CN113137658A - Control method of multi-connected air conditioning unit - Google Patents

Control method of multi-connected air conditioning unit Download PDF

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Publication number
CN113137658A
CN113137658A CN202010059179.3A CN202010059179A CN113137658A CN 113137658 A CN113137658 A CN 113137658A CN 202010059179 A CN202010059179 A CN 202010059179A CN 113137658 A CN113137658 A CN 113137658A
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China
Prior art keywords
outdoor
state
outdoor unit
control method
units
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Granted
Application number
CN202010059179.3A
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Chinese (zh)
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CN113137658B (en
Inventor
隋志蔚
毛守博
罗建文
何建奇
卢大海
武运动
陈宏耀
邱爽
潘艳明
曹慧银
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Qingdao Haier Air Conditioning Electric Co Ltd
Haier Smart Home Co Ltd
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Qingdao Haier Air Conditioning Electric Co Ltd
Haier Smart Home Co Ltd
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Application filed by Qingdao Haier Air Conditioning Electric Co Ltd, Haier Smart Home Co Ltd filed Critical Qingdao Haier Air Conditioning Electric Co Ltd
Priority to CN202010059179.3A priority Critical patent/CN113137658B/en
Priority to PCT/CN2020/091307 priority patent/WO2021142993A1/en
Publication of CN113137658A publication Critical patent/CN113137658A/en
Application granted granted Critical
Publication of CN113137658B publication Critical patent/CN113137658B/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F1/00—Room units for air-conditioning, e.g. separate or self-contained units or units receiving primary air from a central station
    • F24F1/0003—Room units for air-conditioning, e.g. separate or self-contained units or units receiving primary air from a central station characterised by a split arrangement, wherein parts of the air-conditioning system, e.g. evaporator and condenser, are in separately located units
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
    • F24F11/32—Responding to malfunctions or emergencies
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/62—Control or safety arrangements characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
    • F24F11/63—Electronic processing
    • F24F11/64—Electronic processing using pre-stored data
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/70—Control systems characterised by their outputs; Constructional details thereof
    • F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
    • F24F11/83—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers
    • F24F11/84—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers using valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/70—Control systems characterised by their outputs; Constructional details thereof
    • F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
    • F24F11/86—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling compressors within refrigeration or heat pump circuits
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/70—Control systems characterised by their outputs; Constructional details thereof
    • F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
    • F24F11/87—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling absorption or discharge of heat in outdoor units
    • F24F11/871—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling absorption or discharge of heat in outdoor units by controlling outdoor fans
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/88—Electrical aspects, e.g. circuits
    • 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
    • F25B1/00—Compression machines, plants or systems with non-reversible cycle
    • 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
    • F25B13/00—Compression machines, plants or systems, with reversible cycle
    • 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
    • F25B5/00—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity
    • 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
    • F25B5/00—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity
    • F25B5/02—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity arranged in parallel

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Signal Processing (AREA)
  • Fuzzy Systems (AREA)
  • Mathematical Physics (AREA)
  • Air Conditioning Control Device (AREA)
  • Compression-Type Refrigeration Machines With Reversible Cycles (AREA)

Abstract

The invention relates to the technical field of air conditioners, in particular to a control method of a multi-connected air conditioning unit. The invention aims to solve the problems that the heat exchange capacity of an outdoor heat exchanger of an outdoor unit in a running state is limited, and the outdoor heat exchanger of the outdoor unit in a stopped running state is not fully utilized in the conventional multi-connected air conditioning unit. For this purpose, the control method of the multi-connected air conditioning unit provided by the invention judges whether the outdoor units in the stopped state are regulated to the dispersed load state or not based on the related parameters, or controls whether the outdoor units in the dispersed load state are regulated to the stopped state or not. When the outdoor unit is in a dispersed load state, the compressor of the outdoor unit is in a closed state, and the outdoor heat exchanger of the outdoor unit and the outdoor unit in a running state share the compressor to participate in refrigerant circulation, so that the refrigerating or heating capacity and efficiency of the multi-connected air conditioning unit are improved.

Description

Control method of multi-connected air conditioning unit
Technical Field
The invention relates to the technical field of air conditioners, in particular to a control method of a multi-connected air conditioning unit.
Background
A multi-connected air conditioning unit generally includes a plurality of outdoor units and a plurality of indoor units. Each outdoor unit comprises a gas-liquid separator, a compressor and an outdoor heat exchanger, and each indoor unit comprises an indoor heat exchanger and an electronic expansion valve.
In the existing multi-connected air conditioning unit, a plurality of outdoor units are connected in parallel, and a plurality of indoor units are connected in parallel. When the indoor unit is only opened partially, only one outdoor unit is often opened correspondingly; when the indoor units are opened in a large number or all the indoor units are opened, all the outdoor units are opened. When the compressor in the outdoor unit is operated, the outdoor heat exchanger in the outdoor unit is put into use correspondingly.
However, when only a part of the outdoor units are operating, especially when the outdoor temperature is low during heating or high during cooling, the heat exchange capacity of the outdoor heat exchanger of the outdoor unit is limited, and the outdoor heat exchangers of other outdoor units are not fully utilized, so that the cooling or heating capacity and efficiency of the multi-connected air conditioning unit are low.
Accordingly, there is a need in the art for a control method for a multi-connected air conditioning unit that solves the above problems.
Disclosure of Invention
In order to solve the above-mentioned problems in the prior art, i.e. to solve the problem that the existing multi-connected air conditioning unit has low cooling or heating capacity and efficiency because the outdoor heat exchangers of other outdoor units are not fully utilized and the heat exchange capacity of the outdoor heat exchanger of the outdoor unit is limited when only part of the outdoor units are running, especially when the outdoor temperature is low during heating or high during cooling of the outdoor units, the present invention provides a control method for a multi-connected air conditioning unit.
The invention provides a control method of a multi-connected air conditioning unit, wherein the multi-connected air conditioning unit comprises a plurality of outdoor units and a plurality of indoor units, each outdoor unit comprises a compressor and an outdoor heat exchanger, and the control method comprises the following steps: acquiring the total value W of the actual output energy of all the outdoor units in the running statesThe total value W of the actual required energy of all the indoor units in the running statenComparing the parameter WsAnd WnThe size of (d); obtaining the number N of indoor units in a refrigeration running statecAnd the number N of indoor units in heating operation stateh(ii) a Acquiring actual discharge of compressor in outdoor unit in running stateGas pressure value PdOr the actual suction pressure value Ps(ii) a Acquiring the number N of outdoor units in running state in the outdoor unitsrThe number N of outdoor units in a stopped statesAnd the number N of outdoor units in a distributed load statef(ii) a When the outdoor unit is in a dispersed load state, a compressor of the outdoor unit is in a closed state, and an outdoor heat exchanger of the outdoor unit and the outdoor unit in a running state share the compressor and participate in refrigerant circulation; based on the parameter WsAnd WnThe result of the comparison, and the obtained parameter Nc、Nh、PdOr Ps、Nr、Ns、NfWhether the outdoor unit in the stopped state is adjusted to the dispersed load state or not, or whether the outdoor unit in the dispersed load state is adjusted to the stopped state is controlled.
As a preferable technical solution of the control method of the multi-connected air conditioning unit provided by the present invention, the control method includes: judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc> 0 and Nh＝0，Pd＞A1，Nr＞0，Ns＞0，Nf0; if so, adjusting a preset number of outdoor units in the stopped state to a dispersed load state; wherein A is1Is a preset first exhaust pressure threshold.
As a preferable technical solution of the control method of the multi-connected air conditioning unit provided by the present invention, the control method includes: obtaining the last continuous operation time T of the outdoor unit entering the dispersed load statec(ii) a Judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc> 0 and Nh＝0，Pd＞A1，Nr＞0，Ns＞0，Nf＞0，Tc≥T1(ii) a If so, adjusting a preset number of outdoor units in the stopped state to a dispersed load state; wherein A is1Is a preset first exhaust pressure threshold, T1To presetOf the first duration threshold.
As a preferable technical solution of the control method of the multi-connected air conditioning unit provided by the present invention, the control method includes: judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc> 0 and Nh＝0，Pd＜A2，Nr＞0，Ns≥0，NfIs greater than 0; if yes, adjusting a preset number of outdoor units in a dispersed load state to a stop operation state; wherein A is2Is a preset second exhaust pressure threshold.
As a preferable technical solution of the control method of the multi-connected air conditioning unit provided by the present invention, the control method includes: acquiring that the outdoor unit in the running state satisfies the condition Pd＜A2Duration of operation Tr(ii) a When the preset number of outdoor units in the dispersed load state are adjusted to the running stop state, the following conditions are also required to be met: t isr≥T2(ii) a Wherein, T2Is a preset second duration threshold.
As a preferable technical solution of the control method of the multi-connected air conditioning unit provided by the present invention, the control method includes: judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc0 and Nh＞0，Ps＜B1，Nr＞0，Ns＞0，Nf0; if so, adjusting a preset number of outdoor units in the stopped state to a dispersed load state; wherein, B1Is a preset first suction pressure threshold.
As a preferable technical solution of the control method of the multi-connected air conditioning unit provided by the present invention, the control method includes: obtaining the last continuous operation time T of the outdoor unit entering the dispersed load stateh(ii) a Judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc0 and Nh＞0，Ps＜B1，Nr＞0，Ns＞0，Nf＞0，Th≥T1(ii) a If so, adjusting a preset number of outdoor units in the stopped state to a dispersed load state; wherein, B1Is a preset first suction pressure threshold, T1Is a preset first duration threshold.
As a preferable technical solution of the control method of the multi-connected air conditioning unit provided by the present invention, the control method includes: judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc0 and Nh＞0，Ps＞B2，Nr＞0，Ns≥0，NfIs greater than 0; if yes, adjusting a preset number of outdoor units in a dispersed load state to a stop operation state; wherein, B2Is a preset second inspiratory pressure threshold.
As a preferable technical solution of the control method of the multi-connected air conditioning unit provided by the present invention, the control method includes: acquiring that the outdoor unit in the running state satisfies the condition Ps＞B2Duration of operation Tr(ii) a When the preset number of outdoor units in the dispersed load state are adjusted to the running stop state, the following conditions are also required to be met: t isr≥T2(ii) a Wherein, T2Is a preset second duration threshold.
As a preferable technical solution of the control method of the multi-connected air conditioning unit provided by the present invention, the control method includes: acquiring the actual rotating speed n of a fan in an outdoor unit in a running state; when a preset number of outdoor units in a stopped state are adjusted to a dispersed load state, the following conditions are also required: n is more than or equal to ns(ii) a Wherein n issIs a preset rotating speed threshold value.
The control method of the multi-connected air conditioning unit provided by the invention is based on the parameter WsAnd WnThe result of the comparison, and the obtained parameter Nc、Nh、PdOr Ps、Nr、Ns、NfWhether the outdoor unit in the stopped state is adjusted to the dispersed load state or not, or whether the outdoor unit in the dispersed load state is adjusted to the dispersed load state or notAnd regulating to a stop operation state for control. When the outdoor unit is in a dispersed load state, the compressor of the outdoor unit is in a closed state, and the outdoor heat exchanger of the outdoor unit and the outdoor unit in a running state share the compressor to participate in refrigerant circulation, so that the refrigerating or heating capacity and efficiency of the multi-connected air conditioning unit are improved.
The control method of the multi-connected air conditioning unit provided by the invention is based on the parameter WsAnd WnThe result of the comparison, and the obtained parameter Nc、Nh、PdOr Ps、Nr、Ns、NfWhether the outdoor unit in the stopped state is adjusted to the dispersed load state or not, or whether the outdoor unit in the dispersed load state is adjusted to the stopped state is controlled. When the outdoor unit is in a dispersed load state, the compressor of the outdoor unit is in a closed state, and the outdoor heat exchanger of the outdoor unit and the outdoor unit in a running state share the compressor to participate in refrigerant circulation, so that the refrigerating or heating capacity and efficiency of the multi-connected air conditioning unit are improved.
Further, the control method of the multi-connected air conditioning unit provided by the invention obtains the actual rotating speed of the fan in the outdoor unit in the running state; when a preset number of outdoor units in a stopped state are adjusted to a dispersed load state, the following conditions are also required: the actual rotating speed of the fan is greater than or equal to a preset rotating speed threshold value. Therefore, the judgment of whether the outdoor unit in the stopped state needs to be adjusted to the dispersed load state is more reliable.
Drawings
The control method of the multi-connected air conditioning unit according to the invention is described below with reference to the attached drawings and in conjunction with the triple-pipe multi-split air conditioning unit. In the drawings:
fig. 1 is a schematic flow chart of a control method of a multi-connected air conditioning unit according to the present embodiment;
FIG. 2 is a schematic structural diagram of the triple-pipe multi-split air conditioner of the present embodiment;
fig. 3 is a schematic structural view of an outdoor unit in a three-tube type multi-split air conditioner according to this embodiment;
fig. 4 is a schematic structural view of an indoor unit in a three-pipe multi-split air conditioner according to this embodiment.
List of reference numerals
1-an outdoor unit; 111-a first compressor; 112-a first oil separator; 113-a first direction valve; 114 — a first outdoor heat exchanger; 115-a second throttling device; 116-a first one-way valve; 121-a second compressor; 122-a second oil separator; 123-a second reversing valve; 124-a second outdoor heat exchanger; 13-a third reversing valve; 14-a liquid storage tank; 15-gas-liquid separator; 2-an indoor unit; 21-indoor heat exchanger; 22-a fourth directional valve; 23-first throttling means; 3-a first pipeline; 31-a first on-off valve; 4 a second pipeline; 41-a second on-off valve; 5-a third pipeline; 51-third shutoff valve.
Detailed Description
Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only for explaining the technical principle of the present invention, and are not intended to limit the scope of the present invention. Although the control method of the multi-connected air conditioning unit in the embodiment is described in conjunction with the three-pipe multi-connected air conditioning unit in the embodiment, this is not intended to limit the scope of the present invention, and those skilled in the art may apply the present invention to other application scenarios without departing from the principle of the present invention. For example, the multi-connected air conditioner can also realize that the outdoor heat exchanger of the outdoor unit in the stopped operation state and the outdoor unit in the operating state share the compressor to participate in refrigerant circulation by combining a plurality of on-off valves and a plurality of pipelines and other modes, and the control method of the multi-connected air conditioner unit can also be applied.
As shown in fig. 2, fig. 3 and fig. 4, the three-tube multi-split air conditioner provided in the present embodiment includes a plurality of outdoor units 1 and a plurality of indoor units 2, and the present embodiment is described by taking the three-tube multi-split air conditioner including two outdoor units 1 and four indoor units 2 as an example; each outdoor unit 1 includes a first compressor 111, a first outdoor heat exchanger 114, a first direction changing valve 113, and a third direction changing valve 13; each indoor unit 2 comprises an indoor heat exchanger 21, and each indoor unit 2 is also provided with a first throttling device 23 and a fourth reversing valve 22; a first end (i.e., a D end) of the first direction valve 113 is connected to an exhaust port of the first compressor 111, a second end (i.e., a C end) of the first direction valve 113 is connected to a first end of the first outdoor heat exchanger 114, and a third end (i.e., an S end) of the first direction valve 113 is connected to a suction port of the first compressor 111; a second end of the first outdoor heat exchanger 114 is connected with a second end of the indoor heat exchanger 21 through a first pipeline 3, and a first throttling device 23 is arranged between the first pipeline 3 and the second end of the indoor heat exchanger 21; a first end (i.e., end D) of the third direction valve 13 is connected to an exhaust port of the first compressor 111, a second end (i.e., end E) of the third direction valve 13 is connected to a first end (i.e., end D) of the fourth direction valve 22 through the second pipeline 4, and a third end (i.e., end S) of the third direction valve 13 is connected to an intake port of the first compressor 111; a second end (i.e., end E) of the fourth direction valve 22 is connected to a first end of the indoor heat exchanger 21; a third end (i.e., the S end) of the fourth directional valve 22 is connected to the suction port of the first compressor 111 through the third pipe 5; and the first pipes 3 of the outdoor units 1 are connected to the second end of each indoor heat exchanger 21 after being communicated and merged, the second pipes 4 of the outdoor units 1 are connected to the first end (i.e., the D end) of each fourth direction changing valve 22 after being communicated and merged, and the third pipes 5 of the outdoor units 1 are connected to the third end (i.e., the S end) of each fourth direction changing valve 22 after being communicated and merged.
The first direction switching valve 113, the third direction switching valve 13, and the fourth direction switching valve 22 may be implemented by using a three-way valve that can be switched as it is, or may be implemented by connecting both ends of the S-and E-ends of a four-way valve used as the first direction switching valve 113 with a capillary tube, connecting both ends of the C-and S-ends of a four-way valve used as the third direction switching valve 13 with a capillary tube, and connecting both ends of the C-and S-ends of a four-way valve used as the fourth direction switching valve 22 with a capillary tube, as shown in fig. 2 and 3.
The fourth direction valve 22 may be generally provided in the indoor unit 2. The fourth direction changing valve 22 may be a four-way valve as shown in fig. 2, and may be a valve in which the second pipes 4 of the plurality of outdoor units 1 are connected to the first end of each of the indoor heat exchangers 21 through an electronic expansion valve or a solenoid valve after being communicated and merged, and the third pipes 5 of the plurality of outdoor units 1 are connected to the first end of each of the indoor heat exchangers 21 through an electronic expansion valve or a solenoid valve after being communicated and merged. The second pipeline 4 and the third pipeline 5 can be respectively controlled to be communicated with and closed off from the first end of each indoor heat exchanger 21 by an electronic expansion valve or a solenoid valve.
The first throttling device 23 may be a thermal expansion valve, an electronic expansion valve, a capillary tube, etc. for increasing the flow rate, reducing the pressure, and generating a static pressure difference between the refrigerant before entering the first throttling device 23 and the refrigerant after flowing out of the first throttling device 23. The first throttling means 23 in fig. 1 and 3 is an electronic expansion valve, and the first throttling means 23 is provided in the indoor unit 2, but it should be understood by those skilled in the art that the first throttling means 23 may be provided in the outdoor unit 1. As shown in fig. 1 and 2, the triple-pipe multi-split air conditioner may further include a second throttling device 115, the second throttling device 115 is disposed in the outdoor unit 1, and the second throttling device 115 is disposed between the second end of the first outdoor heat exchanger 114 and the first pipeline 3.
It should be noted that, according to the pressure state of the refrigerant in the pipeline, and the gas state and the liquid state, the first pipeline 3 is a liquid pipe, the second pipeline 4 is a high-pressure gas pipe, and the third pipeline 5 is a low-pressure gas pipe in the three-pipe multi-split air-conditioning system of the present embodiment.
The three-pipe multi-split air conditioner provided by the embodiment is provided with a first reversing valve 113, a third reversing valve 13 and a fourth reversing valve 22, as well as a first pipeline 3, a second pipeline 4 and a third pipeline 5. When the heat exchange efficiency of the outdoor heat exchanger is not high due to the reasons of low outdoor temperature during heating of the multi-split air conditioner, high outdoor temperature during cooling of the multi-split air conditioner, etc., the outdoor heat exchanger of the outdoor unit 1 in the stopped state and the outdoor unit 1 in the running state can share the compressor by adjusting the reversing valves (i.e., the first reversing valve 113, the third reversing valve 13, and the fourth reversing valve 22) to participate in refrigerant circulation. Therefore, the refrigerating or heating capacity and efficiency of the multi-connected air conditioning unit are improved. It should be noted that, only the necessary structure and the functions required by the three-tube multi-split air conditioner are briefly described, and how the three-tube multi-split air conditioner realizes that the outdoor heat exchanger of the outdoor unit in the stopped state and the outdoor unit in the running state share the compressor through the first direction changing valve 113, the third direction changing valve 13, the fourth direction changing valve 22, the first pipeline 3, the second pipeline 4, and the third pipeline 5, and the specific operation process and principle of the refrigerant circulation are involved will be described in detail later with the control method of the multi-split air conditioner set.
For convenience of description, in the description, an upper outdoor unit 1 in fig. 1 is referred to as a first outdoor unit, and a lower outdoor unit 1 in fig. 1 is referred to as a second outdoor unit, where necessary. Further, since the first outdoor unit and the second outdoor unit shown in fig. 1 have substantially the same configuration, although the description will be given mainly to the first outdoor unit in fig. 1, a person skilled in the art will clearly understand the configuration of the second outdoor unit and the connection relationship between the respective members.
When the refrigerant is not completely vaporized in the evaporator, the refrigerant containing more liquid directly enters the compressor, which may cause damage to the compressor. In order to prevent this problem, as a preferred embodiment of the above three-pipe multi-split air conditioner provided in this embodiment, a gas-liquid separator 15 may be further provided in the three-pipe multi-split air conditioner. When the gas-liquid separator 15 is provided, the third end (i.e., the S end) of the first direction valve 113, the third end (i.e., the S end) of the third direction valve 13, and the third pipe 5 may be connected to the suction port of the first compressor 111 through the gas-liquid separator 15; and the discharge port of the gas-liquid separator 15 is connected to the suction port of the first compressor 111.
As a preferred embodiment of the three-pipe multi-split air conditioning system provided in this embodiment, the three-pipe multi-split air conditioning system further includes a first oil separator 112; the exhaust port of the first oil separator 112 is connected to a first end (i.e., D-end) of a first direction valve 113; the intake port of the first oil separator 112 is connected to the exhaust port of the first compressor 111. The first oil separator 112 functions to separate lubricating oil from the high-pressure vapor discharged from the first compressor 111, and a liquid discharge port of the first oil separator 112 may be connected to a suction port of the first compressor 111 and may return to the compressor with the refrigerant. To ensure the safe operation of the first compressor 111 and other components in the three-pipe multi-split air conditioner and the whole system.
As a preferred embodiment of the three-pipe multi-split air conditioner provided in this embodiment, the three-pipe multi-split air conditioner further includes a second compressor 121 and a second oil separator 122; the exhaust port of the second oil separator 122 is connected to a first end (i.e., D-end) of the first direction valve 113; the air inlet of the second oil separator 122 is connected to the air outlet of the second compressor 121; the oil discharge port of the first oil separator 112 is connected to the air intake port of the second compressor 121, and the oil discharge port of the second oil separator 122 is connected to the air intake port of the first compressor 111, so that a cross oil return structure is formed. Through the crossed oil return structure, the first compressor 111 and the second compressor 121 are in the same lubricating oil circulation system, and the cooperation of the first compressor 111 and the second compressor 121 is facilitated.
As a preferred embodiment of the three-pipe multi-split air conditioner provided in this embodiment, the three-pipe multi-split air conditioner further includes a pressure balance pipeline, the pressure balance pipeline is connected between the first end (i.e., the D end) of the first direction valve 113 and the suction port of the first compressor 111, and the pressure balance pipeline is provided with a pressure regulating valve. When the discharge pressure of the compressor is large, the pressure regulating valve is opened to reduce the pressure of the refrigerant entering the condenser (the first outdoor heat exchanger 114 during cooling and the indoor heat exchanger 21 during heating).
As a preferred implementation manner of the three-pipe multi-split air conditioner provided in this embodiment, the three-pipe multi-split air conditioner further includes a liquid storage tank 14, and the liquid storage tank 14 is disposed on the first pipeline 3 and located between the first outdoor heat exchanger 114 and the first throttling device 23. The liquid storage tank 14 can automatically adapt to the change of the load, adjust the condensing pressure and avoid the problem that the heat transfer area of the condenser is reduced and the heat transfer effect of the condenser is influenced because the liquid refrigerant is accumulated in the condenser too much, so that the condenser is in the best working condition. Meanwhile, the liquid storage tank 14 can also store liquid components in the refrigerant and adjust the flow rate of the refrigerant according to needs, the liquid storage tank 14 can adapt to the demand of load change of an evaporator (namely an outdoor heat exchanger during heating and an indoor heat exchanger during cooling in an air conditioner) on the supply quantity of the refrigerant, when the evaporation load is increased, the supply quantity is also increased, and the liquid refrigerant stored in the liquid storage tank 14 is supplied; when the load becomes small, the amount of liquid refrigerant required becomes small, and the surplus liquid refrigerant is stored in the receiver tank 14. Therefore, the refrigeration and heating efficiency of the three-pipe multi-split air conditioner is further improved.
As a preferred embodiment of the three-pipe multi-split air conditioner provided in this embodiment, the three-pipe multi-split air conditioner further includes a second reversing valve 123 and a second outdoor heat exchanger 124; a first end (i.e., a D end) of the second direction valve 123 is connected to the discharge port of the first compressor 111, a second end (i.e., a C end) of the second direction valve 123 is connected to a first end of the second outdoor heat exchanger 124, and a third end (i.e., an S end) of the second direction valve 123 is connected to the suction port of the first compressor 111; and a second end of the first outdoor heat exchanger 114 and a second end of the second outdoor heat exchanger 124 are commonly connected to the first pipe 3. In this case, the two ends of the S-terminal and the E-terminal of the four-way valve used as the second direction changing valve 123 are connected by a capillary tube.
In the three-pipe multi-split air conditioner according to the present embodiment, the second compressor 121, the second outdoor heat exchanger 124, and the second direction switching valve 123 are provided in the outdoor unit 1, and are used in parallel with the first compressor 111, the first outdoor heat exchanger 114, and the first direction switching valve 113 in the outdoor unit 1. Thereby further improving the cooling and heating capacity and the operation efficiency of the outdoor unit 1. Since the functions of the second compressor 121, the second outdoor heat exchanger 124, and the second direction switching valve 123 are substantially the same as those of the first compressor 111, the first outdoor heat exchanger 114, and the first direction switching valve 113, the following description will be given by taking only the first compressor 111, the first outdoor heat exchanger 114, and the first direction switching valve 113 as an example for convenience. However, it will be understood by those skilled in the art that the same description of the operation and function of the first compressor 111, the first outdoor heat exchanger 114 and the first direction changing valve 113 applies to the second compressor 121, the second outdoor heat exchanger 124 and the second direction changing valve 123.
As a preferred embodiment of the three-pipe multi-split air conditioning system provided in the present embodiment, the first pipe line 3 is provided with the first on-off valve 31, the second pipe line 4 is provided with the second on-off valve 41, and the third pipe line 5 is provided with the third on-off valve 51. So as to respectively realize the on-off of the first pipeline 3, the second pipeline 4 and the third pipeline 5.
As a preferred embodiment of the three-pipe multi-split air-conditioning system provided in this embodiment, the three-pipe multi-split air-conditioning system further includes a first check valve 116, the first check valve 116 is disposed between the discharge port of the first compressor 111 and the first end (i.e., the D end) of the first direction valve 113, and the first check valve 116 is configured to allow the refrigerant to flow from the discharge port of the first compressor 111 to the first end (i.e., the D end) of the first direction valve 113 only. The first check valve 116 can ensure that the refrigerant can not flow back to the exhaust port of the compressor due to pressure fluctuation and the like, and the problem that the compressor is damaged due to backflow of the refrigerant is avoided.
As a preferred embodiment of the three-pipe multi-split air conditioner provided in this embodiment, the three-pipe multi-split air conditioner further includes a first pressure sensor for monitoring a suction pressure on a suction side of the first compressor 111, and a second pressure sensor for monitoring a discharge pressure on a discharge side of the first compressor 111; and/or a first temperature sensor for monitoring the suction temperature at the suction side of the first compressor 111 and a second temperature sensor for monitoring the discharge temperature at the discharge side of the first compressor 111.
For example, the throttle device or the reversing valve in the three-pipe multi-split air conditioner can be adjusted according to the suction pressure, the discharge pressure, the suction temperature and the discharge temperature of the compressor during operation of the three-pipe multi-split air conditioner, so as to achieve the purpose of efficient cooling and heating.
Accordingly, in order to achieve the same purpose as that achieved by the three-tube multi-connected air conditioning unit, the present embodiment further provides a control method of a multi-connected air conditioning unit, which is mainly used for determining whether the outdoor units in the stopped state need to be adjusted to the distributed load state, and whether the outdoor units in the distributed load state need to be adjusted to the stopped state. It can be understood by those skilled in the art that, although the control method for the multi-connected air conditioning unit in the present embodiment is described in conjunction with the three-pipe multi-connected air conditioning unit in the present embodiment, those skilled in the art may apply the control method to other application scenarios. For example, the multi-split air conditioner may also use a combination of a plurality of on-off valves and a plurality of pipelines, and other ways to realize that the outdoor heat exchanger of the outdoor unit in the stopped state and the outdoor unit in the operating state share the compressor, and participate in the refrigerant circulation, that is, the outdoor unit in the stopped state is adjusted to the dispersed load state.
In this embodiment, a control method for a multi-connected air conditioning unit is provided, where the multi-connected air conditioning unit includes a plurality of outdoor units and a plurality of indoor units, each outdoor unit includes a compressor and an outdoor heat exchanger, and an outdoor unit in the multi-connected air conditioning unit can share the compressor with the outdoor unit in a running state under a condition that the compressor is in a closed state, and participate in refrigerant circulation, as shown in fig. 4, the method includes:
s1, acquiring the total actual output energy value W of all the outdoor units in the running statesThe total value W of the actual required energy of all the indoor units in the running statenComparing the parameter WsAnd WnThe size of (d);
wherein, the total value W of the actual output energy of the outdoor unitsThe actual refrigerating capacity of the outdoor unit is generally measured by how many units, and the refrigerating capacity of one unit of the outdoor unit is generally 2800 watts according to different types of the outdoor unit. In a similar way, according to the difference of the models of the indoor units, each indoor unit is also provided with corresponding matching number when being started. The total value W of the actual output energy of the outdoor unit is generally requiredsIs larger than the total energy demand W of the indoor unitnThe normal operation of the multi-connected air conditioning unit can be ensured.
S2, acquiring the number N of indoor units in the cooling operation statecAnd the number N of indoor units in heating operation stateh；
When an indoor heat exchanger in the indoor unit is used as an evaporator, the indoor unit is in a refrigerating running state; when the indoor heat exchanger in the indoor unit is used as a condenser, the indoor unit is in a heating operation state.
S3, obtaining the actual discharge pressure value P of the compressor in the outdoor unit in the running statedOr the actual suction pressure value Ps；
Wherein, when all the indoor units are in the refrigeration state, the actual exhaust pressure value P needs to be obtainedd(ii) a When all indoor units are in heating state, the actual suction pressure value P needs to be obtaineds. It is understood that the actual exhaust pressure value P may also be obtained simultaneously in different situationsdOr the actual suction pressure value PsAnd selecting the parameters needed to be used when carrying out specific judgment.
S4, obtaining the number N of the outdoor units in the running state in all the outdoor unitsrThe number N of outdoor units in a stopped statesAnd the number N of outdoor units in a distributed load statef；
When the outdoor unit is in a running state, both an outdoor heat exchanger and a compressor of the outdoor unit are in an opening state; when the outdoor unit is in a stop running state, the outdoor heat exchanger and the compressor of the outdoor unit are both in a closed state; when the outdoor unit is in a dispersed load state, the compressor of the outdoor unit is in a closed state, and the outdoor heat exchanger of the outdoor unit and the outdoor unit in a running state share the compressor to participate in refrigerant circulation.
S5, based on parameter WsAnd WnThe result of the comparison, and the obtained parameter Nc、Nh、PdOr Ps、Nr、Ns、NfWhether the outdoor unit in the stopped state is adjusted to the dispersed load state or not, or whether the outdoor unit in the dispersed load state is adjusted to the stopped state is controlled. The specific control method will be described in detail below with reference to the three-pipe multi-split air conditioner shown in fig. 1.
The control method for the multi-connected air conditioning unit provided by the embodiment is based on the parameter WsAnd WnThe result of the comparison, and the obtained parameter Nc、Nh、PdOr Ps、Nr、Ns、NfWhether the outdoor unit in the stopped state is adjusted to the dispersed load state or not, or whether the outdoor unit in the dispersed load state is adjusted to the stopped state is controlled. When the outdoor unit is in a dispersed load state, the compressor of the outdoor unit is in a closed state, and the outdoor heat exchanger of the outdoor unit and the outdoor unit in a running state share the compressor to participate in refrigerant circulation, so that the refrigerating or heating capacity and efficiency of the multi-connected air conditioning unit are improved.
For convenience of description, the specific operation of the triple-tube multi-split air conditioner shown in fig. 1 when the control method of the multi-split air conditioner set is used for adjustment is further described, the distributed load state is further divided into a cooling load distributed state and a heating load distributed state, specifically, the cooling load distributed state refers to the distributed load state of the outdoor unit when all the operating indoor units are in the cooling operation state, and the heating load distributed state refers to the distributed load state of the outdoor unit when all the operating indoor units are in the heating operation state. The upper outdoor unit in fig. 1 is referred to as a first outdoor unit, and the lower outdoor unit in fig. 1 is referred to as a second outdoor unit. Accordingly, there are four specific operations:
(1) the outdoor unit enters a distributed refrigeration load state. Referring to the triple-tube type multi-split air-conditioning system in fig. 2 and 3, when the first outdoor unit of the triple-tube type multi-split air-conditioning system is in an operating state and the second outdoor unit enters a distributed cooling load state, the first end (i.e., the D end) of the first direction valve 113 in the first outdoor unit is communicated with the second end (i.e., the C end), the first end (i.e., the D end) of the third direction valve 13 is communicated with the second end (i.e., the E end), and the electronic expansion valve serving as the second throttling device 115 in the first outdoor unit is opened; a first end (i.e., D end) and a second end (i.e., C end) of the first direction changing valve 113 in the second outdoor unit are connected, and a first end (i.e., D end) and a second end (i.e., E end) of the third direction changing valve 13 are connected; and the second terminal (i.e., the E terminal) and the third terminal (i.e., the S terminal) of the fourth direction changing valve 22 of the indoor unit 2 in the cooling operation state are conducted while the electronic expansion valve serving as the second throttling device 115 in the second outdoor unit is opened. In this case, the refrigerant cycle is as follows: the refrigerant is divided into two paths after flowing out from the first compressor 111 of the first outdoor unit, wherein one path enters the first outdoor heat exchanger 114 through the first reversing valve 113 of the first outdoor unit, and then enters the first pipeline 3; the other path of the refrigerant sequentially enters a first outdoor heat exchanger 114 of the second outdoor unit through a third reversing valve 13 and a second pipeline 4 of the first outdoor unit, and a second pipeline 4, a third reversing valve 13 and a first reversing valve 113 of the second outdoor unit, then enters the first pipeline 3, and the two paths of the refrigerant are converged in the first pipeline 3, then enter the indoor unit 2 in a refrigerating operation state, then enter the third pipeline 5 through a fourth reversing valve 22, and flow back to the first compressor 111 of the first outdoor unit through the third pipeline 5.
(2) The outdoor unit exits the dispersed cooling load state. Referring to the triple-pipe type multi-split air-conditioning system in fig. 2 and 3, the first end (i.e., end D) of the first direction valve 113 in the first outdoor unit is communicated with the second end (i.e., end C), and the first end (i.e., end D) of the third direction valve 13 is communicated with the second end (i.e., end E), while the electronic expansion valve serving as the second throttling device 115 in the first outdoor unit is opened to keep the first outdoor unit normally operating; the first end (i.e., the D end) of the first direction changing valve 113 in the second outdoor unit is communicated with the E end, the first end (i.e., the D end) of the third direction changing valve 13 in the second outdoor unit is communicated with the second end (i.e., the E end), and the electronic expansion valve serving as the second throttling device 115 in the second outdoor unit is closed. Since the first check valve 116 is disposed between the discharge port of the first compressor 111 and the first end (i.e., D-end) of the first direction switching valve 113. At this time, for the second outdoor unit, the refrigerant enters the second pipeline 4 of the second outdoor unit from the second pipeline 4 of the first outdoor unit, and then sequentially passes through the second end (i.e., end E) and the first end (i.e., end D) of the third reversing valve 13 of the second outdoor unit, and the first end (i.e., end D) of the first reversing valve to end E, and the end E and the third end (i.e., end S) are communicated through a capillary tube, only a small amount of refrigerant can flow out from the end S of the first reversing valve, which has an effect equivalent to that the refrigerant is blocked in the second pipeline 4 of the second outdoor unit, thereby blocking a route where an outdoor heat exchanger in the second outdoor unit participates in refrigerant circulation, and enabling the second outdoor unit to exit from a dispersed refrigeration load state.
(3) The outdoor unit enters a distributed heating load state. Referring to the triple-tube multi-split air conditioner in fig. 2 and 3, when the first outdoor unit of the triple-tube multi-split air conditioner is in an operating state and the second outdoor unit enters a heat load distribution state, the second end (i.e., the C end) and the third end (i.e., the S end) of the first direction valve 113 in the first outdoor unit are communicated, the first end (i.e., the D end) and the second end (i.e., the E end) of the third direction valve 13 in the first outdoor unit are communicated, and the electronic expansion valve serving as the second throttling device 115 in the first outdoor unit is opened. The second terminal (i.e., the C terminal) and the third terminal (i.e., the S terminal) of the first direction changing valve 113 in the second outdoor unit are connected, and the first terminal (i.e., the D terminal) and the second terminal (i.e., the E terminal) of the third direction changing valve 13 in the second outdoor unit are connected (this time, corresponding to the off state). And the first end (i.e., D end) and the second end (i.e., E end) of the fourth direction changing valve 22 of the operating indoor unit 2 are conducted while the electronic expansion valve serving as the second throttling device 115 in the second outdoor unit is opened. In this case, the refrigerant cycle is as follows: the refrigerant flows out from the first compressor 111 of the first outdoor unit, enters the indoor unit 2 in the heating state through the second pipeline 4, flows out from the indoor unit 2 in the heating state, then enters the first outdoor heat exchangers 114 of the first outdoor unit and the second outdoor unit through the first pipeline 3, flows out from the second outdoor unit, sequentially passes through the third pipeline 5 of the second outdoor unit and the third pipeline 5 of the first outdoor unit, is merged with the refrigerant flowing out from the first outdoor heat exchanger 114 of the first outdoor unit, and finally flows back to the first compressor 111 of the first outdoor unit.
(4) The outdoor unit exits the state of the distributed heating load. Referring to the triple-pipe type multi-split air-conditioning system in fig. 2 and 3, the second end (i.e., the C end) of the first direction changing valve 113 in the first outdoor unit is connected to the third end (i.e., the S end), the first end (i.e., the D end) of the third direction changing valve 13 in the first outdoor unit is connected to the second end (i.e., the E end), and the electronic expansion valve serving as the second throttling device 115 in the first outdoor unit is opened to keep the first outdoor unit normally operating; the first end (i.e., D end) of the first direction changing valve 113 in the second outdoor unit is connected to the E end, the first end (i.e., D end) of the third direction changing valve 13 in the second outdoor unit is connected to the second end (i.e., E end), and the electronic expansion valve serving as the second throttling device 115 in the second outdoor unit is closed. Since the first check valve 116 is disposed between the discharge port of the first compressor 111 and the first end (i.e., D-end) of the first direction switching valve 113. At this time, for the second outdoor unit, the refrigerant enters the second pipeline 4 of the second outdoor unit from the second pipeline 4 of the first outdoor unit, and then sequentially passes through the second end (i.e., end E) and the first end (i.e., end D) of the third direction valve 13, and the first end (i.e., end D) of the first direction valve is connected to end E, and end E is connected to end S through a capillary tube, so that only a small amount of refrigerant can flow out from end S of the first direction valve.
As a preferred implementation of the control method for the multi-split air conditioning unit provided in this embodiment, the control method includes: judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc> 0 and Nh＝0，Pd＞A1，Nr＞0，Ns＞0，Nf0; if so, adjusting a preset number of outdoor units in the stopped state to a dispersed refrigeration load state; wherein A is1Is a preset first exhaust pressure threshold.
Exemplarily, Ws≥WnThe actual output energy of all the outdoor units in the running state meets the actual required energy of all the indoor units in the running state, and the compressors in other outdoor units do not need to be started. N is a radical ofc> 0 and NhAnd 0 indicates that all the running indoor units are in the cooling running state. N is a radical ofr＞0，Ns＞0，NfWhen the outdoor unit is in the operation state, the outdoor units are in the stop state, and no outdoor unit is in the distributed load state, the outdoor unit is set to 0. In addition, it can be understood that, when the indoor units are all in the cooling operation state, the heat exchangers in the outdoor units in the operation state are all used as condensers. When P is presentd＞A1At time, i.e. at positiveThe actual discharge pressure value of the compressor in the outdoor unit in the running state is greater than the first discharge pressure threshold value, which indicates that the heat exchange efficiency (evaporation efficiency) of the outdoor unit in the running state is low, at this time, a preset number of outdoor units in the stopped running state can be adjusted to the dispersed refrigeration load state, and at this time, the outdoor heat exchangers of the outdoor units in the dispersed refrigeration load state are the same as those of the outdoor units in the running state and are all used as condensers.
As a preferred implementation of the control method for the multi-split air conditioning unit provided in this embodiment, the control method includes: obtaining the last continuous operation time T of the outdoor unit entering the dispersed load statec(ii) a Judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc> 0 and Nh＝0，Pd＞A1，Nr＞0，Ns＞0，Nf＞0，Tc≥T1(ii) a If so, adjusting a preset number of outdoor units in the stopped state to a dispersed refrigeration load state; wherein A is1Is a preset first exhaust pressure threshold, T1Is a preset first duration threshold.
For example, although the three-tube multi-split air conditioner in this embodiment is described by taking two outdoor units as an example, in the three-tube multi-split air conditioner, there may be a plurality of outdoor units, in this case, there may be some outdoor units that have already entered the distributed cooling load state, but the heat exchange efficiency of the outdoor unit in the operating state is still low, and at this time, if there are other outdoor units in the stopped state, the outdoor unit in the stopped state may continue to enter the distributed cooling load state. The actual discharge pressure value P of the outdoor unit in operation state immediately after the last outdoor unit enters the dispersed refrigeration load statedTo reduce the necessary transition time to meet the demand, the necessary transition time may be used as the first duration threshold T1E.g. T1May be 5 minutes, 10 minutes, etc., the first duration threshold T1Can be based on experience or practiceThe situation is set. Accordingly, in this case, for the specific operation of the triple-pipe multi-split air conditioner shown in fig. 1, reference is made to the description of the outdoor unit entering the distributed cooling load state.
As a preferred implementation of the control method for the multi-split air conditioning unit provided in this embodiment, the control method includes: judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc> 0 and Nh＝0，Pd＜A2，Nr＞0，Ns≥0，NfIs greater than 0; if yes, adjusting a preset number of outdoor units in a dispersed load state to be in a stop operation state; wherein A is2Is a preset second exhaust pressure threshold.
Exemplarily, when Pd＜A2The time is that the heat exchange effect of the outdoor unit in the running state is better, and N is in the momentfIf the outdoor unit is more than 0, the outdoor unit is in a dispersed refrigeration load state. In general, it is not necessary to adjust some outdoor units to a distributed cooling load state. A preset number of the outdoor units in the distributed cooling load state can be adjusted to the stopped state. Accordingly, in this case, for the specific operation of the triple-pipe multi-split air conditioner shown in fig. 1, reference is made to the foregoing description of the outdoor unit exiting the distributed cooling load state.
As a preferred implementation of the control method for the multi-split air conditioning unit provided in this embodiment, the control method further includes: acquiring that the outdoor unit in the running state satisfies the condition Pd＜A2Duration of operation Tr(ii) a When the preset number of outdoor units in the dispersed refrigeration load state are adjusted to the stop operation state, the following conditions are also required to be met: t isr≥T2(ii) a Wherein, T2Is a preset second duration threshold. Thus, it can be determined that the outdoor unit in an operating state satisfies the condition P for a long period of timed＜A2Therefore, the judgment of adjusting the outdoor unit in the dispersed refrigeration load state to the stop operation state is more reliable.
As a preferred implementation of the control method for the multi-split air conditioning unit provided in this embodiment, the control method includes: judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc0 and Nh＞0，Ps＜B1，Nr＞0，Ns＞0，Nf0; if yes, adjusting a preset number of outdoor units in the stop operation state to a distributed heating load state; wherein, B1Is a preset first suction pressure threshold.
Exemplary, Ws≥WnThe actual output energy of all the outdoor units in the running state meets the actual required energy of all the indoor units in the running state, and the compressors in other outdoor units do not need to be started. N is a radical ofc0 and NhThe indoor units in operation are all in heating operation state if more than 0. N is a radical ofr＞0，Ns＞0，NfWhen the outdoor unit is in the operation state, the outdoor units are in the stop operation state, and no outdoor unit is in the distributed heating load state, the outdoor unit is set to 0. It is to be understood that, when the indoor units are both in the heating operation state, the heat exchangers in the outdoor units in the operation state are both used as evaporators. When P is presents＜B1When the outdoor unit is in the operating state, that is, the actual suction pressure value of the compressor in the outdoor unit in the operating state is smaller than the first suction pressure threshold value, it indicates that the heat exchange efficiency (condensation efficiency) of the outdoor unit in the operating state is low, at this time, a preset number of outdoor units in the stopped operating state can be adjusted to the distributed heating load state, and at this time, the outdoor heat exchangers of the outdoor units in the distributed heating load state are the same as the outdoor heat exchangers of the outdoor units in the operating state and are all used as evaporators. Accordingly, in this case, for the specific operation of the three-pipe multi-split air conditioner shown in fig. 1, reference is made to the description of the outdoor unit entering the distributed heating load state.
As a preferred implementation of the control method for the multi-split air conditioning unit provided in this embodiment, the control method includes: obtainingLast duration time T of outdoor unit entering into distributed load stateh(ii) a Judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc0 and Nh＞0，Ps＜B1，Nr＞0，Ns＞0，Nf＞0，Th≥T1(ii) a If yes, adjusting a preset number of outdoor units in the stop operation state to a distributed heating load state; wherein, B1Is a preset first suction pressure threshold, T1Is a preset first duration threshold.
For example, although the three-tube multi-split air conditioner in this embodiment is described by taking two outdoor units as an example, in the three-tube multi-split air conditioner, there may be a plurality of outdoor units, in this case, there may be some outdoor units that have already entered the distributed heating load state, but the heat exchange efficiency of the outdoor units is still very low, and at this time, if there are other outdoor units that are in the shutdown operation state, the outdoor units in the shutdown operation state may continue to enter the distributed heating load state. The actual suction pressure value P of the outdoor unit in operation state just after the last outdoor unit enters the dispersed heating load statesTo increase to meet the demand, the necessary transition time may be used as the first duration threshold T1E.g. T1May be 5 minutes, 10 minutes, etc., the first duration threshold T1The setting may be made empirically or actually. Accordingly, in this case, for the specific operation of the three-pipe multi-split air conditioner shown in fig. 1, reference is made to the description of the outdoor unit entering the distributed heating load state.
As a preferred implementation of the control method for the multi-split air conditioning unit provided in this embodiment, the control method includes: judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc0 and Nh＞0，Ps＞B2，Nr＞0，Ns≥0，NfIs greater than 0; if yes, adjusting a preset number of outdoor units in the dispersed heating load stateThe running is stopped; wherein, B2Is a preset second inspiratory pressure threshold.
Exemplarily, when Ps＞B2In time, the heat exchange effect of the outdoor unit is better, and N is obtained at the momentfIf > 0, some outdoor units are in the distributed heating load state. In general, it is not necessary to adjust some outdoor units to a distributed heating load state. A preset number of outdoor units in the distributed heating load state can be adjusted to the stopped state. Accordingly, in this case, for the specific operation of the three-pipe multi-split air conditioner shown in fig. 1, reference is made to the foregoing description of the outdoor unit exiting the distributed heating load state.
As a preferred implementation of the control method for the multi-split air conditioning unit provided in this embodiment, the control method includes: acquiring that the outdoor unit in the running state satisfies the condition Ps＞B2Duration of operation Tr(ii) a When the preset number of outdoor units in the distributed heating load state are adjusted to the stop operation state, the following conditions are also required to be met: t isr≥T2(ii) a Wherein, T2Is a preset second duration threshold. Thus, it can be determined that the outdoor unit in an operating state satisfies the condition P for a long period of times＞B2Therefore, the judgment of whether the outdoor unit in the dispersed heating load state needs to be adjusted to the stop operation state is more reliable.
As a preferred implementation of the control method for the multi-split air conditioning unit provided in this embodiment, the control method includes: further comprising: acquiring the actual rotating speed n of a fan in an outdoor unit in a running state; when a preset number of outdoor units in a stopped state are adjusted to a dispersed load state, the following conditions are also required: n is more than or equal to ns(ii) a Wherein n issIs a preset rotating speed threshold value.
For example, the fan in the outdoor unit can also work in coordination with the outdoor heat exchanger, that is, the fan can automatically adjust according to the heat exchange efficiency of the outdoor heat exchanger, and when the actual rotation speed n of the fan is greater than or equal to nsWatch, clockIt is difficult to improve the heat exchange efficiency of the outdoor heat exchanger by increasing the rotation speed of the fan, so that the judgment of whether the outdoor unit in the stopped state needs to be adjusted to the dispersed load state is more reliable.
It should be noted that although the detailed steps of the method of the present invention have been described in detail, those skilled in the art can combine, separate and change the order of the above steps without departing from the basic principle of the present invention, and the modified technical solution does not change the basic concept of the present invention and thus falls into the protection scope of the present invention. For example, when determining whether a preset number of outdoor units in a stopped state need to be adjusted to a dispersed load state, it may be determined first whether the multiple air conditioning units simultaneously satisfy the following conditions: ws≥Wn，Nc> 0 and Nh＝0，Pd＞A1，Nr＞0，Ns＞0，NfIs greater than 0; if yes, obtaining the last continuous operation time T of the outdoor unit entering the dispersed load statec(ii) a Then judging whether T is satisfiedc≥T1And if so, adjusting a preset number of outdoor units in the stopped state to be in a dispersed load state.
It should be understood by those skilled in the art that the control method of the multi-connected air conditioning unit provided in the present embodiment may be stored as a program in a computer-readable storage medium. The storage medium includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) or a processor (processor) to perform some steps of the methods according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.
Furthermore, those skilled in the art will appreciate that while some embodiments described herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, in the claims of the present invention, any of the claimed embodiments may be used in any combination.
So far, the technical solutions of the present invention have been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of the present invention is obviously not limited to these specific embodiments. Equivalent changes or substitutions of related technical features can be made by those skilled in the art without departing from the principle of the invention, and the technical scheme after the changes or substitutions can fall into the protection scope of the invention.

Claims (10)

1. A control method of a multi-connected air conditioning unit comprises a plurality of outdoor units and a plurality of indoor units, wherein each outdoor unit comprises a compressor and an outdoor heat exchanger, and the control method is characterized by comprising the following steps:
acquiring the total value W of the actual output energy of all the outdoor units in the running statesThe total value W of the actual required energy of all the indoor units in the running statenComparing the parameter WsAnd WnThe size of (d);
obtaining the number N of indoor units in a refrigeration running statecAnd the number N of indoor units in heating operation stateh；
Acquiring the actual discharge pressure value P of the compressor in the outdoor unit in the running statedOr the actual suction pressure value Ps；
Acquiring the number N of outdoor units in running state in all the outdoor unitsrThe number N of outdoor units in a stopped statesAnd the number N of outdoor units in a distributed load statef(ii) a When the outdoor unit is in a dispersed load state, a compressor of the outdoor unit is in a closed state, and an outdoor heat exchanger of the outdoor unit and the outdoor unit in a running state share the compressor and participate in refrigerant circulation;
based on the parameter WsAnd WnThe result of the comparison, and the obtained parameter Nc、Nh、PdOr Ps、Nr、Ns、NfWhether the outdoor unit in the stopped state is adjusted to the dispersed load state or not, or whether the outdoor unit in the dispersed load state is adjusted to the stopped state is controlled.
2. The control method according to claim 1, characterized by comprising:
judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc> 0 and Nh＝0，Pd＞A1，Nr＞0，Ns＞0，Nf＝0；
If so, adjusting a preset number of outdoor units in the stopped state to a dispersed load state;
wherein A is1Is a preset first exhaust pressure threshold.
3. The control method according to claim 1, characterized by comprising:
obtaining the last continuous operation time T of the outdoor unit entering the dispersed load statec；
Judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc> 0 and Nh＝0，Pd＞A1，Nr＞0，Ns＞0，Nf＞0，Tc≥T1；
If so, adjusting a preset number of outdoor units in the stopped state to a dispersed load state;
wherein A is1Is a preset first exhaust pressure threshold, T1Is a preset first duration threshold.
4. The control method according to claim 1, characterized by comprising:
judging whether the multi-connected air conditioning unit simultaneously satisfies the barA piece: ws≥Wn，Nc> 0 and Nh＝0，Pd＜A2，Nr＞0，Ns≥0，Nf＞0；
If yes, adjusting a preset number of outdoor units in a dispersed load state to a stop operation state;
wherein A is2Is a preset second exhaust pressure threshold.
5. The control method according to claim 4, characterized by further comprising:
acquiring that the outdoor unit in the running state satisfies the condition Pd＜A2Duration of operation Tr；
When the preset number of outdoor units in the dispersed load state are adjusted to the running stop state, the following conditions are also required to be met: t isr≥T2；
Wherein, T2Is a preset second duration threshold.
6. The control method according to claim 1, characterized by comprising:
judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc0 and Nh＞0，Ps＜B1，Nr＞0，Ns＞0，Nf＝0；
If so, adjusting a preset number of outdoor units in the stopped state to a dispersed load state;
wherein, B1Is a preset first suction pressure threshold.
7. The control method according to claim 1, characterized by comprising:
obtaining the last continuous operation time T of the outdoor unit entering the dispersed load stateh；
Judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc0 and Nh＞0，Ps＜B1，Nr＞0，Ns＞0，Nf＞0，Th≥T1；
If so, adjusting a preset number of outdoor units in the stopped state to a dispersed load state;
wherein, B1Is a preset first suction pressure threshold, T1Is a preset first duration threshold.
8. The control method according to claim 1, characterized by comprising:
judging whether the multi-connected air conditioning unit simultaneously meets the conditions: ws≥Wn，Nc0 and Nh＞0，Ps＞B2，Nr＞0，Ns≥0，Nf＞0；
If yes, adjusting a preset number of outdoor units in a dispersed load state to a stop operation state;
wherein, B2Is a preset second inspiratory pressure threshold.
9. The control method according to claim 8, characterized by further comprising:
acquiring that the outdoor unit in the running state satisfies the condition Ps＞B2Duration of operation Tr；
When the preset number of outdoor units in the dispersed load state are adjusted to the running stop state, the following conditions are also required to be met: t isr≥T2；
Wherein, T2Is a preset second duration threshold.
10. The control method according to any one of claims 2, 3, 6, and 7, characterized by further comprising:
acquiring the actual rotating speed n of a fan in an outdoor unit in a running state;
when a predetermined number of outdoor units in a stopped state are adjusted to a dispersed load state,the conditions also need to be satisfied: n is more than or equal to ns；
Wherein n issIs a preset rotating speed threshold value.
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