CN111237880A - Heat recovery multi-split air conditioner - Google Patents
Heat recovery multi-split air conditioner Download PDFInfo
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- CN111237880A CN111237880A CN202010135981.6A CN202010135981A CN111237880A CN 111237880 A CN111237880 A CN 111237880A CN 202010135981 A CN202010135981 A CN 202010135981A CN 111237880 A CN111237880 A CN 111237880A
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- control valve
- indoor unit
- air pipe
- outdoor unit
- heat recovery
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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
- F24F1/0007—Indoor units, e.g. fan coil units
- F24F1/0068—Indoor units, e.g. fan coil units characterised by the arrangement of refrigerant piping outside the heat exchanger within the unit casing
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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
- 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
- F24F11/65—Electronic processing for selecting an operating mode
- F24F11/67—Switching between heating and cooling modes
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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
- 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
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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
- F24F12/00—Use of energy recovery systems in air conditioning, ventilation or screening
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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
- F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
- F24F13/24—Means for preventing or suppressing noise
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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
- F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
- F24F13/24—Means for preventing or suppressing noise
- F24F2013/247—Active noise-suppression
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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]
- Y02B30/56—Heat recovery units
Abstract
The invention discloses a heat recovery multi-split air conditioner, comprising: an outdoor unit; a high-low pressure gas pipe connected to the high pressure side and the low pressure side through a controllable valve and a connection pipe, respectively; a low pressure gas pipe connected to a low pressure side of the outdoor unit; at least one indoor unit; the cold and hot switching device is used for controlling the running state of the connected indoor unit to be refrigeration or heating, and comprises a first control valve and a second control valve, wherein the first control valve is connected between the low-pressure air pipe and the indoor air pipe of the indoor unit, and the second control valve is connected between the high-pressure air pipe and the low-pressure air pipe and the indoor air pipe; the outdoor unit controls the controllable valve and the cold-hot switching device is configured to control to close the opened control valve connected with the indoor air pipe and control the opening degree to open the closed control valve connected with the indoor air pipe from small to large when the operation state of the indoor unit is switched. The invention effectively avoids the refrigerant impact sound and the valve opening whistling sound caused by switching the running state of the indoor unit when the indoor unit is in cold and hot running simultaneously.
Description
Technical Field
The invention relates to the technical field of air conditioners, in particular to a heat recovery multi-split air conditioner.
Background
The heat recovery multi-split air conditioner is different from a conventional multi-split air conditioner, the heat recovery multi-split air conditioner can operate a cooling (heating) mode while part of indoor units operate the cooling (heating) mode, and the cooling (cooling) mode is a cold and hot simultaneous mode. The many online products of heat recovery are mostly three controls on the current market, three controls indicate to have high low pressure trachea, medium pressure liquid pipe and three sets of pipelines of low pressure trachea in one set of outer quick-witted system, the many online of heat recovery provides the refrigerant of stable three kinds of states to the system, high pressure, middling pressure and low pressure, indoor set is according to the condition of oneself mode running state, through cold and hot auto-change over device, oneself adjusts the flow direction realization refrigeration of refrigerant and heats the simultaneous operation, wherein changes in temperature auto-change over device and indoor set one-to-one.
In a conventional heat recovery multi-split air conditioner, a cold/hot switching device includes a first control valve and a second control valve, wherein the first control valve is disposed between a low pressure air pipe of an outdoor unit and an indoor unit air pipe, the second control valve is disposed between a high pressure air pipe and a low pressure air pipe of the outdoor unit and the indoor unit air pipe, and an operation state (for example, cooling or heating) of the indoor unit determines an opening/closing of the first control valve and an opening/closing of the second control valve. In the cold and hot simultaneous operation mode of the indoor unit, when the indoor unit performs refrigeration, the first control valve is opened, and the second control valve is closed, so that the indoor unit is called a refrigeration indoor unit; when the indoor unit heats, the second control valve is opened, and the first control valve is closed, so that the indoor unit is called a heating indoor unit.
In the existing heat recovery multi-split air conditioner, when the indoor unit is switched between cold and hot simultaneously in a cold and hot simultaneous operation mode, for example, when the indoor unit is switched from refrigeration to heating, before the switching, the first control valve is opened, the second control valve is closed, at the moment, the indoor side is low pressure, after the switching, the first control valve is closed, the second control valve is opened, and due to the fact that high pressure difference exists on the two sides of the second control valve, refrigerant impact sound and whistle sound generated when the valve is opened can occur during the switching, and the user experience is reduced.
Disclosure of Invention
In order to solve the technical problem, embodiments of the present invention provide a heat recovery multi-split air conditioner, which effectively avoids refrigerant impact sound and valve opening whistling sound caused by switching operation states of an indoor unit when the indoor unit is cold and hot simultaneously, and improves user experience.
In order to realize the purpose of the invention, the invention is realized by adopting the following technical scheme:
the application relates to a heat recovery multi-split air conditioner, comprising: an outdoor unit; a high-low pressure air pipe connected to a high pressure side and a low pressure side of the outdoor unit through a controllable valve and a connection pipe, respectively; a low pressure gas pipe connected to a low pressure side of the outdoor unit; at least one indoor unit; the cold and hot switching device is used for controlling the running state of the connected indoor unit to be refrigeration or heating, and comprises a first control valve and a second control valve, wherein the first control valve is connected between the low-pressure air pipe and an indoor air pipe of the indoor unit, and the second control valve is connected between the high-pressure air pipe and the low-pressure air pipe and the indoor air pipe;
the outdoor unit controls the controllable valve to enable the high-pressure air pipe and the low-pressure air pipe to be connected with the high-pressure side of the outdoor unit, and when the operation state of the indoor unit is switched, the refrigerant switching device is configured to control the opened control valve connected with the indoor air pipe to be closed, and control the opening degree to be increased from small to large to open the closed control valve connected with the indoor air pipe. The valve opening control device is used for avoiding larger refrigerant impact sound and valve opening whistling caused by the opening of the control valve.
In some embodiments of the present application, the specific manner in which the cold-hot switching device controls the opening of the control valve may be: the control valve is opened for a period of time with a small opening degree, and the control valve is completely opened after the pressures on the two sides of the valve are balanced.
In some embodiments of the present application, the first control valve and the second control valve may be selected to be electronic expansion valves, so as to facilitate control and stabilize performance.
In some embodiments of the present application, the second control valve is an electronic expansion valve with a pressure equalizing hole, so as to improve the refrigeration effect of the refrigeration indoor unit that operates in a refrigeration mode when the operation mode of the indoor unit is cold or hot.
In some embodiments of the present application, the controllable valve is a four-way valve; when the four-way valve is in power failure, the high-low pressure air pipe is communicated with the high pressure side of the outdoor unit through a connecting pipeline; and the four-way valve is communicated with the high-low pressure air pipe and the low-pressure air pipe through a connecting pipeline when being electrified.
In some embodiments of the present application, when the heat recovery multi-split air conditioner is switched from cold to hot to complete cooling, the outdoor unit is controlled to stop, the opening degree of the outdoor unit is controlled to be increased from small to large, the second control valve connected with the cooling indoor unit and the first control valve connected with the heating indoor unit are opened, and after a period of time, the outdoor unit is restarted, and the four-way valve is controlled to be powered on for reversing.
In some embodiments of the present application, when the heat recovery multi-split air conditioner switches from complete cooling to cooling and heating, the outdoor unit is controlled to stop, the second control valve connected to the cooling indoor unit is controlled to be closed, the first control valve connected to the heating indoor unit is controlled to be closed, and after a period of time, the outdoor unit is restarted and the four-way valve is controlled to be switched over in a power-down manner.
In some embodiments of the present application, when the heat recovery multi-split air conditioner is switched from cold and hot to complete cooling, after the outdoor unit is controlled to stop and before the outdoor unit is restarted, the outdoor unit is controlled to close the second control valve connected to the heating indoor unit, and then the second control valve connected to the heating indoor unit is controlled to open from small to large by controlling the opening degree again.
In some embodiments of the present application, when the heat recovery multi-split air conditioner is switched from complete cooling to cooling and heating, after the outdoor unit is controlled to stop and before the outdoor unit is restarted, the outdoor unit is controlled to close the second control valve connected to the heating indoor unit, and then the second control valve connected to the heating indoor unit is opened by controlling the opening degree of the outdoor unit to be changed from small to large.
In some embodiments of the present application, the first control valve and the second control valve are both electronic expansion valves, which is convenient for control and has stable performance.
Compared with the prior art, the invention has the advantages and positive effects that: the outdoor unit controls the controllable valve to enable the high-pressure side of the outdoor unit to be communicated with the high-pressure air pipe and the low-pressure air pipe, the cold-hot switching device is opened or closed through the first control valve and the second control valve, refrigeration or heating of an indoor unit connected with the cold-hot switching device is achieved, when the running state of the indoor unit is switched between refrigeration and heating, the control valve needing to be opened is opened until the control valve is completely opened through gradually reducing the opening degree, refrigerant impact sound of the high-pressure side to the low-pressure side is reduced, refrigerant impact sound caused by high-low pressure difference existing on two sides of the valve and whistle sound of the valve opening under the high-pressure difference are effectively.
Other features and advantages of the present invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a structural diagram of a four-way valve connected to a cold-hot switching device and an indoor unit in an embodiment of a heat recovery multi-split air conditioner according to the present invention;
fig. 2 is a connection diagram of a heat recovery multi-split air conditioner according to an embodiment of the present invention when the air conditioner is not fully cooled;
fig. 3 is a connection diagram of the heat recovery multi-split air conditioner according to the embodiment of the present invention in a fully cooling state.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.
All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. In the description of the present invention, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.
In the description of the present invention, it should be noted that the terms "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected unless otherwise explicitly stated or limited. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art. In the foregoing description of embodiments, the particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.
The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.
The present application relates to a heat recovery multi-split air conditioner, as shown in fig. 1, an indoor unit 5 is connected to a high-low pressure air pipe 1 and a low-low pressure air pipe 2 of an outdoor unit (not shown) through a cold-hot switching device 6, and controls a control valve MVS and an MVD in the cold-hot switching device to avoid a large refrigerant impact sound caused when the operation states (including cooling and heating) of the indoor unit 5 are switched.
As shown in fig. 2 and 3, four indoor units are taken as an example.
The four indoor units are an indoor unit 51, an indoor unit 52, an indoor unit 53, and an indoor unit 54, respectively, and each of the indoor units 51 to 54 corresponds to a cold- hot switching device 61, 62, 63, and 64, respectively. The cooling and heating switching devices 61-64 control the indoor units 51-54 to communicate with the high-and low-pressure gas pipes 1 or with the low-pressure gas pipes 2, and medium-pressure liquid pipes (not shown) not shown communicate with liquid pipes (not shown) of the indoor units 61-64.
[ high and low pressure gas pipes ]
The high-low pressure air pipe 1 is branched into a plurality of branches by one pipe according to the number of the indoor units, in this embodiment, the high-low pressure air pipe 1 is branched into four branches, and a high-low pressure air pipe stop valve (not shown) is generally arranged on a main pipe at the front end of the branch, and is used for controlling the communication or closing of the high-low pressure air pipe 1.
The high-low pressure air pipe 1 is respectively connected with the high pressure side of the outdoor unit and the low pressure air pipe 2 through a controllable valve and a connecting pipeline.
Referring to fig. 2 and 3, the controllable valve selection four-way valve 3, which is commonly used in a three-pipe heat recovery multi-split air conditioner, has a first port connected to the high pressure side of the outdoor unit, a second port connected to the high and low pressure pipes 1, a third port connected to the low pressure pipe 2, and a fourth port connected to the bypass valve 4.
The four indoor units 51 to 54 (hereinafter referred to as indoor units) referred to in the present application mainly include simultaneous cooling and heating (i.e., some of the four indoor units perform heating (referred to as heating indoor units), some perform cooling (referred to as cooling indoor units)), complete heating (i.e., all of the four indoor units 51 to 54 perform heating indoor units), and complete cooling (i.e., all of the four indoor units 51 to 54 perform cooling indoor units), wherein both simultaneous cooling and complete heating are also referred to as incomplete cooling.
When the heat recovery multi-split air conditioner works in incomplete refrigeration (namely, an indoor unit works in complete refrigeration), the four-way valve 3 is powered off, so that the high-pressure side is communicated with the high-pressure air pipe 1, and the bypass valve 4 is communicated with the low-pressure air pipe 2, as shown in fig. 2.
When the heat recovery multi-split air conditioner works in complete refrigeration (i.e. the indoor unit works in complete refrigeration), the four-way valve 3 is powered on to change direction, so that the high-pressure air pipe 1 is communicated with the low-pressure air pipe 2 through the connecting pipeline, the high-pressure side of the outdoor unit is communicated with the bypass valve 4, and meanwhile, the high-pressure air pipe 1 is controlled to be communicated with the indoor unit (as described below), as shown in fig. 3.
[ Low-pressure air pipe ]
Similar to the high-low pressure air pipes 1, the low pressure air pipe 2 is branched into a plurality of branches according to the number of the indoor units, in this embodiment, the low pressure air pipe 2 is branched into four branches, and a low pressure air pipe stop valve (not shown) is generally disposed on the trunk pipe at the front end of the branch for controlling the communication or closing of the low pressure air pipe 2.
The low-pressure air pipe 2 is connected with the low-pressure side of the outdoor unit through a connecting pipeline.
[ Cold-Heat switching device ]
The plurality of cooling/heating switching devices according to the present invention have the same configuration, and the cooling/heating switching device 61 to which the indoor unit 51 is connected will be described below as an example.
Referring to fig. 2 and 3, the cold-hot switching device 61 includes a first control valve MVS and a second control valve MVD connected to the indoor unit 51, the first control valve MVS being connected between the air pipe of the indoor unit 51 and the low-pressure air pipe 2, and the second control valve MVD being connected between the air pipe of the indoor unit 51 and the high-and low-pressure air pipes 1.
When the first control valve MVS is controlled to be opened and the second control valve MVD is controlled to be closed, the air pipe of the indoor unit 51 is communicated with the low-pressure air pipe 2, and the indoor unit 51 is a refrigeration indoor unit; when the first control valve MVS is controlled to be closed and the second control valve MVD is controlled to be opened, the air pipe of the indoor unit 51 is communicated with the high-low pressure air pipe 1, and the indoor unit 51 is a heating indoor unit.
[ control strategy ]
As shown in fig. 2 and 3, the outdoor unit according to the present invention can control the power-on or power-off of the four-way valve 3, and when the four-way valve 3 is powered off, the high-pressure and low-pressure gas pipes 1 are communicated with the high-pressure side of the outdoor unit, that is, the indoor unit performs incomplete cooling; when the four-way valve 3 is powered on, the high-low pressure air pipe 1 is communicated with the low-pressure air pipe 2, namely, the indoor unit performs complete refrigeration.
The first control valve MVS and the second control cabinet valve MVD of cold and hot auto-change over device 61 all select for electronic expansion valve in this application, are convenient for control, stable performance.
Referring to fig. 2 and 3, when the indoor units are not fully cooled, both the indoor units 51 and 53 are cooling indoor units, and both the indoor units 52 and 54 are heating indoor units.
The switching between the operation states of the indoor units 51 and 52 will be described as an example.
When the operation state of the indoor unit 51 is switched from cooling to heating, before the switching, the first control valve MVS connected to the air pipe of the indoor unit 51 is opened and the second control valve MVD connected to the air pipe of the indoor unit 51 is closed, that is, the refrigerant flows from the indoor unit 51 to the outdoor unit along the solid arrow in the cold/hot switching device 61, and at this time, the indoor unit 51 side is at a low pressure; on the other hand, if the indoor unit 51 is switched to the heating indoor unit, the first control valve MVS needs to be switched off and the second control valve MVD needs to be switched on, that is, the refrigerant needs to flow from the outdoor unit to the indoor unit 51 along the dashed arrow in the cold/hot switching device 61.
Because the pressure difference between the two sides of the second control valve MVD is relatively large, therefore, in order to avoid the loud refrigerant impact sound caused by the pressure difference (because the second control valve MVD is opened, the high-temperature and high-pressure refrigerant in the high-low pressure air pipe 1 directly impacts and enters the indoor unit 51) and the whistling sound when the second control valve MVD is opened under the relatively large pressure difference, the cold-hot switching device 61 controls the opening degree to gradually open the second control valve MVD from small to large, for example, in the cold-hot switching process, the second control valve MVD is firstly opened by a small opening degree (for example, about 8% of the full opening) to perform pressure regulation on the two sides of the valve, and the second control valve MVD is completely opened after the pressure is balanced, so that the refrigerant impact sound and the whistling sound when the valve is opened can be.
When the operation state of the indoor unit 52 is switched from heating to cooling, before the switching, the first control valve MVS connected to the air pipe of the indoor unit 52 is closed and the second control valve MVD connected to the air pipe of the indoor unit 52 is opened, that is, the refrigerant flows from the outdoor unit to the indoor unit 52 along the dotted arrow in the cold/hot switching device 62, and at this time, the indoor unit 52 side is at a high pressure; if the indoor unit 52 is switched to the cooling indoor unit, the first control valve MVS needs to be switched to be opened and the second control valve MVD needs to be switched to be closed, that is, the refrigerant needs to flow from the indoor unit 52 to the outdoor unit along the solid arrow of the cooling/heating switching device 62.
Because the pressure difference between the two sides of the first control valve MVS is relatively large, therefore, in order to avoid the relatively large refrigerant impact sound (because the first control valve MVS is opened, the high-temperature and high-pressure refrigerant on the indoor unit 52 side directly impacts and enters the high-pressure and low-pressure air pipe 1) caused by the pressure difference and the whistling sound when the first control valve MVS is opened under the relatively large pressure difference, the cold-hot switching device 62 controls the opening degree to gradually open the first control valve MVS from small to large, for example, in the cold-hot switching process, the first control valve MVS is firstly opened by a small opening degree (for example, about 8% of the full opening) to perform pressure regulation on the two sides of the valve, and after the pressure is balanced, the first control valve MVS is completely opened, so that the refrigerant impact sound and the whistling sound.
[ design of pressure equalizing holes ]
At the same time of cooling and heating of the indoor unit, referring to fig. 2, the indoor unit 51 is a cooling indoor unit, the first control valve MVS in the cold-hot switching device 61 is opened, and the second control valve MVD is closed, at this time, the refrigerant flows from the indoor unit 51 to the outdoor unit along the solid arrow in the cold-hot switching device 61, but because the second control valve MVD is closed, the refrigerant remains in the high-low pressure air pipe 1, so that the amount of refrigerant in the indoor unit 51 is relatively small, and the cooling effect is affected.
For solving above-mentioned problem, the second control valve MVD that this application relates to is the electronic expansion valve who has the pressure-equalizing hole, promptly, and the refrigerant of high-pressure side still can get into indoor unit 51 side through second control valve MVD's pressure-equalizing hole when second control valve MVD closes, avoids the refrigerant to be full of the condition of high-low pressure trachea 1, provides the refrigerant for indoor unit 51, guarantees refrigerant volume, effectively improves refrigeration effect.
[ control relating to switching of four-way valves ]
As shown in fig. 2, when the indoor unit performs the incomplete cooling, the operation state of the indoor unit is switched without changing the operation mode of the outdoor unit or operating the four-way valve 3, and the four-way valve 3 is turned off (i.e., turned off).
As shown in fig. 3, when the indoor unit performs the complete cooling, the four-way valve 3 is activated, that is, the four-way valve 3 is powered on (i.e., turned on), and fig. 3 shows a connection diagram between the four-way valve 3 and the high-low pressure gas pipe 1 and the low-low pressure gas pipe 2 when the indoor unit performs the complete cooling.
With continued reference to fig. 3, when the four-way valve 3 is powered on, the high-low pressure air pipe 1 is communicated with the low-pressure air pipe 2 through the connecting pipeline, the bypass valve 4 is communicated with the high-pressure side of the outdoor unit, and the high-low pressure air pipe 1 is controlled to be connected with the indoor unit.
The description will be given taking an example in which the indoor units 51 and 52 form one indoor unit group a.
In fig. 2, the indoor unit 51 is a cooling indoor unit, and the indoor unit 52 is a heating indoor unit. In fig. 3, both the indoor units 51 and 52 are cooling indoor units.
When the indoor unit A is switched to complete refrigeration from cold and hot simultaneously, the four-way valve 3 is switched to be opened from closed, the high-low pressure air pipe 1 is communicated with the low-pressure air pipe 2, and the side A of the indoor unit A is completely changed into low pressure.
Since the indoor unit 51 is kept as a cooling indoor unit, the high-low pressure air pipe 1 is connected to the indoor unit 51 by keeping open the first control valve MVS connected to the indoor unit 51 and controlling open the second control valve MVD connected to the indoor unit 51, and the refrigerant is kept flowing from the indoor unit 51 to the outdoor unit at this time.
In the indoor unit 52, when the indoor unit 52 is switched from heating to cooling, the second control valve MVD and the first control valve MVS connected to the indoor unit 52 are both opened, and thus the high-low pressure air pipe 1 is connected to the indoor unit 52, and at this time, the refrigerant flows from the outdoor unit to the indoor unit 52 to flow from the indoor unit 52 to the outdoor unit, that is, the refrigerant flows from the outdoor unit to the indoor unit 52 (referred to as forward direction) to flow from the indoor unit 52 to the outdoor unit (referred to as reverse direction) in the second control valve MVD connected to the indoor unit 52.
Thus, when the heat recovery multi-split air conditioner is in complete refrigeration, the high-low pressure air pipe 1 is a low-pressure air pipe at the moment, it and the low pressure air pipe 2 form a double low pressure pipeline system, so that the refrigerant can flow to the low pressure air pipe 2 along the first control valve MVS in the cold and hot switching device 61 after passing through the medium pressure liquid pipe to the indoor unit 51 to participate in refrigeration and heat exchange, and flow to the high and low pressure air pipe 1 along the second control valve MVD in the cold and hot switching device 61 to simultaneously return to the outdoor unit to complete the system circulation, and the refrigerant can flow to the low pressure air pipe 2 along the first control valve MVS in the cold and hot switching device 62 after entering the indoor unit 52 through the medium pressure liquid pipe and participating in the refrigeration and heat exchange, and flow to the high and low pressure air pipe 1 along the second control valve MVD in the cold and hot switching device 62, and then return to the outdoor unit to complete the system circulation, thereby greatly improving the refrigerant utilization rate, meanwhile, the pressure drop of the low-pressure side of the outdoor unit is greatly reduced, and the energy efficiency level of the heat recovery multi-split air conditioner during complete refrigeration is greatly improved.
In the switching process of the indoor unit 52, the refrigerant flowing through the second control valve MVD connected to the indoor unit 52 is switched between the forward direction and the reverse direction, that is, the high-pressure and low-pressure air pipe 1 needs to be changed from the original high pressure to the low pressure, so that it is necessary to first close the opened second control valve MVD connected to the indoor unit 52, then reopen the second control valve MVD, and control to open the first control valve MVS connected to the indoor unit 52.
When the indoor unit A is switched from complete refrigeration to cold and hot, the four-way valve 3 is switched from open to close, the high-low pressure air pipe 1 is connected with the high pressure side of the outdoor unit, and the low-pressure air pipe 2 is connected with the bypass valve 4.
In the indoor unit 51, the first control valve MVS connected to the indoor unit 51 is kept open, and the second control valve MVD connected to the indoor unit 51 is controlled to be closed, so that the refrigerant is kept flowing from the indoor unit 51 to the outdoor side.
In the indoor unit 52, when the indoor unit 52 is switched from cooling to heating, it is necessary to open the second control valve MVD connected to the indoor unit 52 and close the first control valve MVS connected to the indoor unit 52, and at this time, the flow of refrigerant from the indoor unit 52 to the outdoor unit is switched from outdoor to indoor unit 52, that is, the flow of refrigerant in the second control valve MVD connected to the indoor unit 52 is changed from indoor unit 52 to the outdoor (i.e., reverse) to outdoor to indoor unit 52 (i.e., forward).
In the switching process of the indoor unit 52, the refrigerant flowing through the second control valve MVD connected to the indoor unit 52 is switched between the forward direction and the reverse direction, that is, the high-pressure and low-pressure air pipe 1 needs to be changed from the original high pressure to the low pressure, so that the second control valve MVD connected to the indoor unit 52 that has been opened needs to be closed first, and then the second control valve MVD needs to be opened again.
Similarly, the indoor units 53 and 54 are also switched in a manner similar to that described above, and the principle and process are referred to as described above and are not described herein again.
When the four-way valve 3 is switched, a large noise is generated, and the forward/reverse flow switching of the refrigerant in the control valves MVS and MVD in the cooling/heating switching devices 61 to 64 also causes a large refrigerant impact sound.
Therefore, in order to reduce the above noise, when the indoor unit switches between the cooling and heating and the complete cooling, the outdoor unit is first controlled to stop, and at the same time, the control valve to be opened is gradually opened from small to large, and then the outdoor unit is completely opened after the pressures on the two sides of the valve are equalized, and after the indoor unit stops for a certain period of time (for example, 180 seconds), the outdoor unit is restarted and the four-way valve 3 is switched. Therefore, through the matching of the outdoor unit and the cold-heat switching devices 61-64, the refrigerant impact sound is effectively avoided, and the user experience is improved.
When the heat recovery multi-split air conditioner is switched between the cooling and heating simultaneous operation and the complete cooling operation, when the heat recovery multi-split air conditioner is in the cooling and heating simultaneous operation, referring to fig. 2, the indoor unit 51 is a cooling indoor unit, the first control valve MVS in the cooling and heating switching device 61 is opened and the second control valve MVD is closed, at this time, the refrigerant flows from the indoor unit 51 to the outdoor unit along the solid arrow in the cooling and heating switching device 61, but at this time, because the second control valve MVD is closed, the refrigerant is left in the high-low pressure air pipe 1, so that the amount of refrigerant in the indoor unit 51 is relatively small, and the cooling effect is.
For solving above-mentioned problem, the second control valve MVD that this application relates to is the electronic expansion valve who has the pressure-equalizing hole, promptly, and the refrigerant of high-pressure side still can get into indoor unit 51 side through second control valve MVD's pressure-equalizing hole when second control valve MVD closes, avoids the refrigerant to be full of the condition of high-low pressure trachea 1, provides the refrigerant for indoor unit 51, guarantees refrigerant volume, effectively improves refrigeration effect.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions.
Claims (9)
1. A heat recovery multi-split air conditioner, comprising:
an outdoor unit;
a high-low pressure air pipe connected to a high pressure side and a low pressure side of the outdoor unit through a controllable valve and a connection pipe, respectively;
a low pressure gas pipe connected to a low pressure side of the outdoor unit;
at least one indoor unit;
the cold and hot switching device is used for controlling the running state of the connected indoor unit to be refrigeration or heating, and comprises a first control valve and a second control valve, wherein the first control valve is connected between the low-pressure air pipe and an indoor air pipe of the indoor unit, and the second control valve is connected between the high-pressure air pipe and the low-pressure air pipe and the indoor air pipe;
when the outdoor unit controls the controllable valve to connect the high-pressure air pipe and the low-pressure air pipe with the high-pressure side of the outdoor unit, and when the operation state of the indoor unit is switched, the cold-hot switching device is configured to control to close the opened control valve connected with the indoor air pipe, and control the opening degree to be increased from small to large to open the closed control valve connected with the indoor air pipe.
2. The heat recovery multi-split air conditioner as claimed in claim 1, wherein the cold-hot switching device controls to open the control valve by: the control valve is opened for a period of time with a small opening degree, and the control valve is completely opened after the pressures on the two sides of the valve are balanced.
3. The heat recovery multi-split air conditioner as recited in claim 1, wherein the first control valve and the second control valve are both electronic expansion valves.
4. The heat recovery multi-split air conditioning unit according to claim 3, wherein the second control valve is an electronic expansion valve with a pressure equalizing hole.
5. The heat recovery multi-split air conditioner according to claim 1,
the controllable valve is a four-way valve;
when the four-way valve is in power failure, the high-low pressure air pipe is communicated with the high pressure side of the outdoor unit through a connecting pipeline;
and the four-way valve is communicated with the high-low pressure air pipe and the low-pressure air pipe through a connecting pipeline when being electrified.
6. The heat recovery multi-split air conditioner according to claim 5,
when the heat recovery multi-split air conditioner is switched from cold and heat to complete refrigeration, the outdoor unit is controlled to stop, the opening degree is controlled to be changed from small to large, a second control valve connected with a refrigeration indoor unit and a first control valve connected with a heating indoor unit are opened, the outdoor unit is restarted after a period of time, and the four-way valve is controlled to be electrified and reversed;
when the heat recovery multi-split air conditioner is switched from complete refrigeration to cold and hot, the outdoor unit is controlled to stop, the second control valve of the outdoor unit connected with the refrigeration indoor unit is controlled to be closed, the first control valve of the outdoor unit connected with the heating indoor unit is controlled to be closed, after the outdoor unit is kept for a period of time, the outdoor unit is restarted, and the four-way valve is controlled to be switched over in a power-down mode.
7. The heat recovery multi-split air conditioner as claimed in claim 6, wherein when the heat recovery multi-split air conditioner is switched from cold to hot to full cooling, after the outdoor unit is controlled to stop and before the outdoor unit is restarted, the outdoor unit is controlled to close the second control valve connected with the heating indoor unit, and then the opening of the second control valve connected with the heating indoor unit is controlled to be opened from small to large;
when the heat recovery multi-split air conditioner is switched from complete refrigeration to cold and heat, after the outdoor unit is controlled to stop and before the outdoor unit is restarted, the second control valve connected with the heating indoor unit is controlled to be closed, and then the second control valve connected with the heating indoor unit is opened by controlling the opening degree from small to large.
8. The heat recovery multi-split air conditioning unit according to any one of claims 5 to 7, wherein the first control valve and the second control valve are both electronic expansion valves.
9. The heat recovery multi-split air conditioner according to claim 8, wherein the second control valve is an electronic expansion valve with a pressure equalizing hole.
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| CN202010135981.6A CN111237880A (en) | 2020-03-02 | 2020-03-02 | Heat recovery multi-split air conditioner |
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| CN202010135981.6A CN111237880A (en) | 2020-03-02 | 2020-03-02 | Heat recovery multi-split air conditioner |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112178893A (en) * | 2020-09-22 | 2021-01-05 | 广东美的暖通设备有限公司 | Air conditioner, control method, and computer-readable storage medium |
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Application publication date: 20200605 |