves are symmetrically arranged on both sides of the testing box (4), namely a first solenoid valve (401), a first check valve (402), a second solenoid valve (403), and a second check valve (404). The inlets of the first check valve (402) and the second check valve (404) are respectively connected to the side wall of the testing box (4), and their outlets are respectively connected to the first solenoid valve (401) and the second solenoid valve. The inlet of (403) is connected to the first solenoid valve (401) and the outlet of the second solenoid valve (403) through a PVC steel wire hose and the inlet of the vacuum pump (12), respectively; the four side walls of the detection box (4) are respectively equipped with a first probe (405), a second probe (406), a third probe (407) and a fourth probe (408), which are all electrically connected to the infrared halogen detection system integrated in the operation box (11); the top of the detection box (4) is equipped with a pressure relief solenoid valve (411), the outlet of which is connected to the inlet of the air filter (412); A vacuum pressure transmitter (409) is installed on one side of the detection box (4); the first solenoid valve (401), the second solenoid valve (403), the pressure relief solenoid valve (411), and the vacuum pressure transmitter (409) are all electrically connected to the PLC control system integrated in the operation box (11); a rubber sealing gasket (410) is installed on the bottom edge of the detection box (4); the operation box (11) and the operation box bracket (10) are hinged at one end, and the other end of the operation box bracket (10) is fixed to a column of the support frame (1); the vacuum pump (12) is installed on the ground on the side of the support frame (1).

2. The rapid pre-detection device for refrigerant leakage in heat pump production according to claim 1, characterized in that: A first hydraulic cylinder (7) and a second hydraulic cylinder (8) are installed on the bottom frames on both sides of the support frame (1), and the output ends of the first hydraulic cylinder (7) and the second hydraulic cylinder (8) are connected to the sliding frame (2).

3. The rapid pre-detection device for refrigerant leakage in heat pump production according to claim 1, characterized in that: A rod-type linear displacement sensor (9) is installed on the bottom frame on both sides of the support frame (1) and parallel to the first hydraulic cylinder (7) and the second hydraulic cylinder (8). The rod-type linear displacement sensor (9) is electrically connected to the PLC control system integrated in the operation box (11).

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