CN107477933B - Control method and system of multi-connected air conditioner and computer readable storage medium - Google Patents
Control method and system of multi-connected air conditioner and computer readable storage medium Download PDFInfo
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- CN107477933B CN107477933B CN201710848877.XA CN201710848877A CN107477933B CN 107477933 B CN107477933 B CN 107477933B CN 201710848877 A CN201710848877 A CN 201710848877A CN 107477933 B CN107477933 B CN 107477933B
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- outdoor unit
- expansion valve
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B41/00—Fluid-circulation arrangements
- F25B41/30—Expansion means; Dispositions thereof
- F25B41/31—Expansion valves
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
- F25B2400/06—Several compression cycles arranged in parallel
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2600/00—Control issues
- F25B2600/25—Control of valves
- F25B2600/2513—Expansion valves
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2700/00—Sensing or detecting of parameters; Sensors therefor
- F25B2700/21—Temperatures
- F25B2700/2115—Temperatures of a compressor or the drive means therefor
- F25B2700/21152—Temperatures of a compressor or the drive means therefor at the discharge side of the compressor
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
Abstract
The invention discloses a control method of a multi-connected air conditioner, a multi-connected air conditioner system and a computer readable storage medium, wherein the method comprises the following steps: detecting whether the superheat degree of each outdoor unit meets the target requirement or not; if yes, carrying out first judgment on whether the difference value between the average exhaust temperature of each outdoor unit and the average exhaust temperature of the outdoor unit system reaches a preset value; if so, carrying out second judgment on whether the superheat degree of a passage where the electronic expansion valve of each outdoor unit is located is larger than a first preset value; performing a third judgment on whether the average discharge temperature of each outdoor unit is greater than the average discharge temperature of the outdoor unit system; when the third judgment result is yes, increasing the opening degree of the electronic expansion valve; and if the third judgment result is 'no', reducing the opening degree of the electronic expansion valve. The invention solves the problem of uneven distribution of the refrigerant, and effectively controls the exhaust temperature of the system by controlling the opening of the injection electronic expansion valve.
Description
Technical Field
The invention relates to the technical field of air conditioners, in particular to a control method of a multi-connected air conditioner, a multi-connected air conditioner system and a computer readable storage medium.
Background
In the actual use process, the multi-connected air conditioning unit, especially the parallel multi-connected air conditioning unit, is affected by the installation position, the installation pipelines, the distance between outdoor units, the drop height and the like, so that uneven distribution of refrigerant among the outdoor units is easy to occur, the outdoor units operate abnormally, the outdoor units with more refrigerant may have liquid return, the outdoor units with less refrigerant have higher exhaust temperature and may lack oil and wear, the outdoor units are damaged in severe cases, and the compressor is damaged.
The outdoor units with different capacities can distribute the refrigerant by the pipe diameters of the mounting pipes in parallel connection and the corresponding valve body control method, so as to realize balance as much as possible; however, when a plurality of outdoor units having the same capacity are connected in parallel, since the pipe diameters and valve controls of the outdoor units are completely the same, the outdoor units may not be uniformly distributed among the outdoor units due to the influences of installation positions, outdoor unit distances, head drops, and the like, and thus the above-mentioned consequences may occur, and the reliability of the refrigeration system is low.
Disclosure of Invention
The present invention is directed to a method for controlling a multi-connected air conditioner, a multi-connected air conditioning system, and a computer readable storage medium, and aims to solve the problem of uneven refrigerant distribution between outdoor units in the multi-connected air conditioning system.
In order to achieve the above object, the present invention provides a method for controlling a multi-connected air conditioner, where the multi-connected air conditioner includes at least two outdoor units, each outdoor unit includes at least one compressor, and the at least two outdoor units constitute an outdoor unit system; the control method of the multi-connected air conditioner comprises the following steps:
detecting whether the superheat degree of each outdoor unit meets a target requirement or not;
when the superheat degree of each outdoor unit meets a target requirement, first judgment is made whether the difference value between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system reaches a preset value;
when the difference value between the average exhaust temperature of each outdoor unit and the average exhaust temperature of the outdoor unit system reaches a preset value, performing second judgment on whether the superheat degree of a passage where the electronic expansion valve of each outdoor unit is located is larger than a first preset value;
performing third judgment on whether the superheat degree of a passage where the electronic expansion valve of each outdoor unit is located is larger than a first preset value and the average discharge temperature of each outdoor unit is larger than the average discharge temperature of an outdoor unit system or not;
when the third judgment result is yes, increasing the opening degree of the electronic expansion valve; and if the third judgment result is 'no', reducing the opening degree of the electronic expansion valve.
Preferably, the detecting whether the degree of superheat of each of the outdoor units meets a target requirement includes:
acquiring the exhaust temperature of each outdoor unit;
obtaining the lowest discharge temperature of all the outdoor units according to the obtained discharge temperature comparison;
and detecting whether the superheat degree of the outdoor unit corresponding to the lowest exhaust temperature meets a target requirement or not.
Preferably, the step of performing a first judgment on whether a difference between an average discharge temperature of each of the outdoor units and an average discharge temperature of the outdoor unit system reaches a preset value includes:
acquiring the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system;
acquiring an absolute value of a difference value between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system according to the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system;
and judging whether the absolute value reaches a preset value.
Preferably, after the step of performing the second determination whether the superheat degree of the passage where the electronic expansion valve of each outdoor unit is located is greater than the first preset value, the method further includes:
when the superheat degree of a passage where the electronic expansion valve of each outdoor unit is located is smaller than or equal to a first preset value, judging whether the superheat degree of the passage where the electronic expansion valve is located is smaller than a second preset value;
and when the superheat degree of the passage where the electronic expansion valve is located is smaller than the second preset value, keeping the current opening degree of the electronic expansion valve unchanged.
Preferably, the step of increasing the opening degree of the electronic expansion valve when the third determination result is yes includes:
when the third judgment result is yes, judging whether the opening degree of the electronic expansion valve of the outdoor unit is smaller than the maximum opening degree;
and when the opening degree of the electronic expansion valve of the outdoor unit is smaller than the maximum opening degree, controlling the electronic expansion valve to increase the opening degree on the basis of the current opening degree.
Preferably, when the third determination result is "no", the step of decreasing the opening degree of the electronic expansion valve includes:
when the third judgment result is 'no', judging whether the opening degree of the electronic expansion valve of the outdoor unit is smaller than the minimum opening degree;
and when the opening degree of the electronic expansion valve of the outdoor unit is larger than the minimum opening degree, controlling the electronic expansion valve to reduce the opening degree on the basis of the current opening degree.
Preferably, the method further comprises:
acquiring the discharge temperature of a compressor of each outdoor unit;
judging whether the exhaust temperature of the compressor of each outdoor unit is within a preset range or not;
and when the exhaust temperature of the compressor of the outdoor unit exceeds a preset range, sending a fault signal.
Preferably, the first preset value in the second determination of whether the superheat degree of the passage where the electronic expansion valve of each outdoor unit is located is greater than the first preset value is changed along with the change of the ambient temperature.
In addition, in order to achieve the above object, the present invention further provides a multi-connected air conditioning system, where the multi-connected air conditioning system includes at least two outdoor units, each outdoor unit includes at least one compressor, and the outdoor unit system includes at least two outdoor units; the outdoor unit also comprises a reversing valve, an outdoor heat exchanger, a gas-liquid separator, an electronic expansion valve, a high-pressure stop valve and a low-pressure stop valve which are connected with the outdoor unit pipeline; the multi-connected air conditioning system further comprises: the system comprises a memory, a processor and a control program of the multi-connected air conditioner, wherein the control program of the multi-connected air conditioner is stored on the memory and can run on the processor, and the steps of the method are realized when the control program of the multi-connected air conditioner is executed by the processor.
In addition, to achieve the above object, the present invention further provides a computer-readable storage medium, wherein a control program of a multi-type air conditioner is stored on the computer-readable storage medium, and the control program of the multi-type air conditioner, when executed by a processor, implements the steps of the control method of the multi-type air conditioner as described above.
The control method of the multi-connected air conditioner detects whether the superheat degree of each outdoor unit meets the target requirement or not; when the superheat degree of each outdoor unit meets a target requirement, first judgment is made whether the difference value between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system reaches a preset value; when the difference value between the average exhaust temperature of each outdoor unit and the average exhaust temperature of the outdoor unit system reaches a preset value, performing second judgment on whether the superheat degree of a passage where the electronic expansion valve of each outdoor unit is located is larger than a first preset value; performing third judgment on whether the superheat degree of a passage where the electronic expansion valve of each outdoor unit is located is larger than a first preset value and the average discharge temperature of each outdoor unit is larger than the average discharge temperature of an outdoor unit system or not; when the third judgment result is yes, increasing the opening degree of the electronic expansion valve; and if the third judgment result is 'no', reducing the opening degree of the electronic expansion valve. The method solves the problem of uneven distribution of the refrigerant in the multi-connected air-conditioning system, and particularly realizes effective control of the exhaust temperature of the system by controlling the opening of the injection electronic expansion valve in the injection enthalpy-increasing multi-connected air-conditioning system.
Drawings
Fig. 1 is a schematic structural diagram of a multi-connected air conditioning system according to the present invention.
FIG. 2 is a schematic flow chart illustrating a control method of a multi-split air conditioner according to a first embodiment of the present invention;
FIG. 3 is a flowchart illustrating a control method of a multi-connected air conditioner according to a second embodiment of the present invention;
FIG. 4 is a flowchart illustrating a control method of a multi-connected air conditioner according to a third embodiment of the present invention;
FIG. 5 is a flowchart illustrating a fourth embodiment of a control method for a multi-split air conditioner according to the present invention;
FIG. 6 is a flowchart illustrating a fifth embodiment of a method for controlling a multi-connected air conditioner according to the present invention;
fig. 7 is a block diagram of a multiple air conditioning system according to the present invention.
The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The invention provides a control method of a multi-connected air conditioner, which is applied to a multi-connected air conditioner system, wherein the multi-connected air conditioner system comprises at least two outdoor units connected in parallel and at least two indoor units connected in parallel, and the indoor units and the outdoor units are connected in series in a one-to-one correspondence manner; the pipeline structure of the outdoor unit comprises a gas-liquid separator 20, a compressor unit, an outdoor heat exchanger 30, a reversing valve 40, an electronic expansion valve 50, an injection electronic expansion valve 60, a high-pressure stop valve 70 and a low-pressure stop valve 80; the reversing valve is a four-way valve. The outdoor unit pipes are connected in a conventional manner in the art, and are not described in detail herein with reference to fig. 1. In addition, the multi-connected air conditioner in the embodiment is an enhanced vapor injection system, and the compressor in the compressor unit is an enhanced vapor injection compressor. In this enhanced vapor injection system, the electronic expansion valves include a jet electronic expansion valve 60 and a conventional electronic expansion valve 50. The control of the opening degree of the electronic expansion valve described in the present embodiment refers to the control of the opening degree of the injection electronic expansion valve 60.
In a first embodiment, referring to fig. 2, the control method of the multi-connected air conditioner includes the steps of:
step S10, detecting whether the superheat degree of each outdoor unit meets the target requirement;
in this embodiment, it is first detected whether the degree of superheat of each of the outdoor units meets a target requirement, so as to determine whether the compressor of each of the outdoor units is in a normal operating state. When the degree of superheat of the outdoor unit is higher than the target value, the degree of superheat of the outdoor unit may be too high due to different resistances of refrigerant flow pipes or different indoor loads, and a compressor of the outdoor unit may be in an overload state. In this case, the flux of the refrigerant should be adjusted so that the degree of superheat of the outdoor unit reaches a target value. Secondly, if the degree of superheat of the outdoor unit is less than a target value, the compressor may be damaged due to the refrigerant flowing into the compressor in a gas-liquid two-phase state; therefore, the flux of the refrigerant in the compressor needs to be reduced to prevent the refrigerant from flowing into the compressor as a gas-liquid two-phase refrigerant and damaging the entire system. And only when the superheat degree of each outdoor unit reaches the target requirement, continuing the next operation, otherwise, adjusting the superheat degree of the compressor to reach the target requirement.
Step S20, when the superheat degree of each outdoor unit meets the target requirement, performing a first judgment whether the difference between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system reaches a preset value;
and when the superheat degree of each outdoor unit meets the target requirement, further judging whether the difference value between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system reaches a preset value. The preset value can be set as required, and when the difference between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system is within the preset value, it indicates that the difference between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system is not large, and the difference falls within an acceptable fluctuation range, and then the operation of the outdoor unit is not required to be adjusted. However, if the difference between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system exceeds the preset value, it indicates that the deviation of the average discharge temperature of each outdoor unit from the average discharge temperature of the outdoor unit system is large at this time, which may affect the normal operation of the outdoor unit, and therefore measures need to be taken to adjust the discharge temperature of the outdoor unit system to the average discharge temperature of the outdoor unit system.
Step S30, when the difference between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system reaches a preset value, performing a second determination as to whether the degree of superheat of the passage in which the electronic expansion valve of each outdoor unit is located is greater than the first preset value;
on the basis of the first judgment of the average discharge temperature of the outdoor unit and the average discharge temperature of the outdoor unit system, whether the superheat degree of a passage where an electronic expansion valve of the outdoor unit is located is larger than a first preset value or not is further judged, wherein the electronic expansion valve refers to an injection electronic expansion valve in the system. The first preset value defines the state that the injection electronic expansion valve is operable, namely, the opening degree of the injection electronic expansion valve can be adjusted when the injection electronic expansion valve is larger than the first preset value.
The superheat of the injection electronic expansion valve is defined as follows: referring to fig. 1, the difference between the temperatures T1 and T2 detected at the injection electronic expansion valve is the superheat of the passage in which the injection electronic expansion valve is located.
Step S40, performing a third judgment on whether the superheat degree of a passage where the electronic expansion valve of each outdoor unit is located is larger than a first preset value and the average discharge temperature of each outdoor unit is larger than the average discharge temperature of an outdoor unit system;
further, when the difference between the obtained average discharge temperature of the outdoor units and the average discharge temperature of the outdoor unit system reaches a preset value, whether the average discharge temperature of each outdoor unit is greater than the average discharge temperature of the outdoor unit system is judged. It should be noted that, the judgment of whether the average discharge temperature of each outdoor unit is greater than the average discharge temperature of the outdoor unit system is performed separately to judge the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system, and the judgment of each outdoor unit is independent. And if the difference value between the average discharge temperature of the outdoor unit and the average discharge temperature of the outdoor unit system reaches a preset value, the outdoor unit is judged to need to be adjusted so that the average discharge temperature of the outdoor unit tends to the average discharge temperature of the outdoor unit system.
Wherein the average discharge temperature of each of the outdoor units is an average value of discharge temperatures of compressors therein. If three outdoor units exist, the average exhaust temperatures of the three outdoor units are TP1, TP2 and TP3, each outdoor unit comprises two compressors, and the exhaust temperatures of the compressors are TP1C1, TP1C2, TP2C1, TP2C2, TP3C1 and TP3C2, respectively, then the average exhaust temperatures of the three outdoor units TP1 are (TP1C1+ TP1C2)/2, TP2 is (TP2C1+ TP2C2)/2, and TP3 is (TP3C1+ TP3C 2)/2. The average discharge temperature of the outdoor unit system is an average value of the average discharge temperatures of the three outdoor units, and TP represents (TP1+ TP2+ TP3)/3, where TP represents the average discharge temperature of the outdoor unit system.
Step S50, if the third determination result is "yes", increasing the opening degree of the electronic expansion valve; and if the third judgment result is 'no', reducing the opening degree of the electronic expansion valve.
The processing method of the judgment result is as follows: if the third determination result is yes, that is, the average discharge temperature of the outdoor unit is higher than the average discharge temperature of the outdoor unit system, it indicates that the average discharge temperature of the outdoor unit is higher than the discharge temperature of the entire outdoor unit system, which indicates that the outdoor unit has less refrigerant, and thus the refrigerant flux needs to be increased. It is further judged in this case whether the degree of superheat of the passage in which the injection electronic expansion valve is located reaches the first preset value. When the superheat degree of a passage where the injection electronic expansion valve is located does not reach a first preset value, because the refrigerant flowing through the injection electronic expansion valve is directly injected back to the compressor, if the superheat degree of the injection electronic expansion valve is not within the first preset value, if the injection electronic expansion valve is opened, the refrigerant may flow into the compressor in a liquid state, liquid accumulation is generated in the compressor, and the compressor is damaged. Therefore, before the injection electronic expansion valve is opened, whether a passage where the injection electronic expansion valve is located reaches a first preset value or not needs to be judged, and when the injection electronic expansion valve reaches the first preset value, the injection electronic expansion valve is controlled to increase the preset opening degree on the basis of the current opening degree so as to increase the refrigerant flowing into the compressor of the outdoor unit from the current opening degree, and further reduce the exhaust temperature of the compressor of the outdoor unit.
In addition, when the third determination is "no", that is, when the average discharge temperature of the outdoor unit is lower than the average discharge temperature of the outdoor unit system, it indicates that the discharge temperature of the compressor of the outdoor unit is too low, that is, the amount of refrigerant of the compressor of the outdoor unit is large, and thus it is necessary to reduce the flow rate of refrigerant of the compressor of the outdoor unit by controlling the valve. Similarly, before controlling the injection electronic expansion valve, whether the superheat degree of the passage where the injection electronic expansion valve is located reaches a first preset value is judged, and when the superheat degree of the passage where the injection electronic expansion valve is located reaches the first preset value, the opening degree of the injection electronic expansion valve is reduced on the basis of the current opening degree of the injection electronic expansion valve, so that the flow rate of the refrigerant flowing into the compressor of the outdoor unit is reduced.
It should be noted that, when the superheat degree of the path where the injection electronic expansion valve is located does not reach the first preset value, the flow rate of the refrigerant of the compressor of the outdoor unit can be controlled by controlling the opening degree of the conventional electronic expansion valve on the main path, or the discharge temperature of the compressor can be balanced by controlling the frequency of the compressor.
It should be further noted that, in this embodiment, the setting of the first preset value of the superheat degree of the passage where the injection electronic expansion valve is located may be changed along with the change of the ambient temperature, and the standard of the first preset value is generally greater than 5 ℃, and may be specifically set according to the requirement.
In addition, when the superheat degree of the passage where the injection electronic expansion valve is located does not reach the first preset value, whether the superheat degree of the passage where the injection electronic expansion valve is located is smaller than a second preset value is further judged, wherein the second preset value is a positive number related to the first preset value, and the second preset value is smaller than the first preset value. And when the superheat degree of the passage where the injection electronic expansion valve is located is smaller than a second preset value, keeping the current opening degree of the injection electronic expansion valve unchanged.
The embodiment detects whether the superheat degree of each outdoor unit meets the target requirement; when the superheat degree of each outdoor unit meets a target requirement, first judgment is made whether the difference value between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system reaches a preset value; when the difference value between the average exhaust temperature of each outdoor unit and the average exhaust temperature of the outdoor unit system reaches a preset value, performing second judgment on whether the superheat degree of a passage where the electronic expansion valve of each outdoor unit is located is larger than a first preset value; when the superheat degree of a passage where the electronic expansion valve of each outdoor unit is located is larger than a first preset value, third judgment is carried out to judge whether the average discharge temperature of each outdoor unit is larger than the average discharge temperature of an outdoor unit system; when the third judgment result is yes, increasing the opening degree of the electronic expansion valve; and if the third judgment result is 'no', reducing the opening degree of the electronic expansion valve. The method solves the problem of uneven refrigerant distribution in the multi-connected air-conditioning system, and particularly realizes effective control of the exhaust temperature of the system by controlling the opening degree of the injection electronic expansion valve in the injection enthalpy-increasing multi-connected air-conditioning system.
Further, referring to fig. 3, based on the first embodiment of the method for controlling a multi-connected air conditioner of the present invention, in the second embodiment of the method for controlling a multi-connected air conditioner of the present invention, the step S10 includes:
step S11, acquiring a discharge temperature of each outdoor unit;
step S12, comparing the obtained discharge temperatures to obtain the lowest discharge temperature of all the outdoor units;
and step S13, detecting whether the degree of superheat of the outdoor unit corresponding to the minimum discharge temperature meets a target requirement.
In this embodiment, the discharge temperature of each outdoor unit is obtained, and then the lowest discharge temperature among all the discharge temperatures is obtained by comparing the obtained discharge temperatures, so as to further determine whether the superheat degree of the outdoor unit corresponding to the lowest discharge temperature meets the target requirement. If the superheat degree of the outdoor unit corresponding to the lowest discharge temperature can meet the target requirement, it indicates that the superheat degrees of the outdoor units corresponding to the other discharge temperatures higher than the lowest discharge temperature can also meet the target requirement. Therefore, it is only necessary to determine whether the degree of superheat of the outdoor unit corresponding to the minimum discharge temperature meets the target requirement.
In the above, the average value of the discharge temperatures of all the compressors of each outdoor unit, which is referred to in the discharge temperature of each outdoor unit, is obtained, and the lowest discharge temperature is obtained by comparison among the discharge temperatures of all the outdoor units.
In this embodiment, by obtaining the lowest discharge temperature among the discharge temperatures of all the outdoor units, and determining whether the degree of superheat of the outdoor unit corresponding to the lowest discharge temperature meets the target requirement, when the degree of superheat of the outdoor unit corresponding to the lowest discharge temperature meets the target requirement, it may be determined that the degrees of superheat of other outdoor units all meet the target requirement. The superheat degree of all outdoor units does not need to be judged, and the operation efficiency is improved.
Further, referring to fig. 4, based on the second embodiment of the method for controlling a multi-connected air conditioner of the present invention, in the third embodiment of the method for controlling a multi-connected air conditioner of the present invention, the step S20 includes:
step S21, acquiring an average discharge temperature of each outdoor unit and an average discharge temperature of the outdoor unit system;
step S22, obtaining an absolute value of a difference between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system according to the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system;
and step S23, judging whether the absolute value reaches a preset value.
In this embodiment, before the step of determining the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system, it is determined whether an absolute value of a difference between the average discharge temperature of the outdoor units and the average discharge temperature of the outdoor unit system reaches a preset value. If the average discharge temperature of the outdoor unit is not equal to the preset value, the difference between the average discharge temperature of the outdoor unit and the average discharge temperature of the outdoor unit system is small, and the difference between the average discharge temperature of the outdoor unit and the average discharge temperature of the outdoor unit system is in a fluctuation range. When the absolute value of the difference value between the average discharge temperature of the compressor of the outdoor unit and the average discharge temperature of the outdoor unit system reaches a preset value, the judgment of the average discharge temperature of the outdoor unit and the average discharge temperature of the outdoor unit system is carried out.
The preset range can be set according to system requirements, and the preset range can enable the average discharge temperature of each outdoor unit to have a fluctuation value in the upper and lower ranges of the average discharge temperature of the outdoor unit system, so as to ensure the stability of system control.
Further, referring to fig. 5, in a fourth embodiment of the method for controlling a multi-split air conditioner according to the present invention, in the step S50, the method further includes:
step S51, when the third determination result is "yes", determining whether the opening degree of the electronic expansion valve of the outdoor unit is smaller than the maximum opening degree;
and step S52, when the opening degree of the electronic expansion valve of the outdoor unit is smaller than the maximum opening degree, controlling the electronic expansion valve to increase the opening degree based on the current opening degree.
In this embodiment, when the average discharge temperature of the compressor of the outdoor unit is higher than the average discharge temperature of the outdoor unit system and the superheat degree of the passage where the injection electronic expansion valve is located is higher than the first preset value, it is further determined whether the current opening degree of the injection electronic expansion valve has reached the maximum opening degree that can be reached by the injection electronic expansion valve. When the injection electronic expansion valve reaches the maximum opening degree which can be reached by the injection electronic expansion valve, the injection electronic expansion valve is indicated to be incapable of increasing the opening degree. Therefore, the injection electronic expansion valve can be continuously controlled to increase the opening degree only when the current opening degree of the injection electronic expansion valve does not reach the maximum opening degree.
When detecting that the injection electronic expansion valve has not reached the maximum opening degree, the injection electronic expansion valve is controlled to increase the opening degree based on the current opening degree to increase the refrigerant flow rate of the compressor of the outdoor unit to lower the discharge temperature thereof.
In the embodiment, whether the opening degree of the injection electronic expansion valve reaches the maximum opening degree is judged, and whether the injection electronic expansion valve can be opened continuously is further judged. The accuracy of controlling the injection electronic expansion valve is improved, and the injection electronic expansion valve and the whole system are protected.
Further, referring to fig. 5, in another embodiment, after the step S50, the method further includes:
step S53, when the third determination result is "no", determining whether the opening degree of the electronic expansion valve of the outdoor unit is greater than the minimum opening degree;
and step S54, when the opening degree of the electronic expansion valve of the outdoor unit is greater than the minimum opening degree, controlling the electronic expansion valve to decrease the opening degree based on the current opening degree.
In this embodiment, when the average discharge temperature of the compressor of the outdoor unit is lower than the average discharge temperature of the outdoor unit system and the superheat degree of the passage where the injection electronic expansion valve is located is higher than the first preset value, it is further determined whether the current opening degree of the injection electronic expansion valve has reached the minimum opening degree that can be reached by the injection electronic expansion valve. When the injection electronic expansion valve reaches the minimum opening degree which can be reached by the injection electronic expansion valve, the injection electronic expansion valve is indicated to be incapable of reducing the opening degree at the moment. Therefore, the injection electronic expansion valve can be continuously controlled to reduce the opening degree only when the current opening degree of the injection electronic expansion valve does not reach the minimum opening degree.
When detecting that the injection electronic expansion valve has not reached the maximum opening degree, the injection electronic expansion valve is controlled to increase the opening degree based on the current opening degree to increase the refrigerant flow rate of the compressor of the outdoor unit to lower the discharge temperature thereof.
In this embodiment, whether the opening degree of the injection electronic expansion valve reaches the minimum opening degree is determined, and then whether the injection electronic expansion valve can be closed continuously is determined. The accuracy of controlling the injection electronic expansion valve is improved, and the injection electronic expansion valve and the whole system are protected.
Further, in another embodiment, referring to fig. 6, the method further includes:
step S00, acquiring a discharge temperature of each outdoor unit;
step S01, determining whether the discharge temperature of the compressor of each outdoor unit is within a preset range;
and step S02, when the discharge temperature of the compressor of the outdoor unit exceeds a preset range, sending a fault signal.
In this embodiment, the discharge temperature of the compressor of each outdoor unit is obtained. And further judging whether the discharge temperature of the compressor of each outdoor unit is within a preset range, and sending a fault signal when the discharge temperature of the compressor exceeds the preset range. The preset range is the exhaust temperature range of the compressor in the normal working state, and can be specifically set according to the actual condition of the system.
Whether the exhaust temperature of each compressor is within a normal preset range or not is detected, so that a warning is timely given out when the compressor fails, and the compressor is prevented from continuously working under the condition of failure to cause larger damage.
The present invention further provides a multi-connected air conditioning system 100, referring to fig. 1 and 7, the multi-connected air conditioning system includes at least two outdoor units, each outdoor unit includes at least one compressor 10, and the at least two outdoor units constitute an outdoor unit system; the outdoor unit further comprises a reversing valve 40, a gas-liquid separator 20, an outdoor heat exchanger 30, an electronic expansion valve, a high-pressure stop valve 70 and a low-pressure stop valve 80 which are connected to the outdoor unit pipeline; the reversing valve is a four-way valve. The outdoor unit pipes are connected in a conventional manner in the art, and are not described in detail herein with reference to fig. 1. In addition, the multi-connected air conditioner in the embodiment is an enhanced vapor injection system, and the compressor in the compressor unit is an enhanced vapor injection compressor. In this enhanced vapor injection system, the electronic expansion valves include a jet electronic expansion valve 60 and a conventional electronic expansion valve 50. The multi-connected air conditioning system 100 further includes: memory 101, processor 102 and a control program for a multi-type air conditioner stored on the memory 101 and executable on the processor 102, the control program for a multi-type air conditioner implementing the steps of the method described below when executed by the processor 102
Detecting whether the superheat degree of each outdoor unit meets a target requirement or not;
when the superheat degree of each outdoor unit meets a target requirement, first judgment is made whether the difference value between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system reaches a preset value;
when the difference value between the average exhaust temperature of each outdoor unit and the average exhaust temperature of the outdoor unit system reaches a preset value, performing second judgment on whether the superheat degree of a passage where the electronic expansion valve of each outdoor unit is located is larger than a first preset value;
performing third judgment on whether the superheat degree of a passage where the electronic expansion valve of each outdoor unit is located is larger than a first preset value and the average discharge temperature of each outdoor unit is larger than the average discharge temperature of an outdoor unit system or not;
when the third judgment result is yes, increasing the opening degree of the electronic expansion valve; and if the third judgment result is 'no', reducing the opening degree of the electronic expansion valve.
In this embodiment, it is first detected whether the degree of superheat of each of the outdoor units meets a target requirement, so as to determine whether the compressor of each of the outdoor units is in a normal operating state. When the degree of superheat of the outdoor unit is higher than the target value, the degree of superheat of the outdoor unit may be too high due to different resistances of refrigerant flow pipes or different indoor loads, and a compressor of the outdoor unit may be in an overload state. In this case, the flux of the refrigerant should be adjusted so that the degree of superheat of the outdoor unit reaches a target value. Secondly, if the degree of superheat of the outdoor unit is less than a target value, the compressor may be damaged due to the refrigerant flowing into the compressor in a gas-liquid two-phase state; therefore, the flux of the refrigerant in the compressor needs to be reduced to prevent the refrigerant from flowing into the compressor as a gas-liquid two-phase refrigerant and damaging the entire system. And only when the superheat degree of each outdoor unit reaches the target requirement, continuing the next operation, otherwise, adjusting the superheat degree of the compressor to reach the target requirement.
When the superheat degree of each outdoor unit reaches a target requirement, and when the superheat degree of each outdoor unit reaches the target requirement, whether the difference value between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system reaches a preset value is further judged. The preset value can be set according to needs, when the difference between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system is within the preset value, it is indicated that the difference between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system is not large at the moment, and the difference belongs to an acceptable toggle range, and at the moment, the operation of the outdoor units is not required to be adjusted. However, if the difference between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system exceeds the preset value, it indicates that the deviation of the average discharge temperature of each outdoor unit from the average discharge temperature of the outdoor unit system is large at this time, which may affect the normal operation of the outdoor unit, and therefore measures need to be taken to adjust the discharge temperature of the outdoor unit system to the average discharge temperature of the outdoor unit system.
On the basis of the first judgment of the average discharge temperature of the outdoor unit and the average discharge temperature of the outdoor unit system, whether the superheat degree of a passage where an electronic expansion valve of the outdoor unit is located is larger than a first preset value or not is further judged, wherein the electronic expansion valve refers to an injection electronic expansion valve in the system. The first preset value defines the state that the injection electronic expansion valve is operable, namely, the opening degree of the injection electronic expansion valve can be adjusted when the injection electronic expansion valve is larger than the first preset value.
The superheat of the injection electronic expansion valve is defined as follows: referring to fig. 1, the difference between the temperatures T1 and T2 detected at the injection electronic expansion valve is the superheat of the passage in which the injection electronic expansion valve is located.
Further, when the difference between the obtained average discharge temperature of the outdoor units and the average discharge temperature of the outdoor unit system reaches a preset value, whether the average discharge temperature of each outdoor unit is greater than the average discharge temperature of the outdoor unit system is judged. It should be noted that, the judgment of whether the average discharge temperature of each outdoor unit is greater than the average discharge temperature of the outdoor unit system is performed separately to judge the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system, and the judgment of each outdoor unit is independent. And if the difference value between the average discharge temperature of the outdoor unit and the average discharge temperature of the outdoor unit system reaches a preset value, the outdoor unit is judged to need to be adjusted so that the average discharge temperature of the outdoor unit tends to the average discharge temperature of the outdoor unit system.
Wherein the average discharge temperature of each of the outdoor units is an average value of discharge temperatures of compressors therein. If three outdoor units exist, the average exhaust temperatures of the three outdoor units are TP1, TP2 and TP3, each outdoor unit comprises two compressors, and the exhaust temperatures of the compressors are TP1C1, TP1C2, TP2C1, TP2C2, TP3C1 and TP3C2, respectively, then the average exhaust temperatures of the three outdoor units TP1 are (TP1C1+ TP1C2)/2, TP2 is (TP2C1+ TP2C2)/2, and TP3 is (TP3C1+ TP3C 2)/2. The average discharge temperature of the outdoor unit system is an average value of the average discharge temperatures of the three outdoor units, and TP represents (TP1+ TP2+ TP3)/3, where TP represents the average discharge temperature of the outdoor unit system.
The processing method of the judgment result is as follows: if the third determination result is yes, that is, the average discharge temperature of the outdoor unit is higher than the average discharge temperature of the outdoor unit system, it indicates that the average discharge temperature of the outdoor unit is higher than the discharge temperature of the entire outdoor unit system, which indicates that the outdoor unit has less refrigerant, and thus the refrigerant flux needs to be increased. It is further judged in this case whether the degree of superheat of the passage in which the injection electronic expansion valve is located reaches the first preset value. When the superheat degree of a passage where the injection electronic expansion valve is located does not reach a first preset value, because the refrigerant flowing through the injection electronic expansion valve is directly injected back to the compressor, if the superheat degree of the injection electronic expansion valve is not within the first preset value, if the injection electronic expansion valve is opened, the refrigerant may flow into the compressor in a liquid state, so that liquid accumulation is generated in the compressor, and the compressor is damaged. Therefore, before the injection electronic expansion valve is opened, whether a passage where the injection electronic expansion valve is located reaches a first preset value or not needs to be judged, and when the injection electronic expansion valve reaches the first preset value, the injection electronic expansion valve is controlled to increase the preset opening degree on the basis of the current opening degree so as to increase the refrigerant flowing into the compressor of the outdoor unit from the current opening degree and reduce the exhaust temperature of the compressor of the outdoor unit.
In addition, when the third determination is "no", that is, when the average discharge temperature of the outdoor unit is lower than the average discharge temperature of the outdoor unit system, it indicates that the discharge temperature of the compressor of the outdoor unit is too low, that is, the amount of refrigerant of the compressor of the outdoor unit is large, and thus it is necessary to reduce the flow rate of refrigerant of the compressor of the outdoor unit by controlling the valve. Similarly, before controlling the injection electronic expansion valve, whether the superheat degree of the passage where the injection electronic expansion valve is located reaches a first preset value is judged, and when the superheat degree of the passage where the injection electronic expansion valve is located reaches the first preset value, the opening degree of the injection electronic expansion valve is reduced on the basis of the current opening degree of the injection electronic expansion valve, so that the flow rate of the refrigerant flowing into the compressor of the outdoor unit is reduced.
It should be noted that, when the superheat degree of the path where the injection electronic expansion valve is located does not reach the first preset value, the flow rate of the refrigerant of the compressor of the outdoor unit can be controlled by controlling the opening degree of the conventional electronic expansion valve on the main path, or the discharge temperature of the compressor can be balanced by controlling the frequency of the compressor.
It should be further noted that, in this embodiment, the setting of the first preset value of the superheat degree of the passage where the injection electronic expansion valve is located may be changed along with the change of the ambient temperature, and the standard of the first preset value is generally greater than 5 ℃, and may be specifically set according to the requirement.
In addition, when the superheat degree of the passage where the injection electronic expansion valve is located does not reach the first preset value, whether the superheat degree of the passage where the injection electronic expansion valve is located is smaller than a second preset value is further judged, wherein the second preset value is a positive number related to the first preset value, and the second preset value is smaller than the first preset value. And when the superheat degree of the passage where the injection electronic expansion valve is located is smaller than a second preset value, keeping the current opening degree of the injection electronic expansion valve unchanged.
The embodiment detects whether the superheat degree of each outdoor unit meets the target requirement; when the superheat degree of each outdoor unit meets a target requirement, first judgment is made whether the difference value between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system reaches a preset value; when the difference value between the average exhaust temperature of each outdoor unit and the average exhaust temperature of the outdoor unit system reaches a preset value, performing second judgment on whether the superheat degree of a passage where the electronic expansion valve of each outdoor unit is located is larger than a first preset value; performing third judgment on whether the superheat degree of a passage where the electronic expansion valve of each outdoor unit is located is larger than a first preset value and the average discharge temperature of each outdoor unit is larger than the average discharge temperature of an outdoor unit system or not; when the third judgment result is yes, increasing the opening degree of the electronic expansion valve; and if the third judgment result is 'no', reducing the opening degree of the electronic expansion valve. The method solves the problem of uneven refrigerant distribution in the multi-connected air-conditioning system, and particularly realizes effective control of the exhaust temperature of the system by controlling the opening degree of the injection electronic expansion valve in the injection enthalpy-increasing multi-connected air-conditioning system.
Further, in an embodiment, when executed by the processor 102, the control program of the multi-connected air conditioner implements the following method steps:
acquiring the exhaust temperature of each outdoor unit;
obtaining the lowest discharge temperature of all the outdoor units according to the obtained discharge temperature comparison;
and detecting whether the superheat degree of the outdoor unit corresponding to the lowest exhaust temperature meets a target requirement or not.
In this embodiment, the discharge temperature of each outdoor unit is obtained, and then the lowest discharge temperature among all the discharge temperatures is obtained by comparing the obtained discharge temperatures, so as to further determine whether the superheat degree of the outdoor unit corresponding to the lowest discharge temperature meets the target requirement. If the superheat degree of the outdoor unit corresponding to the lowest discharge temperature can meet the target requirement, it indicates that the superheat degrees of the outdoor units corresponding to the other discharge temperatures higher than the lowest discharge temperature can also meet the target requirement. Therefore, it is only necessary to determine whether the degree of superheat of the outdoor unit corresponding to the minimum discharge temperature meets the target requirement.
In the above, the discharge temperatures of all the outdoor units of each outdoor unit, which are referred to in the discharge temperature of each of the outdoor units, are obtained, and the lowest discharge temperature is obtained by comparison among the discharge temperatures of all the outdoor units.
In this embodiment, by obtaining the lowest discharge temperature among the discharge temperatures of all the outdoor units, and determining whether the degree of superheat of the outdoor unit corresponding to the lowest discharge temperature meets the target requirement, when the degree of superheat of the outdoor unit corresponding to the lowest discharge temperature meets the target requirement, it may be determined that the degrees of superheat of other outdoor units all meet the target requirement. The superheat degree of all outdoor units does not need to be judged, and the operation efficiency is improved.
Further, in an embodiment, when executed by the processor 102, the control program of the multi-connected air conditioner implements the following method steps:
acquiring the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system;
acquiring an absolute value of a difference value between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system according to the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system;
and judging whether the absolute value reaches a preset value.
In this embodiment, before the step of determining the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system, it is determined whether an absolute value of a difference between the average discharge temperature of the outdoor units and the average discharge temperature of the outdoor unit system reaches a preset value. If the average discharge temperature of the outdoor unit is not equal to the preset value, the difference between the average discharge temperature of the outdoor unit and the average discharge temperature of the outdoor unit system is small, and the difference between the average discharge temperature of the outdoor unit and the average discharge temperature of the outdoor unit system is in a fluctuation range. When the absolute value of the difference value between the average discharge temperature of the compressor of the outdoor unit and the average discharge temperature of the outdoor unit system reaches a preset value, the judgment of the average discharge temperature of the outdoor unit and the average discharge temperature of the outdoor unit system is carried out.
The preset range can be set according to system requirements, and the preset range can enable the average discharge temperature of each outdoor unit to have a fluctuation value in the upper and lower ranges of the average discharge temperature of the outdoor unit system, so as to ensure the stability of system control.
Further, in other embodiments, the control program of the multi-connected air conditioner, when executed by the processor 102, implements the following method steps:
when the third judgment result is yes, judging whether the opening degree of the electronic expansion valve of the outdoor unit is smaller than the maximum opening degree;
and when the opening degree of the electronic expansion valve of the outdoor unit is smaller than the maximum opening degree, controlling the electronic expansion valve to increase the opening degree on the basis of the current opening degree.
In this embodiment, when the average discharge temperature of the compressor of the outdoor unit is higher than the average discharge temperature of the outdoor unit system and the superheat degree of the passage where the injection electronic expansion valve is located is higher than the first preset value, it is further determined whether the current opening degree of the injection electronic expansion valve has reached the maximum opening degree that can be reached by the injection electronic expansion valve. When the injection electronic expansion valve reaches the maximum opening degree which can be reached by the injection electronic expansion valve, the injection electronic expansion valve is indicated to be incapable of increasing the opening degree. Therefore, the injection electronic expansion valve can be continuously controlled to increase the opening degree only when the current opening degree of the injection electronic expansion valve does not reach the maximum opening degree.
When detecting that the injection electronic expansion valve has not reached the maximum opening degree, the injection electronic expansion valve is controlled to increase the opening degree based on the current opening degree to increase the refrigerant flow rate of the compressor of the outdoor unit to lower the discharge temperature thereof.
In the embodiment, whether the opening degree of the injection electronic expansion valve reaches the maximum opening degree is judged, and whether the injection electronic expansion valve can be opened continuously is further judged. The accuracy of controlling the injection electronic expansion valve is improved, and the injection electronic expansion valve and the whole system are protected.
Further, in other embodiments, the control program of the multi-connected air conditioner, when executed by the processor 102, implements the following method steps:
when the third judgment result is 'no', judging whether the opening degree of the electronic expansion valve of the outdoor unit is greater than the minimum opening degree;
and when the opening degree of the electronic expansion valve of the outdoor unit is larger than the minimum opening degree, controlling the electronic expansion valve to reduce the opening degree on the basis of the current opening degree.
In this embodiment, when the average discharge temperature of the compressor of the outdoor unit is lower than the average discharge temperature of the outdoor unit system and the superheat degree of the passage where the injection electronic expansion valve is located is higher than the first preset value, it is further determined whether the current opening degree of the injection electronic expansion valve has reached the minimum opening degree that can be reached by the injection electronic expansion valve. When the injection electronic expansion valve reaches the minimum opening degree which can be reached by the injection electronic expansion valve, the injection electronic expansion valve is indicated to be incapable of reducing the opening degree at the moment. Therefore, the injection electronic expansion valve can be continuously controlled to reduce the opening degree only when the current opening degree of the injection electronic expansion valve does not reach the minimum opening degree.
When detecting that the injection electronic expansion valve has not reached the maximum opening degree, the injection electronic expansion valve is controlled to increase the opening degree based on the current opening degree to increase the refrigerant flow rate of the compressor of the outdoor unit to lower the discharge temperature thereof.
In this embodiment, whether the opening degree of the injection electronic expansion valve reaches the minimum opening degree is determined, and then whether the injection electronic expansion valve can be closed continuously is determined. The accuracy of controlling the injection electronic expansion valve is improved, and the injection electronic expansion valve and the whole system are protected.
Further, in other embodiments, the control program of the multi-connected air conditioner, when executed by the processor 102, implements the following method steps:
acquiring the discharge temperature of a compressor of each outdoor unit;
judging whether the exhaust temperature of the compressor of each outdoor unit is within a preset range or not;
and when the exhaust temperature of the compressor of the outdoor unit exceeds a preset range, sending a fault signal.
In this embodiment, the discharge temperature of the compressor of each outdoor unit is obtained. And further judging whether the discharge temperature of the compressor of each outdoor unit is within a preset range, and sending a fault signal when the discharge temperature of the compressor exceeds the preset range. The preset range is the exhaust temperature range of the compressor in the normal working state, and can be specifically set according to the actual condition of the system.
Whether the exhaust temperature of each compressor is within a normal preset range or not is detected, so that a warning is timely given out when the compressor fails, and the compressor is prevented from continuously working under the condition of failure to cause larger damage.
Furthermore, an embodiment of the present invention further provides a computer-readable storage medium, where a control program of a multi-split air conditioner is stored, and when the control program of the multi-split air conditioner is executed by the processor 102, the method steps of the above-mentioned embodiment are implemented.
The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.
Claims (10)
1. The control method of the multi-connected air conditioner is characterized in that the multi-connected air conditioner comprises at least two outdoor units, each outdoor unit comprises at least one compressor, and an outdoor unit system is formed by the at least two outdoor units; the control method of the multi-connected air conditioner comprises the following steps:
detecting whether the superheat degree of each outdoor unit meets a target requirement or not;
when the superheat degree of each outdoor unit meets a target requirement, first judgment is made whether the difference value between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system reaches a preset value;
when the difference value between the average exhaust temperature of each outdoor unit and the average exhaust temperature of the outdoor unit system reaches a preset value, performing second judgment on whether the superheat degree of a passage where the enhanced vapor injection expansion valve of each outdoor unit is located is larger than a first preset value;
when the superheat degree of a passage where the enhanced vapor injection expansion valve of each outdoor unit is located is larger than a first preset value, performing third judgment on whether the average exhaust temperature of each outdoor unit is larger than the average exhaust temperature of an outdoor unit system;
when the third judgment result is yes, increasing the opening degree of the enhanced vapor injection expansion valve; and when the third judgment result is 'no', reducing the opening degree of the enhanced vapor injection expansion valve.
2. The control method of a multi-type air conditioner according to claim 1, wherein the step of detecting whether the degree of superheat of each of the outdoor units meets a target requirement comprises:
acquiring the exhaust temperature of each outdoor unit;
obtaining the lowest discharge temperature of all the outdoor units according to the obtained discharge temperature comparison;
and detecting whether the superheat degree of the outdoor unit corresponding to the lowest exhaust temperature meets a target requirement or not.
3. The method of claim 1, wherein the first determining whether a difference between an average discharge temperature of each of the outdoor units and an average discharge temperature of the outdoor unit system reaches a predetermined value comprises:
acquiring the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system;
acquiring an absolute value of a difference value between the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system according to the average discharge temperature of each outdoor unit and the average discharge temperature of the outdoor unit system;
and judging whether the absolute value reaches a preset value.
4. The method as claimed in claim 1, wherein the step of performing the second determination of whether the degree of superheat of the path in which the enhanced vapor injection expansion valve of each outdoor unit is located is greater than the first preset value further comprises:
when the superheat degree of a passage where the enhanced vapor injection expansion valve of each outdoor unit is located is smaller than or equal to a first preset value, judging whether the superheat degree of the passage where the enhanced vapor injection expansion valve is located is smaller than a second preset value;
and when the superheat degree of the passage where the enhanced vapor injection expansion valve is located is smaller than the second preset value, keeping the current opening degree of the enhanced vapor injection expansion valve unchanged.
5. The method as claimed in claim 1, wherein the step of increasing the opening degree of the enhanced vapor injection expansion valve when the third determination result is yes comprises:
when the third judgment result is yes, judging whether the opening degree of an electronic expansion valve of the outdoor unit is smaller than the maximum opening degree;
and when the opening degree of an electronic expansion valve of the outdoor unit is smaller than the maximum opening degree, controlling the enhanced vapor injection expansion valve to increase the opening degree on the basis of the current opening degree.
6. The method as claimed in claim 1, wherein the step of decreasing the opening degree of the enhanced vapor injection expansion valve when the third determination result is no includes:
when the third judgment result is 'no', judging whether the opening degree of an electronic expansion valve of the outdoor unit is smaller than the minimum opening degree;
and when the opening degree of the electronic expansion valve of the outdoor unit is larger than the minimum opening degree, controlling the enhanced vapor injection expansion valve to reduce the opening degree on the basis of the current opening degree.
7. The method for controlling a multi-type air conditioner according to any one of claims 1 to 6, further comprising:
acquiring the discharge temperature of a compressor of each outdoor unit;
judging whether the exhaust temperature of the compressor of each outdoor unit is within a preset range or not;
and when the exhaust temperature of the compressor of the outdoor unit exceeds a preset range, sending a fault signal.
8. The method as claimed in any one of claims 1 to 6, wherein the first preset value in the second determination of whether the degree of superheat of the path in which the enhanced vapor injection expansion valve of each outdoor unit is located is greater than the first preset value is changed according to the change of the ambient temperature.
9. The multi-connected air conditioning system is characterized by comprising at least two outdoor units, wherein each outdoor unit comprises at least one compressor, and the outdoor unit system consists of at least two outdoor units; the outdoor unit also comprises a reversing valve, an outdoor heat exchanger, a gas-liquid separator, an electronic expansion valve, a high-pressure stop valve and a low-pressure stop valve which are connected with the outdoor unit pipeline; the multi-connected air conditioning system further comprises: a memory, a processor and a control program of a multi-connected air conditioner stored on the memory and operable on the processor, the control program of the multi-connected air conditioner realizing the steps of the control method of the multi-connected air conditioner according to any one of claims 1 to 8 when executed by the processor.
10. A computer-readable storage medium, characterized in that the computer-readable storage medium has stored thereon a control program of a multi-type air conditioner, which when executed by a processor, implements the steps of the control method of the multi-type air conditioner according to any one of claims 1 to 8.
Priority Applications (7)
| Application Number | Priority Date | Filing Date | Title |
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| CN201710848877.XA CN107477933B (en) | 2017-09-18 | 2017-09-18 | Control method and system of multi-connected air conditioner and computer readable storage medium |
| JP2019550194A JP2020514664A (en) | 2017-09-18 | 2017-12-08 | Control method of multi-type air conditioner, multi-type air conditioner system, and computer-readable storage medium |
| KR1020197023357A KR20190105618A (en) | 2017-09-18 | 2017-12-08 | Control method, system and computer readable storage medium of multi-connected air conditioner |
| PCT/CN2017/115322 WO2019052035A1 (en) | 2017-09-18 | 2017-12-08 | Method for controlling multi-split air conditioner, multi-split air conditioner system, and computer-readable storage medium |
| US16/493,301 US11137157B2 (en) | 2017-09-18 | 2017-12-08 | Method for controlling multi-split air conditioner, multi-split air conditioner system, and computer-readable storage medium |
| EP17925459.4A EP3598013B1 (en) | 2017-09-18 | 2017-12-08 | Method for controlling multi-split air conditioner, multi-split air conditioner system, and computer-readable storage medium |
| ES17925459T ES2932195T3 (en) | 2017-09-18 | 2017-12-08 | Control method of a multi-split air conditioner, a multi-split air conditioning system and a computer-readable storage medium |
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| CN201710848877.XA CN107477933B (en) | 2017-09-18 | 2017-09-18 | Control method and system of multi-connected air conditioner and computer readable storage medium |
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| CN106288028A (en) * | 2016-08-19 | 2017-01-04 | 广东美的暖通设备有限公司 | Air injection enthalpy-increasing air conditioning system |
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