CN112444002A - Air conditioner - Google Patents
Air conditioner Download PDFInfo
- Publication number
- CN112444002A CN112444002A CN202011371833.0A CN202011371833A CN112444002A CN 112444002 A CN112444002 A CN 112444002A CN 202011371833 A CN202011371833 A CN 202011371833A CN 112444002 A CN112444002 A CN 112444002A
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- China
- Prior art keywords
- defrosting
- heat exchanger
- outdoor
- outdoor heat
- refrigerant
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B13/00—Compression machines, plants or systems, with reversible cycle
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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
- F24F5/00—Air-conditioning systems or apparatus not covered by F24F1/00 or F24F3/00, e.g. using solar heat or combined with household units such as an oven or water heater
- F24F5/0007—Air-conditioning systems or apparatus not covered by F24F1/00 or F24F3/00, e.g. using solar heat or combined with household units such as an oven or water heater cooling apparatus specially adapted for use in air-conditioning
- F24F5/001—Compression cycle type
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
- F25B47/02—Defrosting cycles
- F25B47/022—Defrosting cycles hot gas defrosting
- F25B47/025—Defrosting cycles hot gas defrosting by reversing the cycle
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
- F25B2313/025—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple outdoor units
- F25B2313/0251—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple outdoor units being defrosted alternately
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
- F25B2313/027—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means
- F25B2313/02741—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means using one four-way valve
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
- F25B2313/029—Control issues
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
- F25B2400/19—Pumping down refrigerant from one part of the cycle to another part of the cycle, e.g. when the cycle is changed from cooling to heating, or before a defrost cycle is started
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Air Conditioning Control Device (AREA)
Abstract
The invention discloses an air conditioner, comprising: at least one indoor unit; a plurality of outdoor unit modules, each outdoor unit module comprising: a compressor; a flow path switching device; two outdoor heat exchangers; two liquid pipe throttling devices; two gas side valves; a defrosting circuit that branches a part of the refrigerant discharged from the compressor and selects one of the plurality of outdoor heat exchangers in response to the branching of the part of the refrigerant and allows the refrigerant to flow therein; two throttling devices, one end of each throttling device is connected with a main air pipe corresponding to the outdoor heat exchanger, and the other end of each throttling device is connected with a liquid pipe throttling device corresponding to the other outdoor heat exchanger and is connected to the position of a main liquid pipe of the other outdoor heat exchanger; the control device controls each outdoor heat exchanger to be defrosted to sequentially rotate for defrosting or one outdoor heat exchanger to be defrosted in each of the outdoor unit modules to be combined and rotated for defrosting. The invention can control the pressure of the defrosting heat exchanger to defrost and improve the defrosting efficiency and indoor thermal comfort while keeping the uninterrupted heating and indoor machine capability of the air conditioning system to be maximized.
Description
Technical Field
The invention relates to the technical field of air conditioners, in particular to an air conditioner.
Background
The technology of the air source heat pump multi-split air conditioner is mature day by day, and the air source heat pump multi-split air conditioner is widely applied to the fields of household and business. The air source heat pump multi-split air conditioner comprises at least one indoor unit and at least one outdoor unit module, wherein when the number of the indoor units is two or more, the indoor units are arranged in parallel, each indoor unit is provided with an indoor heat exchanger and a corresponding indoor fan, when the number of the outdoor unit modules is two or more, the outdoor unit modules are arranged in parallel, each outdoor unit module is provided with a variable frequency compressor, a four-way valve, a throttling element, at least one outdoor heat exchanger and an outdoor fan, which are communicated through a connecting pipeline, and when the number of the outdoor heat exchangers is at least two, the outdoor heat exchangers are arranged in parallel.
The air source heat pump has a big problem in heating operation: when outdoor temperature and humidity reach certain conditions, outdoor heat exchanger air side can frost, and along with the increase of the volume of frosting, the evaporimeter surface can be blockked up gradually, leads to outdoor heat exchanger surface heat transfer coefficient to reduce, and the gas flow resistance increases, seriously influences the machine effect of heating, consequently, the unit needs regularly to defrost.
At present, a reverse defrosting mode is mostly adopted, the reversing is mainly realized by opening a four-way valve, an outdoor unit is switched into a condenser, the defrosting is realized by utilizing the sensible heat and the latent heat of condensation of a high-temperature and high-pressure refrigerant, the defrosting speed is high, and the reliability is good. However, when defrosting is performed, heating operation is stopped, and heat is absorbed from the indoor space due to the fact that the indoor heat exchanger is switched to the evaporator, so that the indoor temperature is obviously reduced, and indoor thermal comfort is seriously affected.
In order to solve the problems, hot gas bypass defrosting is arranged, namely, the exhaust gas of a compressor is led into an outdoor heat exchanger to be defrosted by using a bypass branch to defrost under the condition that the flow direction of a system refrigerant is not changed.
This defrosting mode has the following disadvantages: 1. the heat converted by the power consumption of the compressor is utilized for defrosting, which belongs to low-pressure defrosting, and the heat is less and the defrosting time is long; 2. when the hot gas bypass defrosting is carried out, low-pressure sensible heat is utilized for defrosting, the temperature is lower, the heat exchange temperature difference with a frost layer is small, and the defrosting reliability is poor; 3. although the flow direction of the refrigerant is not changed during defrosting, the flow rate of the refrigerant of the indoor unit is very small, the system does not supply heat to the indoor unit, the indoor temperature is reduced during defrosting, and the user comfort is poor.
Disclosure of Invention
The embodiment of the invention provides an air conditioner, which can control the pressure and defrost of a defrosting heat exchanger while keeping the uninterrupted heating of an air conditioning system and the maximization of the capacity of an indoor unit, and can improve the defrosting efficiency and the indoor thermal comfort.
In order to realize the purpose of the invention, the invention is realized by adopting the following technical scheme:
the application relates to an air conditioner, its characterized in that includes:
at least one indoor unit;
a plurality of outdoor unit modules, each outdoor unit module comprising:
a compressor;
a flow path switching device for switching a flow path of the refrigerant discharged from the compressor;
two outdoor heat exchangers arranged in parallel;
two liquid pipe throttling devices which are respectively connected with each outdoor heat exchanger and the indoor unit;
two air side valves each connecting the flow path switching device and the air side of each outdoor heat exchanger;
a defrosting circuit that branches a part of the refrigerant discharged from the compressor and selects one of the two outdoor heat exchangers to allow the refrigerant to flow therein;
two throttling devices, one end of each throttling device is connected with a main air pipe corresponding to the outdoor heat exchanger, and the other end of each throttling device is connected with a liquid pipe throttling device corresponding to the other outdoor heat exchanger and is connected to the position of a main liquid pipe of the other outdoor heat exchanger;
a control device for controlling the flow path switching device, the air side valve, the liquid pipe throttling device, the throttling device and the defrosting circuit in each outdoor unit module;
when the outdoor heat exchangers need defrosting, the control device controls the outdoor heat exchangers to be defrosted to sequentially rotate for defrosting or one outdoor heat exchanger combination to be defrosted in each outdoor unit module to be combined and rotated for defrosting, so that the outdoor heat exchangers to be defrosted are used as defrosting heat exchangers to be executed, and the rest outdoor heat exchangers are used as evaporators to be executed;
when the defrosting is performed by turns, the control device controls the flow path switching device in the outdoor unit module where each defrosting heat exchanger is positioned to be powered on; controlling the defrost circuit to communicate a portion of refrigerant discharged from the compressor with a liquid side tube of a defrost heat exchanger; controlling to close a gas side valve and a liquid pipe throttling device which are communicated with the defrosting heat exchanger; and controlling to open a throttling device connected with the air pipe side of the defrosting heat exchanger.
The utility model relates to an air conditioner, when the air conditioner that has a plurality of off-premises station modules carries out the defrosting, flow path auto-change over device, each liquid pipe throttling set, each gas side valve, each throttling arrangement and defrosting return circuit among the control device control each off-premises station module, combine the defrosting selection mode (select to wait that the outdoor heat exchanger of defrosting carries out the cycle defrosting in proper order of one at every turn, or select the outdoor heat exchanger combination cycle defrosting of waiting to defrost in each of a plurality of off-premises station modules, can guarantee when waiting to defrost the outdoor heat exchanger and defrost, all the other outdoor heat exchangers can form the heating cycle with the indoor set, realize the incessant heating simultaneously that the defrosting, utilize the latent heat defrosting of refrigerant, defrost speed is fast, and make indoor set ability maximize simultaneously, promote user's thermal comfort, and indoor temperature can rise fast after the defrosting.
In the present application, in defrosting the defrosting heat exchanger, the control device is configured to:
controlling and opening a throttling device which is arranged in an outdoor unit module where the defrosting heat exchanger is located and connected with the defrosting heat exchanger, and controlling and adjusting the opening of the throttling device according to the outlet supercooling degree of the defrosting heat exchanger and the target outlet supercooling degree range;
and controlling and adjusting the amount of the refrigerant of which one part of the refrigerant discharged by the compressor enters the liquid side pipe of the defrosting heat exchanger according to the defrosting pressure and the target defrosting pressure range.
In this application, control is opened throttling arrangement, according to defrosting heat exchanger's export supercooling degree and target export supercooling degree scope, control adjustment throttling arrangement's aperture specifically is:
setting the supercooling degree range of the target outlet;
calculating the supercooling degree of the outlet of the defrosting heat exchanger;
and comparing whether the outlet supercooling degree is within the target outlet supercooling degree range, if so, keeping the current opening degree of the throttling device, and if not, adjusting the opening degree of the throttling device.
In the present application, the amount of the refrigerant, which is a part of the refrigerant discharged from the compressor and enters the liquid side tube of the defrosting heat exchanger, is controlled and adjusted according to the defrosting pressure and the target defrosting pressure range, specifically:
setting a target defrosting pressure range;
calculating the defrosting pressure of the heat exchanger to be defrosted;
and comparing whether the defrosting pressure is within the target defrosting pressure range, if so, keeping the amount of the refrigerant of a part of the refrigerant discharged by the compressor entering a liquid side pipe of the defrosting heat exchanger, and if not, adjusting the amount of the refrigerant of the part of the refrigerant discharged by the compressor entering the liquid side pipe of the defrosting heat exchanger.
In this application, the opening degree of the throttling device is adjusted, specifically:
when the outlet supercooling degree is larger than the upper limit value of the target outlet supercooling degree range, increasing the opening degree of the throttling device;
and when the outlet supercooling degree is smaller than the lower limit value of the target outlet supercooling degree range, reducing the opening degree of the throttling device.
In this application, the amount of refrigerant passing through the defrost branch is adjusted, specifically:
when the defrosting pressure is larger than the upper limit value of the target defrosting pressure range, reducing the amount of refrigerant of a part of refrigerant discharged by a compressor entering a liquid side pipe of the defrosting heat exchanger;
and when the defrosting pressure is smaller than the lower limit value of the target defrosting pressure range, increasing the amount of the refrigerant of a part of the refrigerant discharged by the compressor entering a liquid side pipe of the defrosting heat exchanger.
In the application, when the defrosting heat exchanger is defrosted, if the first preset defrosting time is reached, the defrosting heat exchanger exits from the defrosting process and enters into a common heating operation process; or
When a plurality of defrosting heat exchangers perform sequential rotation defrosting, if the outlet temperature of the defrosting heat exchanger is greater than or equal to a first temperature preset value and is maintained for a certain period of time, the defrosting heat exchanger exits the defrosting process and enters a normal heating operation process;
when a plurality of defrosting heat exchangers are combined for defrosting by turns, if the outlet temperature of each of all the defrosting heat exchangers which simultaneously defrost is greater than or equal to a first temperature preset value and is maintained for a certain period of time, the defrosting heat exchanger which simultaneously defrosts exits the defrosting process and enters a normal heating operation process.
In this application, the defrosting heat exchanger exits the defrosting process and enters the normal heating operation process, which at least includes:
controlling to cut off a part of the refrigerant discharged from the compressor from entering a liquid side pipe of the defrosting heat exchanger;
controlling to open a liquid pipe throttling device communicated with the defrosting heat exchanger;
and controlling to open a gas side valve communicated with the defrosting heat exchanger.
In this application, the target defrost pressure range is related to the ambient temperature.
In the present application, the defrost circuit comprises:
the two defrosting branches respectively correspond to the two outdoor heat exchangers in each outdoor unit module;
and the two defrosting throttling devices are respectively and correspondingly arranged on each defrosting branch and are controlled by the control device.
In this application, the outdoor unit module further includes:
the two outdoor fans respectively correspond to the two outdoor heat exchangers and are connected with the control device, and each outdoor fan and the corresponding outdoor heat exchanger form an air field;
a separation device for separating adjacent wind farms;
and when the defrosting is performed by turns, the control device controls to close the outdoor fan corresponding to the defrosting heat exchanger.
In the application, when one outdoor heat exchanger in each outdoor unit module is defrosting, the rotating speed of an outdoor fan corresponding to the other outdoor heat exchanger in the outdoor unit module is increased.
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 system structure diagram of an embodiment of an air conditioner according to the present invention;
fig. 2 is a flowchart illustrating a defrosting heat exchanger of an outdoor unit module according to an embodiment of the air conditioner of the present invention.
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.
[ basic operation principle of air conditioner ]
A refrigeration cycle of an air conditioner includes a compressor, a condenser, an expansion valve, and an evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation, and supplies refrigerant to the air that has been conditioned and heat-exchanged.
The compressor compresses a refrigerant gas in a high-temperature and high-pressure state and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process.
The expansion valve expands the liquid-phase refrigerant in a high-temperature and high-pressure state condensed in the condenser into a low-pressure liquid-phase refrigerant. The evaporator evaporates the refrigerant expanded in the expansion valve and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor. The evaporator can achieve a cooling effect by heat-exchanging with a material to be cooled using latent heat of evaporation of a refrigerant. The air conditioner can adjust the temperature of the indoor space throughout the cycle.
The outdoor unit of an air conditioner refers to a portion including a compressor of a refrigeration cycle and includes an outdoor heat exchanger, the indoor unit of an air conditioner includes an indoor heat exchanger, and an expansion valve may be provided in the indoor unit or the outdoor unit of an air conditioner.
The indoor heat exchanger and the outdoor heat exchanger serve as a condenser or an evaporator. When the indoor heat exchanger is used as a condenser, the air conditioner is used as a heater in a heating mode, and when the indoor heat exchanger is used as an evaporator, the air conditioner is used as a cooler in a cooling mode.
[ air-conditioner ]
In the present application, the outdoor unit module is similar to the air conditioning outdoor unit as described above.
The air conditioner of this application design is many online air conditioners.
The air conditioner includes at least one indoor unit, which are arranged in parallel.
Each indoor unit includes indoor heat exchangers 11-1 and 11-2, respectively (i.e., the indoor heat exchangers as described above), and an indoor fan (not shown) for blowing cold or hot air generated by the indoor heat exchangers 11-1 and 11-2, respectively, toward an indoor space.
Of course, the number of indoor units is not limited to the number described above, and the number of indoor heat exchangers and indoor fans in each indoor unit is not limited to the number described above.
The air conditioner comprises at least two outdoor unit modules, and the outdoor unit modules are arranged in parallel.
For example, referring to fig. 1, two parallel outdoor unit modules W1 and W2 are shown.
The outdoor unit module W1/W2 comprises a compressor, a flow path switching device, two outdoor heat exchangers arranged in parallel, two liquid pipe throttling devices, two outdoor fans, a defrosting loop, two gas side valves and a gas-liquid separator.
The outdoor unit modules W1 and W2 have the same structure, and each outdoor unit module includes two parallel outdoor heat exchangers.
The configuration of the outdoor unit module W1 will be described as an example.
The outdoor unit module W1 includes a compressor 1, a check valve 2, a flow switching device 3, two outdoor heat exchangers 4-1 and 4-2 arranged in parallel, two liquid pipe throttles 6-1 and 6-2, two outdoor fans 5-1 and 5-2, a defrost circuit, two gas side valves 20-1 and 20-2, and a gas-liquid separator 14.
The flow path switching device 3 switches a flow path of the refrigerant discharged from the compressor 1 to the indoor unit or the outdoor heat exchanger. In the present application, the flow path switching device 3 is a four-way valve having four terminals C, D, S and E.
When the flow switching device 3 is powered off, the default C is connected with the default D, the default S is connected with the default E, the indoor heat exchangers 11-1 and 11-2 are used as evaporators, the outdoor heat exchangers 4-1 and 4-2 are used as condensers, and the air conditioner refrigerates.
When the four-way valve is electrified and reversed, the C is connected with the S, and the D is connected with the E, so that the heat exchangers 11-1 and 11-2 of the indoor unit are used as condensers, the heat exchangers 4-1 and 4-2 of the outdoor unit are used as evaporators, and the air conditioner heats.
Referring to fig. 1, the number of the outdoor heat exchangers is the same as that of the outdoor fans and corresponds to one another.
The outdoor unit module W1 has an outdoor heat exchanger 4-1/4-2, an outdoor fan 5-1/5-2, a pipe throttling means 6-1/6-2 connecting a liquid pipe of the indoor heat exchanger 11-1/11-2 and a liquid pipe of the outdoor heat exchanger 4-1/4-2, a gas side valve 20-1/20-2 connected between the gas pipe of the outdoor heat exchanger 4-1/4-2 and the flow path switching device 3, a throttling device 19-1 provided between the main gas pipe of the outdoor heat exchanger 4-1 and the position where the liquid pipe throttling device 6-2 is connected to the main liquid pipe of the outdoor heat exchanger 4-2, and a throttling device 19-2 provided between the main gas pipe of the outdoor heat exchanger 4-2 and the position where the liquid pipe throttling device 6-1 is connected to the main liquid pipe of the outdoor heat exchanger 4-1.
Referring to fig. 1, the defrost circuit of the outdoor unit module W1 in the present application includes two defrost branches 21 and 22.
Specifically, the defrosting branch 21 is provided on a pipe between the discharge port of the compressor 1 and the liquid pipe side of the outdoor heat exchanger 4-1, and the defrosting branch 22 is provided on a pipe between the discharge port of the compressor 1 and the liquid pipe side of the outdoor heat exchanger 4-2.
A gas pipe throttling device 18-1 is arranged on the defrosting branch 21, and when the defrosting branch is opened, part of refrigerant discharged by the compressor 1 can be throttled to a proper pressure through the gas pipe throttling device 18-1 to enter the outdoor heat exchanger 4-1 for heat exchange defrosting.
A gas pipe throttling device 18-2 is arranged on the defrosting branch 22, and when the defrosting branch is opened, part of refrigerant discharged by the compressor 1 can be throttled to a proper pressure through the gas pipe throttling device 18-2 to enter the outdoor heat exchanger 4-2 for heat exchange defrosting.
One end of the throttling device 19-1 is connected with a main air pipe of the outdoor heat exchanger 4-1, and the other end is arranged on a pipeline between a junction position where the defrosting branch 22 is connected with a main liquid pipe of the outdoor heat exchanger 4-2 and the liquid pipe throttling device 6-2.
One end of the throttling device 19-2 is connected with a main air pipe of the outdoor heat exchanger 4-2, and the other end is arranged on a pipeline between a junction position where the defrosting branch 21 is connected with a main liquid pipe of the outdoor heat exchanger 4-1 and the liquid pipe throttling device 6-1.
The control means is used to control the opening and closing of the flow path switching means 3, the air side valves 20-1 and 20-2, the liquid pipe throttling means 6-1 and 6-2, the throttling means 19-1 and 19-2, and the defrosting branches 21 and 22 (i.e. to control the opening and closing of the air pipe throttling means 18-1 and 18-2) in the outdoor unit module W1.
In the present application, the air side valves 20-1 and 20-2 are controllable valves such as solenoid valves and large-diameter two-way valves (e.g., reversible two-way valves with extremely small resistance), and do not have a throttling function.
The liquid pipe throttling device 6-1/6-2, the throttling device 19-1/19-2, the indoor side liquid pipe throttling device 10-1/10-2 and the air pipe throttling devices 18-1 and 18-2 can adopt an electronic expansion valve, a bidirectional thermal expansion valve and the like.
In the present application, if there are two outdoor unit modules W1 and W2 as shown in fig. 1, defrosting the defrosting heat exchanger may include the following three cases.
(1) Any one of the outdoor heat exchangers 4-1 and 4-2 in the outdoor unit module W1 is used as a defrosting heat exchanger, and the other one of the outdoor heat exchangers 4-1 and 4-2 in the outdoor unit module W1 and the outdoor heat exchangers 4-1 'and 4-2' in the outdoor unit module W2 are used as evaporators;
after any one of the outdoor heat exchangers 4-1 and 4-2 in the outdoor unit module W1 is used as a defrosting heat exchanger for defrosting, any one of the outdoor heat exchangers which is not defrosted is selected for defrosting, and the rest outdoor heat exchangers are used as evaporators;
until all outdoor heat exchangers finish defrosting;
in this case, the outdoor heat exchangers to be defrosted are sequentially and alternately defrosted;
(2) any one of the outdoor heat exchangers 4-1 'and 4-2' in the outdoor unit module W2 is used as a defrosting heat exchanger, and the other one of the outdoor heat exchangers 4-1 'and 4-2' in the outdoor unit module W2 and the outdoor heat exchangers 4-1 and 4-2 in the outdoor unit module W1 are used as evaporators;
after any one of the outdoor heat exchangers 4-1 'and 4-2' in the outdoor unit module W2 is used as a defrosting heat exchanger for defrosting, any one of the outdoor heat exchangers which is not defrosted is selected for defrosting, and the rest outdoor heat exchangers are used as evaporators;
until all outdoor heat exchangers finish defrosting;
in this case, the outdoor heat exchangers to be defrosted are sequentially and alternately defrosted;
(3) meanwhile, the combination defrosting of the outdoor heat exchanger 4-1 at the left side in the outdoor unit module W1 and the outdoor heat exchanger 4-1 'at the left side in the outdoor unit module W2 is selected, and the outdoor heat exchanger 4-2 at the right side of the outdoor unit module W1 and the outdoor heat exchanger 4-2' at the right side of the outdoor unit module W2 are used as evaporators;
after the outdoor heat exchanger 4-1 and the outdoor heat exchanger 4-1' are combined for defrosting, the outdoor heat exchanger 4-2 and the outdoor heat exchanger 4-2' are selected for combined defrosting, and the outdoor heat exchanger 4-1' are used as evaporators;
until all outdoor heat exchangers finish defrosting;
in this case, the combination of the outdoor heat exchangers to be defrosted rotates to defrost;
that is, at the same time, it is ensured that at most one of the outdoor heat exchangers W1 and W2 is defrosted, and a plurality of outdoor heat exchangers belonging to the same outdoor unit module cannot be defrosted at the same time.
The combination is by turns the defrosting for when guaranteeing that indoor constantly heats, promote defrosting efficiency.
As for whether the air conditioner selects sequential rotation defrosting or combined rotation defrosting, the air conditioner needs to be set in advance at the beginning of operation.
[ operation mode of air conditioner ]
The air conditioner has a normal heating operation mode, a normal cooling operation mode, a reverse defrosting operation mode, and a shift defrosting operation mode.
Heating mode of operation in general
The heating operation mode is not different from the common heating operation mode of the air conditioner.
Since the outdoor unit modules W1 and W2 have the same control method and the same refrigerant flow direction during normal heating operation, only the normal heating operation mode of the air conditioner having the outdoor unit module W1 and at least one indoor unit will be described for convenience of description.
Referring to fig. 1, in some embodiments, when the air conditioner is in a normal heating operation mode, both air side valves 20-1 and 20-2 are opened, both air pipe throttles 18-1 and 18-2 are closed, both liquid pipe throttles 6-1 and 6-2 are opened, both throttles 19-1 and 19-2 are closed, and both outdoor fans 19-1 and 19-2 are opened in the outdoor unit module W1.
In some embodiments, the flow switching device 3 is electrically switched to connect D and E and C and S, the compressor 1 compresses the low-temperature and low-pressure refrigerant into a high-temperature and high-pressure state, and the refrigerant discharged from the compressor 1 passes through the check valve 2 and D and E and enters the indoor heat exchangers 11-1 and 11-2 through the gas side stop valve 13 and the first extension pipe 12.
After heat exchange in the indoor heat exchangers 11-1 and 11-2, condensation heat release is carried out to form liquid refrigerant, and then the refrigerant passes through the indoor machine side throttling devices 10-1 and 10-2, the second extension pipe 9 and the liquid side stop valve 8 and enters the liquid pipe throttling devices 6-1 and 6-2 to be throttled to a low-temperature low-pressure gas-liquid state.
The two-phase refrigerant enters the outdoor heat exchangers 4-1 and 4-2 to be evaporated and absorb heat and is changed into a gas state, the refrigerant coming out of the outdoor heat exchangers 4-1 and 4-2 passes through the gas side valves 20-1 and 20-2, enters the gas-liquid separator 14 through C and S, and is finally sucked into the compressor 1 to be compressed, and the heating cycle is completed.
Similarly, the refrigerant flow direction of the outdoor unit module W2 in the normal heating operation mode is the same as that of the outdoor unit module W1.
The refrigerant flow direction in the normal heating operation mode of the air conditioner having the outdoor unit modules W1 and W2 is indicated by the dotted arrows in fig. 1. The outdoor fans 5-1 and 5-2 are always turned on throughout the normal heating operation mode.
Normal cooling mode of operation
The normal cooling operation mode is the same as the normal cooling operation mode of the air conditioner.
In the normal cooling operation of the outdoor unit modules W1 and W2, the control method and the refrigerant flow direction of the components are the same, and therefore, for convenience of description, only the normal cooling operation mode of the air conditioner having the outdoor unit module W1 and at least one indoor unit will be described.
Referring to fig. 1, in some embodiments, when the air conditioner is in a normal cooling operation mode, both air side valves 20-1 and 20-2 are opened, both air pipe throttles 18-1 and 18-2 are closed, both liquid pipe throttles 6-1 and 6-2 are opened, both throttles 19-1 and 19-2 are closed, and both outdoor fans 5-1 and 5-2 are opened in the outdoor unit module W1.
The flow path switching device 2 is powered off, the default D and C are communicated, the default E and S are communicated, the compressor 1 compresses a low-temperature and low-pressure refrigerant into a high-temperature and high-pressure state, the refrigerant discharged by the compressor 1 passes through the one-way valves 2, the one-way valves D and C, the air-side valves 20-1 and 20-2 and then enters the outdoor heat exchangers 4-1 and 4-2.
After heat exchange of the outdoor heat exchangers 4-1 and 4-2, condensation heat release is carried out to form liquid refrigerant, and then the refrigerant is throttled by the liquid pipe throttling devices 6-1 and 6-2, passes through the liquid side stop valve 8 and the second extension pipe 9, enters the indoor heat exchangers 11-1 and 11-2 to be evaporated and absorbed heat and is changed into gas state.
The refrigerants discharged from the indoor heat exchangers 11-1 and 11-2 pass through the first extension pipe 12, the gas side stop valve 13, and the four-way valves E and S, enter the gas-liquid separator 14, and are finally sucked into the compressor 1 to be compressed, thereby completing the refrigeration cycle.
The outdoor fans 5-1 and 5-2 are always turned on throughout the normal cooling operation mode.
Reverse defrost mode of operation
When the control device of the air conditioner detects and judges that the outdoor heat exchanger 4-1 and/or 4-2 and/or 4-1 'and/or 4-2' needs defrosting, the compressor 1 firstly reduces the frequency or directly stops, and the indoor fan and the outdoor fan stop running.
Then, the four-way valve is powered off and reversed, the compressor 1 is started, the outdoor heat exchangers 4-1, 4-2, 4-1 'and 4-2' are used as condensers to perform defrosting, namely heating of all indoor units is stopped, and defrosting is performed on all the outdoor heat exchangers 4-1, 4-2, 4-1 'and 4-2'.
After the defrosting is completed, the air conditioner reenters the normal heating operation mode.
The reverse defrosting operation mode has the advantages of clean defrosting, but also has a plurality of defects (1) that the heating operation is stopped during defrosting, the indoor temperature is obviously reduced, and the use comfort of users is influenced; (2) during defrosting, the flow direction of the refrigerant needs to be changed, and particularly during heating operation after defrosting, because a large amount of refrigerant is stored in the gas-liquid separator 14 during defrosting, the high-low pressure difference is slowly established after defrosting, the heating capacity is low, and the heating cycle capacity is seriously influenced.
Alternate defrost mode of operation
The alternate defrosting operation mode is operated under the conditions that the outdoor heat exchanger needs to be defrosted and the indoor unit still needs to have certain heating capacity, so that the air conditioner can keep heating continuously while the outdoor heat exchanger to be defrosted is defrosted, the indoor temperature fluctuation is reduced, and the heating comfort of a user is enhanced.
And in the defrosting process, the defrosting pressure of the defrosting heat exchanger is controlled, the latent heat of the refrigerant is utilized for defrosting, compared with hot gas bypass defrosting, sensible heat defrosting is utilized, the defrosting efficiency is high, the defrosting time is short, the heat acquired by the indoor unit is large, and the user comfort level is high.
When a plurality of outdoor heat exchangers exist in W1 and W2 in the outdoor unit module for defrosting, the plurality of outdoor heat exchangers to be defrosted perform sequential rotation defrosting or combined rotation defrosting.
When the outdoor heat exchangers 4-1, 4-2, 4-1 'and 4-2' are sequentially rotated for defrosting, a defrosting process is performed according to defrosting conditions, and defrosting is started, for example, according to a preset sequence, and in the defrosting process, the control device performs control of the defrosting heat exchanger (i.e., the outdoor heat exchanger that is performing defrosting) and the remaining outdoor heat exchangers.
When the outdoor heat exchangers 4-1, 4-2, 4-1 'and 4-2' are combined and rotated for defrosting, a defrosting process is started according to defrosting conditions, and defrosting is started according to a preset combination sequence, for example, and the control device controls the defrosting heat exchanger and the rest of the outdoor heat exchangers in the defrosting process.
The defrosting condition can be judged according to the existing judgment basis, for example, the running time of the compressor and the temperature difference between the ambient temperature and the outdoor unit coil temperature are taken as the criterion.
In the two defrosting processes, if there is a defrosting heat exchanger in the outdoor unit module, the control of the devices related to the defrosting heat exchanger in the outdoor unit module where the defrosting heat exchanger is located is the same, and the rest of the devices in the outdoor unit module are kept in the same state as in the normal heating operation mode.
Specifically, for example, if there is a defrosting heat exchanger in the outdoor unit module, the opening degree of the throttle device 19-1 (19-1 ') and the opening degree control process of the air pipe throttle device 18-1 (18-1 ') are the same for the outdoor unit module W1 (W2) in which the defrosting heat exchanger 4-1 (4-1 ') is located during defrosting.
That is, the outdoor heat exchanger 4-1 is defrosted in the outdoor unit module W1, including two cases.
In the first case: the remaining outdoor heat exchangers 4-2, and the outdoor heat exchangers 4-1 'and 4-2' in the outdoor unit module W2 function as evaporators.
In the second case: one defrosting heat exchanger combination in each of the outdoor unit modules W1 and W2 performs combined alternate defrosting, for example, the outdoor heat exchanger 4-1 in the outdoor unit module W1 and the outdoor heat exchanger 4-1 'in the outdoor unit module W2 perform combined alternate defrosting, and the remaining outdoor heat exchanger 4-2 and the outdoor heat exchanger 4-2' in the outdoor unit module W2 serve as evaporators.
The control process of the opening degree of the throttle device 19-1 and the opening degree of the air pipe throttle device 18-1 in the outdoor heat exchanger W1 is the same as the control process of the opening degree of the throttle device 19-1 'and the opening degree of the air pipe throttle device 18-1' in the outdoor heat exchanger W2.
In some embodiments, referring to fig. 1, the defrosting of the outdoor heat exchanger 4-1 in the outdoor unit module W1 is only described as an example.
The process of defrosting the defrosting heat exchanger is described as follows.
S1: the method comprises the steps of controlling a flow path switching device 2 in an outdoor unit module where a defrosting heat exchanger is located to be electrified, controlling a defrosting loop to enable one part of refrigerant discharged by a compressor 1 to be communicated with the defrosting heat exchanger, controlling a liquid pipe throttling device and a gas side valve which are communicated with the defrosting heat exchanger to be closed, controlling a throttling device which is connected with a gas pipe side of the defrosting heat exchanger to be opened, and executing the rest outdoor heat exchanger as an evaporator.
And (4) taking the outdoor heat exchanger 4-1 in the outdoor unit module as a defrosting heat exchanger to execute, and entering a defrosting process.
The flow path switching device 3 is kept powered on, the air pipe throttling device 18-1 on the defrosting branch 21 is controlled to be opened, the outdoor fan 5-1 is closed, the liquid pipe throttling device 6-1 is closed, the air side valve 20-1 is closed, the throttling device 19-1 is opened, and the rest devices in the outdoor unit module W1 are kept in the same state as in the normal heating operation mode.
The flow path switching device 2, the air pipe throttling device 18-1, the outdoor fan 5-1, the liquid pipe throttling device 6-1, the air side valve 20-1 and the throttling device 19-1 are all devices in the outdoor unit module W1.
In the first case, each device in the outdoor unit module W2 remains the same as it is in the normal heating operation mode.
In the second case, S1 is also correspondingly performed for the outdoor heat exchanger 4-1 in the outdoor unit module W2 and each device in the outdoor heat exchanger 4-2' in the outdoor unit module W2 remains the same as it is in the normal heating operation mode.
Referring to fig. 1, solid arrows indicate a refrigerant flow direction during a defrosting process of the outdoor heat exchanger 4-1, in which the outdoor heat exchanger 4-2 of the outdoor unit module W1 and the outdoor heat exchangers 4-1 and 4-2 of the outdoor unit module W2 are both implemented as evaporators.
When entering the alternate defrosting operation mode, the compressor 1 compresses a low-temperature and low-pressure refrigerant into a high-temperature and high-pressure state, and discharges the high-temperature and high-pressure refrigerant through the check valve 2.
A part of the high-temperature and high-pressure refrigerant passes through the flow switching devices 3D and E, the gas-side shutoff valve 13, and the first extension pipe 12, and enters the indoor heat exchangers 11-1 and 11-2.
After heat exchange in the indoor heat exchangers 11-1 and 11-2, condensation heat release is carried out to form liquid refrigerant, and then the refrigerant enters the liquid pipe throttling device 6-2 to be throttled to a low-temperature low-pressure gas-liquid state through the indoor machine side throttling devices 10-1 and 10-2, the second extension pipe 9 and the liquid side stop valve 8.
And the other part of high-temperature and high-pressure refrigerant is throttled to a proper pressure by the air pipe throttling device 18-1 on the defrosting branch 21 and then enters the outdoor heat exchanger 4-1 for heat exchange and defrosting.
The defrosted refrigerant is throttled by the throttling device 19-1, then is merged with the refrigerant throttled by the liquid pipe throttling device 6-2, then enters the outdoor heat exchanger 4-2 together for heat exchange, then enters the gas-liquid separator 14 through the gas side valve 20-2 and the C and S of the flow path switching device 3, and finally is sucked into the compressor 1.
Of course, the number of outdoor unit modules is not limited to two, and the air conditioner may include more than two outdoor unit modules.
Regardless of the number of outdoor unit modules, when the outdoor heat exchangers in the outdoor unit modules are sequentially rotated for defrosting or combined rotated for defrosting, two outdoor heat exchangers in each outdoor unit module are rotated for defrosting.
If the defrosting heat exchanger exists in the outdoor unit module, the control of devices related to the defrosting heat exchanger in the outdoor unit module where the defrosting heat exchanger is located is the same.
For example, the outdoor heat exchanger 4-1 in the outdoor heat exchanger W1 is a defrosting heat exchanger, and the opening degree of the throttling device 19-1 is controlled and adjusted according to the supercooling degree of the outlet of the outdoor heat exchanger 4-1 and the target supercooling degree range of the outlet, so that the supercooling degree of the outlet of the outdoor heat exchanger 4-1 tends to be maintained in the target supercooling degree range of the outlet; according to the defrosting pressure of the outdoor heat exchanger 4-1 and the target defrosting pressure range, the opening degree of the air pipe throttling device 18-1 is controlled and adjusted to ensure that the defrosting pressure of the defrosting heat exchanger 4-1 tends to be maintained in the target defrosting pressure range, the defrosting pressure is ensured, the latent heat is utilized for defrosting, the defrosting speed and efficiency are improved, the capacity of an indoor unit is maximized, and the indoor thermal comfort of a user is improved.
In defrosting the outdoor heat exchanger 4-1, how to control the opening degree of the throttle device 19-1 and the opening degree of the air pipe throttle device 18-1 is described in detail with reference to fig. 2.
Before entering the defrosting process, the initial opening degree of the defrosting time throttling device 19-1 and the air pipe throttling device 18-1 needs to be set.
S1': the target outlet supercooling degree range of the outdoor heat exchanger 4-1 and the target defrosting pressure range are set.
In the present application, there is a range for the target outlet supercooling degree Te1sco, for example, 0 ℃ C. ltoreq. Te1 sco. ltoreq.10 ℃.
A target outlet supercooling degree range (Te 1sco- λ, Te1sco + λ) is set, for example, 0 ℃ < λ < 3 ℃ based on the target outlet supercooling degree Te1 sco.
In the present application, the target defrosting pressure Pfo is a function Pfo = f (Ta) of the ambient temperature Ta, and the function Pfo = f (Ta) may be a preset function determined when the air conditioner is commissioned.
When the ambient temperature sensor detects the ambient temperature Ta, the range of the target defrosting pressure Pfo can be known from the function f (Ta).
A target defrosting pressure range (Pfo-delta, Pfo + delta) is set based on the target defrosting pressure Pfo, for example, 0MPa < delta < 0.5 MPa.
S2': and calculating the supercooling Te1sc of the outlet of the outdoor heat exchanger 4-1.
The outlet supercooling degree Te1sc of the outdoor heat exchanger 4-1 is calculated by the defrosting pressure Pm (detected by the pressure sensor 222) and the outlet temperature Te1 (detected by the temperature sensor 233) of the outdoor heat exchanger 4-1.
That is, Te1sc = Tec-Te1, where Tec is the corresponding saturation temperature at the defrost pressure Pm, obtainable by prior art inquiry.
S3': comparing whether the outlet supercooling degree Te1sc is in the target outlet supercooling degree range;
s31': if the outlet supercooling degree Te1sc is in the target outlet supercooling degree range, keeping the current opening degree of the throttling device 19-1, and executing to S4'; if not, the current opening degree of the throttle device 19-1 is adjusted, and the process goes to S4'.
The process of specifically adjusting the current opening degree of the throttle device 19-1 is described as follows.
S32': if the outlet supercooling degree Te1sc is greater than the upper limit value of the target outlet supercooling degree range, the opening degree of the throttle device 19-1 is increased by one adjustment step number, and execution is performed to S4'.
That is, the next opening degree EV19-1(n +1) = EV19-1(n) + Δ EV19-1 of the throttle device 19-1, where Δ EV19-1 is the number of adjustment steps, where the number of adjustment steps may be selected to be 0.1% -10% pls (i.e., the number of steps) of the total opening degree.
S33': if the outlet supercooling degree Te1sc is smaller than the lower limit value of the target outlet supercooling degree range, the opening degree of the throttle device 19-1 is decreased by one adjustment step number, and execution is performed to S4'.
That is, the next opening degree EV19-1(n +1) = EV19-1(n) - Δ EV19-1 of the throttle device 19-1, where Δ EV19-1 is the number of adjustment steps, where the number of adjustment steps may be selected to be 0.1% -10% pls (i.e., the number of steps) of the total opening degree.
S4': whether the defrost pressure Pm is within the target defrost pressure range is compared, if yes, the amount of refrigerant passing through the defrost branch 21 is maintained and is performed to S2, and if no, the amount of refrigerant passing through the defrost branch 21 is adjusted and is performed to S2.
The amount of refrigerant passing through the defrost branch 21 is adjusted by controlling the opening of the air pipe throttling device 18-1 on the defrost branch 21, as follows.
S41': if the defrost pressure Pm is within the target defrost pressure range, the opening degree of the air pipe throttle device 18-1 is maintained, and the process goes to S2.
S42': if the defrost pressure Pm is greater than the upper limit value of the target defrost pressure range, the opening degree of the air pipe throttling device 18-1 is decreased by one adjustment step number, and the process goes to S2.
That is, the next opening degree EV18-1(n +1) = EV18-1(n) - Δ EV18-1 of the tracheal throttle device 18-1, where Δ EV18-1 is the number of adjustment steps, where the number of adjustment steps may be selected to be 0.1% -10% pls (i.e., the number of steps) of the total opening degree.
S43': if the defrost pressure Pm is less than the lower limit value of the target defrost pressure range, the opening degree of the air pipe throttling device 18-1 is increased by one adjustment step number, and the process goes to S2.
That is, the next opening degree EV18-1(n +1) = EV18-1(n) + Δ EV18-1 of the tracheal throttle device 18-1, where Δ EV18-1 is the number of adjustment steps, where the number of adjustment steps may be selected to be 0.1% -10% pls (i.e., the number of steps) of the total opening degree.
S2: and judging whether defrosting is finished or not, if so, exiting the defrosting process, otherwise, returning to S2', and adjusting the opening degrees of the throttling device 19-1 and the air pipe throttling device 18-1 again.
As the defrosting end condition, it may be determined whether the defrosting time period T1 reaches a first preset time T1, or whether the outlet temperature Te1 of the outdoor heat exchanger 4-1 is greater than or equal to a first preset temperature Tef (e.g., 2 ℃ < Tef < 20 ℃) and is maintained for a certain time period T; and if one of the two conditions is met, indicating that the defrosting is finished, otherwise, continuing to judge.
Of course, the defrosting end condition is not limited to this, and for example, it may be determined by using whether or not the air pipe temperature Tg of the outdoor heat exchanger 4-1 is equal to or higher than the set temperature Tn and whether or not the suction pressure Ps of the compressor 1 is equal to or higher than the set pressure Po; alternatively, the number of times of adjustment of the opening degrees of the throttle device 19-1 and the pipe throttle device 18-1, and the like may be used.
Although S3 'is performed before S4' as described above, the order of S3 'and S4' is not limited, i.e., S4 'may also be performed before S3'.
And after the defrosting of the outdoor heat exchanger 4-1 is finished, the defrosting process is quitted, and then the normal heating operation process is carried out.
The outdoor heat exchanger 4-1 exits the defrosting process and enters a normal heating operation process, which specifically comprises the following steps:
(1) controlling the air pipe throttling device 18-1 on the defrosting branch 21 to be closed;
(2) opening an outdoor fan 5-1;
(3) opening the pipe throttling device 6-1;
(4) opening the air side valve 20-1;
(5) the throttle device 19-1 is closed.
Thereafter, the outdoor heat exchanger 4-2 serves as a defrosting heat exchanger to enter a defrosting process, and the outdoor heat exchanger 4-1 serves as an evaporator to maintain a normal heating operation process.
And keeping the flow path switching device 3 powered on, controlling the air pipe throttling device 18-2 on the defrosting branch 22 to open and the throttling device 19-2, and closing the outdoor fan 5-2, the liquid pipe throttling device 6-2 and the air side valve 20-2, wherein the rest devices are kept in the same state as in the normal heating operation mode.
The defrosting process of the outdoor heat exchanger 4-2 is referred to as the defrosting process of the outdoor heat exchanger 4-1.
When the outdoor heat exchanger 4-2 is defrosted, the outdoor heat exchanger 4-1 performs a normal heating operation process.
Similarly, after the outdoor heat exchanger 4-2 exits defrosting, one of the outdoor heat exchangers to be defrosted in the outdoor unit module W2 (for example, the outdoor heat exchanger 4-1 'is implemented as a defrosting heat exchanger), and the outdoor heat exchanger 4-2' in the outdoor unit module W2 performs a normal heating operation process.
The above description mainly describes the control of each device of the outdoor unit module where the defrosting heat exchanger is located when the defrosting is sequentially switched.
Similarly, when the outdoor heat exchangers in the outdoor unit modules W1 and W2 are combined and rotated for defrosting, the defrosting heat exchangers in the outdoor unit modules are defrosted by the defrosting control method as described above for each outdoor unit module.
And when all defrosting heat exchangers defrosting simultaneously meet defrosting ending conditions, defrosting can be ended and a normal heating operation mode is entered.
Referring to fig. 1, for example, when the outdoor heat exchanger 4-1 and the outdoor heat exchanger 4-1' perform combined defrosting, the outdoor heat exchanger 4-1 and the outdoor heat exchanger 4-1' simultaneously enter defrosting, and the outdoor heat exchanger 4-2' function as evaporators.
In the defrosting process, the outdoor unit module W1 is defrosted by the defrosting process described above for the outdoor heat exchanger 4-1, and the outdoor unit module W2 is defrosted by the defrosting process described above for the outdoor heat exchanger 4-1', and the specific process is described above and is not described herein again.
And after the outdoor heat exchanger 4-1 and the outdoor heat exchanger 4-1' both meet the defrosting ending condition, the defrosting process is quitted and the normal heating operation mode is entered.
For example, whether the defrosting time period T1 reaches the first preset time T1, or whether both the outlet temperature Te1 of the outdoor heat exchanger 4-1 and the outlet temperature Te1 'of the outdoor heat exchanger 4-1' are greater than or equal to the first preset temperature Tef and are maintained for a certain time period T; and if one of the two conditions is met, indicating that the defrosting is finished, otherwise, continuing to judge.
Thereafter, the outdoor heat exchanger 4-2 and the outdoor heat exchanger 4-2' are subjected to combined defrosting.
After the outdoor heat exchangers 4-1, 4-2, 4-1 'and 4-2' are alternately defrosted for multiple times, a reverse defrosting operation mode can be selected to completely defrost the outdoor heat exchangers 4-1, 4-2, 4-1 'and 4-2'. Of course, the reverse defrost mode of operation may be selected under other conditions.
[ isolation of wind field ]
For each outdoor unit module, for example, the outdoor unit module W1, two outdoor fans 5-1 and 5-2 are provided, which correspond to the outdoor heat exchangers 4-1 and 4-2, respectively.
The outdoor fans 5-1 and 5-2 are respectively and independently controlled by the control device, the outdoor heat exchanger 4-1 and the outdoor fan 5-1 form a first air field, and the outdoor heat exchanger 4-2 and the outdoor fan 5-2 form a second air field.
Since the outdoor fan 5-2 is kept in operation during defrosting of the outdoor heat exchanger 4-1, in order to avoid a situation where the outdoor heat exchanger 4-1 cannot be effectively defrosted due to the wind field generated by the outdoor fan 5-2 blowing through the outdoor heat exchanger 4-1, a partition device (not shown) for partitioning the wind field is provided in the present application (see patent document No. 202010279447.2 entitled "outdoor unit of air conditioner").
The separating device is used for separating the first wind field from the second wind field.
That is, when the outdoor fan 5-1 is operated and the outdoor fan 5-2 is not operated, it does not blow wind to the outdoor heat exchanger 4-2, and when the outdoor fan 5-2 is operated and the outdoor fan 5-1 is not operated, it does not blow wind to the outdoor heat exchanger 4-1.
Thus, when the outdoor heat exchanger 4-1 performs defrosting, the first wind field and the second wind field are separated by the separating device, and therefore, even if the outdoor fan 5-2 still operates, the first wind field is not affected.
Therefore, the situation that the air blows over the surface of the outdoor heat exchanger 4-1 when defrosting is carried out is effectively avoided, the situation that the defrosting cannot be effectively carried out due to overlarge condensation load when the outdoor temperature is low is further prevented, and uninterrupted heating of a full-temperature area can be realized.
In addition, when the outdoor fan 5-1 stops running (namely the outdoor heat exchanger 4-1 is defrosting), the rotating speed of the outdoor fan 5-2 can be properly increased, the heating effect is further enhanced, the indoor temperature fluctuation is reduced, and the heating capacity of the air conditioner and the heating comfort of users are greatly improved.
And when the outdoor heat exchanger 4-1 exits the defrosting process and enters the normal heating operation process, the outdoor fan 5-1 is correspondingly turned on and the outdoor fan 5-2 is turned off.
Similarly, the outdoor unit module W2 also has the separating device therein, which is used to separate the adjacent wind fields formed between the outdoor fan and the corresponding outdoor heat exchanger in the outdoor unit module W2, to improve the effectiveness of the alternate defrosting in the outdoor unit module W2, and to improve the indoor thermal comfort.
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 (10)
1. An air conditioner, comprising:
at least one indoor unit;
a plurality of outdoor unit modules, each outdoor unit module comprising:
a compressor;
a flow path switching device for switching a flow path of the refrigerant discharged from the compressor;
two outdoor heat exchangers arranged in parallel;
two liquid pipe throttling devices which are respectively connected with each outdoor heat exchanger and the indoor unit;
two air side valves each connecting the flow path switching device and the air side of each outdoor heat exchanger;
a defrosting circuit that branches a part of the refrigerant discharged from the compressor and selects one of the two outdoor heat exchangers to allow the refrigerant to flow therein;
two throttling devices, one end of each throttling device is connected with a main air pipe corresponding to the outdoor heat exchanger, and the other end of each throttling device is connected with a liquid pipe throttling device corresponding to the other outdoor heat exchanger and is connected to the position of a main liquid pipe of the other outdoor heat exchanger;
a control device for controlling the flow path switching device, the air side valves, the liquid pipe throttling devices, the throttling devices and the defrosting circuit in each outdoor unit module;
when the outdoor heat exchangers need defrosting, the control device controls the outdoor heat exchangers to be defrosted to sequentially rotate for defrosting or one outdoor heat exchanger combination to be defrosted in each outdoor unit module to be combined and rotated for defrosting, so that the outdoor heat exchangers to be defrosted are used as defrosting heat exchangers to be executed, and the rest outdoor heat exchangers are used as evaporators to be executed;
when the defrosting is performed by turns, the control device controls the flow path switching device in the outdoor unit module where each defrosting heat exchanger is positioned to be powered on; controlling a defrost circuit to communicate a portion of refrigerant discharged from the compressor with a liquid side tube of the defrost heat exchanger; controlling to close a gas side valve and a liquid pipe throttling device which are communicated with the defrosting heat exchanger; and controlling to open a throttling device connected with the air pipe side of the defrosting heat exchanger.
2. The air conditioner according to claim 1,
in defrosting the defrosting heat exchanger, the control device is configured to:
controlling and opening a throttling device which is arranged in an outdoor unit module where the defrosting heat exchanger is located and connected with the defrosting heat exchanger, and controlling and adjusting the opening of the throttling device according to the outlet supercooling degree of the defrosting heat exchanger and the target outlet supercooling degree range;
and controlling and adjusting the amount of the refrigerant of which one part of the refrigerant discharged by the compressor enters the liquid side pipe of the defrosting heat exchanger according to the defrosting pressure and the target defrosting pressure range.
3. The air conditioner according to claim 2,
controlling and opening the throttling device, and controlling and adjusting the opening degree of the throttling device according to the outlet supercooling degree of the defrosting heat exchanger and the target outlet supercooling degree range, wherein the method specifically comprises the following steps:
setting the supercooling degree range of the target outlet;
calculating the supercooling degree of the outlet of the defrosting heat exchanger;
comparing whether the outlet supercooling degree is within the target outlet supercooling degree range, if so, keeping the current opening degree of the throttling device, and if not, adjusting the opening degree of the throttling device;
controlling and adjusting the amount of the refrigerant, which is a part of the refrigerant discharged by the compressor and enters the liquid side pipe of the defrosting heat exchanger, according to the defrosting pressure and the target defrosting pressure range, specifically:
setting a target defrosting pressure range;
calculating the defrosting pressure of the heat exchanger to be defrosted;
and comparing whether the defrosting pressure is in the target defrosting pressure range, if so, keeping the amount of the refrigerant of a part of the refrigerant discharged by the compressor entering a liquid side pipe of the defrosting heat exchanger, and if not, adjusting the amount of the refrigerant of the part of the refrigerant discharged by the compressor entering the liquid side pipe of the defrosting heat exchanger.
4. The air conditioner according to claim 3,
adjusting the opening degree of the throttling device, specifically:
when the outlet supercooling degree is larger than the upper limit value of the target outlet supercooling degree range, increasing the opening degree of the throttling device;
when the outlet supercooling degree is smaller than the lower limit value of the target outlet supercooling degree range, reducing the opening degree of the throttling device;
adjusting the amount of refrigerant passing through the defrost branch, specifically:
when the defrosting pressure is larger than the upper limit value of the target defrosting pressure range, reducing the amount of refrigerant of a part of refrigerant discharged by the compressor entering a liquid side pipe of the defrosting heat exchanger;
when the defrosting pressure is less than the lower limit value of the target defrosting pressure range, the amount of the refrigerant of which a part of the refrigerant discharged by the compressor enters a liquid side pipe of the defrosting heat exchanger is increased.
5. The air conditioner according to any one of claims 1 to 4,
when the defrosting heat exchanger carries out defrosting, if the first preset defrosting time is reached, the defrosting heat exchanger exits the defrosting process and enters a normal heating operation process; or
When a plurality of defrosting heat exchangers perform sequential rotation defrosting, if the outlet temperature of the defrosting heat exchanger is greater than or equal to a first temperature preset value and is maintained for a certain period of time, the defrosting heat exchanger exits the defrosting process and enters a normal heating operation process;
when a plurality of defrosting heat exchangers are combined for defrosting by turns, if the outlet temperature of each of all the defrosting heat exchangers which simultaneously defrost is greater than or equal to a first temperature preset value and is maintained for a certain period of time, the defrosting heat exchanger which simultaneously defrosts exits the defrosting process and enters a normal heating operation process.
6. The air conditioner of claim 5, wherein the defrost heat exchanger exits the defrost process and enters a normal heating operation process comprising at least:
controlling to cut off a part of the refrigerant discharged from the compressor from entering a liquid side pipe of the defrosting heat exchanger;
controlling to open a liquid pipe throttling device communicated with the defrosting heat exchanger;
and controlling to open a gas side valve communicated with the defrosting heat exchanger.
7. The air conditioner according to any one of claims 2 to 4,
the target defrost pressure range is related to an ambient temperature.
8. The air conditioner of claim 1, wherein the defrost circuit comprises:
the two defrosting branches respectively correspond to the two outdoor heat exchangers in each outdoor unit module;
and the two defrosting throttling devices are respectively and correspondingly arranged on each defrosting branch and are controlled by the control device.
9. The air conditioner of any one of claims 1 to 4 and 6, wherein the outdoor unit module further comprises:
the two outdoor fans respectively correspond to the two outdoor heat exchangers and are connected with the control device, and each outdoor fan and the corresponding outdoor heat exchanger form an air field;
a separation device for separating adjacent wind farms;
and when the defrosting is performed by turns, the control device controls to close the outdoor fan corresponding to the defrosting heat exchanger.
10. The air conditioner according to claim 9,
and when one outdoor heat exchanger in each outdoor unit module is defrosting, increasing the rotating speed of an outdoor fan corresponding to the other outdoor heat exchanger in the outdoor unit module.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202011371833.0A CN112444002A (en) | 2020-11-30 | 2020-11-30 | Air conditioner |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202011371833.0A CN112444002A (en) | 2020-11-30 | 2020-11-30 | Air conditioner |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114484586A (en) * | 2022-01-21 | 2022-05-13 | 珠海格力电器股份有限公司 | Modularized multi-connected unit and control method thereof |
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