Air conditioning system piping treatment device and control method thereof

Abstract

The application provides an air conditioner system pipeline processing device and a control method thereof. The air conditioner system pipeline processing device comprises a refrigerant driving assembly, the refrigerant driving assembly comprises a compressor, a first pipeline in controllable communication with a suction port of the compressor, and a second pipeline in controllable communication with a discharge port of the compressor. The first pipeline has a first interface in communication with a first target refrigerant pipeline of an air conditioner system, and the second pipeline has a second interface in communication with a second target refrigerant pipeline of the air conditioner system. A throttling element is connected in series in the first pipeline. The device further comprises a refrigerant recovery tank in controllable communication with the discharge port through a refrigerant recovery pipeline. The second pipeline further has a system flushing interface for communication with a cleaning component. The cleaning component is used to provide a pressure cleaning fluid. The first pipeline further has a vent port for discharging the pressure cleaning fluid. The entire operation process of the application can be performed through the selection of an operation mode, without the need for excessive manual intervention, and the operation is simple.

Description

Technical Field

[0001] This invention belongs to the technical field of air conditioning system piping treatment equipment design, specifically relating to an air conditioning system piping treatment device and its control method. Background Technology

[0002] With the rapid development of communication technology and the country's vigorous promotion of the construction of communication base stations and data centers, the market demand for data center cooling equipment is steadily increasing. At the same time, since temperature control energy consumption accounts for a large proportion of data center energy consumption, the market's requirements for the energy efficiency of data center cooling equipment are becoming increasingly stringent, leading to frequent product upgrades. In the renovation of old data centers and the replacement of old units with new ones, many long connecting pipes are buried in the walls and cannot be replaced. Failure to thoroughly clean the old pipes can affect the operation of the new unit. During air conditioning repairs, failure to clean the system before replacing parts can affect the lifespan of the unit after repair. Furthermore, the manual operation of refilling and replenishing refrigerant oil after replacing or repairing units is complex and prone to errors. Summary of the Invention

[0003] Therefore, the present invention provides an air conditioning system pipeline processing device and its control method, which can solve the technical problems of the prior art where the recovery of refrigerant in the air conditioning unit and the cleaning of the corresponding pipelines are carried out manually, the operation process is relatively complicated, and the labor cost is high.

[0004] To address the aforementioned problems, this invention provides an air conditioning system piping treatment device, comprising a refrigerant driving assembly. The refrigerant driving assembly includes a compressor, a first piping controllably connected to the compressor's intake port, and a second piping controllably connected to the compressor's exhaust port. The first piping has a first interface connected to a first target refrigerant pipe of the air conditioning system, and the second piping has a second interface connected to a second target refrigerant pipe of the air conditioning system. A throttling element is connected in series within the first piping. The device also includes a refrigerant recovery tank, which is controllably connected to the exhaust port via the refrigerant recovery piping. The second piping also has a system flushing interface for connecting to a cleaning component, which provides pressurized cleaning fluid. The first piping also has a vent for discharging the pressurized cleaning fluid.

[0005] In some embodiments, a first solenoid valve is connected in series on the first pipeline, a second solenoid valve is connected in series on the second pipeline, a third solenoid valve is connected in series on the pipeline between the refrigerant recovery tank and the exhaust port, a fourth solenoid valve is connected in series on the pipeline between the vent port and the first pipeline, the refrigerant recovery pipeline is connected to the second pipeline, and the connection point is between the exhaust port and the second solenoid valve; and / or, the pressure cleaning fluid is nitrogen.

[0006] In some embodiments, a filter is also connected in series on the first pipeline between the first solenoid valve and the throttling element; and / or, the compressor, the throttling element, the third solenoid valve, the refrigerant recovery tank, and the pipelines between them are located on a first weighing device.

[0007] In some embodiments, the air conditioning system piping processing device further includes a vacuum pump, which is connected to the second piping via a third piping, and the connection point between the third piping and the second piping is located between the second solenoid valve and the second interface, and a fifth solenoid valve is connected in series on the third piping.

[0008] In some embodiments, the air conditioning system piping processing device further includes a refrigerant oil filling assembly, which includes an oil tank and an oil pump. The inlet of the oil pump is connected to the oil tank, and the outlet of the oil pump is controllably connected to the second pipeline through a fourth pipeline. The connection point between the fourth pipeline and the second pipeline is located between the exhaust port of the compressor and the second solenoid valve. A sixth solenoid valve is connected in series on the fourth pipeline.

[0009] In some embodiments, the air conditioning system piping processing device further includes a refrigerant charging assembly, which includes a refrigerant charging tank. The outlet of the refrigerant charging tank is connected to the fourth pipeline via a refrigerant charging pipeline, and the connection point between the refrigerant charging pipeline and the fourth pipeline is located between the sixth solenoid valve and the second solenoid valve. A seventh solenoid valve is connected in series on the refrigerant charging pipeline.

[0010] In some embodiments, the refrigerant charging line is also connected to the first line via a fifth line, the connection point of the fifth line and the first line being located between the first solenoid valve and the throttling element, and the throttling element being an electronic expansion valve; and / or, the oil tank and the refrigerant charging tank are simultaneously on a second weighing device.

[0011] In some embodiments, a one-way valve is also connected in series on the fourth pipe. The one-way valve is located between the seventh solenoid valve and the second solenoid valve, and the conduction direction of the one-way valve is from the seventh solenoid valve to the second solenoid valve.

[0012] The present invention also provides a control method for the air conditioning system piping processing device as described above, comprising the following steps:

[0013] Obtain the operating mode of the air conditioning system piping processing device;

[0014] When the operating mode is refrigerant recovery mode, the real-time pressure Ps inside the refrigerant recovery tank is obtained.

[0015] When the real-time pressure Ps inside the tank is lower than the high pressure limit P1 of the refrigerant recovery tank, the first and third solenoid valves are turned on and the second solenoid valve is turned off, and the compressor is controlled to run. When the suction pressure Pi of the compressor is lower than the low pressure limit P2, the first and third solenoid valves are turned off, and the compressor is controlled to stop running.

[0016] A high-pressure alarm is triggered when the real-time pressure Ps inside the tank is not lower than the high-pressure limit P1 of the refrigerant recovery tank.

[0017] In some embodiments, when the air conditioning system piping processing device includes a first weighing device, after the compressor's suction pressure Pi is lower than the low pressure limit P2 and the first and third solenoid valves are controlled to shut off, the mass change value of the component on the first weighing device is obtained.

[0018] In some implementations, when the operating mode is system cleaning mode, the first solenoid valve, the second solenoid valve, and the fourth solenoid valve are controlled to be in the cut-off state, and pressure cleaning fluid is introduced into the air conditioning system. When the system pressure P0 of the air conditioning system is greater than the venting limit P3, the fourth solenoid valve is controlled to open to realize the venting of the pressure cleaning fluid.

[0019] In some embodiments, the fourth solenoid valve is emptied multiple times, and the fourth solenoid valve is turned on for a first preset duration between two cycles.

[0020] In some embodiments, when the air conditioning system piping handling device includes a vacuum pump and the operating mode is system vacuuming mode, the fifth solenoid valve is turned on, the first, second, and fourth solenoid valves are all turned off, and the vacuum pump is controlled to operate.

[0021] In some embodiments, the system pressure P0 of the air conditioning system is acquired during the operation of the vacuum pump, and the fifth solenoid valve is controlled to shut off when the system pressure P0 is lower than the preset vacuum level for a continuous second preset time period.

[0022] In some embodiments, during a third consecutive preset time period after the fifth solenoid valve is shut off, the relationship between the system pressure P0 and the preset vacuum degree is continuously acquired. When the system pressure P0 is less than the preset vacuum degree during the third consecutive preset time period, the vacuum pump is controlled to stop operating. When the system pressure P0 is not less than the preset vacuum degree during the third consecutive preset time period, the fifth solenoid valve is controlled to open again. The third preset time period is longer than the second preset time period.

[0023] In some embodiments, when the air conditioning system piping processing device includes a refrigerant oil filling component and the operating mode is the system refrigerant oil filling mode, the first, third, fourth, and fifth solenoid valves are all shut off, the second and sixth solenoid valves are opened, and the oil pump is operated to add a first preset mass of refrigerant oil into the air conditioning system. Then, the oil pump is stopped and the sixth solenoid valve is shut off.

[0024] In some embodiments, when the air conditioning system piping processing device includes a refrigerant charging component, a refrigerant charging pipeline connected to the first pipeline, and the operating mode is the system refrigerant charging mode, the seventh and second solenoid valves are turned on, and the first, third, fourth, fifth, and sixth solenoid valves are turned off, so that at least a portion of the refrigerant in the refrigerant charging tank is injected into the air conditioning system by utilizing the pressure difference between the refrigerant charging tank and the air conditioning system.

[0025] In some embodiments, during the process of connecting the refrigerant charging tank to the air conditioning system, the change value |△P0| of the system pressure P0 of the air conditioning system within a preset time is obtained. When the change value |△P0| is not higher than the set pressure difference value, the compressor is controlled to operate until the amount of refrigerant injected into the air conditioning system is the second preset mass. At this point, the compressor is controlled to stop operating, and the second solenoid valve and the seventh solenoid valve are controlled to cut off. The sum of the first preset mass and the second preset mass is equal to the mass change value.

[0026] In some implementations, the refrigerant recovery mode, system cleaning mode, system vacuuming mode, system refrigeration oil charging mode, and system refrigerant charging mode are executed sequentially.

[0027] The air conditioning system piping processing device and control method provided by the present invention have the following beneficial effects:

[0028] The air conditioning system piping treatment device has both refrigerant recovery and storage functions for the air conditioning system and cleaning functions for the piping of various components within the air conditioning system. The entire operation process can be carried out by selecting the operating mode, requiring minimal manual intervention and is simple to operate. Attached Figure Description

[0029] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0030] Figure 1This is a schematic diagram of the system principle of the air conditioning system piping processing device according to an embodiment of the present invention;

[0031] Figure 2 Figure 1 A schematic diagram of the connection status of the air conditioning system piping processing device applied within the air conditioning system;

[0032] Figure 3 This is a schematic diagram of the control flow of the air conditioning system piping treatment device in the refrigerant recovery mode according to an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of the control flow of the air conditioning system pipeline processing device in the system cleaning mode according to an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the control flow of the air conditioning system piping processing device in the vacuum mode of the operating system according to an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of the control flow of the air conditioning system pipeline processing device in the operation of the system refrigerant oil charging mode and the system refrigerant charging mode according to an embodiment of the present invention.

[0036] The attached figures are labeled as follows:

[0037] 11. Compressor; 121. First interface; 122. Throttling element; 123. Drain port; 124. Filter; 131. Second interface; 132. System flushing interface; 21. Refrigerant recovery tank; 211. Refrigerant tank charging port; 3. Cleaning components; 41. First solenoid valve; 42. Second solenoid valve; 43. Third solenoid valve; 44. Fourth solenoid valve; 45. Fifth solenoid valve; 46. Sixth solenoid valve; 47. Seventh solenoid valve; 48. Check valve; 51. Vacuum pump; 61. First weighing device; 62. Second weighing device; 71. Oil tank; 72. Oil pump; 81. Refrigerant charging tank; 91. First pressure sensor; 92. Second pressure sensor; 93. Third pressure sensor; 100. System outdoor unit; 101. System indoor unit; 102. First connecting valve; 103. Second connecting valve; 104. Third connecting valve; 105. Fourth connecting valve. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0040] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90° or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0041] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0042] See Figure 1 and Figure 6As shown, according to an embodiment of the present invention, an air conditioning system piping processing device is provided, including a refrigerant driving assembly (not labeled in the figure). The refrigerant driving assembly includes a compressor 11, a first piping (not labeled in the figure) controllably connected to the suction port of the compressor 11, and a second piping (not labeled in the figure) controllably connected to the discharge port of the compressor 11. The first piping has a first interface 121 connected to a first target refrigerant pipe of the air conditioning system (e.g., with...). Figure 2 The second pipeline is connected to one of the first connecting valve 102 and the second connecting valve 103, or one of the third connecting valve 104 and the fourth connecting valve 105, and has a second interface 131 connected to the second target refrigerant pipe of the air conditioning system (e.g., with...). Figure 2 The system is connected to one of the first connecting valve 102 and the second connecting valve 103, or one of the third connecting valve 104 and the fourth connecting valve 105. It is understood that the aforementioned first interface 121 and second interface 131 should not be simultaneously connected to the same side of the refrigerant pipe of the air conditioning system (the specific connection depends on whether the system is an outdoor unit 100 or an indoor unit 101). A throttling element 122 is connected in series in the first pipe. The throttling element 122 can reduce the probability of liquid slugging during the suction of the compressor 11. The system also includes a refrigerant recovery tank 21 (which is a pressure vessel). The refrigerant recovery tank 21 and the exhaust port are controllably connected through a refrigerant recovery pipe (not labeled in the figure). The second pipe also has a system flushing interface 132, which is used to connect to a cleaning component 3. The cleaning component 3 is used to provide pressurized cleaning fluid. The first pipe also has a vent 123 for discharging the pressurized cleaning fluid. The aforementioned vent 123 can be directly connected to the outside atmosphere or connected to the corresponding pressure vessel, depending on the type of pressurized cleaning fluid. The aforementioned refrigerant recovery tank 21 has a refrigerant tank refrigerant inlet 211, through which the recovered refrigerant can be further processed.

[0043] See details Figure 2 As shown, in a specific application, when recovering refrigerant from the air conditioning system, the first interface 121 is connected to the second connecting valve 103 of the air conditioning system, and the second interface 131 is connected to the fourth connecting valve 105 of the air conditioning system. Then, the compressor 11 is run and the corresponding pipelines are connected, thereby realizing the recovery and storage of refrigerant in the air conditioning system. After the refrigerant recovery of the air conditioning system is completed, the cleaning component 3 can be connected to the system flushing interface 132. In this way, the pressure cleaning fluid can be used to flush the components in the air conditioning system to ensure the cleanliness of the components in the air conditioning system.

[0044] In this technical solution, the air conditioning system pipeline processing device has both the function of refrigerant recovery and storage for the air conditioning system and the function of cleaning the pipelines of various components in the air conditioning system. The entire operation process can be carried out by selecting the operating mode, without much manual intervention. It is simple to operate and can reduce labor costs.

[0045] In this technical solution, the system flushing interface 132 configured on the second pipeline is used to connect with the cleaning component 3, thereby cleaning the various components in the air conditioning system after the refrigerant has been recovered, effectively removing impurities such as oil deposits and oxide scale from the air conditioning system, and ensuring the subsequent normal and stable operation of the air conditioning system. The aforementioned pressure cleaning fluid is preferably an environmentally friendly pressurized gas, such as nitrogen. Thus, provided that the refrigerant is environmentally friendly, the vent 123 can be directly connected to the outside atmosphere during system cleaning, and the aforementioned cleaning component 3 can be a nitrogen tank. Generally speaking, the nitrogen tank is preferably configured separately and flexibly as a component not belonging to the processing device of this invention. Of course, in some cases, the processing device of this invention can also be equipped with the nitrogen tank. Specifically, the amount of nitrogen required for nitrogen cleaning of the air conditioning system is very large, which makes the nitrogen tank in the processing device too large, causing inconvenience in use. For maintenance and installation personnel, nitrogen is readily available. In addition, nitrogen tanks are high-pressure tanks, which pose a safety hazard if placed in places where people frequently walk. Therefore, generally speaking, it is not necessary to use a nitrogen tank as a standard configuration of the processing device of this invention.

[0046] In one specific embodiment, a first solenoid valve 41 is connected in series on the first pipeline, a second solenoid valve 42 is connected in series on the second pipeline, a third solenoid valve 43 is connected in series on the pipeline between the refrigerant recovery tank 21 and the exhaust port, and a fourth solenoid valve 44 is connected in series on the pipeline between the vent port 123 and the first pipeline. The refrigerant recovery pipeline is connected to the second pipeline, and the connection position is between the exhaust port and the second solenoid valve 42. By setting the aforementioned solenoid valves on the corresponding pipelines, the on / off state switching of the aforementioned solenoid valves can be controlled more flexibly and conveniently to realize the flow direction under different operating modes of the processing device and complete the corresponding processing purpose.

[0047] In some embodiments, a filter 124 is connected in series on the first pipeline between the first solenoid valve 41 and the throttling element 122, so as to perform necessary filtration and cleaning on the refrigerant flowing out of the air conditioning system, i.e. the refrigerant to be recovered, to prevent impurities from entering the compressor 11 and damaging the compressor 11.

[0048] In a preferred embodiment, the compressor 11, throttling element 122, third solenoid valve 43, refrigerant recovery tank 21, and their interconnecting pipelines (i.e., the pipelines connecting the components) are mounted on a first weighing device 61, which can be a commercially available weighing scale. In this technical solution, the first weighing device 61 can accurately weigh the amount of refrigerant recovered from the air conditioning system, thus allowing for the estimation of the amount of refrigerant to be injected into the air conditioning system subsequently, ensuring the accuracy of the refrigerant injection amount.

[0049] In a preferred embodiment, the air conditioning system piping processing device further includes a vacuum pump 51, which is connected to the second piping via a third piping (not labeled in the figure), and the connection point between the third piping and the second piping is located between the second solenoid valve 42 and the second interface 131. A fifth solenoid valve 45 is connected in series on the third piping.

[0050] In this technical solution, a vacuum pump 51 is connected to a second pipeline near the second interface 131. Operating the vacuum pump 51 evacuates the air conditioning system, preventing residual air or pressure cleaning fluid from remaining in the system after refrigerant is added, which could lead to lower system performance. The connection point between the third pipeline and the second pipeline is located between the second solenoid valve 42 and the second interface 131. This allows the second solenoid valve 42 to cut off the second pipeline during vacuuming, ensuring effective vacuuming of the external air conditioning system.

[0051] In some embodiments, the air conditioning system piping processing device further includes a refrigerant oil filling assembly (not labeled in the figure), which includes an oil tank 71 and an oil pump 72. The inlet of the oil pump 72 is connected to the oil tank 71, and the outlet of the oil pump 72 is controllably connected to the second pipeline through a fourth pipeline (not labeled in the figure). The connection point between the fourth pipeline and the second pipeline is located between the exhaust port of the compressor 11 and the second solenoid valve 42. A sixth solenoid valve 46 is connected in series on the fourth pipeline.

[0052] In this technical solution, the refrigerant filling component can refill the air conditioning system with a preset amount of refrigerant after the refrigerant in the original air conditioning system has been recovered, cleaned and vacuumed, thus ensuring the normal operation of the air conditioning system.

[0053] In some embodiments, the air conditioning system piping processing device further includes a refrigerant charging assembly (not shown in the figure). The refrigerant charging assembly includes a refrigerant charging tank 81, the outlet of which is connected to the fourth pipeline via a refrigerant charging pipeline (not shown in the figure). The connection point between the refrigerant charging pipeline and the fourth pipeline is located between the sixth solenoid valve 46 and the second solenoid valve 42. A seventh solenoid valve 47 is connected in series on the refrigerant charging pipeline. In this technical solution, the refrigerant charging assembly can recharge a preset amount of refrigerant into the air conditioning system after the original refrigerant has been recovered, cleaned, and evacuated, and after the air conditioning system has been refilled with refrigerant oil, ensuring the normal operation of the air conditioning system.

[0054] In some embodiments, the refrigerant charging line is also connected to the first line via a fifth line. The connection point between the fifth line and the first line is between the first solenoid valve 41 and the throttling element 122, and the throttling element 122 is an electronic expansion valve. In this case, the opening degree of the throttling element 122 can be controlled to ensure that the compressor 11 pressurizes and injects the refrigerant in the charging refrigerant tank 81 into the air conditioning system during operation. In a more preferred embodiment, a one-way valve 48 is also connected in series on the fourth line. The one-way valve 48 is located between the seventh solenoid valve 47 and the second solenoid valve 42, and the conduction direction of the one-way valve 48 is from the seventh solenoid valve 47 to the second solenoid valve 42. The one-way valve 48 can prevent short-circuiting between the suction port and the discharge port of the compressor 11 during operation.

[0055] The oil tank 71 and the refrigerant charging tank 81 are simultaneously mounted on the second weighing device 62, which monitors the amount of refrigeration oil and refrigerant added in real time. The aforementioned second weighing device 62 can be a commercially available component with the required specifications and weighing accuracy; this invention does not provide special protection for it.

[0056] According to an embodiment of the present invention, a control method for the air conditioning system piping processing device as described above is also provided, comprising the following steps:

[0057] Obtain the operating mode of the air conditioning system piping processing device;

[0058] When the operating mode is refrigerant recovery mode, the real-time pressure Ps inside the refrigerant recovery tank 21 is obtained by the third pressure sensor 93 installed on the refrigerant recovery tank 21.

[0059] When the real-time pressure Ps inside the tank is lower than the high-pressure limit P1 of the refrigerant recovery tank 21 (preset by the control system of the processing device, specifically related to the remaining volume inside the refrigerant recovery tank 21, generally the pressure value that the air conditioning system can withstand), the first solenoid valve 41 and the third solenoid valve 43 are opened, the second solenoid valve 42 is cut off, and the compressor 11 is controlled to operate. When the suction pressure Pi of the compressor 11 (obtained by the second pressure sensor 92, which is specifically set downstream of the refrigerant outlet of the throttling element 122) is lower than the low-pressure limit, the compressor 11 is controlled to operate. When the value P2 (preset by the control system of the processing device, which can be determined according to the refrigerant recovery rate requirement) is reached, it indicates that the refrigerant recovery is complete. The first solenoid valve 41 and the third solenoid valve 43 are shut off, and the compressor 11 is stopped, ending the operation of the refrigerant recovery mode. When the real-time pressure Ps in the tank is not lower than the high pressure limit P1 of the refrigerant recovery tank 21, it indicates that the tank volume is insufficient. At this time, a high pressure alarm should be triggered to remind the operator to replace the refrigerant recovery tank in time. This can be achieved, for example, through voice alarm, photoelectric alarm, etc.

[0060] When the air conditioning system piping processing device includes a first weighing device 61, after the suction pressure Pi of the compressor 11 is lower than the low pressure limit P2, and the first solenoid valve 41 and the third solenoid valve 43 are controlled to be cut off, the mass change value of the components on the first weighing device 61 is obtained, thereby recording the amount of refrigerant recovered from the air conditioning system.

[0061] In this mode, the second solenoid valve 42, the fourth solenoid valve 44, the sixth solenoid valve 46 and the seventh solenoid valve 47 should be in the cut-off state. The on / off state of the fifth solenoid valve 45 will not affect the aforementioned refrigerant recovery process. Therefore, its state can be in the set initial state.

[0062] Specifically Figure 3 Taking the example shown, the operating logic of the refrigerant recovery mode is further explained as follows:

[0063] S401, Start, the controller confirms the start, and the control method begins execution;

[0064] S402, detects the third pressure sensor 93 pressure Ps, and checks the pressure of the refrigerant tank before recovery to ensure that the refrigerant tank volume is sufficient;

[0065] S403: Compare Ps with the high-pressure limit P1. The high-pressure limit P1 is a preset value of the system program, which is generally the pressure value that the air conditioning system can withstand. By comparing Ps with the high-pressure limit P1, it can be determined whether the refrigerant tank volume is sufficient, thereby determining whether refrigerant recovery can be started. When the refrigerant tank pressure Ps is greater than or equal to the high-pressure limit P1, the high-pressure alarm S404 for refrigerant tank recovery is triggered. When the refrigerant tank pressure Ps is less than the high-pressure limit P1, the first solenoid valve 41 and the third solenoid valve 45 are opened in S405.

[0066] S404, Refrigerant tank high pressure alarm: When the refrigerant tank pressure Ps is greater than or equal to the high pressure limit P1, refrigerant cannot be recovered and an alarm is required.

[0067] S405, open the first solenoid valve 41 and the third solenoid valve 43. When the refrigerant tank pressure Ps is less than the high pressure limit P1, refrigerant recovery can begin. Therefore, open the first solenoid valve 41 and the third solenoid valve 43.

[0068] S406, start compressor 11 to recover refrigerant. After opening the first solenoid valve 41 and the third solenoid valve 43, the refrigerant recovery flow path of the component is opened, and compressor 11 can be started to recover the refrigerant of the indoor and outdoor units into the refrigerant recovery tank.

[0069] S407, detect the pressure Pi of the second pressure sensor 92. During the recovery process, the detection value Pi of the second pressure sensor 92 is the low pressure value of the system. The degree of refrigerant recovery can be judged by Pi.

[0070] S408 compares Pi with the low-pressure limit P2. The low-pressure limit P2 is a preset value of the system program, and its value is set according to the minimum allowable suction pressure of the compressor. By comparing Pi with the low-pressure limit P2, it can be determined whether the refrigerant recovery is completed. When Pi is greater than or equal to P2, it returns to the detection pressure PsS402. When Pi is less than P2, it enters the process of closing the first solenoid valve 41 and the third solenoid valve 43S409.

[0071] S409, close the first solenoid valve 41 and the third solenoid valve 43. After the refrigerant recovery is completed by judging by the pressure, immediately close the first solenoid valve 41 and the third solenoid valve 43 to prevent the refrigerant from flowing back.

[0072] S410, shut down compressor 11, close the first solenoid valve 41 and the third solenoid valve 43, shut down compressor 11;

[0073] S411, record the weighing value M1 of the first weighing device 61. After the recovery is completed, use the first weighing device 61 to weigh and calculate the weight M1 added to the electronic expansion valve (i.e. the aforementioned throttling element 122), compressor 11, third solenoid valve 43 and refrigerant recovery tank 21 at this time, so as to compare and determine the amount of oil and refrigerant that should be refilled in the future.

[0074] S412, End. Refrigerant recovery weighing is complete after weighing.

[0075] When the operating mode is system cleaning mode, the first solenoid valve 41, the second solenoid valve 42, and the fourth solenoid valve 44 are controlled to be in the cut-off state, and pressure cleaning fluid is introduced into the air conditioning system. When the system pressure P0 of the air conditioning system is greater than the venting limit P3, the fourth solenoid valve 44 is controlled to open to realize the venting of the pressure cleaning fluid. At this time, the pressure cleaning fluid in the cleaning component 3 flows through the system flushing port 132 and the second port 131 along... Figure 2 In the state shown, the second connecting valve 103 enters the indoor unit 101 of the air conditioning system. Since the fourth solenoid valve 44 is in the cut-off state during this process, the cleaning fluid forms a certain pressure in the air conditioning system. After a period of time, the fourth solenoid valve 44 is opened, and the pressurized fluid flows through the indoor unit 101 and is discharged through the fourth connecting valve 105-first interface 121-vent 123, thereby cleaning the indoor pipe components of the air conditioning system. Similarly, when it is necessary to clean the outdoor pipe components of the air conditioning system, the first interface 121 is connected to the third connecting valve 104 on the outdoor side, and the second interface 131 is connected to the first connecting valve 102 on the outdoor side. The operation method is the same as described above and will not be repeated here.

[0076] In some embodiments, the fourth solenoid valve 44 is emptied multiple times (e.g., 20 times), and the fourth solenoid valve 44 is turned on for a first preset time (e.g., 10 seconds) between two cycles. Multiple intermittent alternating flushes can improve the cleaning effect on the air conditioning system.

[0077] In this mode, the first solenoid valve 41, the second solenoid valve 42, and the fifth solenoid valve 45 should be in the cut-off state. The on / off state of the third solenoid valve 43, the sixth solenoid valve 46, and the seventh solenoid valve 47 should not affect the aforementioned flushing process. Therefore, their states can be in the set initial state.

[0078] Specifically Figure 4 Taking the example shown, the operating logic of the system cleanup mode is further explained as follows:

[0079] S501, Start, the controller confirms the start, and the control method begins execution;

[0080] S502, the nitrogen tank is connected to the system flushing interface 132. The unit (i.e. the processing device of the present invention) is not normally equipped with a nitrogen tank. To use the nitrogen cleaning system function, the nitrogen tank needs to be manually connected to the system flushing interface 132.

[0081] S503, purging times X = 0, using nitrogen to clean the refrigerant system (i.e., the air conditioning system) requires multiple nitrogen purgings. In this embodiment, the purging times are set to 20 times.

[0082] S504, obtain the pressure P0 detected by the first pressure sensor 91. During the venting process, the pressure value P0 detected by the first pressure sensor 91 is the pressure value of the indoor unit and the outdoor unit. It can be used to determine whether the venting limit P3 has been reached, thereby controlling the opening of the fourth solenoid valve 44 to vent.

[0083] S505 compares P0 with the venting limit P3. The venting limit P3 is a preset value of the system program, generally between 1500kPa and 2500kPa, and the specific value needs to be set according to the pressure value of the connected nitrogen tank and the length of the pipeline system. By comparing P0 with the venting limit P3, it can be determined whether to vent. When P0 is less than or equal to P3, the pressure of the first pressure sensor 91 is continued to P0. When P0 is greater than P3, venting can be performed, and logically the venting count is incremented by 1.

[0084] S506, X = X + 1, increment the number of emptying cycles by 1;

[0085] S507, the fourth solenoid valve 44 is opened for 10 seconds and then closed. When the system pressure reaches the venting limit, the fourth solenoid valve 44 needs to be opened for venting. In order to allow sufficient time for the nitrogen venting and cleaning process, the opening time of the fourth solenoid valve 44 during the venting and cleaning phase is set to 10 seconds.

[0086] S508, compare X with 20. In this embodiment, the number of purging cycles is set to 20. When the number of purging cycles has not reached 20, the nitrogen purging and cleaning process is repeated. When the number of purging cycles reaches 20, the entire nitrogen cleaning system is about to end.

[0087] S509, Remove nitrogen tank. The unit is not normally equipped with a nitrogen tank. The nitrogen tank must be removed after using the nitrogen cleaning system.

[0088] S510, End, the function ends after completing 20 nitrogen purging cycles.

[0089] When the air conditioning system piping treatment device includes a vacuum pump 51 and the operating mode is system vacuuming mode, the fifth solenoid valve 45 is turned on, the first solenoid valve 41, the second solenoid valve 42, and the fourth solenoid valve 44 are all turned off, and the vacuum pump 51 is controlled to run, so as to achieve the purpose of vacuuming the cleaned air conditioning system, preventing the presence of non-refrigerant fluids such as residual air in the system after refrigerant is added, which would reduce the performance of the air conditioning.

[0090] During the operation of the vacuum pump 51, the system pressure P0 of the air conditioning system is acquired. If the system pressure P0 is lower than the preset vacuum level (e.g., 50 kPa) for a continuous second preset time period (e.g., 10 seconds), it indicates that the vacuum level of the air conditioning system has reached the design requirements, and therefore the fifth solenoid valve 45 is controlled to shut off. Further, for a continuous third preset time period (e.g., 10 minutes) after the fifth solenoid valve 45 shuts off, the relationship between the system pressure P0 and the preset vacuum level is continuously acquired. If the system pressure P0 is lower than the preset vacuum level for a continuous third preset time period, it indicates that there are no leaks in any component of the air conditioning system, and therefore the vacuum pump 51 is controlled to stop operating. If the system pressure P0 is not lower than the preset vacuum level for a continuous third preset time period, it indicates that the system vacuum level has rebounded, and the fifth solenoid valve 45 needs to be opened again to perform a vacuuming operation to ensure the stability of the vacuum state. The third preset time period is longer than the second preset time period. During this process, the first solenoid valve 41, the second solenoid valve 42, and the fourth solenoid valve 44 should all be in the cut-off state. The on / off state of the third solenoid valve 43, the sixth solenoid valve 46, and the seventh solenoid valve 47 will not affect the aforementioned vacuuming process. Therefore, their states can be in the set initial state.

[0091] Specifically Figure 5 Taking the example shown, the operating logic of the system's vacuum mode is further explained as follows:

[0092] S601, Start, the controller confirms the start, and the control method begins execution;

[0093] S602, open the fifth solenoid valve 45. Before evacuating, open the fifth solenoid valve 45 to connect the system to the vacuum pump 51.

[0094] S603, turn on vacuum pump 51 to begin system vacuuming;

[0095] S604, detect the pressure P0 of the first pressure sensor 91. During the evacuation process, the pressure value P0 detected by the first pressure sensor 91 is the pressure value of the indoor unit and the outdoor unit. It can be used to determine whether the system pressure has reached below 50kPa, thereby controlling the closure of the fifth solenoid valve 45 to maintain pressure.

[0096] S605, continuously compare P0 with 50kPa. By continuously comparing P0 with 50kPa, it can be used to determine whether the system has completed evacuation. If P0 is not less than 50kPa within 10 seconds, it means that evacuation has not been completed, and continue evacuation to detect the pressure P0 of the first pressure sensor 91. If P0 is less than 50kPa for 10 consecutive seconds, it means that the system has completed the first evacuation, and the fifth solenoid valve 45 can be closed to maintain pressure.

[0097] S606, close the fifth solenoid valve 45. When P0 is less than 50 kPa for 10 consecutive seconds, it indicates that the system has completed the first evacuation and the fifth solenoid valve 45 can be closed to maintain pressure.

[0098] S607, detect the pressure P0 of the first pressure sensor 91. During the pressure holding process, the pressure value P0 detected by the first pressure sensor 91 is the pressure value of the indoor unit and the outdoor unit. It can be used to determine whether the system can hold the pressure, thereby determining whether the vacuuming has been completed.

[0099] S608 continuously compares P0 with 50 kPa. Unlike S604, the comparison in S608 is used to determine whether the system has completed the pressure holding process. If P0 is not less than 50 kPa within 10 minutes, it indicates that the system pressure has rebounded and the vacuuming is not complete. It is necessary to return to S602 to continue the vacuuming process. If P0 is less than 50 kPa for 10 consecutive minutes, it indicates that the system vacuuming is complete and the system vacuuming process can be terminated.

[0100] S609, turn off vacuum pump 51. After confirming that the system has been evacuated, turn off vacuum pump 51.

[0101] S610, End, complete the system vacuum control method, end function.

[0102] When the air conditioning system piping processing device includes a refrigerant oil filling component and the operating mode is system refrigerant oil filling mode, the first solenoid valve 41, the third solenoid valve 43, the fourth solenoid valve 44, and the fifth solenoid valve 45 are all shut off, the second solenoid valve 42 and the sixth solenoid valve 46 are opened, and the oil pump 72 is operated to add a first preset mass of refrigerant oil into the air conditioning system. Then, the oil pump 72 is stopped, and the sixth solenoid valve 46 is shut off. At this time, the refrigerant oil, driven by the oil pump 72, enters the air conditioning system via the sixth solenoid valve 46, the one-way valve 48, the second solenoid valve 42, and the second interface 131. The aforementioned first preset mass can be obtained from the difference in weight of the second weighing device 62. In this mode, the seventh solenoid valve 47 should be kept in the shut-off state.

[0103] In some embodiments, when the air conditioning system piping handling device includes a refrigerant charging assembly, a refrigerant charging pipeline connected to the first pipeline, and the operating mode is the system refrigerant charging mode, the seventh solenoid valve 47 and the second solenoid valve 42 are turned on, while the first solenoid valve 41, the third solenoid valve 43, the fourth solenoid valve 44, the fifth solenoid valve 45, and the sixth solenoid valve 46 are turned off. At least a portion of the refrigerant in the refrigerant charging tank 81 is injected into the air conditioning system using the pressure difference between the refrigerant charging tank 81 and the air conditioning system. Preferably, before the compressor 11 operates, the throttling element 122 is controlled to be in a cut-off state to prevent refrigerant from entering the compressor 11 during the process of injecting refrigerant into the air conditioning system based on the pressure difference. In this technical solution, the refrigerant is injected into the air conditioning system via the seventh solenoid valve 47, the one-way valve 48, the second solenoid valve 42, and the second interface 131 under the action of the pressure difference between the refrigerant charging tank 81 and the air conditioning system.

[0104] Preferably, during the process of connecting the refrigerant charging tank 81 to the air conditioning system, the change value |△P0| of the system pressure P0 of the air conditioning system within a preset time (e.g., 1 minute) is obtained. When the change value |△P0| is not higher than the set pressure difference value (e.g., 100 kPa), the compressor 11 is controlled to operate to increase the refrigerant charging pressure and ensure that the amount of refrigerant charged meets the requirements. The compressor 11 is controlled to stop operating when the amount of refrigerant injected into the air conditioning system is the second preset mass, and the second solenoid valve 42 and the seventh solenoid valve 47 are controlled to be cut off. The sum of the first preset mass and the second preset mass is equal to the mass change value.

[0105] Specifically Figure 6 Taking the example shown, the operating logic of the system's refrigeration oil charging mode and refrigerant charging mode is further explained as follows:

[0106] S701, Start, the controller confirms the start, and the control method begins execution.

[0107] S702, open the second solenoid valve 42 and the sixth solenoid valve 46. During the filling process, add oil first. Open the second solenoid valve 42 and the sixth solenoid valve 46. In this way, the refrigeration oil in the oil tank 71 can be added into the indoor and outdoor refrigeration system (i.e., the air conditioning system) through the oil pump 72.

[0108] S703, turn on oil pump 72, and after opening the sixth solenoid valve 46 of the oil circuit, turn on oil pump 72 to start refueling the system;

[0109] S704, when the weighing value of the second weighing device 62 reaches M2, the oil pump 72 and the sixth solenoid valve 46 are closed. M2 corresponds to the amount of refrigeration oil that needs to be added to the system, which is set by the installation and maintenance personnel. When the change value of the second weighing device 62 reaches M2, the refrigeration oil filling is completed, the oil pump 72 and the sixth solenoid valve 46 are closed, and the filling is completed.

[0110] S705, after opening the seventh solenoid valve 47 and completing the refueling process, the refrigerant filling process needs to be carried out. Before filling, the seventh solenoid valve 47 should be opened to connect the refrigerant filling tank 81 to the internal and external refrigeration system.

[0111] S706, detect the change value |△P0| of the first pressure sensor 91 within 1 minute. During the filling process, the pressure value P0 detected by the first pressure sensor 91 is the pressure value of the indoor unit and the outdoor unit. The magnitude of its change value within a specified time can be used to determine whether the system is pressure balanced.

[0112] S707, compare |△P0| with 100kPa. |△P0| is the pressure change value detected by the first pressure sensor 91 within 1 minute. If it is greater than 100kPa, it means that the system pressure has not yet been balanced. The change value |△P0| of the first pressure sensor 91 within 1 minute can be detected again, and refrigerant can continue to be injected into the system based solely on the pressure difference. If it is less than or equal to 100kPa, it can be basically determined that the system pressure has been balanced. The compressor 11 needs to be turned on to continue injecting refrigerant to the required amount.

[0113] S708, turn on compressor 11. When it is determined that |△P0|≤100kPa, it is necessary to continue injecting to the required injection volume with the help of compressor 11, so turn on compressor 11.

[0114] S709, when the weighing value of the second weighing device 62 reaches M1, the second solenoid valve 42, the seventh solenoid valve 47 and the compressor 11 are closed. The value of M1 corresponds to the amount of refrigerant recovered by the first weighing device 61. When the total change of the oil tank 71 and the refrigerant charging tank 81 weighed by the second weighing device 62 is the same as M1, the charging process is completed, and the second solenoid valve 42, the seventh solenoid valve 47 and the compressor 11 are closed.

[0115] S710, End. Completed the method for adding refrigeration oil and refrigerant control, and ended the function.

[0116] As a preferred embodiment, the refrigerant recovery mode, system cleaning mode, system vacuuming mode, system refrigerant oil charging mode, and system refrigerant charging mode are executed sequentially, thereby automating the refrigerant recovery, system cleaning, system vacuuming, system refrigerant oil charging, and system refrigerant charging processes of old air conditioning systems.

[0117] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0118] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. An air conditioning system piping processing device, characterized in that, The system includes a refrigerant-driven assembly, which includes a compressor (11), a first pipeline controllably connected to the intake port of the compressor (11), and a second pipeline controllably connected to the exhaust port of the compressor (11). The first pipeline has a first interface (121) connected to a first target refrigerant pipe of the air conditioning system, and the second pipeline has a second interface (131) connected to a second target refrigerant pipe of the air conditioning system. A throttling element (122) is connected in series in the first pipeline. The system also includes a refrigerant recovery tank (21), which is controllably connected to the exhaust port through the refrigerant recovery pipeline. The second pipeline also has a system flushing interface (132), which is used to connect to a cleaning component (3). The cleaning component (3) is used to provide pressurized cleaning fluid. The first pipeline also has an vent (123) for discharging the pressurized cleaning fluid.

2. The air conditioning system piping processing device according to claim 1, characterized in that, A first solenoid valve (41) is connected in series on the first pipeline, a second solenoid valve (42) is connected in series on the second pipeline, a third solenoid valve (43) is connected in series on the pipeline between the refrigerant recovery tank (21) and the exhaust port, a fourth solenoid valve (44) is connected in series on the pipeline between the vent port (123) and the first pipeline, the refrigerant recovery pipeline is connected to the second pipeline, and the connection position is between the exhaust port and the second solenoid valve (42); and / or, the pressure cleaning fluid is nitrogen.

3. The air conditioning system piping processing device according to claim 2, characterized in that, A filter (124) is connected in series on the first pipeline between the first solenoid valve (41) and the throttling element (122); and / or, the compressor (11), the throttling element (122), the third solenoid valve (43), the refrigerant recovery tank (21) and the pipelines between them are on the first weighing device (61).

4. The air conditioning system piping processing device according to claim 2, characterized in that, It also includes a vacuum pump (51), which is connected to the second pipeline through a third pipeline, and the connection position of the third pipeline and the second pipeline is between the second solenoid valve (42) and the second interface (131). A fifth solenoid valve (45) is connected in series on the third pipeline.

5. The air conditioning system piping processing device according to claim 4, characterized in that, It also includes a refrigeration oil filling assembly, which includes an oil tank (71) and an oil pump (72). The inlet of the oil pump (72) is connected to the oil tank (71), and the outlet of the oil pump (72) is controllably connected to the second pipeline through a fourth pipeline. The connection position between the fourth pipeline and the second pipeline is between the exhaust port of the compressor (11) and the second solenoid valve (42). A sixth solenoid valve (46) is connected in series on the fourth pipeline.

6. The air conditioning system piping processing device according to claim 5, characterized in that, It also includes a refrigerant charging assembly, which includes a refrigerant charging tank (81). The outlet of the refrigerant charging tank (81) is connected to the fourth pipeline through a refrigerant charging pipeline. The connection position between the refrigerant charging pipeline and the fourth pipeline is between the sixth solenoid valve (46) and the second solenoid valve (42). A seventh solenoid valve (47) is connected in series on the refrigerant charging pipeline.

7. The air conditioning system piping processing device according to claim 6, characterized in that, The refrigerant charging pipeline is also connected to the first pipeline through a fifth pipeline. The connection point between the fifth pipeline and the first pipeline is between the first solenoid valve (41) and the throttling element (122), and the throttling element (122) is an electronic expansion valve; and / or, the oil tank (71) and the refrigerant charging tank (81) are simultaneously on the second weighing device (62).

8. The air conditioning system piping processing device according to claim 7, characterized in that, A one-way valve (48) is also connected in series on the fourth pipe. The one-way valve (48) is located between the seventh solenoid valve (47) and the second solenoid valve (42), and the conduction direction of the one-way valve (48) is from the seventh solenoid valve (47) to the second solenoid valve (42).

9. A control method for an air conditioning system piping processing device as described in any one of claims 2 to 8, characterized in that, Includes the following steps: Obtain the operating mode of the air conditioning system piping processing device; When the operating mode is refrigerant recovery mode, the real-time pressure Ps inside the refrigerant recovery tank (21) is obtained; When the real-time pressure Ps inside the tank is lower than the high pressure limit P1 of the refrigerant recovery tank (21), the first solenoid valve (41) and the third solenoid valve (43) are turned on and the second solenoid valve (42) is turned off, and the compressor (11) is turned on. When the suction pressure Pi of the compressor (11) is lower than the low pressure limit P2, the first solenoid valve (41) and the third solenoid valve (43) are turned off, and the compressor (11) is turned off. When the real-time pressure Ps inside the tank is not lower than the high pressure limit P1 of the refrigerant recovery tank (21), a high pressure alarm is triggered.

10. The control method according to claim 9, characterized in that, When the air conditioning system piping processing device includes a first weighing device (61), after the suction pressure Pi of the compressor (11) is lower than the low pressure limit P2, and the first solenoid valve (41) and the third solenoid valve (43) are controlled to be cut off, the mass change value of the component on the first weighing device (61) is obtained.

11. The control method according to claim 10, characterized in that, When the operating mode is system cleaning mode, the first solenoid valve (41), the second solenoid valve (42), and the fourth solenoid valve (44) are controlled to be in the cut-off state, and pressure cleaning fluid is introduced into the air conditioning system. When the system pressure P0 of the air conditioning system is greater than the venting limit P3, the fourth solenoid valve (44) is controlled to open to realize the venting of the pressure cleaning fluid.

12. The control method according to claim 11, characterized in that, The fourth solenoid valve (44) is emptied multiple times, and the fourth solenoid valve (44) is turned on for a first preset time between two cycles.

13. The control method according to claim 11, characterized in that, When the air conditioning system piping processing device includes a vacuum pump (51) and the operating mode is system vacuum mode, the fifth solenoid valve (45) is turned on, the first solenoid valve (41), the second solenoid valve (42), and the fourth solenoid valve (44) are all turned off, and the vacuum pump (51) is controlled to run.

14. The control method according to claim 13, characterized in that, During the operation of the vacuum pump (51), the system pressure P0 of the air conditioning system is obtained, and when the system pressure P0 is lower than the preset vacuum level for a continuous second preset time period, the fifth solenoid valve (45) is controlled to cut off.

15. The control method according to claim 14, characterized in that, Within a third consecutive preset time period after the fifth solenoid valve (45) is cut off, the relationship between the system pressure P0 and the preset vacuum degree is continuously acquired. When the system pressure P0 is less than the preset vacuum degree during the third consecutive preset time period, the vacuum pump (51) is controlled to stop operating. When the system pressure P0 is not less than the preset vacuum degree during the third consecutive preset time period, the fifth solenoid valve (45) is controlled to open again. The third preset time period is longer than the second preset time period.

16. The control method according to claim 13, characterized in that, When the air conditioning system piping processing device includes a refrigerant oil filling component and the operating mode is the system refrigerant oil filling mode, the first solenoid valve (41), the third solenoid valve (43), the fourth solenoid valve (44), and the fifth solenoid valve (45) are all shut off, the second solenoid valve (42) and the sixth solenoid valve (46) are turned on, and the oil pump (72) is operated to add a first preset mass of refrigerant oil to the air conditioning system. Then, the oil pump (72) is stopped and the sixth solenoid valve (46) is shut off.

17. The control method according to claim 16, characterized in that, When the air conditioning system piping processing device includes a refrigerant charging component, a refrigerant charging pipeline connected to the first pipeline, and the operating mode is the system refrigerant charging mode, the seventh solenoid valve (47) and the second solenoid valve (42) are turned on, and the first solenoid valve (41), the third solenoid valve (43), the fourth solenoid valve (44), the fifth solenoid valve (45), and the sixth solenoid valve (46) are turned off, and at least part of the refrigerant in the refrigerant charging tank (81) is injected into the air conditioning system by utilizing the pressure difference between the refrigerant charging tank (81) and the air conditioning system.

18. The control method according to claim 17, characterized in that, During the process of connecting the refrigerant tank (81) with the air conditioning system, the change value of the system pressure P0 of the air conditioning system within a preset time, |△P0|, is obtained. When the change value |△P0| is not higher than the set pressure difference value, the compressor (11) is controlled to operate until the amount of refrigerant injected into the air conditioning system is the second preset mass. Then the compressor (11) is controlled to stop operating, and the second solenoid valve (42) and the seventh solenoid valve (47) are controlled to be cut off. The sum of the first preset mass and the second preset mass is equal to the mass change value.

19. The control method according to claim 17, characterized in that, The refrigerant recovery mode, system cleaning mode, system vacuuming mode, system refrigeration oil charging mode, and system refrigerant charging mode are executed sequentially.

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