Leakage detection device of heat pump system, heat pump system and leakage detection method

Abstract

The invention relates to the field of air tightness detection, and discloses a leak detection device of a heat pump system, the heat pump system and a leak detection method.The leak detection device of the heat pump system comprises a leak detection connecting end, an air source connecting end, a charging passage, a recycling passage and a first pump; the charging passage and the recycling passage are both connected between the leak detection connecting end and the air source connecting end; the first pump comprises a first output end and a first input end, and the first input end is connected with the leak detection connecting end through a recovery channel and connected with the air source connecting end through a charging channel; the first output end is connected with the gas source connecting end through a recovery channel and connected with the leak detection connecting end through a charging channel, and the charging channel and the recovery channel are communicated alternately. The leakage detection medium is injected into the heat exchange device at high pressure through the first pump, the leakage detection medium in the heat exchange device is emptied through the first pump, the emptying effect is improved, the first pump is reused, the device is simplified, and the cost is saved.

Description

Technical Field

[0001] The present application belongs to the field of air tightness detection, and in particular 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 exchanger is in operation, the pressure inside the device is relatively high, and strict requirements are placed on the pressure resistance and leakage resistance of the pipeline. Leakage of the heat exchange medium in the heat exchanger will affect the normal operation of the equipment and may cause damage to the compressor of the heat exchanger. The commonly used leak detection methods are the pressure difference method and the foam method, among which hidden leak points are difficult to find and are greatly affected by human factors.

[0003] Existing leak detection devices achieve high-precision leak detection by inputting high-pressure gas into the heat exchange device. However, after the detection is completed, the gas is directly discharged into the air, resulting in a waste of resources. Summary of the invention

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

[0005] On the one hand, an embodiment of the present application provides a leak detection device for a heat pump system, comprising: a leak detection connection end, an air source connection end, a filling passage, a recovery passage and a first pump, the leak detection connection end is used to be connected to a heat exchange device of the heat pump system; the air source connection end is used to be connected to a leak detection medium source of the heat pump system; the filling passage is connected between the leak detection connection end and the air source connection end; the recovery passage is connected between the leak detection connection end and the air source connection end; the first pump comprises 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 air source connection end through the filling passage; the first output end is connected to the air 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 connected.

[0006] In some embodiments of the present application, the filling passage includes a first filling branch and a second filling branch which 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 connected, and in the second filling state, the first filling branch is connected.

[0007] In some embodiments 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 is connected; in the second recovery state, the recovery path is connected.

[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, wherein the heat exchange medium source includes at least one carbon dioxide storage tank; and the leak detection medium source includes at least one helium storage tank.

[0016] On the other hand, an embodiment of the present application also provides a leak detection method for a heat pump system, comprising: 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 in which 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 in which 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; and comparing the current pressure value with the first preset pressure value to determine the leakage condition of the heat exchange device.

[0017] The leak detection device, heat pump system and leak detection method of the heat pump system in the embodiments of the present application recycle the leak detection medium by setting a recovery passage, thereby reducing resource waste, allowing the leak detection medium to be recycled, and improving the utilization rate of the leak detection medium; and the filling passage and the recovery passage reuse the first pump, and high-pressure injection of the leak detection medium into the heat exchange device is achieved by the first pump, and the leak detection medium in the heat exchange device is emptied by the first pump, thereby improving the emptying effect, and reusing the first pump simplifies the device and saves costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Figure 1 A schematic diagram of a leak detection device for a heat pump system provided in some embodiments of the present application; Figure 2 Another schematic diagram of a leak detection device for a heat pump system provided in some embodiments of the present application; Figure 3 Another schematic diagram of a leak detection device for a heat pump system provided in some embodiments of the present application; Figure 4 Another schematic diagram of a leak detection device for a heat pump system provided in some embodiments of the present application; Figure 5 A schematic diagram of a control device for a heat pump system provided in some embodiments of the present application; Figure 6 A flow chart of a leak detection method for a heat pump system provided in some embodiments of the present application.

[0020] Description of reference numerals: 101, leak detection connection terminal; 102, gas source connection terminal; 103, first pump; 103a, first output terminal; 103b, first input terminal; 104, pressure reducing valve; 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 one-way valve; 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; 131, second pump; 131a, second input terminal; 131b, second output terminal; 132, ninth control valve; 140, heat exchange 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 exchange medium source; 401, carbon dioxide storage tank; 402, manual valve; 500, PLC controller; 501, touch screen; 502, sound and light alarm; 503, emergency stop button; 504, concentration data acquisition module. DETAILED DESCRIPTION

[0021] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with 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 to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0022] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0023] The heat pump system is an efficient energy conversion and utilization system. Based on the principle of thermodynamics, the heat pump system transfers heat energy from low-level heat sources to high-level heat sources by consuming high-level energy such as electrical energy. Specifically, the working medium in the heat pump unit absorbs heat energy from the low-temperature heat source in the evaporator, and after the compressor increases the temperature and pressure, it releases heat energy in the condenser, thereby realizing the transfer of heat energy.

[0024] The 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. It transfers the heat absorbed by low-temperature heat sources such as groundwater and underground thermal energy to high-temperature heat sources such as heating and hot water through the process of cyclic compression refrigeration. The carbon dioxide heat pump system has high thermal efficiency and can make full use of the heat energy in the low-temperature heat source and convert it into high-temperature heat energy, thereby achieving high efficiency and energy saving. As a natural refrigerant, carbon dioxide has almost zero damage to the ozone layer and has a low global warming potential, which meets environmental protection requirements. Carbon dioxide has good chemical stability and safety, is non-flammable, and is suitable for various lubricants and common mechanical parts materials. It does not decompose and produce harmful gases even at high temperatures.

[0025] Since the critical pressure of carbon dioxide is relatively high, for example, it is usually 7.37MPa, the working pressure of the heat pump system may reach more than 10MPa in the transcritical cycle, which places higher requirements on the material strength, sealing and pipeline connection of the heat pump system. Therefore, before the carbon dioxide heat pump system works, leak detection is required. The existing leak detection is to introduce nitrogen into the heat pump system and detect the leak location by pressure difference method and foam method. After the detection is completed, the nitrogen is discharged into the air, which will cause a waste of nitrogen resources and the nitrogen emptying effect in the heat pump system is not good.

[0026] In view of this, the present application provides a leak detection device for a heat pump system, which realizes the filling and recovery of the leak detection medium through a first pump, avoids waste of resources, and has a better effect of emptying the leak detection medium of the heat pump system.

[0027] The leak detection device for the heat pump system of the present application can also be applied to leak detection in other systems, for example, refrigeration systems, gas systems, vacuum systems, industrial storage systems, automobile fuel systems, etc.

[0028] Figure 1 A schematic diagram of a leak detection device for a heat pump system provided in some embodiments of the present application. Figure 1As shown, some embodiments of the present application provide a leak detection device for a heat pump system, including a leak detection connection end 101, an air source connection end 102, a filling passage 110, a recovery passage 120 and a first pump 103, wherein the leak detection connection end 101 is used to connect to a heat exchange device 200 of the heat pump system; the air source connection end 102 is used to connect to 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 air source connection end 102; the recovery passage 120 is connected to the leak detection connection end 101 and the air source connection end 102; The first pump 103 includes a first output terminal 103a and a first input terminal 103b, the first input terminal 103b is connected to the leak detection connection terminal 101 through a recovery passage 120, and is connected to the gas source connection terminal 102 through a filling passage 110; the first output terminal 103a is connected to the gas source connection terminal 102 through a recovery passage 120, and is connected to the leak detection connection terminal 101 through a filling passage 110, and the filling passage 110 and the recovery passage 120 are alternately connected.

[0029] The leak detection connection end 101 is the connection end between 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 end opening position of the pipeline or the end opening position of the channel. There can be one or more leak detection connection ends 101.

[0030] 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 an end opening position of a pipeline or an end opening position of a channel. There can be one or more gas source connection ends 102.

[0031] The filling passage 110 is a passage connecting the heat exchange device 200 and the leak detection medium source 300 when the leak detection medium is filled into the heat exchange device 200. Exemplarily, the filling passage 110 may be a pipe or a passage formed on a block. The filling passage 110 may be one or more.

[0032] The recovery passage 120 is a passage connecting the heat exchange device 200 and the leak detection medium source 300 when the leak detection medium is recovered from the heat exchange device 200. Exemplarily, the recovery passage 120 may be a pipe or a passage formed on a block. The recovery passage 120 may be one or more.

[0033] The first pump 103 can be a liquid pump or a gas pump based on different leak detection media. The first pump 103 is multiplexed and connected to the filling passage 110 and the recovery passage 120. The first pump 103 is communicated with the filling passage 110 and the recovery passage 120 respectively.

[0034] Exemplarily, the leak detection medium may be nitrogen or helium. In other embodiments of the present application, the leak detection medium may be a liquid. Among them, the content of helium in the atmosphere is less than that of nitrogen, which can improve the sensitivity and accuracy of leak detection.

[0035] 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 of 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.

[0036] Exemplarily, the heat pump system includes a leak detection device and a heat exchange device 200, which are connected via a leak detection connection terminal 101. When the heat exchange device 200 needs to be tested for air tightness, the leak detection device fills the leak detection medium in the leak detection medium source 300 into the heat exchange device 200, and detects the leak detection medium at multiple locations of the heat exchange device 200 through the detection equipment, thereby completing the air tightness test of the heat exchange device 200. When the air tightness test is completed, the leak detection device recovers the leak detection medium in the heat exchange device 200 into the leak detection medium source 300.

[0037] The recovery passage 120 is provided to recycle the leak detection medium, thereby reducing resource waste, enabling the leak detection medium to be recycled and improving the utilization rate of the leak detection medium; and the filling passage 110 and the recovery passage 120 reuse the first pump 103, and the high-pressure injection of the leak detection medium into the heat exchange device 200 is achieved through the first pump 103, simulating the working pressure of the heat exchange device 200 and improving the accuracy of leak detection; the leak detection medium in the heat exchange device 200 is emptied through the first pump 103, thereby improving the emptying effect, and reusing the first pump 103 simplifies the device and saves costs.

[0038] Figure 2 Another schematic diagram of a leak detection device for a heat pump system provided in some embodiments of the present application.

[0039] like Figure 2 As shown, in an optional embodiment of the present application, the filling passage 110 includes a first filling branch 111 and a second filling branch 112 which are 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 filling branch 111; 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 112 is turned on, and in the second filling state, the first filling branch 111 is turned on.

[0040] The first filling branch 111 can be unidirectional or bidirectional. The second filling branch 112 can be unidirectional or bidirectional. The number of the first filling branch 111 and the second filling branch 112 can be one or more.

[0041] Exemplarily, the inner diameter of the first filling branch 111 may be the same as or different from the inner diameter of the second filling branch 112. In one example, the inner diameter of the second filling branch 112 is larger than the inner diameter of the first filling branch 111, thereby improving the filling efficiency, reducing the impact pressure of the first pump 103, and extending the service life of the first pump 103.

[0042] Exemplarily, in the first filling state, the second filling branch 112 is opened and the first filling branch 111 is closed, and in the second filling state, the first filling branch 111 is opened and the second filling branch 112 can be opened or closed. In one example, a one-way conducting member is provided in the second filling branch 112, and the detection medium flows from the gas source connection end 102 to the leak detection connection end 101.

[0043] For example, at the initial stage of filling, the pressure of the gas source connection end 102 is greater than the pressure of the leak detection connection end 101, and the leak detection medium can be quickly filled into the heat exchange device 200 through the second filling branch 112, thereby improving the filling efficiency. During the filling process, when the pressure of the gas source connection end 102 is equal to the pressure of the leak detection connection end 101, the leak detection medium is further injected into the heat exchange device 200 through the first filling 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 when the heat exchange device 200 is working, thereby improving the accuracy of leak detection.

[0044] Furthermore, in an optional embodiment of the present application, in the first filling state, the pressure value of the leak detection connection end 101 is less than the pressure value of the gas source connection end 102. This can improve the filling efficiency and ensure rapid filling.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] Figure 3 Another schematic diagram of a leak detection device for a heat pump system provided in some embodiments of the present application.

[0051] 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.

[0052] Exemplarily, the first recovery branch 121 may be unidirectional or bidirectional. The second recovery branch 122 may be unidirectional or bidirectional. The number of the first recovery branch 121 and the second recovery branch 122 may be one or more.

[0053] Exemplarily, the inner diameter of the first recovery branch 121 may be the same as or different from the inner diameter of the second recovery branch 122. In one example, the inner diameter of the second recovery branch 122 is larger than the inner diameter of the first recovery branch 121, thereby improving the recovery efficiency, reducing the impact pressure of the first pump 103, and extending the service life of the first pump 103.

[0054] 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 recovery passage 120 is first placed in the first recovery state and then in the second recovery state. Specifically, after the air tightness test is completed, since the pressure value of the leak detection connection end 101 is greater than the pressure value of 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 of the leak detection connection end 101 is equal to the pressure value of the gas source connection end 102, the first recovery branch 121 is opened, the first pump 103 is turned on, 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 of the leak detection connection end 101 reaches the second preset value.

[0055] The recovery passage 120 improves the recovery efficiency of the leak detection medium by providing the first recovery branch 121 and the second recovery branch 122. In addition, both the recovery passage 120 and the filling passage 110 are provided with a fast branch, namely the second recovery branch 122 and the second filling branch 112, to facilitate the fast switching of different working states. For example, a main switch is provided before the first filling branch 111 and the second filling branch 112 to achieve fast closing and reduce the error rate and failure rate.

[0056] Furthermore, in a specific embodiment of the present application, in the first recovery state, the pressure value of the gas source connection end 102 is less than the pressure value of the leak detection connection end 101. This can improve the recovery efficiency and ensure rapid recovery.

[0057] Continue to refer Figures 1 to 3 In some optional embodiments of the present application, the first filling 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 filling 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.

[0058] Exemplarily, the first control valve 113 , the branch control valve 115 and the second control valve 114 may be manual, electrically controlled or hydraulically controlled on-off valves.

[0059] Exemplarily, in the first filling 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 filling 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.

[0060] like Figure 1 and Figure 2 As shown, in other embodiments of the present application, the recovery passage 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.

[0061] Exemplarily, the third control valve 123 and the fifth control valve 127 may be manual, electrically controlled or hydraulically controlled switch valves.

[0062] 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 an air tightness test. After the air 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 ​​of 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.

[0063] like Figure 1 and Figure 3 As 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.

[0064] Exemplarily, the third control valve 123 , the fourth control valve 124 and the fifth control valve 127 may be manual, electrically controlled or hydraulically controlled switch valves.

[0065] 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 an air tightness test. After the air 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 ​​of 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 through the first pump 103.

[0066] Among them, one end of the second control valve 114 can be set between the leak detection connection end 101 and the branch control valve 115, or can be set between the branch control valve 115 and the first output end 103a of the first pump 103, and the switching state of the branch control valve 115 is selected in the first filling state and the second filling state based on the set position.

[0067] In other embodiments of the present application, the leak detection device of the heat pump system also includes a first one-way valve 125, which is arranged between the leak detection connection end 101 and the recovery passage 120, and the conduction direction of the first one-way valve 125 is from the leak detection connection end 101 to the gas source connection end 102.

[0068] Exemplarily, the first one-way valve 125 is disposed between the leak detection connection end 101 and the first input end 103 b of the first pump 103 .

[0069] For example, in the second charging state, the first control valve 113 and the second control valve 114 may both be in an open state. In the second recovery state, the third control valve 123 and the fourth control valve 124 may both be in an open state.

[0070] The air tightness of the control valve is relatively poor, and in order to improve the air tightness of each passage, a first check valve 125 is provided. For example, each control valve may be provided with a check valve in series.

[0071] Figure 4 Another schematic diagram of a leak detection device for a heat pump system provided in some embodiments of the present application.

[0072] like Figure 4 As shown, in some embodiments of the present application, the filling passage 110 further includes a second one-way valve 116, and the recovery passage 120 further includes a third one-way valve 126. The conduction direction of the second one-way valve 116 is from the gas source connection end 102 to the leak detection connection end 101. The conduction direction of the third one-way valve 126 is from the leak detection connection end 101 to the gas source connection end 102. The second one-way valve 116 is arranged between the leak detection connection end 101 and the second control valve 114, and the third one-way valve 126 is arranged between the first output end 103a of the first pump 103 and the third control valve 123.

[0073] Exemplarily, the second one-way valve 116 is disposed between the branch control valve 115 and the second control valve 114 , and the third one-way valve 126 is disposed between the branch control valve 115 and the third control valve 123 .

[0074] Continue to refer 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 .

[0075] Exemplarily, the fifth control valve 127 is disposed between the first check valve 125 and the first input end 103 b of the first pump 103 .

[0076] In other embodiments of the present application, the leak detection device of the heat pump system also includes a pressure reducing valve 104, which is arranged between the gas source connection end 102 and the first input end 103b of the first pump 103, and is used to protect the first pump 103 to avoid excessive pressure at the gas source connection end 102, which affects the service life of the first pump 103.

[0077] In addition, continue to refer to Figure 4 In some optional embodiments of the present application, the leak detection device of the heat pump system also 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 connected to the atmosphere, and the second input end 131a is connected to the leak detection connection end 101.

[0078] Exemplarily, the second output end 131 b is suspended to discharge the gas in the heat exchange device 200 into the atmosphere.

[0079] After the recovery passage 120 has recovered the leak detection medium in the heat exchange device 200, the recovery passage 120 is closed. The second pump 131 is turned on to evacuate the heat exchange device 200, so that the heat exchange medium subsequently filled into the heat exchange device 200 has a higher purity.

[0080] In one embodiment of the present application, the leak detection device of the heat pump system also includes a sixth control valve 150 and a seventh control valve 151. The sixth control valve 150 is arranged between the leak detection connection terminal 101 and the filling passage 110 and the recovery passage 120, and the seventh control valve 151 is arranged between the leak detection connection terminal 101 and the second input terminal 131a of the second pump 131.

[0081] The sixth control valve 150 can simultaneously control the connection and disconnection of the filling passage 110 and the recovery passage 120 with the leak detection connection terminal 101 .

[0082] In addition, in some other embodiments of the present application, the leak detection device of the heat pump system also 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.

[0083] For example, there may be one or more heat exchange medium injection passages 140 .

[0084] Exemplarily, the first end of the heat exchange medium injection passage 140 is connected to the second input end 131 a , and the heat exchange medium injection passage 140 can be evacuated by the second pump 131 to improve the purity of the heat exchange medium filled into the heat exchange device 200 .

[0085] Exemplarily, the first end of the heat exchange medium injection passage 140 is connected to the leak detection connection end 101 to fill the heat exchange medium of the heat exchange medium source 400 into the heat exchange device 200. In one example, the heat exchange medium injection passage 140 is first evacuated by the second pump 131, and then the heat exchange medium is filled into the heat exchange device 200.

[0086] 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 evacuated, the manual valve 402 is closed and the eighth control valve 141 is opened.

[0087] Furthermore, in some other embodiments of the present application, the leak detection device of the heat pump system also includes a ninth control valve 132, the ninth control valve 132 is arranged between the seventh control valve 151 and the second pump 131, and 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.

[0088] When the heat exchange device 200 is charged with heat exchange medium, the seventh control valve 151 is opened and the ninth control valve 132 is closed.

[0089] like Figures 1 to 4 As shown, an embodiment of the present application also provides a heat pump system, including a leak detection device, a leak detection medium source 300 and a heat exchange device 200 of the heat pump system of the above embodiment, the heat exchange device 200 is connected to the leak detection connection terminal 101, and the leak detection medium source 300 is connected to the gas source connection terminal 102.

[0090] In one embodiment of the present application, a first pressure detection component is provided at the heat exchange device 200 and / or the leak detection connection end 101, and a second pressure detection component is provided at the gas source connection end 102 and / or the leak detection medium source 300. The first pressure detection component and the second pressure detection component may be pressure sensors or pressure gauges.

[0091] In one example, a first pressure detection component is provided at the connection between the heat exchange device 200 and the leak detection connection end 101 , and a second pressure detection component is provided at the connection between the leak detection medium source 300 and the gas source connection end 102 .

[0092] In one embodiment of the present application, the leak detection medium source 300 includes at least one helium storage tank 301. For example, the leak detection medium source 300 includes three helium storage tanks 301. Of course, in other embodiments of the present application, other helium storage devices may be used.

[0093] Exemplarily, the helium storage tank 301 is connected to the filling passage 110 and the recovery passage 120 through a control valve.

[0094] In one 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 at the same time to avoid a small amount of air being introduced when replacing a gas cylinder due to insufficient gas filling in a single bottle, thereby 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.

[0095] Figure 5 Schematic diagram of a control device for a heat pump system provided in some embodiments of the present application.

[0096] like Figure 5 As shown, in one embodiment of the present application, the heat pump system also 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 element (not shown in the figure).

[0097] The PLC controller 500 is respectively connected to the touch screen 501, the pressure data acquisition module, the helium concentration data acquisition module 504, the sound and light alarm 502, the emergency stop button 503 and the temperature detection element for communication.

[0098] 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.

[0099] The PLC controller 500 includes a pressure-maintaining mode, a leak detection mode, a recovery mode, a CO2 heat pump system vacuuming mode, and a CO2 charging mode. Different working modes can be selected through the touch screen 501. And the first preset pressure value can be set through the touch screen 501. Intelligent integrated control reduces the impact of human factors and improves the work efficiency of personnel.

[0100] The control device selects different working modes, starts the corresponding control valve action under the working mode, and completes the corresponding function; in the leak detection process, different pressure holding parameters are set according to the different operating media of the heat exchanger, and the current pressure of the heat exchanger after the pressure holding time is reached is calculated by collecting the indoor temperature changes where the heat exchanger is located, and the pressure holding result is obtained by comparison and judgment; during the leak detection, a helium concentration probe is used to perform fine detection of welding points and thread points to facilitate the identification of hidden leaks, improve the leak detection efficiency of the heat pump system, and avoid the influence of room temperature and human subjective factors.

[0101] Figure 6 A flow chart of a leak detection method for a heat pump system provided in some embodiments of the present application.

[0102] like Figures 1 to 6 As shown, an embodiment of the present application further provides a leak detection method for a heat pump system, and the method can be based on the heat exchange system of the above embodiment, specifically including steps S1 to S4.

[0103] S1: Filling a leak detection medium into the heat exchange device 200, and when the pressure of the heat exchange device 200 reaches a first preset pressure value, obtaining a first temperature value of the environment where the heat exchange device 200 is located.

[0104] Exemplarily, the pressure-maintaining mode is selected, and the first preset pressure value is set to P1. In the pressure-maintaining mode, the second control valve 114, the branch control valve 115 and the sixth control valve 150 are first opened. When the pressure value of the first pressure detection component is equal to the pressure value of the second pressure detection component, there is a prompt of the sound and light alarm 502, the second control valve 114 is closed, the first pump 103 and the first control valve 113 are opened, until the pressure value detected by the first pressure detection component is equal to the first preset pressure value, there is a prompt of the sound and light alarm 502, and the first control valve 113, the branch control valve 115, the first pump 103 and the sixth control valve 150 are closed. Under the state of the first preset pressure value, the first temperature value T1 of the current environment is detected by the first temperature detection component.

[0105] In one example, the leak detection medium is helium.

[0106] S2: Maintaining the pressure of the heat exchange device 200 for a preset time, and obtaining a second temperature value of the environment where the heat exchange device 200 is located.

[0107] Exemplarily, the leak detection mode is switched to maintain the pressure of the heat exchange device 200. The preset pressure maintenance time may be greater than or equal to 24 hours. The second temperature value T2 of the current environment is detected by the first temperature detection component.

[0108] S3: Determine the current pressure value of the heat exchange device 200 according to the first preset pressure value, the first temperature value and the second temperature value.

[0109] 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 pressure holding.

[0110] S4: Compare the current pressure value with the first preset pressure value to determine the leakage condition of the heat exchange device 200.

[0111] 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 is a hidden leak point in the heat exchange device 200 and the leak point needs to be further searched.

[0112] By combining the change of the ambient temperature, the accuracy of leak point detection is improved.

[0113] 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.

[0114] Exemplarily, the helium detection probe is placed close to the weld seam and the threaded connection of the heat exchange device 200 by about 3 mm and moved uniformly at a speed of 10 - 20 mm / s for leak detection. When the read helium concentration ≥ He1 + 1%, the sound and light alarm 502 indicates that there is a leak here, otherwise there is no leak point here.

[0115] The embodiment of the present application also provides a leak detection method for a heat pump system, which further includes step S5: S5: Recover the leak detection medium in the heat exchange device 200 into the leak detection medium source 300.

[0116] 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 of the first pressure detection member is equal to the pressure value of the second pressure detection member, there is a prompt of the sound and light alarm 502, and then close the fourth control valve 124 and open the first pump 103 and the third control valve 123. Until the pressure value of the first pressure detection member is equal to the second preset pressure value P3, there is a prompt of the sound and light alarm 502, and then close the sixth control valve 150, the fifth control valve 127, the first pump 103, and the third control valve 123.

[0117] Exemplarily, P3 < 0.05 Mpa.

[0118] S6: Evacuate the heat exchange device 200 and part of the leak detection device.

[0119] Exemplarily, the CO2 heat pump system is switched to vacuum mode, and the third preset pressure value is set to P4. The seventh control valve 151, the ninth control valve 132, the second pump 131, and the eighth control valve 141 are opened, and the manual valve 402 is closed.

[0120] When the pressure value of the first pressure detection element is equal to the third preset pressure value, the sound and light alarm 502 prompts to close the ninth control valve 132 and the second pump 131.

[0121] S7: Fill the heat exchange device 200 with heat exchange medium.

[0122] Exemplarily, switch to CO2 filling mode, and set the fourth preset pressure value to P5. Open the manual valve 402. Fill CO2 into the heat exchange device 200 until the pressure value of 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.

[0123] 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 prompts 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, open the seventh control valve 151, and the eighth control valve 141. Fill CO2 into the heat exchange device 200 until the pressure value of the first pressure detection component reaches the fourth preset pressure value P5, and 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 switching the seventh control valve 151 and the eighth control valve 141, the system safety is improved.

[0124] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A leak detection device for a heat pump system, characterized in that: include: A leak detection connection terminal, used for connecting to a heat exchange device of a heat pump system; A gas source connection end, used for connecting to a leak detection medium source of the heat pump system; A filling passage connected 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; The first pump includes a first output end and a first input end, wherein 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 connected.

2. The heat pump system leak detection device according to claim 1, characterized in that: The filling passage comprises a first filling branch and a second filling branch which 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 conductive. In the second filling state, the first filling branch is conductive.

3. The heat pump system leak detection device according to claim 2, 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 filling branch is connected; in the second recovery state, the recovery path is connected.

4. The heat pump system leak detection device according to claim 3, characterized in that: In the first filling state, the pressure value of the leak detection connection end is smaller 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 smaller than the pressure value of the leak detection connection end.

5. The heat pump system leak detection device according to claim 2, characterized in that: 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.

6. The heat pump system leak detection device according to any one of claims 1 to 5, characterized in that: The recovery passage comprises a first recovery branch and a second recovery branch which 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 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 connected; in the second recovery state, the first recovery branch is connected.

7. The heat pump system leak detection device according to claim 6, 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.

8. The heat pump system leak detection device according to claim 1, characterized in that: It also includes a second pump, which includes 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.

9. The heat pump system leak detection device according to claim 8, characterized in that: It also includes a heat exchange medium injection passage, which 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.

10. A heat pump system, characterized in that: include: The leak detection device, leak detection medium source and heat exchange device of the heat pump system according to any one of claims 1 to 9, 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.

11. The heat pump system according to claim 10, characterized in that: Also included is a heat exchange medium source, the heat exchange medium source comprising at least one carbon dioxide storage tank; The leak detection medium source includes at least one helium storage tank.

12. A leak detection method for a heat pump system, characterized in that: include: 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 an 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 according to the first preset pressure value, the first temperature value and the second temperature value; The current pressure value is compared with the first preset pressure value to determine the leakage condition of the heat exchange device.

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