Oil balancing control method, device and air conditioning unit

Abstract

The present disclosure proposes an oil balancing control method, device and air-conditioning unit, which relate to the technical field of air-conditioning units. Among them, the oil balancing control method includes: in response to the oil balancing control mode being triggered, controlling the passage between the plate heat exchanger and the liquid reservoir in the main line of the air-conditioning unit to be closed, the main line is a pipeline from the compressor, through the oil separator and the plate heat exchanger, to the liquid reservoir; controlling the branch between the oil separator and the target pressure vessel component in the air-conditioning unit to be conductive, so as to balance the oil through the branch between the oil separator and the target pressure vessel component, the target pressure vessel component includes at least one of the liquid reservoir, the compressor, and the gas-liquid separator. Through the above method, the self-oil balancing control process of the air-conditioning unit can be realized.

Description

Technical Field

[0001] The present disclosure relates to the technical field of air-conditioning units, and in particular to an oil balancing control method, device and air-conditioning unit. Background Art

[0002] Air conditioning units mainly include air source multi-split units and water source multi-split units. The market share of water source multi-split units is increasing year by year due to its advantages such as high energy efficiency, small footprint and good economic payback rate.

[0003] At present, water source multi-split units have the following characteristics: First, each water source multi-split unit needs to be filled with a certain amount of lubricating oil before leaving the factory, and the amount of oil required is relatively large; second, the internal space size of the outdoor unit of the water source multi-split unit is limited, and a large-volume oil-gas separator cannot be used; third, the water source multi-split unit usually uses a plate heat exchanger for exchanging water and refrigerant (referred to as water-cooled plate exchanger). Compared with the tube-fin heat exchanger in the air source multi-split unit, the volume of this plate heat exchanger is too small, only about 1 / 5 of the tube-fin heat exchanger.

[0004] Due to the large amount of oil required by the water-source multi-split unit, the limited volume of the oil-gas separator, and the small volume of the water-cooled plate, the oil in the oil-gas separator will be pressed into the water-cooled plate during the startup of the water-source multi-split unit, thereby forming an "oil seal" on the water-cooled plate, or on the electronic expansion valve of the indoor unit, the heating electronic expansion valve of the outdoor unit and other components with small flow diameters. The presence of oil seals at these locations will not only cause flow blockage in the system branches, but also affect effective heat exchange, and may eventually cause the system high pressure (i.e. condensing pressure) to be artificially high during the refrigeration process, thereby causing the compressor to reduce frequency, ultimately affecting comfort. Summary of the invention

[0005] The present disclosure provides an oil balancing control method, device and air conditioning unit.

[0006] According to the first aspect of the present disclosure, an oil balancing control method is proposed, comprising: in response to the oil balancing control mode being triggered, controlling the passage between the plate heat exchanger and the liquid reservoir in the main line of the air-conditioning unit to be closed, the main line being a pipeline from the compressor, through the oil separator and the plate heat exchanger, to the liquid reservoir; controlling the branch line between the oil separator and the target pressure vessel component in the air-conditioning unit to be conductive, so as to balance the oil through the branch line between the oil separator and the target pressure vessel component, the target pressure vessel component including at least one of a liquid reservoir, a compressor, and a gas-liquid separator.

[0007] In some embodiments, the branch between the oil separator and the target pressure vessel component includes a boost branch between the oil separator and the liquid reservoir, and controlling the conduction of the branch between the oil separator and the target pressure vessel component in the air-conditioning unit includes: opening the pressurization valve on the boost branch between the oil separator and the liquid reservoir to make the boost branch between the oil separator and the liquid reservoir in the air-conditioning unit conductive.

[0008] In some embodiments, the branch between the oil separator and the target pressure vessel component includes a boost branch between the oil separator and the liquid reservoir, and a subcooling branch from the liquid reservoir via the subcooler to the gas-liquid separator. The control of the conduction of the branch between the oil separator and the target pressure vessel component in the air-conditioning unit includes: opening the pressurizing valve on the boost branch between the oil separator and the liquid reservoir to connect the boost branch between the oil separator and the liquid reservoir in the air-conditioning unit; opening the subcooling valve and the subcooling electronic expansion valve on the subcooling branch from the liquid reservoir via the subcooler to the gas-liquid separator in the air-conditioning unit.

[0009] In some embodiments, the branch between the oil separator and the target pressure vessel component includes a bypass branch between the oil separator and the gas-liquid separator, and controlling the conduction of the branch between the oil separator and the target pressure vessel component in the air-conditioning unit includes: opening the gas bypass valve on the bypass branch between the oil separator and the gas-liquid separator to make the bypass branch between the oil separator and the gas-liquid separator in the air-conditioning unit conductive.

[0010] In some embodiments, the branch between the oil separator and the target pressure vessel component includes an oil return branch between the oil separator and the compressor, and controlling the conduction of the branch between the oil separator and the target pressure vessel component in the air-conditioning unit includes: opening the oil return valve on the oil return branch between the oil separator and the compressor to make the oil return branch between the oil separator and the compressor conductive.

[0011] In some embodiments, the control of closing the passage between the plate heat exchanger and the liquid reservoir in the main line of the air-conditioning unit includes: closing the heating electronic expansion valve arranged on the passage between the plate heat exchanger and the liquid reservoir to close the passage between the plate heat exchanger and the liquid reservoir in the main line of the air-conditioning unit.

[0012] In some embodiments, it also includes: in the oil equalization control mode, detecting the condensing pressure or condensing temperature of the air-conditioning unit; and adjusting the compressor frequency of the air-conditioning unit according to the condensing pressure or condensing temperature of the air-conditioning unit.

[0013] In some embodiments, the adjusting the compressor frequency of the air-conditioning unit according to the condensing pressure or condensing temperature of the air-conditioning unit includes: when the condensing pressure of the air-conditioning unit is greater than or equal to a first pressure threshold in a continuous first time interval, reducing the frequency of the compressor by a specified frequency step; when the condensing pressure of the air-conditioning unit is greater than a second pressure threshold and less than the first pressure threshold in a continuous first time interval, keeping the frequency of the compressor unchanged; when the condensing pressure of the air-conditioning unit is less than or equal to the second pressure threshold, increasing the frequency of the compressor by a specified frequency step, and the first pressure threshold is greater than the second pressure threshold.

[0014] In some embodiments, adjusting the compressor frequency of the air-conditioning unit according to the condensing pressure or condensing temperature of the air-conditioning unit includes: when the condensing temperature of the air-conditioning unit is greater than or equal to a first temperature threshold in a continuous first time interval, reducing the frequency of the compressor by a specified frequency step; when the condensing temperature of the air-conditioning unit is greater than a second temperature threshold and less than the first temperature threshold in a continuous first time interval, keeping the frequency of the compressor unchanged; when the condensing pressure of the air-conditioning unit is less than or equal to the second temperature threshold, increasing the frequency of the compressor by a specified frequency step, and the first temperature threshold is greater than the second temperature threshold.

[0015] In some embodiments, the frequency of the compressor is greater than or equal to a first frequency threshold and less than or equal to a second frequency threshold.

[0016] In some embodiments, it also includes: judging whether the oil balancing control termination condition is met; and terminating the oil balancing control mode if the oil balancing control termination condition is met.

[0017] In some embodiments, the oil equalization control termination conditions include: the duration of the oil equalization control mode is greater than or equal to the second time interval, or the duration of the evaporation pressure of the air-conditioning unit being less than a third pressure threshold is greater than or equal to the third time interval, or the duration of the evaporation temperature of the air-conditioning unit being less than a third temperature threshold is greater than or equal to the third time interval.

[0018] According to a second aspect of the present disclosure, an oil balancing control device is provided, comprising: a first control module, configured to control the closure of a passage between a plate heat exchanger and a liquid reservoir in a main line of an air-conditioning unit in response to an oil balancing control mode being triggered, wherein the main line is a pipeline from a compressor, through an oil separator and a plate heat exchanger, to the liquid reservoir; a second control module, configured to control the conduction of a branch line between the oil separator and a target pressure vessel component in the air-conditioning unit, so as to balance oil through the branch line between the oil separator and the target pressure vessel component, wherein the target pressure vessel component comprises at least one of a liquid reservoir, a compressor, and a gas-liquid separator.

[0019] According to a third aspect of the present disclosure, an air-conditioning unit is proposed, comprising: the oil balancing control device of the air-conditioning unit as described above.

[0020] According to a fourth aspect of the present disclosure, an electronic device is proposed, comprising: a memory; and a processor coupled to the memory, wherein the processor is configured to execute the oil balancing control method of the air-conditioning unit as described above based on instructions stored in the memory.

[0021] According to a fifth aspect of the present disclosure, a computer-readable storage medium is provided, on which computer program instructions are stored, and when the instructions are executed by a processor, the oil balancing control method of the air-conditioning unit as described above is implemented.

[0022] Other features and advantages of the present disclosure will become apparent from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0024] The present disclosure may be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0025] Figure 1 is a partial structural schematic diagram of an air conditioning unit according to some embodiments of the present disclosure;

[0026] Figure 2 is a flow chart of an oil balancing control method according to some embodiments of the present disclosure;

[0027] Figure 3 is a flow chart of an oil balancing control method according to other embodiments of the present disclosure;

[0028] Figure 4 It is a flowchart of the oil balancing control step according to some embodiments of the present disclosure;

[0029] Figure 5is a structural schematic diagram of an oil balancing control device according to some embodiments of the present disclosure;

[0030] Figure 6 is a structural schematic diagram of an air conditioning unit according to some embodiments of the present disclosure;

[0031] Figure 7 It is a structural schematic diagram of an oil balancing control device according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0032] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present disclosure unless otherwise specifically stated.

[0033] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0034] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0035] Technologies, methods, and apparatus known to ordinary technicians in the relevant field may not be discussed in detail, but where appropriate, such technologies, methods, and apparatus should be considered part of the authorization specification.

[0036] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0037] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0038] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0039] After the air conditioning unit is started, the exhaust pressure gradually forms due to the increase in the compressor frequency, which presses out the lubricating oil in the oil-gas separator and then enters the plate heat exchanger for heat exchange between water and refrigerant. Since the internal volume of the plate heat exchanger is small, once a certain amount of lubricating oil flows into the plate heat exchanger and other narrow channels (such as millimeter level), it may cause oil sealing in the narrow channels. At the same time, due to the continuous exhaust of the compressor, there is a "short-term" high-pressure accumulation, which triggers the protective adjustment process of the system's excessive high pressure, which in turn causes the compressor frequency to drop and reduce the frequency, which ultimately affects comfort.

[0040] In view of this, the present disclosure proposes an oil balancing control method, device and air-conditioning unit, which can realize the self-oil balancing control process of the outdoor unit of the air-conditioning unit, so that the lubricating oil in the oil separator in an overflowing state can be more evenly distributed to each pressure vessel component, effectively avoiding various system problems caused by "oil seal" in the air-conditioning unit system after subsequent formal operation.

[0041] Figure 1 FIG. 1 is a partial structural diagram of an air conditioning unit according to some embodiments of the present disclosure. Figure 1 As shown, the air conditioning unit of the embodiment of the present disclosure includes a compressor 1, an oil separator 2, a plate heat exchanger 3, a liquid storage tank 4, a gas-liquid separator 5, and a subcooler 6.

[0042] Multiple pipelines are formed between multiple components in the air-conditioning unit, including: 1. The main pipeline is a pipeline from the compressor 1, through the oil separator 2 and the plate heat exchanger 3, to the liquid reservoir 4; 2. The branch between the oil separator 2 and the target pressure vessel component, specifically including a boost branch between the oil separator 2 and the liquid reservoir 4, a gas bypass branch between the oil separator 2 and the gas-liquid separator 5, an oil return branch between the oil separator 2 and the compressor 1, and a subcooling branch between the liquid reservoir 4 and the gas-liquid separator 5.

[0043] On the main line, the exhaust pipe of the compressor 1 is connected to the inlet pipe of the oil separator, the outlet pipe of the oil separator 2 is connected to one side of the plate heat exchanger 3 via the four-way valve 109, and the other side of the plate heat exchanger is connected to the liquid reservoir 4 via the heating electronic expansion valve 101.

[0044] On the boost branch, the outlet pipe of the oil separator 2 is connected to the liquid reservoir via the pressure valve 102. Further, a capillary tube 110 is provided on the boost branch, and the capillary tube 110 is provided between the oil separator 2 and the pressure valve 102.

[0045] During the engineering commissioning process, if the oil separator is full, in order to prevent "oil seal blocking the pipeline" after formal operation, the boost branch can be opened to bypass the oil-containing refrigerant into the liquid receiver, thereby alleviating the problem of unnecessary high-pressure protection or excessive exhaust temperature caused by the oil seal, affecting comfort.

[0046] On the gas bypass branch, the outlet pipe of the oil separator 2 is connected to the inlet pipe (or inlet pipe) of the gas-liquid separator 5 via the gas bypass valve 105 .

[0047] During the engineering commissioning process, if the oil separator is full, in order to prevent "oil seal blocking the pipeline" after formal operation, the gas bypass branch can be opened to bypass the high-temperature and high-pressure gas containing oil to the inlet pipe of the gas-liquid separator 5, thereby alleviating the problem of unnecessary high-pressure protection or excessive exhaust temperature protection caused by the oil seal, affecting comfort.

[0048] On the oil return branch, the oil return pipe of the oil separator 2 is connected to the suction pipe of the compressor 1 via the oil return solenoid valve 106. In addition, a low pressure sensor 108 can be arranged on the exhaust port side of the compressor 1 to measure the system low pressure (evaporation pressure), and a high pressure sensor 107 can be arranged between the oil separator 2 and the four-way valve 109 to measure the system high pressure (condensation pressure).

[0049] During the engineering commissioning process, if the oil separator is full, in order to prevent the oil seal from clogging the pipeline after formal operation, the oil return branch can be opened and the oil can be bypassed to the compressor suction pipe by utilizing the oil return characteristics, thereby alleviating the problem of unnecessary high-pressure protection or excessive exhaust temperature caused by the oil seal, which affects comfort.

[0050] On the subcooling branch, the outlet pipe of the liquid storage device 4 is connected to the subcooler 6 via the subcooler electronic expansion valve 103, and the subcooler 6 is connected to the suction pipe of the gas-liquid separator 5 via the subcooling solenoid valve 104. In addition, a low pressure sensor 111 can also be provided on the subcooling branch to measure the system low pressure (evaporation pressure).

[0051] During the engineering commissioning process, if the oil separator is full, in order to prevent the oil seal from clogging the pipeline after formal operation, the supercooling branch can be opened to quickly connect the low pressure, and the large system pressure difference formed can be used to accelerate the circulation speed of the refrigerant (including oil) inside the outdoor unit, and promote the disappearance of the "oil seal characteristic" formed by the water-cooled plate exchanger, and finally alleviate the problem of unnecessary high-pressure protection or excessive exhaust temperature protection caused by the oil seal, which affects the comfort.

[0052] Figure 2 FIG. 1 is a flow chart of an oil balancing control method according to some embodiments of the present disclosure. Figure 2 As shown, the oil balancing control method of the air-conditioning unit according to the embodiment of the present disclosure includes:

[0053] Step S210: In response to the oil balancing control mode being triggered, the passage between the plate heat exchanger and the liquid storage tank in the main pipe of the air-conditioning unit is controlled to be closed.

[0054] The main pipeline is the pipeline from the compressor, through the oil separator and the plate heat exchanger, to the liquid storage tank. Figure 1As shown, on the main line, the exhaust pipe of the compressor is connected to the inlet pipe of the oil separator, the outlet pipe of the oil separator is connected to the plate heat exchanger via a four-way valve, and the plate heat exchanger is connected to the liquid receiver via a heating electronic expansion valve.

[0055] After the unit is started, as the compressor frequency increases, exhaust pressure gradually forms, directly pushing the overflowing lubricating oil in the oil separator out of the oil separator and into the plate heat exchanger. Because the internal volume of the plate heat exchanger is small and the refrigerant channels or gaps are all in millimeter size, once a certain amount of lubricating oil flows into the plate heat exchanger, heating electronic expansion valve, internal electronic expansion valve and other components with narrow channels (millimeter level), it is possible that the oil's high viscosity, low density, and non-phase change (compared to liquid refrigerant) characteristics will cause the narrow channel "oil sealing" phenomenon. At this time, due to the continuous discharge of the compressor exhaust, there is a "short-term" high-pressure accumulation, which triggers the system's protective adjustment of excessive high pressure, causing the compressor to reduce frequency, and ultimately affecting comfort.

[0056] In view of this, in step S210, the passage between the plate heat exchanger and the liquid reservoir in the main line is closed to cut off the refrigerant channel in the main line to prevent oil from entering the plate heat exchanger as much as possible.

[0057] In some embodiments, a heating electronic expansion valve is provided on the passage between the plate heat exchanger and the liquid reservoir, and step S210 includes: closing the heating electronic expansion valve provided on the passage between the plate heat exchanger and the liquid reservoir to close the passage between the plate heat exchanger and the liquid reservoir in the main passage. Through step S210, the oil in the oil separator can be effectively prevented from entering the plate heat exchanger, and oil seals can be prevented from appearing in the main passage.

[0058] Step S220: controlling the branch between the oil separator and the target pressure vessel component in the air-conditioning unit to be conductive, so as to perform oil equalization through the branch between the oil separator and the target pressure vessel component.

[0059] The target pressure vessel component includes at least one of a liquid storage device, a compressor, and a gas-liquid separator.

[0060] In some embodiments, the branch between the oil separator and the target pressure vessel component includes a boost branch between the oil separator and the liquid reservoir, and step S220 includes: opening the pressurization valve on the boost branch between the oil separator and the liquid reservoir to make the boost branch between the oil separator and the liquid reservoir in the air-conditioning unit conductive.

[0061] In some embodiments, the branch between the oil separator and the target pressure vessel component includes a boost branch between the oil separator and the liquid reservoir, and a subcooling branch from the liquid reservoir via the subcooler to the gas-liquid separator. Step S220 includes: opening the pressurizing valve on the boost branch between the oil separator and the liquid reservoir to connect the boost branch between the oil separator and the liquid reservoir in the air-conditioning unit; at the same time, opening the subcooling valve and the subcooling electronic expansion valve on the subcooling branch from the liquid reservoir via the subcooler to the gas-liquid separator in the air-conditioning unit.

[0062] In some embodiments, the branch between the oil separator and the target pressure vessel component includes a bypass branch between the oil separator and the gas-liquid separator, and step S220 includes: opening the gas bypass valve on the bypass branch between the oil separator and the gas-liquid separator to make the bypass branch between the oil separator and the gas-liquid separator in the air-conditioning unit conductive.

[0063] In some embodiments, the branch between the oil separator and the target pressure vessel component includes an oil return branch between the oil separator and the compressor, and step S220 includes: opening the oil return valve on the oil return branch between the oil separator and the compressor to make the oil return branch between the oil separator and the compressor conductive.

[0064] In some embodiments, the branch between the oil separator and the target pressure vessel component includes: a boost branch between the oil separator and the liquid reservoir; a subcooling branch from the liquid reservoir, via the subcooler to the gas-liquid separator; a bypass branch between the oil separator and the gas-liquid separator; and an oil return branch between the oil separator and the compressor, and step S220 includes: opening the pressurization valve disposed on the boost branch to conduct the boost branch; opening the subcooling valve and the subcooling electronic expansion valve disposed on the subcooling branch to conduct the subcooling branch; opening the gas bypass valve disposed on the bypass branch to conduct the bypass branch; opening the oil return valve disposed on the oil return branch to conduct the oil return branch. In this way, the oil in the oil separator in an overflowing state can be evenly distributed to the liquid reservoir, the gas-liquid separator, and the compressor with larger volumes, thereby alleviating the oil seal problem of the plate heat exchanger and ensuring the stability and comfort of the subsequent operation of the air conditioning unit.

[0065] In some embodiments, the oil balancing control method further includes: in the oil balancing control mode, setting the frequency of the compressor to a specified frequency value. For example, setting the frequency of the compressor to 30 Hz. Through this process, the compressor can be kept running at a low frequency to avoid the oil in the oil separator from overflowing into the plate heat exchanger due to excessive system high pressure (condensing pressure).

[0066] In the disclosed embodiment, the above steps realize the self-oil equalization control process of the outdoor unit of the air-conditioning unit, so that the lubricating oil in the oil separator that is overflowing can be more evenly distributed to each pressure vessel component, effectively avoiding various system problems caused by "oil seal" in the air-conditioning unit system after the subsequent formal operation, thereby ensuring the stability and comfort of the subsequent operation of the air-conditioning unit.

[0067] Figure 3 FIG. 2 is a flow chart of an oil balancing control method according to other embodiments of the present disclosure. Figure 3 As shown, the oil balancing control method of the embodiment of the present disclosure includes:

[0068] Step S310: Perform health status detection on the air conditioning unit.

[0069] In some embodiments, step S310 includes: detecting the communication between the units of the air conditioning unit, whether the components are faulty, etc. If the communication between the units of the air conditioning unit is normal and the components are not faulty, it is confirmed that the air conditioning unit has passed the health status detection; otherwise, it is confirmed that the air conditioning unit has not passed the health status detection.

[0070] In some embodiments, before step S310, it also includes: allocating and entering information such as the address, quantity, and model of the sample machine to facilitate subsequent debugging of the air conditioning unit, such as health status detection.

[0071] Step S320: When the air-conditioning unit passes the health status detection, the oil equalization control mode is triggered.

[0072] In some embodiments, it also includes: when the air-conditioning unit fails the health status detection, a fault alarm message is sent to the terminal device corresponding to the maintenance personnel to remind the maintenance personnel to repair the fault of the air-conditioning unit.

[0073] Step S330: Perform oil equalization control.

[0074] In some embodiments, by Figure 4 The process shown in the figure performs oil equalization control on the air conditioning unit. Figure 4 As shown, the oil equalization control step includes step S331 and step S332.

[0075] Step S331: close the heating electronic expansion valve, open the pressurizing valve, open the gas bypass valve, open the oil return valve, open the subcooling electronic expansion valve, and open the subcooling valve.

[0076] In some embodiments, Figure 1As shown, the air conditioning unit includes a main line, a boost branch, a subcooling branch, an oil return branch, and an air bypass branch. Among them, the main line is a pipeline from the compressor, through the oil separator and the plate heat exchanger, the heating electronic expansion valve to the liquid reservoir; the boost branch is a pipeline from the oil separator, through the pressurizing valve to the liquid reservoir; the subcooling branch is a pipeline from the liquid reservoir, through the subcooler electronic expansion valve, the subcooler, the subcooling solenoid valve to the gas-liquid separator; the oil return branch is a pipeline from the oil separator, through the oil return valve to the compressor; the gas bypass branch is a pipeline from the oil separator, through the gas bypass valve to the gas-liquid separator. In these embodiments, closing the heating electronic expansion valve can prevent the main line from being oil-sealed, and opening the pressurizing valve, the gas bypass valve, the oil return valve, the subcooling electronic expansion valve, and the subcooling valve can allow the oil-containing refrigerant to bypass the larger volume of the liquid reservoir, the gas-liquid separator, and the compressor, thereby preventing the main line from being oil-sealed.

[0077] Step S332: adjusting the frequency of the compressor according to the condensing pressure or condensing temperature of the air-conditioning unit.

[0078] In some embodiments, step S332 includes: when the condensing pressure of the air-conditioning unit is greater than or equal to the first pressure threshold in a continuous first time interval, reducing the frequency of the compressor by a specified frequency step; when the condensing pressure of the air-conditioning unit is greater than the second pressure threshold and less than the first pressure threshold in a continuous first time interval, keeping the frequency of the compressor unchanged; when the condensing pressure of the air-conditioning unit is less than or equal to the second pressure threshold, increasing the frequency of the compressor by a specified frequency step, and the first pressure threshold is greater than the second pressure threshold.

[0079] In some embodiments, step S332 includes: when the condensing temperature of the air-conditioning unit is greater than or equal to the first temperature threshold within a continuous first time interval, reducing the frequency of the compressor by a specified frequency step; when the condensing temperature of the air-conditioning unit is greater than the second temperature threshold and less than the first temperature threshold within a continuous first time interval, keeping the frequency of the compressor unchanged; when the condensing pressure of the air-conditioning unit is less than or equal to the second temperature threshold, increasing the frequency of the compressor by a specified frequency step, and the first temperature threshold is greater than the second temperature threshold.

[0080] In some embodiments, in the oil equalization control mode, the frequency of the compressor is set to be greater than or equal to a first frequency threshold and less than or equal to a second frequency threshold.

[0081] For example, after executing step S331 for a specified time interval (for example, 1 minute), the system condensing temperature is detected; if the system condensing temperature is greater than or equal to 39°C for 10 consecutive seconds, the frequency of the compressor is reduced by 2Hz, and the frequency of the compressor is ensured to be no less than the first frequency threshold of 10Hz; if the system condensing temperature is greater than 28°C and less than 38°C for 10 consecutive seconds, the frequency of the compressor is kept unchanged; if the system condensing temperature is less than or equal to 28°C for 10 consecutive seconds, the frequency of the compressor is increased by 2Hz, and the frequency of the compressor is ensured to be no greater than the second frequency threshold of 35Hz.

[0082] In the embodiment of the present disclosure, the frequency of the compressor is adjusted according to the condensing pressure or the condensing temperature so that the driving force for the oil-containing refrigerant is moderate. The system will not shut down due to excessively high system pressure, causing the system to lose the power to continuously push the oil flow, nor will the driving force for the oil-containing refrigerant be too small due to too low system pressure, thereby improving the oil balancing effect.

[0083] Step S340: Determine whether the oil equalization control end condition is met.

[0084] In some embodiments, step S340 includes: determining whether the duration of the oil balancing control mode is greater than or equal to a second time interval. If the duration of the oil balancing control mode is greater than or equal to the second time interval, determining that the oil balancing control end condition is satisfied.

[0085] For example, it is determined whether the duration of the oil balancing control mode is greater than or equal to 30 minutes. If so, it is determined that the oil balancing control termination condition is met.

[0086] In some embodiments, step S340 includes: determining whether the duration for which the evaporation pressure (i.e., system low pressure) of the air-conditioning unit is less than a third pressure threshold is greater than or equal to a third time interval, or determining whether the duration for which the evaporation temperature of the air-conditioning unit is less than a third temperature threshold is greater than or equal to a third time interval.

[0087] For example, determine whether the evaporation temperature of the air-conditioning unit (ie, the saturation temperature corresponding to the evaporation pressure) is less than or equal to -10°C for 10 consecutive minutes; if so, determine that the oil equalization control end condition is met.

[0088] In some embodiments, step S340 includes: determining whether the duration of the oil balancing control mode is greater than or equal to a second time interval; and determining whether the duration that the evaporating pressure of the air-conditioning unit is less than a third pressure threshold is greater than or equal to a third time interval; if the duration of the oil balancing control mode is greater than or equal to the second time interval, or the duration that the evaporating pressure of the air-conditioning unit is less than the third pressure threshold is greater than or equal to the third time interval, it is determined that the oil balancing control termination condition is met.

[0089] In some embodiments, step S340 includes: determining whether the duration of the oil balancing control mode is greater than or equal to a second time interval; and determining whether the duration that the evaporating temperature of the air-conditioning unit is less than a third temperature threshold is greater than or equal to a third time interval; if the duration of the oil balancing control mode is greater than or equal to the second time interval, or the duration that the evaporating temperature of the air-conditioning unit is less than the third temperature threshold is greater than or equal to the third time interval, it is determined that the oil balancing control termination condition is met.

[0090] For example, determine whether the duration of the oil balancing control mode is greater than or equal to 30 minutes, and determine whether the evaporating temperature of the air-conditioning unit (i.e., the saturation temperature corresponding to the evaporating pressure) is less than or equal to -10°C for 10 consecutive minutes; if the duration of the oil balancing control mode is greater than or equal to 30 minutes, or the evaporating temperature of the air-conditioning unit is less than or equal to -10°C for 10 consecutive minutes, it is determined that the conditions for ending the oil balancing control are met.

[0091] If the judgment result of step S340 is yes, execute step S350; otherwise, continue to execute S330.

[0092] Step S350: End the oil equalization control mode.

[0093] In some embodiments, after the oil equalization control mode ends, the system returns to a normal standby state.

[0094] In some embodiments, in normal standby mode, the frequency of the compressor is set to 0 Hz, the heating electronic expansion valve is opened, the pressurizing valve is closed, the gas bypass valve is closed, the oil return valve is closed, the subcooling electronic expansion valve is closed, and the subcooling valve is closed.

[0095] In the disclosed embodiment, by first performing a health status check on the air-conditioning unit and then performing oil balancing control after the air-conditioning unit passes the health status check, it is possible to avoid the situation where oil balancing control cannot be performed due to a failure of the air-conditioning unit, which helps to improve the reliability of oil balancing control; by judging whether the oil balancing control termination conditions are met and then terminating the oil balancing control after the oil balancing control termination conditions are met, the oil balancing control effect can be further improved.

[0096] Figure 5 FIG. 1 is a schematic diagram of the structure of an oil balancing control device according to some embodiments of the present disclosure. Figure 5 As shown, the oil balancing control device 500 according to the embodiment of the present disclosure includes: a first control module 510 and a second control module 520 .

[0097] The first control module 510 is configured to control the passage between the plate heat exchanger and the liquid reservoir in the main pipeline of the air-conditioning unit to be closed in response to the oil balance control mode being triggered, wherein the main pipeline is a pipeline from the compressor, through the oil separator and the plate heat exchanger, to the liquid reservoir.

[0098] In some embodiments, a heating electronic expansion valve is provided on the passage between the plate heat exchanger and the liquid reservoir, and the first control module 510 is configured to close the heating electronic expansion valve provided on the passage between the plate heat exchanger and the liquid reservoir, so as to close the passage between the plate heat exchanger and the liquid reservoir in the main pipeline. Through the above processing, the oil in the oil separator can be effectively prevented from entering the plate heat exchanger, and oil seal can be prevented from occurring in the main pipeline.

[0099] The second control module 520 is configured to control the conduction of a branch between the oil separator and the target pressure vessel component in the air-conditioning unit so as to balance the oil through the branch between the oil separator and the target pressure vessel component, wherein the target pressure vessel component includes at least one of a liquid reservoir, a compressor, and a gas-liquid separator.

[0100] In some embodiments, the branch between the oil separator and the target pressure vessel device includes: a boost branch between the oil separator and the liquid reservoir; a subcooling branch from the liquid reservoir, via the subcooler to the gas-liquid separator; a bypass branch between the oil separator and the gas-liquid separator; and an oil return branch between the oil separator and the compressor. The second control module 520 is configured to: open the pressurization valve disposed on the boost branch to conduct the boost branch; open the subcooling valve and the subcooling electronic expansion valve disposed on the subcooling branch to conduct the subcooling branch; open the gas bypass valve disposed on the bypass branch to conduct the bypass branch; open the oil return valve disposed on the oil return branch to conduct the oil return branch. In this way, the oil in the oil separator in an overflowing state can be evenly distributed to the liquid reservoir, gas-liquid separator, and compressor with larger volumes, thereby alleviating the oil seal problem of the plate heat exchanger and ensuring the stability and comfort of the subsequent operation of the air conditioning unit.

[0101] In the disclosed embodiment, the above device is used to realize the self-oil equalization control process of the outdoor unit of the air-conditioning unit, so that the lubricating oil in the oil separator that is overflowing can be more evenly distributed to each pressure vessel component, effectively avoiding various system problems caused by "oil seal" in the air-conditioning unit system after the subsequent formal operation, thereby ensuring the stability and comfort of the subsequent operation of the air-conditioning unit.

[0102] Figure 6 FIG. 1 is a schematic diagram of the structure of an air conditioning unit according to some embodiments of the present disclosure. Figure 6 As shown, the air conditioning unit 600 according to the embodiment of the present disclosure includes an oil balancing control device 610 .

[0103] In some embodiments, the air conditioning unit 600 is Figure 1The water source multi-split unit shown includes an oil balancing control device 610. The oil balancing control device 610 is configured to: in response to the oil balancing control mode being triggered, control the passage between the plate heat exchanger and the liquid reservoir in the main line of the air-conditioning unit to be closed, the main line is a pipeline from the compressor, through the oil separator and the plate heat exchanger, to the liquid reservoir; control the branch between the oil separator and the target pressure vessel component in the air-conditioning unit to be connected, so as to balance the oil through the branch between the oil separator and the target pressure vessel component, the target pressure vessel component includes at least one of the liquid reservoir, the compressor, and the gas-liquid separator.

[0104] In the disclosed embodiment, the self-oil equalization control process of the outdoor unit of the air-conditioning unit is realized through the above air-conditioning unit, so that the lubricating oil in the oil separator that is in an overflowing state can be more evenly distributed to each pressure vessel component, effectively avoiding various system problems caused by "oil seal" in the air-conditioning unit system after subsequent formal operation, thereby ensuring the stability and comfort of subsequent operation of the air-conditioning unit.

[0105] Figure 7 It is a structural schematic diagram of an oil balancing control device according to some embodiments of the present disclosure.

[0106] like Figure 7 As shown, the oil balancing control device 700 includes a memory 710; and a processor 720 coupled to the memory 710. The memory 710 is used to store instructions for executing the corresponding embodiments of the oil balancing control method. The processor 720 is configured to execute the oil balancing control method in any of the embodiments of the present disclosure based on the instructions stored in the memory 710.

[0107] Here, various aspects of the present disclosure are described with reference to flowcharts and / or block diagrams of methods, devices, and computer program products according to embodiments of the present disclosure. It should be understood that each frame of the flowchart and / or block diagram and the combination of frames can be implemented by computer-readable program instructions.

[0108] These computer-readable program instructions may be provided to a processor of a general-purpose computer, a special-purpose computer or other programmable device to produce a machine, so that the processor executes the instructions to produce means for implementing the functions specified in one or more blocks in the flowchart and / or block diagram.

[0109] These computer-readable program instructions may also be stored in a computer-readable memory, which cause the computer to work in a specific manner to produce an article of manufacture, including instructions for implementing the functions specified in one or more blocks in the flowchart and / or block diagram.

[0110] The present disclosure can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects.

[0111] Through the oil balancing control method, device and air-conditioning unit in the above-mentioned embodiments, the self-oil balancing control process of the outdoor unit of the air-conditioning unit is realized, which can make the lubricating oil in the oil separator in an overflowing state more evenly distributed to each pressure vessel component, and effectively avoid various system problems caused by "oil seal" in the air-conditioning unit system after subsequent formal operation, thereby ensuring the stability and comfort of subsequent operation of the air-conditioning unit.

[0112] So far, the oil balancing control method, device and air conditioning unit according to the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

Claims

1. An oil balancing control method, comprising: In response to the oil balance control mode being triggered, the passage between the plate heat exchanger and the liquid reservoir in the main pipeline of the air-conditioning unit is controlled to be closed, wherein the main pipeline is a pipeline from the compressor, through the oil separator and the plate heat exchanger, to the liquid reservoir; The branch between the oil separator and the target pressure vessel component in the air conditioning unit is controlled to be conductive so as to balance the oil through the branch between the oil separator and the target pressure vessel component, wherein the target pressure vessel component includes at least one of a liquid reservoir, a compressor, and a gas-liquid separator.

2. The oil balancing control method according to claim 1, wherein: The branch between the oil separator and the target pressure vessel component includes a pressurization branch between the oil separator and the liquid reservoir, and the controlling of the conduction of the branch between the oil separator and the target pressure vessel component in the air conditioning unit includes: The pressurizing valve on the pressurizing branch between the oil separator and the liquid reservoir is opened to make the pressurizing branch between the oil separator and the liquid reservoir in the air conditioning unit conductive.

3. The oil balancing control method according to claim 1, wherein: The branch between the oil separator and the target pressure vessel component includes a pressurization branch between the oil separator and the liquid reservoir, and a subcooling branch from the liquid reservoir to the gas-liquid separator via the subcooler. The control of the conduction of the branch between the oil separator and the target pressure vessel component in the air conditioning unit includes: Opening the pressurizing valve on the pressurizing branch between the oil separator and the liquid reservoir to make the pressurizing branch between the oil separator and the liquid reservoir in the air conditioning unit conductive; The subcooling valve and the subcooling electronic expansion valve arranged on the subcooling branch from the liquid reservoir through the subcooler to the gas-liquid separator are opened to make the subcooling branch from the liquid reservoir through the subcooler to the gas-liquid separator in the air-conditioning unit conductive.

4. The oil balancing control method according to claim 1, wherein: The branch between the oil separator and the target pressure vessel component includes a bypass branch between the oil separator and the gas-liquid separator, and the controlling of the conduction of the branch between the oil separator and the target pressure vessel component in the air conditioning unit includes: The gas bypass valve on the bypass branch between the oil separator and the gas-liquid separator is opened to make the bypass branch between the oil separator and the gas-liquid separator in the air conditioning unit conductive.

5. The oil balancing control method according to claim 1, wherein: The branch between the oil separator and the target pressure vessel component includes an oil return branch between the oil separator and the compressor, and the controlling of the conduction of the branch between the oil separator and the target pressure vessel component in the air conditioning unit includes: The oil return valve disposed on the oil return branch between the oil separator and the compressor is opened to allow the oil return branch between the oil separator and the compressor to be conductive.

6. The oil balancing control method according to claim 1, wherein: The controlling method of closing a passage between the plate heat exchanger and the liquid storage in the main passage of the air conditioning unit comprises: The heating electronic expansion valve disposed on the passage between the plate heat exchanger and the liquid reservoir is closed, so that the passage between the plate heat exchanger and the liquid reservoir in the main pipeline of the air-conditioning unit is closed.

7. The oil balancing control method according to claim 1, further comprising: In the oil equalization control mode, detecting the condensing pressure or condensing temperature of the air conditioning unit; The compressor frequency of the air-conditioning unit is adjusted according to the condensing pressure or the condensing temperature of the air-conditioning unit.

8. The oil balancing control method according to claim 7, wherein: The adjusting the compressor frequency of the air-conditioning unit according to the condensing pressure or the condensing temperature of the air-conditioning unit comprises: When the condensing pressure of the air-conditioning unit is greater than or equal to the first pressure threshold value within a continuous first time interval, reducing the frequency of the compressor by a specified frequency step; When the condensing pressure of the air-conditioning unit is greater than the second pressure threshold and less than the first pressure threshold within a continuous first time interval, maintaining the frequency of the compressor unchanged; When the condensing pressure of the air-conditioning unit is less than or equal to the second pressure threshold, the frequency of the compressor is increased by a specified frequency step, and the first pressure threshold is greater than the second pressure threshold.

9. The oil balancing control method according to claim 7, wherein: The adjusting the compressor frequency of the air-conditioning unit according to the condensing pressure or the condensing temperature of the air-conditioning unit comprises: When the condensing temperature of the air-conditioning unit is greater than or equal to the first temperature threshold value within a continuous first time interval, reducing the frequency of the compressor by a specified frequency step; When the condensing temperature of the air-conditioning unit is greater than the second temperature threshold and less than the first temperature threshold within a continuous first time interval, maintaining the frequency of the compressor unchanged; When the condensing pressure of the air-conditioning unit is less than or equal to the second temperature threshold, the frequency of the compressor is increased by a specified frequency step, and the first temperature threshold is greater than the second temperature threshold.

10. The oil balancing control method according to claim 8 or 9, wherein: The frequency of the compressor is greater than or equal to a first frequency threshold and less than or equal to a second frequency threshold.

11. The oil balancing control method according to claim 1, further comprising: Determine whether the oil equalization control end condition is met; When the oil balancing control termination condition is satisfied, the oil balancing control mode is terminated.

12. The oil balancing control method according to claim 11, wherein the oil balancing control termination condition comprises: The duration of the oil equalization control mode is greater than or equal to the second time interval, or the duration of the evaporation pressure of the air-conditioning unit being less than the third pressure threshold is greater than or equal to the third time interval, or the duration of the evaporation temperature of the air-conditioning unit being less than the third temperature threshold is greater than or equal to the third time interval.

13. An oil balancing control device, comprising: A first control module is configured to control the passage between the plate heat exchanger and the liquid reservoir in the main pipeline of the air-conditioning unit to be closed in response to the oil balance control mode being triggered, wherein the main pipeline is a pipeline from the compressor, through the oil separator and the plate heat exchanger, to the liquid reservoir; The second control module is configured to control the conduction of a branch between the oil separator and the target pressure vessel component in the air-conditioning unit so as to balance the oil through the branch between the oil separator and the target pressure vessel component, wherein the target pressure vessel component includes at least one of a liquid reservoir, a compressor, and a gas-liquid separator.

14. An air conditioning unit, comprising: The oil balancing control device as claimed in claim 13.

15. An oil balancing control device, comprising: Memory; as well as A processor coupled to the memory, wherein the processor is configured to execute the oil balancing control method according to any one of claims 1 to 12 based on instructions stored in the memory.

16. A computer-readable storage medium having computer program instructions stored thereon, wherein the instructions, when executed by a processor, implement the oil balancing control method according to any one of claims 1 to 12.

Images