System high-pressure pressure control method and water-cooled multi-connected unit

Abstract

This invention relates to the field of air conditioning technology, specifically providing a system high-pressure control method and a water-cooled multi-split air conditioning unit, aiming to solve the problem that existing water-cooled multi-split air conditioning unit high-pressure regulation methods affect system energy efficiency and reliability. To this end, this application provides a system high-pressure control method and a water-cooled multi-split air conditioning unit. The unit is equipped with a booster pipe and / or a depressurization pipe. The two ends of the booster pipe are connected to the compressor's exhaust port and the first port of the indoor heat exchanger, respectively. The two ends of the depressurization pipe are connected to the first port of the indoor heat exchanger and the compressor's suction port, respectively. The method includes: acquiring the system high-pressure; comparing the system high-pressure with the warning pressure threshold corresponding to the current operating mode; and controlling the connection of the corresponding pipes based on the comparison result. Through the above setup, the system high-pressure can be adjusted by controlling the connection of the corresponding pipes, reducing or avoiding compressor frequency adjustments, while ensuring system energy efficiency and reliability.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, specifically providing a system high-pressure control method and a water-cooled multi-split unit. Background Technology

[0002] As a highly efficient air conditioning solution for medium and large buildings, water-cooled multi-split units work by using circulating cooling water to exchange heat with refrigerant in a plate heat exchanger on the outdoor side. This replaces the fan and condenser of traditional air-cooled units, achieving more stable and energy-efficient cooling and heating output than traditional air-cooling methods.

[0003] However, this design also has certain limitations: during the transitional seasons, excessively low cooling water temperatures can cause a sharp drop in system condensing pressure, resulting in low system high pressure and affecting the normal operation of the unit. This forces the compressor to increase its frequency to maintain the basic pressure difference, leading to high energy consumption under low load. Conversely, during the harsh winter when high water temperatures are required for heating, the system high pressure is necessary to meet indoor high temperature demands, affecting the normal and stable operation of the unit. Even if the compressor frequency is reduced to the minimum, the pressure remains high, potentially leading to a high-pressure protection shutdown due to exceeding the compressor's operating range. Summary of the Invention

[0004] This application aims to solve the aforementioned technical problem, namely, to address the issue that existing high-pressure regulation methods for water-cooled multi-split units affect system energy efficiency and reliability.

[0005] In a first aspect, this application provides a system high-pressure control method for a water-cooled multi-split air conditioning unit, wherein the water-cooled multi-split air conditioning unit is provided with a booster pipeline and / or a depressurization pipeline, wherein the two ends of the booster pipeline are respectively connected to the exhaust port of the compressor and the first port of the indoor heat exchanger, and the two ends of the depressurization pipeline are respectively connected to the first port of the indoor heat exchanger and the suction port of the compressor.

[0006] The control method includes:

[0007] Obtain the system high pressure;

[0008] Compare the system's high-pressure level with the warning pressure threshold corresponding to the current operating mode;

[0009] Based on the comparison results, control the connection of the corresponding pipelines;

[0010] The high-pressure system pressure is the pressure measured at the exhaust port of the compressor.

[0011] With the above technical solution, the water-cooled multi-split unit can adjust the system high pressure by controlling the connection of the corresponding booster or depressurizer pipelines, thereby reducing or avoiding the need to adjust the compressor frequency, while ensuring the energy efficiency of the water-cooled multi-split unit and the reliability of the system.

[0012] In the preferred embodiment of the above-mentioned high-pressure control method, the step of controlling the corresponding pipeline connection based on the comparison result further includes:

[0013] When the water-cooled multi-split unit is equipped with a booster pipe, if the current operating mode is cooling mode, and the system high pressure is less than the warning pressure threshold corresponding to the cooling mode, the booster pipe is connected; and / or when the water-cooled multi-split unit is equipped with a pressure reducing pipe, if the current operating mode is heating mode, and the system high pressure is greater than the warning pressure threshold corresponding to the heating mode, the pressure reducing pipe is connected.

[0014] In the preferred embodiment of the above-mentioned high-pressure control method for the system, the high-pressure control method further includes:

[0015] After controlling the connection of the corresponding pipelines, continuously monitor the high pressure of the system;

[0016] When the high pressure of the system reaches the safe pressure threshold corresponding to the current operating mode, the corresponding pipeline is shut off.

[0017] In the preferred embodiment of the above-mentioned high-pressure control method for the system, the high-pressure control method further includes:

[0018] After controlling the connection of the corresponding pipeline, if the high pressure of the system cannot reach the safe pressure threshold, the opening of the electronic expansion valve and / or the operating frequency of the compressor are adjusted.

[0019] When the above technical solution is adopted, if the pressure regulating effect of the booster or depressurizer is poor, the system pressure can be forced back to the normal range by adjusting the opening of the electronic expansion valve or the operating frequency of the compressor. This ensures the normal operation of the system while maximizing the user's cooling or heating experience.

[0020] In the preferred embodiment of the above-mentioned high-pressure control method, adjusting the opening degree of the electronic expansion valve and / or the operating frequency of the compressor further includes:

[0021] Prioritize adjusting the opening degree of the electronic expansion valve;

[0022] After the opening of the electronic expansion valve is adjusted to its maximum opening, the operating frequency of the compressor is then adjusted.

[0023] By adopting the above technical solution, the impact on system energy efficiency or reliability can be minimized by prioritizing the adjustment of the opening of the electronic expansion valve and then adjusting the compressor frequency.

[0024] In the preferred embodiment of the above-mentioned high-pressure control method, adjusting the opening degree of the electronic expansion valve and / or the operating frequency of the compressor further includes:

[0025] If the high pressure of the system does not reach the first controllable pressure threshold corresponding to the current operating mode, the opening of the electronic expansion valve and / or the operating frequency of the compressor shall be adjusted.

[0026] Among them, the first controllable pressure threshold corresponding to both heating mode and cooling mode is less than the warning pressure threshold, the first controllable pressure threshold corresponding to heating mode is greater than the safety pressure threshold, and the first controllable pressure threshold corresponding to cooling mode is less than the safety pressure threshold.

[0027] In the preferred embodiment of the above-mentioned high-pressure control method for the system, the high-pressure control method further includes:

[0028] When the water-cooled multi-split unit is equipped with a booster pipeline, if the current operating mode is cooling mode, when the system high pressure reaches the warning pressure threshold, the opening of the electronic expansion valve and / or the operating frequency of the compressor will stop being adjusted; and / or when the water-cooled multi-split unit is equipped with a pressure reducing pipeline, if the current operating mode is heating mode, when the system high pressure reaches the second controllable pressure threshold, the opening of the electronic expansion valve and / or the operating frequency of the compressor will stop being adjusted; wherein, the second controllable pressure threshold is less than the first controllable pressure threshold corresponding to the heating mode, and greater than the safety pressure threshold corresponding to the heating mode.

[0029] In a second aspect, this application provides a water-cooled multi-split air conditioning unit, which includes an outdoor unit and an indoor unit. The outdoor unit includes a compressor, a four-way reversing valve group, an outdoor heat exchanger, an electronic expansion valve, and an interface module. The interface module is provided with a liquid pipe interface, a high-pressure gas pipe interface, and a low-pressure gas pipe interface. The interface module is used to connect to the indoor unit.

[0030] The four-way reversing valve assembly is connected to the exhaust port of the compressor, the first port of the outdoor heat exchanger, the high-pressure gas pipe interface, and the suction port of the compressor. The second port of the outdoor heat exchanger is connected to the first port of the electronic expansion valve. The second port of the electronic expansion valve is connected to the liquid pipe interface. The low-pressure gas pipe interface is connected to the suction port of the compressor.

[0031] The outdoor unit is equipped with a booster pipe and / or a depressurization pipe. The two ends of the booster pipe are connected to the exhaust port of the compressor and the first port of the electronic expansion valve, respectively. The booster pipe is equipped with a first control valve group. The two ends of the depressurization pipe are connected to the liquid pipe interface and the suction port of the compressor, respectively. The depressurization pipe is equipped with a second control valve group.

[0032] In the preferred embodiment of the above-mentioned water-cooled multi-split unit, the water-cooled multi-split unit further includes a controller, which is configured to execute the system high-pressure control method as described in any of the preceding claims.

[0033] In the preferred embodiment of the above-mentioned water-cooled multi-split unit, when the water-cooled multi-split unit is equipped with a booster pipeline, the exhaust port of the compressor is connected to the four-way reversing valve assembly and the first end of the booster pipeline, respectively, and the second end of the booster pipeline is connected to the pipeline between the second port of the outdoor heat exchanger and the first port of the electronic expansion valve; and / or when the water-cooled multi-split unit is equipped with a pressure-reducing pipeline, the first end of the pressure-reducing pipeline is connected to the pipeline between the liquid pipe interface and the second port of the electronic expansion valve, and the second end of the pressure-reducing pipeline is connected to the pipeline between the first port of the outdoor heat exchanger and the four-way reversing valve assembly. Attached Figure Description

[0034] The high-pressure control method and water-cooled multi-unit system of this application are described below with reference to the accompanying drawings. In the drawings:

[0035] Figure 1 This is a flowchart of the main steps of the high-pressure control method of the system in this application;

[0036] Figure 2 This is a schematic diagram of the structure of the water-cooled multi-split unit of this application.

[0037] List of reference numerals

[0038] 1. Compressor; 11. Oil separator; 12. High-pressure sensor; 2. Four-way reversing valve assembly; 3. Outdoor heat exchanger; 4. Electronic expansion valve; 5. Interface module; 51. Liquid pipe interface; 52. High-pressure gas pipe interface; 53. Low-pressure gas pipe interface; 6. Subcooler; 7. Gas-liquid separator; 8. Boosting pipeline; 81. First control valve assembly; 9. Pressure reducing pipeline; 91. Second control valve assembly. Detailed Implementation

[0039] Preferred embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application. For example, although the water-cooled multi-split unit in the drawings is equipped with both booster and depressurization pipelines, this is not intended to limit the scope of protection of this application. Without departing from the principles of this application, those skilled in the art may, as needed, install only one of the pipelines.

[0040] It should be noted that in the description of this application, terms such as "left" and "right" indicating direction or positional relationships are based on the direction or positional relationships shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] Furthermore, it should be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0042] As described in the background section, water-cooled multi-split units, as a highly efficient air conditioning solution for medium and large buildings, utilize circulating cooling water to exchange heat with refrigerant in a plate heat exchanger on the outdoor side. This replaces the fan and condenser of traditional air-cooled units, achieving more stable and energy-efficient cooling and heating output than traditional air-cooling methods.

[0043] However, this design also has certain limitations: during the transitional seasons, excessively low cooling water temperatures can cause a sharp drop in system condensing pressure, resulting in low system high pressure and affecting the normal operation of the unit. This forces the compressor to increase its frequency to maintain the basic pressure difference, leading to high energy consumption under low load. Conversely, during the harsh winter when high water temperatures are required for heating, the system high pressure is necessary to meet indoor high temperature demands, affecting the normal and stable operation of the unit. Even if the compressor frequency is reduced to the minimum, the pressure remains high, potentially leading to a high-pressure protection shutdown due to exceeding the compressor's operating range.

[0044] To address the issue of existing high-pressure regulation methods in water-cooled multi-split air conditioning units affecting system energy efficiency and reliability, this application provides a high-pressure control method for water-cooled multi-split air conditioning units. The water-cooled multi-split air conditioning unit is equipped with a booster pipe and / or a pressure reducing pipe. The two ends of the booster pipe are connected to the compressor's discharge port and the first port of the indoor heat exchanger, respectively. The two ends of the pressure reducing pipe are connected to the first port of the indoor heat exchanger and the compressor's suction port, respectively. In cooling mode, part of the refrigerant discharged from the compressor releases heat in the outdoor heat exchanger, while the other part bypasses the outdoor heat exchanger through the booster pipe. The two refrigerant streams merge, are throttled and depressurized, and then enter the indoor heat exchanger through the first port to absorb heat. Finally, they return to the compressor's suction port through the second port of the indoor heat exchanger. In heating mode, the refrigerant discharged from the compressor first enters the indoor heat exchanger through the second port of the indoor heat exchanger to release heat. Then, a portion of the refrigerant flowing out from the first port of the indoor heat exchanger enters the outdoor heat exchanger to absorb heat after being throttled and depressurized, while the other portion bypasses the outdoor heat exchanger through the pressure reducing pipeline. Then, the two streams of refrigerant merge and return to the compressor's suction port.

[0045] The following reference Figure 1 The high-pressure control method of the system in this application will be described below. Among them, Figure 1 This is a flowchart of the main steps of the high-pressure control method for the system in this application.

[0046] like Figure 1 As shown, the system's high-pressure control method mainly includes the following steps:

[0047] S101, Obtain the system high-pressure. The system high-pressure is the pressure measured at the compressor's discharge port. For example, the system high-pressure can be monitored in real time by installing a pressure sensor at the compressor's discharge port.

[0048] S102 compares the system high-pressure pressure with the warning pressure threshold corresponding to the current operating mode. For example, the system high-pressure pressure should be within a reasonable range, and the system high-pressure pressure depends on the condensing temperature. Therefore, if the system high-pressure pressure is too low during cooling in the transitional season, the warning pressure threshold corresponding to the cooling mode is low. If high water temperature heating is required in the cold winter, the system high-pressure pressure may be too high, so the warning pressure threshold corresponding to the heating mode is high.

[0049] S103, based on the comparison results, control the connection of the corresponding pipelines. For example, if the water-cooled multi-split unit is equipped with a booster pipeline, and the current operating mode is cooling mode, and the system high pressure is less than the warning pressure threshold corresponding to the cooling mode, control the connection of the booster pipeline. If the water-cooled multi-split unit is equipped with a pressure reducing pipeline, and the current operating mode is heating mode, and the system high pressure is greater than the warning pressure threshold corresponding to the heating mode, control the connection of the pressure reducing pipeline. In this embodiment, the water-cooled multi-split unit is equipped with both booster and pressure reducing pipelines. Furthermore, the warning pressure threshold corresponding to the cooling mode is 1.8 MPa. In cooling mode, if the currently detected system high pressure is less than 1.8 MPa, the booster pipeline is connected. The warning pressure threshold corresponding to the heating mode is 3.4 MPa. In heating mode, if the currently detected system high pressure is greater than 3.4 MPa, the pressure reducing pipeline is connected.

[0050] With the above technical solution, the water-cooled multi-split unit can adjust the system high pressure by controlling the connection of the corresponding booster or depressurizer pipelines, thereby reducing or avoiding the need to adjust the compressor frequency, while ensuring the energy efficiency of the water-cooled multi-split unit and the reliability of the system.

[0051] In some implementations, the system high-pressure control method further includes:

[0052] After controlling the connection of the corresponding pipelines, continuously monitor the high pressure of the system;

[0053] When the system high pressure reaches the safe pressure threshold corresponding to the current operating mode, the corresponding pipeline will be shut off.

[0054] It should be explained that, similarly, the safety pressure threshold for cooling mode is a low value, while the safety pressure threshold for heating mode is a high value. Furthermore, during the process of the system's high pressure reaching the safety pressure threshold corresponding to the current operating mode, "reaching" only means that the system's high pressure has changed from the warning pressure threshold to the safety pressure threshold; in other words, "reaching" can mean either "reaching downwards" or "reaching upwards."

[0055] In this embodiment, the safety pressure threshold for cooling mode is 2.2 MPa, and the safety pressure threshold for heating mode is 2.8 MPa. For example, after connecting the booster pipe, if the system high pressure rises from below the warning pressure threshold of 1.8 MPa to a state greater than or equal to the safety pressure threshold of 2.2 MPa, it indicates that the system high pressure has returned to a reasonable range, and the booster pipe is then closed. After connecting the depressurization pipe, if the system high pressure falls from above the warning pressure threshold of 3.4 MPa to a state less than or equal to the safety pressure threshold of 2.8 MPa, the depressurization pipe is then closed. Of course, the settings of the warning pressure threshold and the safety pressure threshold are not fixed; those skilled in the art can change the specific numerical settings of the warning pressure threshold and the safety pressure threshold according to their needs.

[0056] In some implementations, the system high-pressure control method further includes:

[0057] After controlling the connection of the corresponding pipelines, if the system high pressure cannot reach the safe pressure threshold, adjust the opening of the electronic expansion valve and / or the operating frequency of the compressor.

[0058] In this embodiment, if the system high pressure still fails to reach the safe pressure threshold after a period of time following the connection of the corresponding pipeline, it indicates that connecting the pipeline is ineffective in regulating the system high pressure. To ensure the normal operation of the unit, the system high pressure can be assisted by adjusting the opening of the electronic expansion valve and the operating frequency of the compressor. Specifically, after controlling the connection of the booster pipeline, if the system high pressure fails to reach the safe pressure threshold corresponding to the cooling mode, the opening of the electronic expansion valve can be reduced, and the operating frequency of the compressor can be increased. Conversely, the adjustment method for the heating mode is the opposite. If the system high pressure fails to reach the safe pressure threshold corresponding to the heating mode, the opening of the electronic expansion valve can be increased, and the operating frequency of the compressor can be decreased.

[0059] When the above technical solution is adopted, if the pressure regulating effect of the booster or depressurizer is poor, the system pressure can be forced back to the normal range by adjusting the opening of the electronic expansion valve or the operating frequency of the compressor. This ensures the normal operation of the system while maximizing the user's cooling or heating experience.

[0060] Furthermore, in some embodiments, adjusting the opening degree of the electronic expansion valve and / or the operating frequency of the compressor further includes:

[0061] Prioritize adjusting the opening degree of the electronic expansion valve;

[0062] After the electronic expansion valve is adjusted to its maximum opening, the operating frequency of the compressor is then adjusted.

[0063] In this embodiment, if the system high pressure cannot reach the safe pressure threshold, the system high pressure can be adjusted primarily by regulating the opening of the electronic expansion valve. If the system high pressure reaches the safe pressure threshold during this process, adjusting the opening of the electronic expansion valve can be stopped, and there is no need to adjust the compressor's operating frequency. If the system high pressure still cannot reach the safe pressure threshold after adjusting the electronic expansion valve to its maximum opening, then the compressor's operating frequency is adjusted to force the system high pressure back to the normal range.

[0064] It should be explained that the maximum opening degree of the electronic expansion valve differs in different modes. In heating mode, the electronic expansion valve reduces the system's high-pressure level by increasing its opening degree; in this case, the maximum opening degree of the electronic expansion valve can be fully open. In cooling mode, the electronic expansion valve regulates the system's high-pressure level by decreasing its opening degree; in this case, the maximum opening degree of the electronic expansion valve must be the minimum opening degree, such as 20%, to ensure the normal operation of the system. Of course, this specific value can be set by those skilled in the art according to their needs. By adopting the above technical solution, prioritizing the adjustment of the electronic expansion valve's opening degree and then adjusting the compressor frequency, the impact on system energy efficiency or reliability can be minimized.

[0065] It should also be explained that the above implementation method is not fixed. In an alternative implementation method, if the method of connecting pipelines has a poor effect on regulating the system high pressure, the system high pressure can be forced back to the normal range simply by adjusting the operating frequency of the compressor. That is, the opening of the electronic expansion valve is not adjusted at this time. However, considering the need to reduce the impact on the system, it is a better choice to adjust the opening of the electronic expansion valve first and then adjust the compressor frequency.

[0066] Furthermore, in some embodiments, adjusting the opening degree of the electronic expansion valve and / or the operating frequency of the compressor further includes:

[0067] If the system high pressure does not reach the first controllable pressure threshold corresponding to the current operating mode, adjust the opening of the electronic expansion valve and / or the operating frequency of the compressor.

[0068] Among them, the first controllable pressure threshold corresponding to both heating mode and cooling mode is less than the warning pressure threshold, the first controllable pressure threshold corresponding to heating mode is greater than the safety pressure threshold, and the first controllable pressure threshold corresponding to cooling mode is less than the safety pressure threshold.

[0069] It should be noted that, similarly, the first controllable pressure threshold for cooling mode is a low value, while the first controllable pressure threshold for heating mode is a high value. Specifically, the first controllable pressure threshold for cooling mode is 1.7 MPa, which is less than the warning pressure threshold of 1.8 MPa and less than the safety pressure threshold of 2.2 MPa. The first controllable pressure threshold for heating mode is 3.0 MPa, which is less than the warning pressure threshold of 1.8 MPa and greater than the safety pressure threshold of 2.8 MPa.

[0070] In this embodiment, after a certain period of time following the connection of the corresponding pipelines, i.e., after the system stabilizes, although the system high pressure may still not reach the corresponding safe pressure threshold after certain changes, it may still be within an acceptable pressure fluctuation range and will not affect the normal operation of the system. Therefore, it is not necessary to adjust the opening of the electronic expansion valve or the operating frequency of the compressor at this time. However, if the system high pressure cannot even reach the first controllable pressure threshold corresponding to the current operating mode, it indicates that the adjustment effect of the booster or depressurizer pipeline on the system high pressure is too poor. At this time, it is necessary to start adjusting the opening of the electronic expansion valve and / or the operating frequency of the compressor.

[0071] For example, in cooling mode, if the initially monitored system high pressure is 1.4 MPa, since this value is less than the warning pressure threshold of 1.8 MPa corresponding to the cooling mode, the booster pipe is connected at this time. After the system stabilizes, the monitored system high pressure is 1.6 MPa, which is still less than the first controllable pressure threshold of 1.7 MPa. This indicates that the booster pipe has a limited effect on regulating the system high pressure. At this time, the opening of the electronic expansion valve or the operating frequency of the compressor can be adjusted, and the adjustment can also be carried out in the priority order of the previous embodiment.

[0072] In heating mode, if the initially monitored system high pressure is 3.5 MPa, this value is greater than the warning pressure threshold of 3.4 MPa corresponding to the heating mode. Therefore, the pressure reducing pipeline is connected at this time. After the system stabilizes, the monitored system high pressure is 3.2 MPa, which is still greater than the first controllable pressure threshold of 3.0 MPa. This indicates that the pressure reducing pipeline has limited effect on regulating the system high pressure. At this point, the opening of the electronic expansion valve or the operating frequency of the compressor can be adjusted. Of course, the setting of the first controllable pressure threshold is not fixed. Those skilled in the art can change the specific value of the first controllable pressure threshold according to their needs.

[0073] Furthermore, in some embodiments, the system high-pressure control method further includes:

[0074] When a water-cooled multi-split unit is equipped with a booster pipeline, if the current operating mode is cooling mode, the opening of the electronic expansion valve and / or the operating frequency of the compressor will stop being adjusted when the system high pressure reaches the warning pressure threshold.

[0075] In this embodiment, if the current operating mode is cooling mode, and the adjustment of the electronic expansion valve opening or compressor operating frequency is initiated due to the poor effect of regulating the system high pressure solely through the booster pipeline, then once the system high pressure reaches the warning pressure threshold, the adjustment of the electronic expansion valve opening or compressor operating frequency can be stopped. At this point, only the booster pipeline remains connected. Once the system high pressure reaches the safety pressure threshold, the booster pipeline can be shut off. For example, during the adjustment of the electronic expansion valve opening or compressor operating frequency, if the monitored system high pressure is greater than or equal to the warning pressure threshold of 1.8 MPa corresponding to the cooling mode, the adjustment of the electronic expansion valve opening or compressor operating frequency can be stopped. Once the system high pressure is greater than or equal to the safety pressure threshold of 2.2 MPa, the booster pipeline can be shut off.

[0076] When a water-cooled multi-split unit is equipped with a pressure-reducing pipeline, if the current operating mode is heating mode, once the system high pressure reaches the second controllable pressure threshold, the adjustment of the electronic expansion valve opening and / or the compressor operating frequency will cease. The second controllable pressure threshold is lower than the first controllable pressure threshold corresponding to the heating mode, but higher than the safety pressure threshold corresponding to the heating mode.

[0077] In this embodiment, the second controllable pressure threshold is set to 2.9 MPa. If the current operating mode is heating mode, and the opening of the electronic expansion valve or the operating frequency of the compressor is adjusted after the pressure reducing pipeline is connected, then the adjustment of the opening of the electronic expansion valve or the operating frequency of the compressor can be stopped after the system high pressure is less than or equal to the second controllable pressure threshold of 2.9 MPa. At this time, only the pressure reducing pipeline is kept connected. After the system high pressure is less than or equal to the safety pressure threshold of 2.8 MPa, the pressure reducing pipeline can be closed.

[0078] It should be explained that the setting of the second controllable pressure threshold is not fixed. Those skilled in the art can change the specific value of the second controllable pressure threshold according to their needs. Furthermore, although in this embodiment, in cooling mode, the adjustment of the electronic expansion valve opening and the compressor operating frequency stops after the system high pressure reaches the warning pressure threshold, this setting is not mandatory. In an alternative embodiment, a second controllable pressure threshold corresponding to the cooling mode can also be set, and the adjustment of the electronic expansion valve opening and the compressor operating frequency can stop after the system high pressure reaches the second controllable pressure threshold. Correspondingly, in heating mode, the adjustment of the electronic expansion valve opening and the compressor operating frequency can also stop after the system high pressure reaches the warning pressure threshold corresponding to the heating mode.

[0079] Secondly, this application also provides a water-cooled multi-split air conditioning unit, as described below. Figure 2 The water-cooled multi-split air conditioning unit of this application will be described below. Figure 2 This is a schematic diagram of the structure of the water-cooled multi-split unit of this application.

[0080] In a preferred embodiment, the water-cooled multi-split unit includes a controller configured to execute the system high-pressure control method as described in any of the above embodiments. Furthermore, the water-cooled multi-split unit includes an outdoor unit and an indoor unit, such as... Figure 2 As shown, the outdoor unit includes a compressor 1, a four-way reversing valve assembly 2, an outdoor heat exchanger 3, an electronic expansion valve 4, an interface module 5, a subcooler 6, a gas-liquid separator 7, a booster line 8, and a pressure-reducing line 9. The interface module 5 is equipped with a liquid pipe interface 51, a high-pressure gas pipe interface 52, and a low-pressure gas pipe interface 53. The interface module 5 is used to connect to the indoor unit (not shown in the figure). Specifically, the indoor unit includes an indoor heat exchanger. The liquid pipe interface 51 is used to connect to the first port of the indoor heat exchanger, and both the high-pressure gas pipe interface 52 and the low-pressure gas pipe interface 53 are used to connect to the second port of the indoor heat exchanger. The compressor 1 includes a body and an oil separator 11. The body is connected to the oil separator 11. A high-pressure sensor 12 is installed at the exhaust port of the oil separator 11, and the exhaust port of the oil separator 11 is connected to both the four-way reversing valve assembly 2 and the booster line 8. The four-way reversing valve assembly 2 includes two four-way reversing valves. The four-way reversing valve assembly 2 is connected to the exhaust port of the compressor 1, the first port of the outdoor heat exchanger 3 (the left port in the direction shown in the figure), the high-pressure gas pipe interface 52, and the suction port of the compressor 1. The S port and E port of the four-way reversing valve on the left are also connected by a capillary tube, and the S port and C port of the four-way reversing valve on the right are also connected by a capillary tube. The four-way reversing valve assembly 2 can realize the switching between heating mode and cooling mode of the water-cooled multi-split unit. The specific connection method is shown in the figure, and the switching principle is existing technology and will not be described in detail here.

[0081] The second port (right port in the direction shown in the figure) of the outdoor heat exchanger 3 is connected to the first port (left port in the direction shown in the figure) of the electronic expansion valve 4 of the main system circuit. The second port (right port in the direction shown in the figure) of the electronic expansion valve 4 is connected to the subcooler 6. The subcooler 6 is connected to the liquid pipe interface 51. The low-pressure gas pipe interface 53 is connected to the inlet of the gas-liquid separator 7. The outlet of the gas-liquid separator 7 is connected to the suction port of the compressor 1.

[0082] The two ends of the booster pipe 8 are connected to the discharge port of the compressor 1 and the first port of the electronic expansion valve 4, respectively. Specifically, the first end of the booster pipe 8 is connected to the pipeline between the discharge port of the compressor 1 and the four-way reversing valve group 2, and the second end of the booster pipe 8 is connected to the pipeline between the second port of the outdoor heat exchanger 3 and the first port of the electronic expansion valve 4. The booster pipe 8 is equipped with a first control valve group 81, which includes a solenoid valve and a check valve. The two ends of the pressure reducing pipe 9 are connected to the liquid pipe interface 51 and the suction port of the compressor 1, respectively. Specifically, the first end of the pressure reducing pipe 9 is connected to the pipeline between the subcooler 6 and the second port of the electronic expansion valve 4, and the second end of the pressure reducing pipe 9 is connected to the pipeline between the first port of the outdoor heat exchanger 3 and the four-way reversing valve group 2. The pressure reducing pipe 9 is equipped with a second control valve group 91, which includes a solenoid valve and a check valve.

[0083] The following is combined Figure 2 This paper describes the refrigerant flow direction of the water-cooled multi-split unit in different modes.

[0084] In cooling mode, compressor 1 discharges high-temperature, high-pressure refrigerant gas, which first enters the outdoor heat exchanger 3 through ports D and C of the four-way reversing valve located on the left. At this time, the refrigerant gas releases heat, which is absorbed by the water, and then it becomes medium-temperature, high-pressure refrigerant liquid. The medium-temperature, high-pressure refrigerant liquid is throttled and depressurized by the electronic expansion valve 4 in the main circuit, and then splits into two paths. One path is subcooled through the main circuit of the subcooler 6, and then enters the indoor superheater through the liquid pipe interface 51. The refrigerant gas from the indoor superheater enters the gas-liquid separator 7 through the low-pressure gas pipe 53, and then returns to compressor 1. The other path, after being throttled and depressurized by the electronic expansion valve in the auxiliary circuit, enters the auxiliary circuit of the subcooler 6, absorbs heat, and becomes low-temperature, low-pressure refrigerant gas before returning to compressor 1.

[0085] When it is determined that the system high pressure is lower than the warning pressure threshold corresponding to the cooling mode, the booster pipe 8 needs to be connected. At this time, it is only necessary to open the solenoid valve in the first control valve group 81. At this time, a small portion of the high-temperature and high-pressure refrigerant gas still enters the outdoor heat exchanger 3 for heat exchange, and then merges with the other large portion of refrigerant flowing out from the booster pipe 8, and then flows to the subcooler 6. The subsequent refrigerant flow direction can be referred to the above process.

[0086] In heating mode, both electronic expansion valves are switched so that ports D and E are connected, and ports C and S are connected. Compressor 1 discharges high-temperature, high-pressure refrigerant gas, which first enters the indoor heat exchanger through ports D and E of the four-way reversing valve on the right and the high-pressure gas pipe interface 52. The refrigerant from the indoor superheater passes through the liquid pipe interface 51, the subcooler 6, and the electronic expansion valve 4 before entering the outdoor heat exchanger 3 to absorb heat. Then, it enters the gas-liquid separator 7 through ports C and S of the four-way reversing valve on the left, and finally returns to compressor 1.

[0087] When it is determined that the system high pressure is greater than the warning pressure threshold corresponding to the heating mode, the pressure reducing pipeline 9 needs to be connected. At this time, it is only necessary to open the solenoid valve in the second control valve group 91. At this time, part of the refrigerant coming out of the subcooler 6 still enters the outdoor heat exchanger 3 to absorb heat through the electronic expansion valve 4, while the other part of the refrigerant directly merges with the refrigerant flowing out of the outdoor heat exchanger 3 through the pressure reducing pipeline 9, and then returns to the compressor 1 through the four-way reversing valve on the left and the gas-liquid separator 7 in sequence.

[0088] It needs to be explained that, Figure 2 Only one possible structural diagram of a water-cooled multi-split air conditioning unit is shown, but its configuration is not fixed. Those skilled in the art can make adjustments as needed, such as adding or deleting components or changing the piping configuration, as long as it does not affect the normal functioning of the booster line 8 and the pressure reducing line 9. In an alternative embodiment, only one of the booster line 8 and the pressure reducing line 9 may be provided. Furthermore, the configuration of the first control valve group 81 and the second control valve group 91 is also not fixed. In an alternative embodiment, the solenoid valves can be replaced with electric ball valves, etc., as long as it does not affect the normal functioning of the booster line 8 and the pressure reducing line 9.

[0089] Those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, any of the claimed embodiments in the claims of this application can be used in any combination.

[0090] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A system high-pressure control method for water-cooled multi-unit chillers, characterized in that, The water-cooled multi-split unit is equipped with a booster pipe and / or a pressure reducing pipe. The two ends of the booster pipe are connected to the exhaust port of the compressor and the first port of the indoor heat exchanger, respectively. The two ends of the pressure reducing pipe are connected to the first port of the indoor heat exchanger and the suction port of the compressor, respectively. The control method includes: Obtain the system high pressure; Compare the system's high-pressure level with the warning pressure threshold corresponding to the current operating mode; Based on the comparison results, control the connection of the corresponding pipelines; The high-pressure system pressure is the pressure measured at the exhaust port of the compressor.

2. The system high-pressure control method according to claim 1, characterized in that, The control of the corresponding pipeline connection based on the comparison results further includes: When the water-cooled multi-split unit is equipped with a booster pipe, if the current operating mode is cooling mode, and the system high pressure is less than the warning pressure threshold corresponding to the cooling mode, the booster pipe is connected; and / or when the water-cooled multi-split unit is equipped with a pressure reducing pipe, if the current operating mode is heating mode, and the system high pressure is greater than the warning pressure threshold corresponding to the heating mode, the pressure reducing pipe is connected.

3. The system high-pressure control method according to claim 1, characterized in that, The system high-pressure control method also includes: After controlling the connection of the corresponding pipelines, continuously monitor the high pressure of the system; When the high pressure of the system reaches the safe pressure threshold corresponding to the current operating mode, the corresponding pipeline is shut off.

4. The system high-pressure control method according to claim 3, characterized in that, The system high-pressure control method also includes: After controlling the connection of the corresponding pipeline, if the high pressure of the system cannot reach the safe pressure threshold, the opening of the electronic expansion valve and / or the operating frequency of the compressor are adjusted.

5. The system high-pressure control method according to claim 4, characterized in that, The adjustment of the opening degree of the electronic expansion valve and / or the operating frequency of the compressor further includes: Prioritize adjusting the opening degree of the electronic expansion valve; After the opening of the electronic expansion valve is adjusted to its maximum opening, the operating frequency of the compressor is then adjusted.

6. The system high-pressure control method according to claim 4, characterized in that, The adjustment of the opening degree of the electronic expansion valve and / or the operating frequency of the compressor further includes: If the high pressure of the system does not reach the first controllable pressure threshold corresponding to the current operating mode, the opening of the electronic expansion valve and / or the operating frequency of the compressor shall be adjusted. Among them, the first controllable pressure threshold corresponding to both heating mode and cooling mode is less than the warning pressure threshold, the first controllable pressure threshold corresponding to heating mode is greater than the safety pressure threshold, and the first controllable pressure threshold corresponding to cooling mode is less than the safety pressure threshold.

7. The system high-pressure control method according to claim 6, characterized in that, The system high-pressure control method also includes: When the water-cooled multi-split unit is equipped with a booster pipeline, if the current operating mode is cooling mode, when the system high pressure reaches the warning pressure threshold, the opening of the electronic expansion valve and / or the operating frequency of the compressor will be stopped; and / or when the water-cooled multi-split unit is equipped with a pressure reducing pipeline, if the current operating mode is heating mode, when the system high pressure reaches the second controllable pressure threshold, the opening of the electronic expansion valve and / or the operating frequency of the compressor will be stopped. The second controllable pressure threshold is less than the first controllable pressure threshold corresponding to the heating mode, but greater than the safe pressure threshold corresponding to the heating mode.

8. A water-cooled multi-split chiller unit, characterized in that, The water-cooled multi-split unit includes an outdoor unit and an indoor unit. The outdoor unit includes a compressor, a four-way reversing valve assembly, an outdoor heat exchanger, an electronic expansion valve, and an interface module. The interface module is equipped with a liquid pipe interface, a high-pressure gas pipe interface, and a low-pressure gas pipe interface. The interface module is used to connect to the indoor unit. The four-way reversing valve assembly is connected to the exhaust port of the compressor, the first port of the outdoor heat exchanger, the high-pressure gas pipe interface, and the suction port of the compressor. The second port of the outdoor heat exchanger is connected to the first port of the electronic expansion valve. The second port of the electronic expansion valve is connected to the liquid pipe interface. The low-pressure gas pipe interface is connected to the suction port of the compressor. The outdoor unit is equipped with a booster pipe and / or a depressurization pipe. The two ends of the booster pipe are connected to the exhaust port of the compressor and the first port of the electronic expansion valve, respectively. The booster pipe is equipped with a first control valve group. The two ends of the depressurization pipe are connected to the liquid pipe interface and the suction port of the compressor, respectively. The depressurization pipe is equipped with a second control valve group.

9. The water-cooled multi-split unit according to claim 8, characterized in that, The water-cooled multi-unit also includes a controller configured to perform the system high-pressure control method as described in any one of claims 1-7.

10. The water-cooled multi-split unit according to claim 8, characterized in that, When the water-cooled multi-split unit is equipped with a booster pipeline, the compressor's exhaust port is connected to both the four-way reversing valve assembly and the first end of the booster pipeline, and the second end of the booster pipeline is connected to the pipeline between the second port of the outdoor heat exchanger and the first port of the electronic expansion valve; and / or when the water-cooled multi-split unit is equipped with a pressure-reducing pipeline, the first end of the pressure-reducing pipeline is connected to the pipeline between the liquid pipe interface and the second port of the electronic expansion valve, and the second end of the pressure-reducing pipeline is connected to the pipeline between the first port of the outdoor heat exchanger and the four-way reversing valve assembly.

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