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CN-116928842-B - Control method and device of multi-connected air conditioner and multi-connected air conditioner

CN116928842BCN 116928842 BCN116928842 BCN 116928842BCN-116928842-B

Abstract

The invention discloses a control method and a device of a multi-connected air conditioner and the multi-connected air conditioner, and relates to the technical field of air conditioners, wherein the control method of the multi-connected air conditioner comprises the steps of detecting the load reduction amount of an indoor unit of the multi-connected air conditioner, and detecting the number of open-end outdoor units when the load reduction amount of the indoor unit exceeds a preset threshold value; when the number of the starting-up outdoor units is reduced to a preset number, the high-pressure of the starting-up outdoor units is monitored and recorded as a first high-pressure, the high-pressure of the stopping-up outdoor units is monitored and recorded as a second high-pressure, and when the first high-pressure is larger than the second high-pressure, the expansion valve of the stopping-up outdoor units or the expansion valve of the stopping-up indoor units is controlled to be opened based on the operation mode of the multi-connected air conditioner, the first high-pressure and the second high-pressure so as to reduce the high-pressure of the starting-up outdoor units. According to the invention, when the high-pressure of the starting-up outdoor unit is higher, the refrigerant at the starting-up outdoor unit side flows to the low-pressure side, so that the high-pressure of the starting-up outdoor unit side is reduced, and the high-pressure protection risk is reduced.

Inventors

  • LI LIKE
  • LIU HEXIN
  • CHEN HUA

Assignees

  • 宁波奥克斯电气股份有限公司

Dates

Publication Date
20260508
Application Date
20230628

Claims (8)

  1. 1. A control method of a multi-connected air conditioner, the multi-connected air conditioner including a plurality of outdoor units, the method comprising: detecting the load reduction amount of the indoor units of the multi-connected air conditioner, and detecting the number of the outdoor units started when the load reduction amount of the indoor units exceeds a preset threshold value; When the number of the starting-up outdoor units is reduced to a preset number, monitoring the high-pressure of the starting-up outdoor units, recording the high-pressure as a first high-pressure, and monitoring the high-pressure of the shutdown outdoor units, recording the high-pressure as a second high-pressure; When the first high-pressure is greater than the second high-pressure, controlling an expansion valve of the shutdown outdoor unit or an expansion valve of the shutdown indoor unit to be opened based on an operation mode of the multi-connected air conditioner, the first high-pressure and the second high-pressure so as to reduce the high-pressure of the startup outdoor unit; The step of controlling the expansion valve of the shutdown outdoor unit or the expansion valve of the shutdown indoor unit to be opened based on the operation mode of the multi-connected air conditioner, the first high pressure and the second high pressure includes: When the operation mode is a refrigeration mode, monitoring outdoor environment temperature, determining an outer ring correction coefficient based on the outdoor environment temperature, and calculating a target opening of an expansion valve of the shutdown outdoor unit based on the first high pressure and the second high pressure of the outer ring correction coefficient, wherein the target opening is positively correlated with the first high pressure, and the outer ring correction coefficient is positively correlated with the outdoor environment temperature; And when the operation mode is a heating mode, periodically judging whether the first high pressure Pd1 and the second high pressure Pd2 meet Pd 1-Pd 2>0, and if so, controlling an expansion valve of the shutdown indoor unit to increase a second preset opening degree every period.
  2. 2. The control method of a multi-connected air conditioner as set forth in claim 1, wherein the step of periodically controlling the expansion valve opening degree of the outdoor unit based on the outdoor ambient temperature, the first high pressure and the second high pressure includes: and periodically calculating the target opening degree of the expansion valve of the shutdown outdoor unit, and controlling the expansion valve of the shutdown outdoor unit to operate at the target opening degree, wherein the calculation formula of the target opening degree is P=N (Pd 1-Pd 2), pd1 is the first high pressure, pd2 is the second high pressure, and N is an outer ring correction coefficient.
  3. 3. The control method of the multi-connected air conditioner as claimed in claim 2, further comprising: when the outdoor environment temperature Tao is less than or equal to T1 ℃, the value of the outer ring correction coefficient N is a; When T1 ℃ is less than the outdoor environment temperature Tao and less than or equal to T2 ℃, the value of the outer ring correction coefficient N is b; when the temperature T2 ℃ is less than the outdoor environment temperature Tao and less than or equal to T3 ℃, the value of the outer ring correction coefficient N is C; and when the outdoor environment temperature Tao > T3 ℃, the outer ring correction coefficient N takes a value d, wherein a < b < C < d.
  4. 4. The control method of the multi-connected air conditioner as claimed in claim 2, further comprising: If Pd1-Pd2>0 is detected in the continuous preset number of periods, controlling the frequency of the compressor of the starting-up outdoor unit to reduce the first preset frequency, and controlling the opening of the expansion valve of the starting-up indoor unit to increase the first preset opening; and if Pd1-Pd2 is less than or equal to 0 in the preset number of periods continuously, controlling the expansion valve of the shutdown outdoor unit to be closed.
  5. 5. The control method of a multi-connected air conditioner as set forth in claim 1, further comprising: And if Pd1-Pd2>0 is detected in the continuous preset number of periods, controlling the opening of the expansion valve of the shutdown outdoor unit to increase a third preset opening in each period.
  6. 6. The control method of the multi-connected air conditioner as set forth in claim 5, further comprising: monitoring defrosting temperature, air suction temperature and low pressure of the shutdown outdoor unit after the expansion valve of the shutdown outdoor unit is opened; If the continuous preset number of periods detect Pd1-Pd2 to be less than or equal to 0, or the continuous preset number of periods detect that the defrosting temperature, the air suction temperature and the rising rate of the low pressure are all greater than the preset rate, the expansion valve of the shutdown outdoor unit is controlled to be closed, and the frequency of the compressor of the startup outdoor unit is controlled to reduce the second preset frequency.
  7. 7. A control device of a multi-connected air conditioner, comprising: The detection module is used for detecting the load reduction amount of the indoor units of the multi-connected air conditioner, and detecting the number of the outdoor units when the load reduction amount of the indoor units exceeds a preset threshold value; the monitoring module is used for monitoring the high-pressure of the starting-up outdoor unit when the number of the starting-up outdoor units is reduced to a preset number, and recording the high-pressure as a first high-pressure, and monitoring the high-pressure of the stopping-up outdoor unit, and recording the high-pressure as a second high-pressure; the control module is used for controlling the expansion valve of the shutdown outdoor unit or the expansion valve of the shutdown indoor unit to be opened based on the operation mode of the multi-connected air conditioner, the first high pressure and the second high pressure so as to reduce the high pressure of the startup outdoor unit; The control module is further configured to monitor an outdoor environment temperature when the operation mode is a cooling mode, determine an outer ring correction coefficient based on the outdoor environment temperature, and calculate a target opening of the expansion valve of the shutdown indoor unit based on the first high pressure and the second high pressure of the outer ring correction coefficient, where the target opening is positively correlated with the first high pressure, and the outer ring correction coefficient is positively correlated with the outdoor environment temperature, and periodically determine whether the first high pressure Pd1 and the second high pressure Pd2 meet Pd 1-Pd 2>0 when the operation mode is a heating mode, and if yes, control the expansion valve of the shutdown indoor unit to increase a second preset opening every period.
  8. 8. A multi-connected air conditioner, comprising a plurality of outdoor units, a computer readable storage medium storing a computer program and a processor, wherein the computer program is read and run by the processor to implement the method according to any one of claims 1-6.

Description

Control method and device of multi-connected air conditioner and multi-connected air conditioner Technical Field The invention relates to the technical field of air conditioners, in particular to a control method and device of a multi-connected air conditioner and the multi-connected air conditioner. Background The multi-connected air conditioner generally comprises an outdoor unit and a plurality of indoor units, is applied to large places such as markets and office buildings, is used in places with larger refrigeration requirements, can be used in parallel under the condition that the number of the outdoor units cannot be increased when one outdoor unit cannot meet the requirements of the plurality of indoor units, such as when the multi-connected air conditioner comprises two outdoor units, if the indoor units are larger in starting load, the two outdoor units can be used at the same time, if the indoor units are smaller in starting load, the outdoor units are converted from double-outdoor-unit operation to single-outdoor-unit operation, but when the number of the starting outdoor units of the multi-connected air conditioner is reduced, a large amount of refrigerant is easily accumulated on the starting outdoor unit side, so that the high pressure of the starting outdoor unit side is rapidly increased, and a large high-pressure protection risk exists. Disclosure of Invention In order to solve the problems, the invention provides a control method and a device for a multi-connected air conditioner, and the multi-connected air conditioner, which can enable a refrigerant at the side of a startup outdoor unit to flow to a low-pressure side when the high-pressure of the startup outdoor unit is higher, reduce the high-pressure of the side of the startup outdoor unit and reduce the high-pressure protection risk. According to the embodiment of the invention, in one aspect, a control method of a multi-connected air conditioner is provided, wherein the multi-connected air conditioner comprises a plurality of outdoor units, the method comprises the steps of detecting load reduction of indoor units of the multi-connected air conditioner, detecting the number of the outdoor units when the load reduction of the indoor units exceeds a preset threshold, detecting high-pressure of the outdoor units when the number of the outdoor units is reduced to the preset number, recording the high-pressure of the outdoor units as first high-pressure, monitoring high-pressure of the outdoor units to be stopped, recording the high-pressure of the outdoor units as second high-pressure, and controlling an expansion valve of the outdoor units to be stopped or the expansion valve of the indoor units to be started on the basis of the operation mode of the multi-connected air conditioner when the first high-pressure is larger than the second high-pressure, so as to reduce the high-pressure of the outdoor units. By adopting the technical scheme, when the load reduction amount of the indoor units is more, the number of the starting-up outdoor units is reduced, and the high-pressure of the starting-up outdoor units is higher, the expansion valve of the stopping-up outdoor units or the expansion valve of the stopping-up indoor units is controlled to be opened according to the high-pressure of the starting-up outdoor units and the high-pressure of the stopping-up outdoor units, so that the refrigerant at the side of the starting-up outdoor units flows to the low-pressure side, the high-pressure of the side of the starting-up outdoor units is reduced, and the high-pressure protection risk is reduced. Preferably, the step of controlling the expansion valve of the shutdown outdoor unit or the expansion valve of the shutdown indoor unit to be opened based on the operation mode, the first high pressure and the second high pressure of the multi-connected air conditioner comprises the steps of monitoring the outdoor environment temperature when the operation mode is a refrigeration mode, periodically controlling the opening degree of the expansion valve of the shutdown outdoor unit based on the outdoor environment temperature, the first high pressure and the second high pressure, and periodically controlling the opening degree of the expansion valve of the shutdown indoor unit based on the first high pressure and the second high pressure when the operation mode is a heating mode. By adopting the technical scheme, the expansion valve of the shutdown outdoor unit is controlled to be opened during the refrigeration mode, so that the refrigerant at the side of the startup outdoor unit flows into the condenser of the shutdown outdoor unit, the high pressure of the startup outdoor unit is reduced, and the expansion valve of the shutdown indoor unit is controlled to be opened during the heating mode, so that the refrigerant at the side of the startup outdoor unit flows into the low pressure side, and the high pressure protection risk is reduced. Preferably, th