Leak detection device for heat pump system, heat pump system and leak detection method

Abstract

The present application relates to the field of airtightness detection, and discloses a leak detection device for a heat pump system, a heat pump system and a leak detection method. Among them, the leak detection device for the heat pump system includes a leak detection connection end, a gas source connection end, a filling passage, a recovery passage and a first pump; both the filling passage and the recovery passage are connected between the leak detection connection end and the gas source connection end; the first pump includes a first output end and a first input end, the first input end is connected to the leak detection connection end through the recovery passage and is connected to the gas source connection end through the filling passage; the first output end is connected to the gas source connection end through the recovery passage and is connected to the leak detection connection end through the filling passage, and the filling passage and the recovery passage are alternately conducted. The first pump is used to inject the leak detection medium into the heat exchange device under high pressure, and the first pump is used to empty the leak detection medium in the heat exchange device, improving the emptying effect, and reusing the first pump simplifies the device and saves costs.

Description

Technical Field

[0001] This application belongs to the field of airtightness detection, and particularly relates to a leak detection device for a heat pump system, a heat pump system, and a leak detection method. Background Art

[0002] When the heat exchange device is operating, the pressure inside the device is relatively high, and strict requirements are imposed on the pressure resistance and leak tightness of the pipeline. The leakage of the heat exchange medium of the heat exchange device will affect the normal operation of the equipment and may cause damage to the compressor of the heat exchange device. Currently, the commonly used leak detection methods are the differential pressure method and the foam method, among which hidden leak points are not easy to find and the influence of human factors is relatively large.

[0003] The existing leak detection device realizes high-precision leak detection by inputting high-pressure gas into the heat exchange device. However, after the detection is completed, the gas will be directly discharged into the air, resulting in waste of resources. Summary of the Invention

[0004] The embodiments of this application provide a leak detection device for a heat pump system, a heat pump system, and a leak detection method, which can improve the resource utilization rate.

[0005] On the one hand, the embodiments of this application provide a leak detection device for a heat pump system, including: a leak detection connection end, a gas source connection end, a filling passage, a recovery passage, and a first pump. The leak detection connection end is used to connect with the heat exchange device of the heat pump system; the gas source connection end is used to connect with the leak detection medium source of the heat pump system; the filling passage is connected between the leak detection connection end and the gas source connection end; the recovery passage is connected between the leak detection connection end and the gas source connection end; the first pump includes a first output end and a first input end. The first input end is connected to the leak detection connection end through the recovery passage and is connected to the gas source connection end through the filling passage; the first output end is connected to the gas source connection end through the recovery passage and is connected to the leak detection connection end through the filling passage, and the filling passage and the recovery passage are alternately conducted.

[0006] In some embodiments of this application, the filling passage includes a first filling branch and a second filling branch that are arranged in parallel between the leak detection connection end and the gas source connection end, and the first pump is arranged in the first filling branch; the leak detection device of the heat pump system includes a first filling state and a second filling state. In the first filling state, the second filling branch is conducted, and in the second filling state, the first filling branch is conducted.

[0007] In some embodiments of this application, the leak detection device of the heat pump system includes a first recovery state and a second recovery state. In the first recovery state, the second filling branch is conducted; in the second recovery state, the recovery passage is conducted.

[0008] In some embodiments of the present application, in the first filling state, the pressure value of the leak detection connection end is less than the pressure value of the gas source connection end, and in the first recovery state, the pressure value of the gas source connection end is less than the pressure value of the leak detection connection end.

[0009] In some embodiments of the present application, the first filling branch includes a first control valve and a branch control valve, the first input end of the first pump is connected to the gas source connection end through the first control valve, and the first output end of the first pump is connected to the leak detection connection end through the branch control valve; the second filling branch includes a second control valve, and the second control valve is connected between the leak detection connection end and the gas source connection end.

[0010] In some embodiments of the present application, the recovery passage includes a first recovery branch and a second recovery branch arranged in parallel between the leak detection connection end and the gas source connection end, and the first pump is arranged in the first recovery branch; the leak detection device of the heat pump system includes a first recovery state and a second recovery state, in the first recovery state, the second recovery branch is turned on; in the second recovery state, the first recovery branch is turned on.

[0011] In some embodiments of the present application, the first recovery branch includes a third control valve and a fifth control valve, the first output end of the first pump is connected to the gas source connection end through the third control valve, and the first input end of the first pump is connected to the leak detection connection end through the fifth control valve; the second recovery branch includes a fourth control valve, and the fourth control valve is connected between the leak detection connection end and the gas source connection end.

[0012] In some embodiments of the present application, the leak detection device of the heat pump system further includes a second pump, the second pump including a second output end and a second input end, the second output end is connected to the atmosphere, and the second input end is connected to the leak detection connection end.

[0013] In some embodiments of the present application, the leak detection device of the heat pump system also includes a heat exchange medium injection passage, the heat exchange medium injection passage includes a first end and a second end, the first end is connected to the leak detection connection end and the second input end, and the second end is used to connect to a heat exchange medium source.

[0014] On the other hand, an embodiment of the present application also provides a heat pump system, comprising: a leak detection device, a leak detection medium source and a heat exchange device of the heat pump system provided in the above embodiment, wherein the heat exchange device is connected to the leak detection connection end, and the leak detection medium source is connected to the gas source connection end.

[0015] In some embodiments of the present application, the heat pump system further includes a heat exchange medium source, and the heat exchange medium source includes at least one carbon dioxide storage tank; the leak detection medium source includes at least one helium storage tank.

[0016] In another aspect, an embodiment of the present application further provides a method for detecting leaks in a heat pump system, including: filling a leak detection medium into a heat exchange device, and when the pressure of the heat exchange device reaches a first preset pressure value, obtaining a first temperature value of the environment where the heat exchange device is located; maintaining the pressure of the heat exchange device for a preset time, and obtaining a second temperature value of the environment where the heat exchange device is located; determining a current pressure value of the heat exchange device through the first preset pressure value, the first temperature value, and the second temperature value; comparing the current pressure value with the first preset pressure value to determine the leak situation of the heat exchange device.

[0017] The leak detection device, heat pump system, and leak detection method for the heat pump system according to the embodiments of the present application recover the leak detection medium through the set recovery path, reduce resource waste, enable the leak detection medium to be recycled, and improve the utilization rate of the leak detection medium; and the filling path and the recovery path share the first pump. The first pump is used to inject the leak detection medium into the heat exchange device at high pressure, and the first pump is used to empty the leak detection medium in the heat exchange device, improving the emptying effect. Moreover, sharing the first pump simplifies the device and saves costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a schematic diagram of a leak detection device for a heat pump system provided by some embodiments of the present application;

[0020] Figure 2 It is another schematic diagram of a leak detection device for a heat pump system provided by some embodiments of the present application;

[0021] Figure 3 It is yet another schematic diagram of a leak detection device for a heat pump system provided by some embodiments of the present application;

[0022] Figure 4 It is still another schematic diagram of a leak detection device for a heat pump system provided by some embodiments of the present application;

[0023] Figure 5 It is a schematic diagram of a control device for a heat pump system provided by some embodiments of the present application;

[0024] Figure 6Flowchart of the leak detection method for the heat pump system provided by some embodiments of the present application.

[0025] Description of the reference numerals:

[0026] 101, leak detection connection end; 102, gas source connection end; 103, first pump; 103a, first output end; 103b, first input end; 104, pressure reducing valve;

[0027] 110, filling passage; 111, first filling branch; 112, second filling branch; 113, first control valve; 114, second control valve; 115, branch control valve; 116, second check valve;

[0028] 120, recovery passage; 121, first recovery branch; 122, second recovery branch; 123, third control valve; 124, fourth control valve; 125, first check valve; 126, third check valve; 127, fifth control valve;

[0029] 131, second pump; 131a, second input end; 131b, second output end; 132, ninth control valve; 140, heat transfer medium injection passage; 141, eighth control valve; 150, sixth control valve; 151, seventh control valve; 200, heat exchange device; 300, leak detection medium source; 301, helium storage tank; 400, heat transfer medium source; 401, carbon dioxide storage tank; 402, manual valve; 500, PLC controller; 501, touch screen; 502, audible and visual alarm; 503, emergency stop button; 504, concentration data acquisition module. Detailed implementation manners

[0030] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than limiting the present application. For those skilled in the art, the present application can be implemented without some of these specific details. The following description of the embodiments is only intended to provide a better understanding of the present application by showing examples of the present application.

[0031] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0032] A heat pump system is an efficient energy conversion and utilization system. Based on the principles of thermodynamics, the heat pump system transfers the heat energy in the low-temperature heat source to the high-temperature heat source by consuming high-grade energy such as electrical energy. Specifically, the working medium in the heat pump unit absorbs the heat energy in the low-temperature heat source in the evaporator, and after the temperature and pressure are increased by the compressor, the heat energy is released in the condenser, thus realizing the transfer of heat energy.

[0033] A carbon dioxide heat pump system is a heat pump system that uses carbon dioxide as the working medium. The working principle of the carbon dioxide heat pump system is similar to that of other heat pump systems. Through the process of cyclic compression refrigeration, the heat absorbed from low-temperature heat sources such as groundwater and geothermal energy is transferred to high-temperature heat sources such as heating and hot water. The carbon dioxide heat pump system has high thermal efficiency, can make full use of the heat energy in the low-temperature heat source, and convert it into high-temperature heat energy, thus achieving high efficiency and energy conservation. As a natural refrigerant, carbon dioxide has almost zero damage to the ozone layer and a low global warming potential value, meeting the environmental protection requirements. Carbon dioxide has good chemical stability and safety, is non-flammable, is compatible with various lubricating oils and common mechanical component materials, and does not decompose to produce harmful gases even at high temperatures.

[0034] Due to the relatively high critical pressure of carbon dioxide, for example, usually 7.37 MPa, in a transcritical cycle, the working pressure of the heat pump system may reach more than 10 MPa, posing higher requirements for aspects such as the material strength, sealing and pipeline connection of the heat pump system. Therefore, before the carbon dioxide heat pump system operates, leak detection is required. The existing leak detection method is to introduce nitrogen into the heat pump system and detect the leak location through the differential pressure method and the foam method. After the detection is completed, the nitrogen is discharged into the air, which will cause waste of nitrogen resources and the nitrogen evacuation effect in the heat pump system is not good.

[0035] In view of this, the present application provides a leak detection device for a heat pump system, which realizes the filling and recovery of a leak detection medium through a first pump, avoids waste of resources, and has a better evacuation effect of the leak detection medium of the heat pump system.

[0036] The leak detection device of the heat pump system of the present application can also be applied to leak detection of other systems, such as a refrigeration system, a gas circuit system, a vacuum system, an industrial storage system, an automotive fuel system, etc.

[0037] Figure 1 FIG. is a schematic diagram of a leak detection device for a heat pump system provided by some embodiments of the present application. As Figure 1 shown, some embodiments of the present application provide a leak detection device for a heat pump system, including a leak detection connection end 101, a gas source connection end 102, a filling passage 110, a recovery passage 120, and a first pump 103. The leak detection connection end 101 is used to connect with a heat exchange device 200 of the heat pump system; the gas source connection end 102 is used to connect with a leak detection medium source 300 of the heat pump system; the filling passage 110 is connected between the leak detection connection end 101 and the gas source connection end 102; the recovery passage 120 is connected between the leak detection connection end 101 and the gas source connection end 102; the first pump 103 includes a first output end 103a and a first input end 103b. The first input end 103b is connected to the leak detection connection end 101 through the recovery passage 120 and is connected to the gas source connection end 102 through the filling passage 110; the first output end 103a is connected to the gas source connection end 102 through the recovery passage 120 and is connected to the leak detection connection end 101 through the filling passage 110, and the filling passage 110 and the recovery passage 120 are alternately conducted.

[0038] The leak detection connection end 101 is the connection end of the heat exchange device 200 and the leak detection device. The leak detection connection end 101 realizes the connection between the heat exchange device 200 and the leak detection device. In one example, the leak detection connection end 101 can be the opening position at the end of a pipeline or the opening position at the end of a channel. The leak detection connection end 101 can be one or more.

[0039] The gas source connection end 102 is the connection end of the leak detection device and the leak detection medium source 300. The gas source connection end 102 realizes the connection between the leak detection device and the leak detection medium source 300. In one example, the gas source connection end 102 can be the opening position at the end of a pipeline or the opening position at the end of a channel. The gas source connection end 102 can be one or more.

[0040] The filling passage 110 is a channel that conducts the heat exchange device 200 and the leak detection medium source 300 when filling the heat exchange device 200 with the leak detection medium. Exemplarily, the filling passage 110 can be a pipeline or a channel formed on a block. The filling passage 110 can be one or more.

[0041] The recovery passage 120 is a passage that connects the heat exchange device 200 and the leak detection medium source 300 when recovering the leak detection medium for the heat exchange device 200. Exemplarily, the recovery passage 120 can be a pipeline or a passage formed on a block. The recovery passage 120 can be one or more.

[0042] Based on the different leak detection media, the first pump 103 can be a liquid pump or a gas pump. The first pump 103 is multiplexed and connected to the filling passage 110 and the recovery passage 120, and the first pump 103 is respectively communicated with the filling passage 110 and the recovery passage 120.

[0043] Exemplarily, the leak detection medium can be nitrogen or helium. In other embodiments of the present application, the leak detection medium can be a liquid. Among them, compared with nitrogen, the content of helium in the atmosphere is less, which can improve the sensitivity and accuracy of the leak detection work.

[0044] Exemplarily, the leak detection device includes a filling state and a recovery state. In the filling state, the filling passage 110 is opened, the recovery passage 120 is closed, and the first pump 103 fills the leak detection medium from the leak detection medium source 300 into the heat exchange device 200 through the filling passage 110. In the recovery state, the recovery passage 120 is opened, the filling passage 110 is closed, and the first pump 103 recovers the leak detection medium in the heat exchange device 200 to the leak detection medium source 300 through the recovery passage 120.

[0045] Exemplarily, the heat pump system includes a leak detection device and a heat exchange device 200. The leak detection device and the heat exchange device 200 are connected through a leak detection connection end 101. When it is necessary to perform an airtightness detection on the heat exchange device 200, the leak detection device fills the leak detection medium in the leak detection medium source 300 into the heat exchange device 200, and the airtightness detection of the heat exchange device 200 is completed by detecting the leak detection medium at multiple positions of the heat exchange device 200 through a detection device. When the airtightness detection is completed, the leak detection device recovers the leak detection medium in the heat exchange device 200 to the leak detection medium source 300.

[0046] By setting the recovery passage 120 to recover the leak detection medium, resource waste is reduced, the leak detection medium is recycled, and the utilization rate of the leak detection medium is improved; and the filling passage 110 and the recovery passage 120 share the first pump 103. Through the first pump 103, high-pressure injection of the leak detection medium into the heat exchange device 200 is realized, the working pressure of the heat exchange device 200 is simulated, and the leak detection accuracy is improved; through the first pump 103, the leak detection medium in the heat exchange device 200 is emptied, the emptying effect is improved, and sharing the first pump 103 simplifies the device and saves costs.

[0047] Figure 2 Another schematic diagram of the leak detection device of the heat pump system provided by some embodiments of the present application.

[0048] As shown Figure 2 In an alternative embodiment of the present application, the charging passage 110 includes a first charging branch 111 and a second charging branch 112 connected in parallel between the leak detection connection end 101 and the gas source connection end 102. The first pump 103 is disposed in the first charging branch 111. The leak detection device of the heat pump system includes a first charging state and a second charging state. In the first charging state, the second charging branch 112 is turned on. In the second charging state, the first charging branch 111 is turned on.

[0049] The conduction of the first charging branch 111 can be unidirectional or bidirectional. The conduction of the second charging branch 112 can be unidirectional or bidirectional. The number of the first charging branch 111 and the second charging branch 112 can be one or more.

[0050] Exemplarily, the inner diameter of the first charging branch 111 can be the same as or different from the inner diameter of the second charging branch 112. In one example, the inner diameter of the second charging branch 112 is larger than the inner diameter of the first charging branch 111, which improves the charging efficiency, reduces the impact pressure on the first pump 103, and prolongs the service life of the first pump 103.

[0051] Exemplarily, in the first charging state, the second charging branch 112 is opened and the first charging branch 111 is closed. In the second charging state, the first charging branch 111 is opened, and the second charging branch 112 can be opened or closed. In one example, a one-way conduction member is provided in the second charging branch 112, and the detection medium flows from the gas source connection end 102 to the leak detection connection end 101.

[0052] Exemplarily, at the initial stage of charging, the pressure at the gas source connection end 102 is greater than the pressure at the leak detection connection end 101. The leak detection medium can be quickly charged into the heat exchange device 200 through the second charging branch 112, improving the charging efficiency. During the charging process, when the pressure at the gas source connection end 102 is equal to the pressure at the leak detection connection end 101, the leak detection medium is further injected into the heat exchange device 200 through the first charging branch 111 and the first pump 103, so that the pressure in the heat exchange device 200 reaches the preset pressure, ensuring that the leak detection pressure reaches the pressure during the operation of the heat exchange device 200 and improving the leak detection accuracy.

[0053] Further, in an alternative embodiment of the present application, in the first charging state, the pressure value at the leak detection connection end 101 is less than the pressure value at the gas source connection end 102. The charging efficiency can be improved and rapid charging can be ensured.

[0054] Exemplarily, when the pressure value of the leak detection connection end 101 is less than the pressure value of the gas source connection end 102, the leak detection medium is filled into the heat exchange device 200 through the second filling branch 112 until the pressure value of the leak detection connection end 101 is equal to the pressure value of the gas source connection end 102, and the first filling branch 111 is opened, and the leak detection medium is filled into the heat exchange device 200 through the first pump 103 until the pressure of the leak detection connection end 101 reaches the first preset pressure.

[0055] Continue to refer Figure 1 and Figure 2 In an optional embodiment of the present application, the leak detection device of the heat pump system includes a first recovery state and a second recovery state. In the first recovery state, the second filling branch 112 is connected; in the second recovery state, the recovery path 120 is connected.

[0056] The recovery path 120 can be unidirectional or bidirectional. The second filling branch 112 can be bidirectional. The number of the recovery path 120 and the second filling branch 112 can be one or more.

[0057] Exemplarily, after the filling into the heat exchange device 200 is completed, the first filling branch 111 and the second filling branch 112 are closed. After the air tightness test is completed, the second filling branch 112 is opened, and due to the pressure difference between the heat exchange device 200 and the leak detection medium source 300, the leak detection medium in the heat exchange device 200 is quickly filled into the leak detection medium source 300. When the pressure value of the leak detection connection end 101 is equal to the pressure value of the gas source connection end 102, the second filling branch 112 is closed, the recovery passage 120 is opened, and the leak detection medium in the heat exchange device 200 is continuously recovered into the leak detection medium source 300 through the first pump 103 until the pressure of the leak detection connection end 101 reaches the second preset pressure.

[0058] The second filling branch 112 is used to realize rapid recovery of the leak detection medium. The second filling branch 112 is used during rapid filling and rapid recovery to improve the leak detection efficiency and simplify the structure of the leak detection device.

[0059] Figure 3 Another schematic diagram of a leak detection device for a heat pump system provided in some embodiments of the present application.

[0060] like Figure 3 As shown, in another optional embodiment of the present application, the recovery passage 120 includes a first recovery branch 121 and a second recovery branch 122 arranged in parallel between the leak detection connection terminal 101 and the gas source connection terminal 102, and the first pump 103 is arranged in the first recovery branch 121; the leak detection device of the heat pump system includes a first recovery state and a second recovery state. In the first recovery state, the second recovery branch 122 is turned on; in the second recovery state, the first recovery branch 121 is turned on.

[0061] Exemplarily, the conduction of the first recovery branch 121 can be unidirectional conduction or bidirectional conduction. The conduction of the second recovery branch 122 can be unidirectional conduction or bidirectional conduction. The number of the first recovery branch 121 and the second recovery branch 122 can be one or more.

[0062] Exemplarily, the inner diameter of the first recovery branch 121 and the inner diameter of the second recovery branch 122 can be the same or different. In one example, the inner diameter of the second recovery branch 122 is greater than the inner diameter of the first recovery branch 121, which can improve the recovery efficiency, reduce the impact pressure on the first pump 103, and extend the service life of the first pump 103.

[0063] Exemplarily, after the filling of the heat exchange device 200 is completed, the first filling branch 111 and the second filling branch 112 are closed. After the airtightness detection is completed, the recovery path 120 is first in the first recovery state and then in the second recovery state. Specifically, after the airtightness detection is completed, since the pressure value at the leak detection connection end 101 is greater than the pressure value at the gas source connection end 102, the second recovery branch 122 is opened, and the leak detection medium in the heat exchange device 200 is quickly recovered into the leak detection medium source 300 through the pressure difference. When the pressure value at the leak detection connection end 101 is equal to the pressure value at the gas source connection end 102, the first recovery branch 121 is opened, and the first pump 103 is started, and the leak detection medium in the heat exchange device 200 is continuously recovered into the leak detection medium source 300 through the first pump 103 until the pressure value at the leak detection connection end 101 reaches the second preset value.

[0064] The recovery path 120 improves the recovery efficiency of the leak detection medium by providing the first recovery branch 121 and the second recovery branch 122. And both the recovery path 120 and the filling path 110 are provided with fast branches, namely the second recovery branch 122 and the second filling branch 112, which is convenient for quick switching between different working states. For example, a main switch is provided in front of the first filling branch 111 and the second filling branch 112 to achieve quick closing, reducing the error rate and failure rate.

[0065] Furthermore, in a specific embodiment of the present application, in the first recovery state, the pressure value at the gas source connection end 102 is less than the pressure value at the leak detection connection end 101. This can improve the recovery efficiency and ensure quick recovery.

[0066] Continue to refer to Figures 1 to 3, in some alternative embodiments of the present application, the first charging branch 111 includes a first control valve 113 and a branch control valve 115. The first output end 103a of the first pump 103 is connected to the leak detection connection end 101 through the branch control valve 115, and the first input end 103b of the first pump 103 is connected to the gas source connection end 102 through the first control valve 113; the second charging branch 112 includes a second control valve 114, and the second control valve 114 is connected between the leak detection connection end 101 and the gas source connection end 102.

[0067] Exemplarily, the first control valve 113, the branch control valve 115, and the second control valve 114 can be manual, electrically controlled, or hydraulically controlled on-off valves.

[0068] Exemplarily, in the first charging state, the first control valve 113 and the branch control valve 115 are in the open state, and the second control valve 114 is in the closed state. In the second charging state, the second control valve 114 and the branch control valve 115 are in the open state, and the first control valve 113 is in the closed state.

[0069] As Figure 1 and Figure 2 shown, in other embodiments of the present application, the recovery path 120 includes a third control valve 123 and a fifth control valve 127. The first output end 103a of the first pump 103 is connected to the gas source connection end 102 through the third control valve 123, and the first input end 103b of the first pump 103 is connected to the leak detection connection end 101 through the fifth control valve 127.

[0070] Exemplarily, the third control valve 123 and the fifth control valve 127 can be manual, electrically controlled, or hydraulically controlled on-off valves.

[0071] After the charging is completed, the first control valve 113, the branch control valve 115, and the second control valve 114 are closed to keep the pressure of the heat exchange device 200 and perform a leak tightness test. After the leak tightness test is completed, the second control valve 114 is opened to quickly recover the leak detection medium in the heat exchange device 200. When the pressure values at the leak detection connection end 101 and the gas source connection end 102 are equal or the difference is within a preset range, the second control valve 114 is closed, the third control valve 123 and the fifth control valve 127 are opened, the branch control valve 115 is closed, and the leak detection medium in the heat exchange device 200 is recovered through the first pump 103.

[0072] As Figure 1 and Figure 3As shown, in some other embodiments of the present application, the first recovery branch 121 includes a third control valve 123 and a fifth control valve 127. The first output end 103a of the first pump 103 is connected to the gas source connection end 102 through the third control valve 123, and the first input end 103b of the first pump 103 is connected to the leak detection connection end 101 through the fifth control valve 127. The second recovery branch 122 includes a fourth control valve 124, and the fourth control valve 124 is connected between the leak detection connection end 101 and the gas source connection end 102.

[0073] Exemplarily, the third control valve 123, the fourth control valve 124, and the fifth control valve 127 can be manual, electrically controlled, or hydraulically controlled switching valves.

[0074] After the filling is completed, the first control valve 113, the branch control valve 115, and the second control valve 114 are closed to maintain the pressure of the heat exchange device 200 and perform a leak tightness test. After the leak tightness test is completed, the fourth control valve 124 is opened to quickly recover the leak detection medium in the heat exchange device 200. When the pressure values at the gas source connection end 102 and the leak detection connection end 101 are equal or the difference is within a preset range, the fourth control valve 124 is closed, the third control valve 123 and the fifth control valve 127 are opened, the branch control valve 115 is closed, and the leak detection medium in the heat exchange device 200 is recovered by the first pump 103.

[0075] Wherein, one end of the second control valve 114 can be arranged between the leak detection connection end 101 and the branch control valve 115, or can be arranged between the branch control valve 115 and the first output end 103a of the first pump 103. Based on the set position, the switching state of the branch control valve 115 is selected in the first filling state and the second filling state.

[0076] In other embodiments of the present application, the leak detection device of the heat pump system further includes a first check valve 125. The first check valve 125 is arranged between the leak detection connection end 101 and the recovery passage 120, and the conduction direction of the first check valve 125 is from the leak detection connection end 101 to the gas source connection end 102.

[0077] Exemplarily, the first check valve 125 is arranged between the leak detection connection end 101 and the first input end 103b of the first pump 103.

[0078] Exemplarily, in the second filling state, the first control valve 113 and the second control valve 114 can both be in the open state. In the second recovery state, the third control valve 123 and the fourth control valve 124 can both be in the open state.

[0079] Since the airtightness of the control valve is poor, in order to improve the airtightness of each passage, the first check valve 125 is provided. Exemplarily, a check valve can be serially arranged for each control valve.

[0080] Figure 4 Another schematic diagram of the leak detection device for the heat pump system provided by some embodiments of the present application.

[0081] As Figure 4 shown, in some embodiments of the present application, the charging passage 110 further includes a second check valve 116, and the recovery passage 120 further includes a third check valve 126. The conducting direction of the second check valve 116 is from the gas source connection end 102 to the leak detection connection end 101. The conducting direction of the third check valve 126 is from the leak detection connection end 101 to the gas source connection end 102. The second check valve 116 is disposed between the leak detection connection end 101 and the second control valve 114, and the third check valve 126 is disposed between the first output end 103a of the first pump 103 and the third control valve 123.

[0082] Exemplarily, the second check valve 116 is disposed between the branch control valve 115 and the second control valve 114, and the third check valve 126 is disposed between the branch control valve 115 and the third control valve 123.

[0083] Continuing to refer to Figure 1 and 4 , in some embodiments of the present application, the recovery passage 120 further includes a fifth control valve 127, and the fifth control valve 127 is disposed between the leak detection connection end 101 and the first pump 103.

[0084] Exemplarily, the fifth control valve 127 is disposed between the first check valve 125 and the first input end 103b of the first pump 103.

[0085] In some other embodiments of the present application, the leak detection device of the heat pump system further includes a pressure reducing valve 104. The pressure reducing valve 104 is disposed between the gas source connection end 102 and the first input end 103b of the first pump 103, for protecting the first pump 103 to avoid excessive pressure at the gas source connection end 102 and affecting the service life of the first pump 103.

[0086] In addition, continuing to refer to Figure 4 , in some alternative embodiments of the present application, the leak detection device of the heat pump system further includes a second pump 131. The second pump 131 includes a second output end 131b and a second input end 131a. The second output end 131b is in communication with the atmosphere, and the second input end 131a is in communication with the leak detection connection end 101.

[0087] Exemplarily, the second output end 131b is suspended to discharge the gas in the heat exchange device 200 to the atmosphere.

[0088] After the recovery of the leak detection medium in the heat exchange device 200 in the recovery passage 120 is completed, the recovery passage 120 is closed. The second pump 131 is turned on to evacuate the heat exchange device 200, so that the purity of the heat exchange medium subsequently charged into the heat exchange device 200 is higher.

[0089] In an embodiment of the present application, the leak detection device of the heat pump system further includes a sixth control valve 150 and a seventh control valve 151. The sixth control valve 150 is disposed between the leak detection connection end 101, the charging passage 110, and the recovery passage 120, and the seventh control valve 151 is disposed between the leak detection connection end 101 and the second input end 131a of the second pump 131.

[0090] The on-off of the charging passage 110 and the recovery passage 120 with the leak detection connection end 101 can be simultaneously controlled by the sixth control valve 150.

[0091] In addition, in some other embodiments of the present application, the leak detection device of the heat pump system further includes a heat exchange medium injection passage 140. The heat exchange medium injection passage 140 includes a first end and a second end. The first end is connected to the leak detection connection end 101 and the second input end 131a, and the second end is used to connect to the heat exchange medium source 400.

[0092] Exemplarily, the heat exchange medium injection passage 140 can be one or more.

[0093] Exemplarily, the first end of the heat exchange medium injection passage 140 is connected to the second input end 131a, and the second pump 131 can be used to evacuate the heat exchange medium injection passage 140 to improve the purity of the heat exchange medium charged into the heat exchange device 200.

[0094] Exemplarily, the first end of the heat exchange medium injection passage 140 is connected to the leak detection connection end 101 to realize charging the heat exchange medium of the heat exchange medium source 400 into the heat exchange device 200. In one example, after the heat exchange medium injection passage 140 is evacuated by the second pump 131, the heat exchange medium is charged into the heat exchange device 200.

[0095] In some other embodiments of the present application, the heat exchange medium source 400 includes at least one carbon dioxide storage tank 401. The carbon dioxide storage tank 401 includes a manual valve 402, and the leak detection device of the heat pump system further includes an eighth control valve 141. The eighth control valve 141 is connected between the heat exchange medium injection passage 140 and the manual valve 402. When the second pump 131 is in the evacuated state, the manual valve 402 is closed and the eighth control valve 141 is opened.

[0096] Further, in some other embodiments of the present application, the leak detection device of the heat pump system further includes a ninth control valve 132, which is disposed between the seventh control valve 151 and the second pump 131. The first end of the heat exchange medium injection passage 140 is connected between the seventh control valve 151 and the ninth control valve 132.

[0097] When filling the heat exchange device 200 with the heat exchange medium, the seventh control valve 151 is opened and the ninth control valve 132 is closed.

[0098] As Figures 1 to 4 shown, an embodiment of the present application further provides a heat pump system, including the leak detection device of the heat pump system in the above embodiment, a leak detection medium source 300, and a heat exchange device 200. The heat exchange device 200 is connected to the leak detection connection end 101, and the leak detection medium source 300 is connected to the gas source connection end 102.

[0099] In an embodiment of the present application, a first pressure detection member is provided at the heat exchange device 200 and / or the leak detection connection end 101, and a second pressure detection member is provided at the gas source connection end 102 and / or the leak detection medium source 300. The first pressure detection member and the second pressure detection member may be a pressure sensor or a pressure gauge.

[0100] In one example, a first pressure detection member is provided at the connection between the heat exchange device 200 and the leak detection connection end 101. A second pressure detection member is provided at the connection between the leak detection medium source 300 and the gas source connection end 102.

[0101] In an embodiment of the present application, the leak detection medium source 300 includes at least one helium gas storage tank 301. For example, the leak detection medium source 300 includes three helium gas storage tanks 301. Of course, in other embodiments of the present application, other helium gas storage devices may be used.

[0102] Exemplarily, the helium gas storage tank 301 is connected to the filling passage 110 and the recovery passage 120 through a control valve.

[0103] In an embodiment of the present application, the heat pump system further includes a heat exchange medium source 400, and the heat exchange medium source 400 includes at least one carbon dioxide storage tank 401. For example, the heat exchange medium source 400 includes three carbon dioxide storage tanks 401. Multiple carbon dioxide storage tanks 401 are filled simultaneously to avoid introducing a small amount of air when replacing gas cylinders due to insufficient filling amount of a single gas cylinder, ensuring the purity of CO2 in the heat exchange device 200. Of course, in other embodiments of the present application, other carbon dioxide storage devices may be used.

[0104] Figure 5 It is a schematic diagram of the control device of the heat pump system provided in some embodiments of the present application.

[0105] As Figure 5As shown, in an embodiment of the present application, the heat pump system further includes a control device, which includes a PLC controller 500, a touch screen 501, a pressure data acquisition module (not shown in the figure), a helium concentration data acquisition module 504, an audible and visual alarm 502, an emergency stop button 503, and a temperature detection component (not shown in the figure).

[0106] The PLC controller 500 is communicatively connected to the touch screen 501, the pressure data acquisition module, the helium concentration data acquisition module 504, the audible and visual alarm 502, the emergency stop button 503, and the temperature detection component respectively.

[0107] The pressure data acquisition module includes a first pressure detection component and a second pressure detection component. The helium concentration data acquisition module 504 may include a helium detection probe. The temperature detection component includes a temperature sensor.

[0108] The PLC controller 500 includes a pressure maintaining mode, a leak detection mode, a recovery mode, a CO2 heat pump system vacuum pumping mode, and a CO2 filling mode. Different working modes are selected through the touch screen 501. And a first preset pressure value can be set through the touch screen 501. Intelligent integrated control reduces the influence of human factors and improves the work efficiency of personnel.

[0109] The control device starts the corresponding control valve action in the working mode by selecting different working modes to complete the corresponding functions; during the leak detection process, different pressure maintaining parameters are set according to the operating medium of the heat exchange device, and the current pressure of the heat exchange device after reaching the pressure maintaining time is calculated independently by collecting the indoor temperature change where the heat exchange device is located, and the pressure maintaining result is obtained through comparison and judgment; during the leak detection, a helium concentration probe is used to detect the welding points and thread points in detail, which is convenient for finding hidden leak points, improves the leak detection efficiency of the heat pump system, and avoids the influence of room temperature and human subjective factors.

[0110] Figure 6 It is a flowchart of a leak detection method for a heat pump system provided in some embodiments of the present application.

[0111] As Figures 1 to 6 shown, an embodiment of the present application also provides a leak detection method for a heat pump system, and this method can be based on the heat exchange system of the above embodiment, specifically including steps S1 to S4.

[0112] S1: Fill the heat exchange device 200 with a leak detection medium, and when the pressure of the heat exchange device 200 reaches the first preset pressure value, obtain the first temperature value of the environment where the heat exchange device 200 is located.

[0113] Exemplarily, select the holding pressure mode and set the first preset pressure value to P1. In the holding pressure mode, first open the second control valve 114, the branch control valve 115, and the sixth control valve 150. When the pressure value detected by the first pressure detection component is equal to the pressure value detected by the second pressure detection component, there is a prompt from the audible and visual alarm 502, then close the second control valve 114, open the first pump 103 and the first control valve 113. Until the pressure value detected by the first pressure detection component is equal to the first preset pressure value, there is a prompt from the audible and visual alarm 502, and then close the first control valve 113, the branch control valve 115, the first pump 103, and the sixth control valve 150. In the state of the first preset pressure value, detect the first temperature value T1 of the current environment through the first temperature detection component.

[0114] In one example, the leak detection medium is helium.

[0115] S2: Hold the pressure of the heat exchange device 200 for a preset time, and obtain the second temperature value of the environment where the heat exchange device 200 is located.

[0116] Exemplarily, switch to the leak detection mode and hold the pressure of the heat exchange device 200. The preset holding time can be greater than or equal to 24 hours. Detect the second temperature value T2 of the current environment through the first temperature detection component.

[0117] S3: Determine the current pressure value of the heat exchange device 200 based on the first preset pressure value, the first temperature value, and the second temperature value.

[0118] Exemplarily, according to the pressure formula: P2 = P1×(T2 + 273) / (T1 + 273), where P2 is the current pressure value of the heat exchange device 200 after holding the pressure.

[0119] S4: Compare the current pressure value with the first preset pressure value to determine the leakage situation of the heat exchange device 200.

[0120] When P2 - 0.05 ≤ P1 ≤ P2 + 0.05, the pressure holding of the heat exchange device 200 is completed, and the leak detection mode is exited; when P1 > P2 + 0.05 or P1 < P2 - 0.05, there are hidden leak points in the heat exchange device 200, and the leak points need to be further searched.

[0121] By combining the change of the ambient temperature, the accuracy of leak point detection is improved.

[0122] Furthermore, the embodiment of the present application also provides a leak detection method for a heat pump system. After step S1, it further includes detecting the helium concentration at a specified position of the heat exchange device 200.

[0123] Exemplarily, place the helium detection probe approximately 3 mm close to the weld joint and threaded connection of the heat exchange device 200, and move it uniformly at a speed of 10 - 20 mm / s for leak detection. When the detected helium concentration ≥ He1 + 1%, the audible and visual alarm 502 indicates that there is a leak here; otherwise, there is no leak point here.

[0124] The embodiment of the present application further provides a leak detection method for a heat pump system, which further includes step S5:

[0125] S5: Recover the leak detection medium in the heat exchange device 200 into the leak detection medium source 300.

[0126] Exemplarily, switch to the recovery mode and set the second preset pressure value to P3. Open the sixth control valve 150, the fifth control valve 127, and the fourth control valve 124. When the pressure value detected by the first pressure detection component is equal to the pressure value detected by the second pressure detection component, there is a prompt from the audible and visual alarm 502, then close the fourth control valve 124, and open the first pump 103 and the third control valve 123. Until the pressure value detected by the first pressure detection component is equal to the second preset pressure value P3, there is a prompt from the audible and visual alarm 502, then close the sixth control valve 150, the fifth control valve 127, the first pump 103, and the third control valve 123.

[0127] Exemplarily, P3 < 0.05 Mpa.

[0128] S6: Evacuate the heat exchange device 200 and part of the leak detection device.

[0129] Exemplarily, switch to the vacuum pumping mode of the CO2 heat pump system and set the third preset pressure value to P4. Open the seventh control valve 151, the ninth control valve 132, the second pump 131, and the eighth control valve 141, and close the manual valve 402.

[0130] When the pressure value detected by the first pressure detection component is equal to the third preset pressure value, there is a prompt from the audible and visual alarm 502, then close the ninth control valve 132 and the second pump 131.

[0131] S7: Charge the heat exchange device 200 with a heat exchange medium.

[0132] Exemplarily, switch to the CO2 charging mode and set the fourth preset pressure value to P5. Open the manual valve 402. Charge CO2 into the heat exchange device 200 until the pressure value detected by the first pressure detection component reaches the fourth preset pressure value P5. For example, the first preset pressure value P1 can be equal to P5.

[0133] In other examples, in step S6, when the pressure value of the first pressure detection component is equal to the third preset pressure value, the sound and light alarm 502 gives a prompt to close the seventh control valve 151, the ninth control valve 132, the second pump 131, and the eighth control valve 141. In step S7, switch to the CO2 filling mode, and set the fourth preset pressure value to P5. Open the manual valve 402, the seventh control valve 151, and the eighth control valve 141. Fill the heat exchange device 200 with CO2 until the pressure value of the first pressure detection component reaches the fourth preset pressure value P5, and then close the seventh control valve 151 and the eighth control valve 141. For example, the first preset pressure value P1 can be equal to P5. By opening and closing the seventh control valve 151 and the eighth control valve 141, the system safety is improved.

[0134] As described above, the foregoing are only specific embodiments of the present application. Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, modules, and units described above can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here. It should be understood that the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present application, and these modifications or substitutions should all be covered by the protection scope of the present application.

Claims

1. A leak detection device for a heat pump system, characterized in that, Comprising: A leak detection connection end for connecting to a heat exchange device of a heat pump system; A gas source connection end for connecting to a leak detection medium source of the heat pump system; A charging passage connected between the leak detection connection end and the gas source connection end; the charging passage includes a first charging branch and a second charging branch arranged in parallel between the leak detection connection end and the gas source connection end; A recovery passage connected between the leak detection connection end and the gas source connection end; A first pump including a first output end and a first input end, the first input end is connected to the leak detection connection end through the recovery passage and is connected to the gas source connection end through the charging passage; the first pump is arranged in the first charging branch, the first output end is connected to the gas source connection end through the recovery passage and is connected to the leak detection connection end through the charging passage, and the charging passage and the recovery passage are alternately conducted; The leak detection device of the heat pump system includes a first charging state and a second charging state. In the first charging state, the second charging branch is conducted. In the second charging state, the first charging branch is conducted.

2. The leak detection device for the heat pump system according to claim 1, characterized in that, The leak detection device of the heat pump system includes a first recovery state and a second recovery state. In the first recovery state, the second charging branch is conducted; in the second recovery state, the recovery passage is conducted.

3. The leak detection device of the heat pump system according to claim 2, characterized in that In the first charging state, the pressure value of the leak detection connection end is less than the pressure value of the gas source connection end. In the first recovery state, the pressure value of the gas source connection end is less than the pressure value of the leak detection connection end.

4. The leak detection device for a heat pump system according to claim 1, characterized in that, The first charging branch includes a first control valve and a branch control valve. The first input end of the first pump is connected to the gas source connection end through the first control valve, and the first output end of the first pump is connected to the leak detection connection end through the branch control valve; The second charging branch includes a second control valve, and the second control valve is connected between the leak detection connection end and the gas source connection end.

5. The leak detection device for a heat pump system according to any one of claims 1 to 4, characterized in that, The recovery passage includes a first recovery branch and a second recovery branch arranged in parallel between the leak detection connection end and the gas source connection end, and the first pump is arranged in the first recovery branch; The leak detection device of the heat pump system includes a first recovery state and a second recovery state. In the first recovery state, the second recovery branch is conducted; in the second recovery state, the first recovery branch is conducted.

6. The leak detection device for a heat pump system according to claim 5, characterized in that, The first recovery branch includes a third control valve and a fifth control valve. The first output end of the first pump is connected to the gas source connection end through the third control valve, and the first input end of the first pump is connected to the leak detection connection end through the fifth control valve; The second recovery branch includes a fourth control valve, and the fourth control valve is connected between the leak detection connection end and the gas source connection end.

7. The leak detection device for a heat pump system according to claim 1, characterized in that It further includes a second pump. The second pump includes a second output end and a second input end. The second output end is communicated with the atmosphere, and the second input end is communicated with the leak detection connection end.

8. The leak detection device for a heat pump system according to claim 7, characterized in that, It further includes a heat exchange medium injection passage, the heat exchange medium injection passage including a first end and a second end, the first end being connected to the leak detection connection end and the second input end, and the second end being used for connection to a heat exchange medium source.

9. A heat pump system, characterized in that, Comprising: The leak detection device, the leak detection medium source and the heat exchange device of the heat pump system according to any one of claims 1 to 8, the heat exchange device being connected to the leak detection connection end, and the leak detection medium source being connected to the gas source connection end.

10. The heat pump system according to claim 9, characterized in that, It further includes a heat exchange medium source, the heat exchange medium source including at least one carbon dioxide storage tank; The leak detection medium source includes at least one helium storage tank.

11. A leak detection method for the heat pump system according to claim 9 or 10, characterized in that, Comprising: Filling a leak detection medium into the heat exchange device, and when the pressure of the heat exchange device reaches a first preset pressure value, obtaining a first temperature value of the environment where the heat exchange device is located; Maintaining the pressure of the heat exchange device for a preset time, and obtaining a second temperature value of the environment where the heat exchange device is located; Determining the current pressure value of the heat exchange device through the first preset pressure value, the first temperature value and the second temperature value; Comparing the current pressure value with the first preset pressure value to determine the leakage condition of the heat exchange device.

Images