CN115031350B - Air conditioner and defrosting control method thereof - Google Patents

Air conditioner and defrosting control method thereof Download PDF

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Publication number
CN115031350B
CN115031350B CN202210757838.XA CN202210757838A CN115031350B CN 115031350 B CN115031350 B CN 115031350B CN 202210757838 A CN202210757838 A CN 202210757838A CN 115031350 B CN115031350 B CN 115031350B
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time
temperature
defrosting
time threshold
air conditioner
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CN115031350A (en
Inventor
邹海如
陈海群
李林
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Hisense Guangdong Air Conditioning Co Ltd
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Hisense Guangdong Air Conditioning Co Ltd
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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
    • F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
    • F24F11/41—Defrosting; Preventing freezing
    • F24F11/42—Defrosting; Preventing freezing of outdoor units
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/50—Control or safety arrangements characterised by user interfaces or communication
    • F24F11/61—Control or safety arrangements characterised by user interfaces or communication using timers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/62—Control or safety arrangements characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
    • F24F11/63—Electronic processing
    • F24F11/64—Electronic processing using pre-stored data
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/62—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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/20—Disposition of valves, e.g. of on-off valves or flow control valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/30—Expansion means; Dispositions thereof
    • 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
    • F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2140/00—Control inputs relating to system states
    • F24F2140/20—Heat-exchange fluid temperature

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Thermal Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Signal Processing (AREA)
  • Fuzzy Systems (AREA)
  • Mathematical Physics (AREA)
  • Human Computer Interaction (AREA)
  • Analytical Chemistry (AREA)
  • Power Engineering (AREA)
  • Air Conditioning Control Device (AREA)

Abstract

The invention discloses an air conditioner and a defrosting control method of the air conditioner, wherein the air conditioner comprises the following components: the device comprises a compressor, a four-way valve, an outdoor heat exchanger, a flash evaporator, a switching valve, an indoor heat exchanger, a first one-way valve, a first throttle, a second one-way valve, a second throttle and a controller, wherein the switching valve is arranged on a pipeline between an air outlet pipe of the flash evaporator and an air suction port of the compressor; the first one-way valve and the first throttle are arranged in parallel between a first liquid pipe of the flash evaporator and the indoor heat exchanger, and a liquid inlet of the first one-way valve is connected with the first liquid pipe; the second one-way valve and the second throttle are arranged in parallel between a second liquid pipe of the flash evaporator and the outdoor heat exchanger, and a liquid inlet of the second one-way valve is connected with the second liquid pipe; the controller is connected with the switch valve, and the controller is configured to: detecting that the air conditioner is switched to a defrosting mode, recording the accumulated time of the air conditioner in the defrosting mode, determining that the accumulated time is lower than a first time threshold value, and controlling the switch valve to be switched on.

Description

Air conditioner and defrosting control method thereof
Technical Field
The invention relates to the technical field of air conditioners, in particular to an air conditioner and a defrosting control method of the air conditioner.
Background
When outdoor ambient temperature is lower in winter, when the air conditioner runs the heating mode for a long time, the outdoor unit of the air conditioner is easy to frost on the evaporation side, and then the heating effect is reduced, and as the frost layer is thicker along with the increase of the frosting time, the heat transfer resistance of the outdoor unit of the air conditioner can be increased by the frost layer, so that the outdoor air circulation area is reduced, the flow resistance is increased, the air quantity of the outdoor unit is reduced, the outdoor evaporation temperature is further reduced, the heat exchange is poor, the indoor ambient comfort is reduced, the user requirements cannot be met, and the user experience is reduced. Thus, after a certain period of operation of the air conditioner, it is required to defrost the air conditioner effectively in time. The current defrosting technology mainly comprises refrigeration mode (reverse circulation) defrosting, bypass defrosting and phase change energy storage defrosting.
In the related art, when the outdoor unit is defrosted in the conventional defrosting mode, after entering the defrosting mode, the low-temperature refrigerant enters the indoor heat exchanger to absorb heat so as to defrost the indoor heat exchanger, and when defrosting is completed and heating is performed again, the indoor unit may be required to defrost, the heating effect is poor, and user comfort is reduced.
Disclosure of Invention
The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, an object of the present invention is to provide an air conditioner, which prevents frosting of an outdoor heat exchanger during defrosting, thereby avoiding poor heating effect when defrosting is completed and heating is performed again, and improving comfort of users.
Another object of the present invention is to provide a defrosting control method for an air conditioner.
In order to achieve the above object, an air conditioner according to an embodiment of a first aspect of the present invention includes: the device comprises a compressor, a four-way valve, an outdoor heat exchanger, a flash evaporator and an indoor heat exchanger, wherein the flash evaporator is provided with a first liquid pipe, a second liquid pipe and an air outlet pipe, and the air outlet pipe is connected with an air suction port of the compressor; the switch valve is arranged on a pipeline between the air outlet pipe and the air suction port of the compressor; the first one-way valve and the first throttle are arranged in parallel between a first liquid pipe of the flash evaporator and the indoor heat exchanger, and a liquid inlet of the first one-way valve is connected with the first liquid pipe; the second one-way valve and the second restrictor are arranged in parallel between a second liquid pipe of the flash evaporator and the outdoor heat exchanger, and a liquid inlet of the second one-way valve is connected with the second liquid pipe; a controller connected to the on-off valve, the controller configured to: detecting that the air conditioner is switched to a defrosting mode, recording the accumulated time of the air conditioner in the defrosting mode, determining that the accumulated time is lower than a first time threshold value, and controlling the switch valve to be switched on.
According to the air conditioner provided by the embodiment of the invention, the flash evaporator is arranged in the refrigerant loop between the outdoor heat exchanger and the indoor heat exchanger, the switch valve is arranged between the flash evaporator and the air suction port of the compressor, in a defrosting mode, the switch valve is controlled to be switched on, so that most of liquid refrigerant which is cooled and depressurized through the second throttle device and becomes low-temperature and low-pressure is directly led back to the compressor through the switch valve, and only very little liquid refrigerant with low temperature and low pressure can flow through the indoor heat exchanger, so that the indoor heat exchanger is ensured not to be frosted, the problem of poor heating effect caused by defrosting the indoor machine when defrosting is completed and the indoor machine enters a heating mode again is avoided, and the comfort level of a user is improved.
In some embodiments of the present invention, the air conditioner further includes: the temperature sensor is used for collecting the temperature of the outdoor coil; the controller is connected to the temperature sensor and is further configured to: and determining that the accumulated time of the air conditioner in the defrosting mode is higher than the first time threshold, and controlling the switch valve to be switched on or off according to the accumulated time and the outdoor coil temperature. The outdoor unit can be defrosted quickly when the control switch valve is turned off, so that the outdoor unit is prevented from being defrosted uncleanly.
In some embodiments of the invention, the controller is further configured to determine whether the accumulated time is above a second time threshold if the outdoor coil temperature is below a first temperature threshold, and if the accumulated time is above the second time threshold and below a third time threshold, then control the on-off valve to turn off until the accumulated time is above the third time threshold, and control the air conditioner to exit the defrost mode, wherein the third time threshold > the second time threshold > the first time threshold. When the accumulated time is higher than the third time threshold, the defrosting time is considered to be long enough, and the frost layer in the outdoor unit can be completely removed, so that the air conditioner is controlled to exit the defrosting mode.
In some embodiments of the present invention, the controller is further configured to determine whether the accumulated time reaches a third time threshold if the outdoor coil temperature is above a first temperature threshold and below a second temperature threshold, and if the accumulated time does not reach the third time threshold, control the on-off valve to remain on until the accumulated time reaches the third time threshold, and control the air conditioner to exit the defrost mode, wherein the second temperature threshold is greater than the first temperature threshold and the third time threshold is greater than the first time threshold. When the frost amount in the outdoor unit is basically in a normal state, the outdoor unit can be defrosted in a mode of controlling the switch valve to be turned on, and the defrosting time is relatively long, so that the outdoor unit can be ensured to be defrosted cleanly, the indoor heat exchanger can be ensured not to be frosted in the defrosting process, and the situations that when defrosting is completed and the indoor unit needs to be defrosted and the heating effect is poor when the indoor unit reenters the heating mode are avoided
In some embodiments of the present invention, the air conditioner is further configured to determine whether the accumulated time reaches a second time threshold or a third time threshold if the outdoor coil temperature is higher than a second temperature threshold, and to control the air conditioner to exit the defrost mode if the accumulated time reaches the second time threshold or the third time threshold. Wherein, through real-time detection outdoor coil pipe temperature, can know the off-premises station frosting or defrost condition in real time, and based on the off-premises station frosting condition, the different defrosting modes of adaptation switching, in order to reach corresponding defrosting effect, can promote the defrosting ability to the off-premises station, in order to realize quick defrosting, even also can guarantee to defrost under operating conditions such as low temperature high humidity, can also guarantee when operating defrosting mode that indoor heat exchanger can not frost, and then can avoid the defrosting to accomplish and reenter the problem that the heating effect that needs to defrost the indoor machine and cause when heating the mode is poor, promote user's comfort level
In order to achieve the above object, a second aspect of the present invention provides a defrosting control method for an air conditioner, which is used in the air conditioner described in the above embodiment, and the method includes: detecting that the air conditioner is switched to a defrosting mode; recording the accumulated time of the air conditioner in the defrosting mode; and determining that the accumulated time is lower than a first time threshold value, and controlling a switching valve between an air outlet pipe of the flash evaporator and an air suction port of the compressor to be connected.
According to the defrosting control method for the air conditioner, which is provided by the embodiment of the invention, in the defrosting mode, the switch valve is controlled to be switched on, so that most of liquid refrigerant which is cooled and depressurized by the second throttle device and becomes low-temperature low-pressure liquid refrigerant is directly led back to the compressor by the switch valve, and only very little low-temperature low-pressure liquid refrigerant can flow through the indoor heat exchanger, so that the indoor heat exchanger is ensured not to be frosted, the problem of poor heating effect caused by defrosting the indoor machine when defrosting is completed and the air conditioner enters a heating mode again is solved, and the comfort level of a user is improved.
In some embodiments of the invention, the method further comprises: acquiring the temperature of an outdoor coil; and controlling the on/off of the switch valve according to the accumulated time and the outdoor coil temperature.
In some embodiments of the invention, controlling the on/off valve to be on or off according to the accumulated time and the outdoor coil temperature includes: if the temperature of the outdoor coil is lower than a first temperature threshold, judging whether the accumulated time is higher than a second time threshold; and if the accumulated time is higher than the second time threshold and lower than a third time threshold, controlling the switch valve to be turned off until the accumulated time is higher than the third time threshold, and controlling the air conditioner to exit the defrosting mode, wherein the third time threshold is larger than the second time threshold and larger than the first time threshold.
In some embodiments of the invention, controlling the on/off valve to be on or off according to the accumulated time and the outdoor coil temperature includes: if the temperature of the outdoor coil is higher than the first temperature threshold and lower than the second temperature threshold, judging whether the accumulated time reaches a third time threshold; and if the accumulated time does not reach the third time threshold, controlling the switch valve to be kept on until the accumulated time reaches the third time threshold, and controlling the air conditioner to exit the defrosting mode, wherein the second temperature threshold is larger than the first temperature threshold, and the third time threshold is larger than the first time threshold.
In some embodiments of the invention, controlling the on/off valve to be on or off according to the accumulated time and the outdoor coil temperature includes: if the temperature of the outdoor coil is higher than a second temperature threshold, judging whether the accumulated time reaches a second time threshold or whether the accumulated time reaches a third time threshold, wherein the third time threshold is larger than the second time threshold and larger than the first time threshold; and if the accumulated time reaches the second time threshold or the third time threshold, controlling the air conditioner to exit the defrosting mode.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic view of an air conditioner;
fig. 2 is a schematic view of an air conditioner according to an embodiment of the present invention;
fig. 3 is a schematic view of an air conditioner according to another embodiment of the present invention;
fig. 4 is a flowchart of a defrosting control method of an air conditioner according to an embodiment of the present invention;
fig. 5 is a flowchart of a defrosting control method of an air conditioner according to another embodiment of the present invention;
fig. 6 is a flowchart of a defrosting control method of an air conditioner according to still another embodiment of the present invention;
fig. 7 is a flowchart of a defrosting control method of an air conditioner according to still another embodiment of the present invention;
fig. 8 is a flowchart of a defrosting control method of an air conditioner according to still another embodiment of the present invention;
fig. 9 is a flowchart of a defrosting control method of an air conditioner according to still another embodiment of the present invention.
Reference numerals:
an air conditioner 100;
the compressor 1, the four-way valve 2, the outdoor heat exchanger 3, the flash evaporator 4, the indoor heat exchanger 5, the switching valve 6, the first check valve 7, the first throttle 8, the second check valve 9, the second throttle 10, the controller 11 and the temperature sensor 12.
Detailed Description
Embodiments of the present application will be described in detail below, by way of example with reference to the accompanying drawings.
The current defrosting technology mainly comprises refrigeration mode (reverse circulation) defrosting, bypass defrosting and phase change energy storage defrosting. When defrosting is carried out in a refrigerating mode, the indoor heat exchanger is used as an evaporation end, frosting of the indoor unit can be caused, and then defrosting of the indoor unit is needed when defrosting is completed and the indoor unit enters a heating mode again, so that the heating effect of the air conditioner is poor, and user comfort experience is affected.
And then can avoid the defrosting and reenter the heating mode when accomplishing the defrosting and need carry out the problem that the heating effect that defrosting caused to the indoor set is poor, promote user's comfort level.
Based on the above, in order to solve the problem that indoor heat exchange is poor because indoor units need to be defrosted when entering a heating mode due to frosting of the indoor units in a defrosting mode, the embodiment of the application provides an air conditioner defrosting control method and an air conditioner adopting the method.
The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
Fig. 1 is a schematic view of an air conditioner, and a basic structure of the air conditioner can be understood in conjunction with fig. 1, in which the air conditioner performs a cooling/heating cycle of the air conditioner by using a compressor, a condenser, an expansion valve, and an evaporator. Among them, the refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation, and supplies a refrigerant to air that has been conditioned and heat-exchanged.
The compressor compresses 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 may achieve a cooling effect by exchanging heat with a material to be cooled using latent heat of evaporation of a refrigerant. The air conditioner may adjust the temperature of the indoor space throughout the cycle.
The outdoor unit of the air conditioner refers to a portion of the system cycle including a compressor and an outdoor heat exchanger, the indoor unit of the air conditioner includes an indoor heat exchanger, and an expansion valve may be provided in the indoor unit or the outdoor unit.
The indoor heat exchanger and the outdoor heat exchanger function as a condenser or an evaporator. When the indoor heat exchanger is used as a condenser, the air conditioner is used as a heater of a heating mode, and when the indoor heat exchanger is used as an evaporator, the air conditioner is used as a cooler of a cooling mode.
An air conditioner according to some embodiments of the present application includes an air conditioner indoor unit installed in an indoor space. The indoor unit of the air conditioner is connected to the outdoor unit of the air conditioner installed in the outdoor space through a pipe. The air conditioner outdoor unit may be provided with a compressor, an outdoor heat exchanger, an outdoor fan, an expander and the like for system circulation, and the air conditioner indoor unit may be provided with an indoor heat exchanger and an indoor fan.
An air conditioner according to an embodiment of the present application is described below with reference to fig. 2 and 3.
In some embodiments of the present application, as shown in fig. 2, a schematic diagram of an air conditioner according to an embodiment of the present application is shown. The air conditioner 100 includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, a flash evaporator 4, an indoor heat exchanger 5, an on-off valve 6, a first check valve 7, a first restrictor 8, a second check valve 9, a second restrictor 10, and a controller 11.
Wherein, flash evaporator 4 has first liquid pipe, second liquid pipe and outlet duct, and the outlet duct is connected with the induction port of compressor 1. Specifically, as shown in fig. 2, the air outlet pipe is disposed at the upper portion of the flash evaporator 4, and the first liquid pipe and the second liquid pipe are both disposed at the bottom of the flash evaporator 4. The flash evaporator 4 is used for decompressing the refrigerant flowing through, so as to establish a new vapor-liquid balance under the pressure level.
The on-off valve 6 is provided in a pipe line between the outlet pipe 40 and the suction port of the compressor 1. The switch valve 6 may be an electronic expansion valve, and the switch valve 6 is used for controlling the flow direction of the refrigerant when being opened or closed.
Wherein, first check valve 7 and first choke 8 parallelly connected setting are between the first liquid pipe of flash vessel 4 and indoor heat exchanger 5, and the inlet and the first liquid pipe of first check valve 7 are connected. Specifically, when the first check valve 7 is turned on, the refrigerant flows out of the first liquid pipe of the flash evaporator 4 and flows into the indoor heat exchanger 5 through the first check valve 7, and when the first check valve 7 is turned off, the refrigerant flows out of the indoor heat exchanger 5 and flows into the first liquid pipe of the flash evaporator 4 through the first throttle 8. The second one-way valve 9 and the second restrictor 10 are arranged in parallel between the second liquid pipe of the flash evaporator 4 and the outdoor heat exchanger 3, and the liquid inlet of the second one-way valve 9 is connected with the second liquid pipe. Specifically, when the second check valve 9 is turned on, the refrigerant flows out of the second liquid pipe of the flash evaporator 4 and flows into the outdoor heat exchanger 3 through the second check valve 9, and when the second check valve 9 is turned off, the refrigerant flows out of the outdoor heat exchanger 3 and flows into the second liquid pipe of the flash evaporator 4 through the second throttle 10. The first restrictor 8 and the second restrictor 10 are heating capillary and refrigerating capillary, respectively, and can be replaced by throttle devices such as throttle valve or electronic expansion valve.
The controller 11 is connected to the on-off valve 6, wherein the controller 11 may be a Processor having data processing and analyzing functions, such as a CPU (Central Processing Unit/Processor, central processing unit) in the air conditioner 100, and the controller 11 may include a monitoring unit, a judging unit, a control unit, and the like, for implementing data processing and analyzing.
It is to be understood that the indoor side of the air conditioner 100 is further provided with an indoor fan, and the outdoor side is provided with an outdoor fan. When the air conditioner 100 operates in the heating mode, the outdoor heat exchanger 3 serves as an evaporator and the indoor heat exchanger 5 serves as a condenser. In the heating mode, the controller 11 controls the compressor 1 to start and run, the indoor fan is started, the outdoor fan is started, the four-way valve 2 is electrified, the switching valve 6 is opened, the first one-way valve 7 is closed, and the second one-way valve 10 is conducted, at this time, the flow direction of the refrigerant discharged from the exhaust port of the compressor 1 is as follows: the exhaust port of the compressor 1, the E port of the four-way valve 2, the indoor heat exchanger 5, the first restrictor 8 and the flash evaporator 4. Further, the gas refrigerant separated in the flash evaporator 4 flows out through the gas outlet pipe of the flash evaporator 4 and flows back to the air suction port of the compressor 1 through the switch valve 6. And, the liquid refrigerant separated in the flash evaporator 4 enters the outdoor heat exchanger 3 to absorb heat and become a gas refrigerant, and the flow direction of the gas refrigerant is as follows: the second liquid pipe of the flash evaporator 4, the second one-way valve 10, the outdoor heat exchanger 3, the C port of the four-way valve 2, the S port of the four-way valve 2 and the air suction port of the compressor 1, and the two paths of refrigerants finally return to the liquid storage device of the compressor 1, are further compressed by the compressor 1 again and are then discharged after being called high-temperature and high-pressure gas refrigerants, so that the refrigerant circulation under a heating mode is realized.
In some embodiments of the invention, the controller 11 is configured to: it is detected that the air conditioner 100 is switched to the defrost mode.
In the heating mode, the outdoor heat exchanger 3 works as an evaporator for a long time, which easily causes frosting of the outdoor unit, and at this time, the air conditioner 100 needs to be controlled to operate in a defrosting mode in time, so that the outdoor unit is defrosted in time.
In the defrosting mode, the high-temperature and high-pressure gas refrigerant discharged from the exhaust port of the compressor 1 passes through the four-way valve 2 and then enters the outdoor heat exchanger 3, at this time, the outdoor heat exchanger 3 serves as a condenser, and the indoor heat exchanger 5 serves as an evaporator. The high-temperature high-pressure gas refrigerant condenses and dissipates heat in the outdoor heat exchanger 3 to become a medium-temperature medium-pressure liquid refrigerant, then enters the flash evaporator 4 to be cooled and depressurized to become a low-temperature low-pressure liquid refrigerant, and the switch valve 6 is arranged to be used for distributing and controlling the flow direction of the low-temperature low-pressure liquid refrigerant next, so that the defrosting effect of the outdoor unit is achieved. In the defrosting mode, the controller 11 controls the first check valve 7 to be turned on and controls the second check valve 9 to be turned off, that is, the on-off states of the first check valve 7 and the second check valve 9 in the defrosting mode are opposite to the on-off states in the heating mode, that is, the flow direction of the refrigerant in the circulation pipeline in the defrosting mode is opposite to the flow direction of the refrigerant in the heating mode.
In addition, in the defrosting mode, the controller 11 also controls the compressor 1 to be turned on and operated, the outdoor fan and the indoor fan to be turned off, and the four-way valve 2 to be unpowered.
In other embodiments, the cumulative time that the air conditioner 100 is operating in the defrost mode is recorded.
When the air conditioner 100 initially enters the defrosting mode, the compressor 1 is started to operate, so that the operation state of the compressor 1 may not be stable enough in an initial period of time, and thus the time of the air conditioner 100 in the defrosting mode needs to be accumulated, so as to determine the operation state of the compressor 1, and simultaneously, in a subsequent defrosting operation process, the defrosting mode is also convenient to be adjusted according to the accumulated time of the defrosting mode.
In other embodiments, the control switch valve 6 is turned on when the accumulated time is determined to be below the first time threshold.
The first time threshold may be set as required, where the first time threshold should be set to a smaller value, for example, 1min less than or equal to the first time threshold less than or equal to 5min may be set, for example, 1min or 2min or 3min or 5min may be set. When the air conditioner 100 initially enters the defrost mode, the controller 11 controls the compressor 1 to start operating, so that the operating state of the compressor 1 may not be stable enough for an initial period of time, and thus a first time threshold needs to be set, and the on-off valve 6 is controlled to be turned on during the first time threshold.
Further, after the switch valve 6 is turned on, the refrigerant discharged from the exhaust port of the compressor 1 includes two flow directions, and the first flow direction is: the exhaust port of the compressor 1, the D port of the four-way valve 2, the C port of the four-way valve 2, the outdoor heat exchanger 3, the second restrictor 10, the flash evaporator 4, the switch valve 6 and the air suction port of the compressor 1; the second path of flow direction is as follows: the exhaust port of the compressor 1, the D port of the four-way valve 2, the C port of the four-way valve 2, the outdoor heat exchanger 3, the second restrictor 10, the flash evaporator 4, the first one-way valve 7, the indoor heat exchanger 5, the E port of the four-way valve 2, the S port of the four-way valve 2 and the air suction port of the compressor 1.
As can be seen from the above, in the defrosting mode, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 enters the outdoor heat exchanger 3 to condense and release heat, then enters the second throttle 10 to cool and decompress to become low-temperature and low-pressure liquid refrigerant, then enters the flash evaporator 4, and the flash evaporator 4 can perform distribution control on the flow direction of the low-temperature and low-pressure liquid refrigerant, wherein most of the low-temperature and low-pressure liquid refrigerant can be directly led into the compressor 1 to avoid frosting of the indoor heat exchanger 5. That is, when the switching valve 6 is in the on state, most of the low-temperature low-pressure liquid refrigerant separated in the flash evaporator 4 is directly introduced into the suction port of the compressor 1 through the switching valve 6, and only a very small portion of the low-temperature low-pressure liquid refrigerant flows into the suction port of the compressor 1 in the second flow direction, so that the indoor heat exchanger 5 is not frosted when the outdoor unit is defrosted, thereby avoiding the situation that the heating effect is poor because the indoor unit needs to be frosted when the air conditioner 100 reenters the heating mode after the defrosting is completed.
According to the air conditioner 100 provided by the embodiment of the invention, the flash evaporator 4 is arranged in the refrigerant loop between the outdoor heat exchanger 3 and the indoor heat exchanger 5, and the switch valve 6 is arranged between the flash evaporator 4 and the air suction port of the compressor 1, so that in a defrosting mode, most of liquid refrigerant which is cooled and depressurized through the second throttle 10 to be low-temperature and low-pressure is directly led back to the compressor 1 through the switch valve 6, and only very little low-temperature and low-pressure liquid refrigerant can flow through the indoor heat exchanger 5, so that the indoor heat exchanger 5 is ensured not to be frosted, and the problem of poor heating effect caused by defrosting the indoor machine when defrosting is completed and the indoor machine enters a heating mode again can be avoided, and the comfort level of a user is improved.
In some embodiments of the present invention, as shown in fig. 2, a block diagram of an air conditioner according to another embodiment of the present invention, in which a temperature sensor 12 may be provided in a coil of the outdoor heat exchanger 3 for collecting an outdoor coil temperature. The outdoor coil temperature can intuitively reflect the frosting condition in the outdoor unit, for example, when the outdoor coil temperature is relatively low, the frosting layer in the outdoor unit is relatively thick and frosted more, the defrosting capability of the air conditioner 100 needs to be improved, and when the outdoor coil temperature is relatively high, the frosting layer in the outdoor unit is relatively thin and frosted less, and the defrosting is relatively easy.
The controller 11 is connected to the temperature sensor 12 and is further configured to: it is determined that the accumulated time for the operation of the air conditioner 100 in the defrost mode is higher than the first time threshold, and the on-off valve 6 is controlled to be turned on or off according to the accumulated time and the outdoor coil temperature.
When the accumulated time of the operation of the air conditioner 100 in the defrosting mode is higher than the first time threshold, it is confirmed that the operation of the compressor 1 is stable, and the frosting condition in the outdoor unit needs to be further determined at this time, so that the air conditioner 100 is controlled to perform targeted defrosting operation according to the amount of frost in the outdoor unit.
The bypass defrosting mode is that after entering defrosting, part of high-temperature and high-pressure gas refrigerant discharged by a compressor passes through an outdoor heat exchanger, and the purpose of defrosting is achieved by utilizing heat released by exhaust. The other part passes through the indoor heat exchanger, and the defrosting mode has the advantages that the indoor heat exchanger still keeps heating operation, namely is in a high-temperature state, so that frosting of the indoor unit cannot occur, and when defrosting is completed and the indoor unit reenters the heating mode, the heating effect of the indoor unit is good, and the indoor comfort can be ensured by the bypass defrosting mode. However, the bypass defrosting time is longer and is more than 2 times of that of reverse circulation defrosting, the defrosting is slower, and the problems of uncleanness in defrosting are easy to occur under some low-temperature high-humidity working conditions.
When the air conditioner operates in a refrigeration mode (reverse circulation) defrosting mode, namely a normal defrosting mode, the refrigerant flows back to the compressor 1 through the indoor heat exchanger 5, the refrigerant is evaporated and absorbed into a low-temperature low-pressure gas refrigerant through the indoor heat exchanger 5, and the refrigerant absorbs heat again to become high-temperature high-pressure gas after flowing back to the compressor 1. In the present embodiment, as can be seen from the above description, when the switch valve 6 is in the on state, most of the low-temperature low-pressure liquid refrigerant is directly led into the compressor 1 to avoid frosting of the indoor heat exchanger 5, the refrigerant does not pass through the indoor heat exchanger 5, which is equivalent to a step lacking in the heat of the refrigerant in the primary lifting pipeline, and the refrigerant is compressed by the compressor 1 only to become high-temperature high-pressure gas, so that the heat in the refrigerant flowing through the outdoor heat exchanger 3 is less than the heat of the refrigerant after two-stage energy lifting, the defrosting effect is limited, and the method is suitable for the conditions of thinner frost layer and less frost amount in the outdoor unit. When the temperature of the outdoor coil pipe is higher, the switch valve 6 can be controlled to be switched on, so that the effective defrosting of the outdoor unit can be realized, the frosting of the indoor unit can be ensured, and the comfort level of a user can be improved.
In the defrosting mode, when the controller 11 controls the switch valve 6 to be turned off, the flow direction of the refrigerant in the pipeline is as follows: the air outlet of the compressor 1, the D port of the four-way valve 2, the C port of the four-way valve 2, the outdoor heat exchanger 3, the second restrictor 10, the flash evaporator 4, the first one-way valve 7, the indoor heat exchanger 5, the E port of the four-way valve 2, the S port of the four-way valve 2, the air suction port of the compressor 1, namely, the refrigerant in the pipeline is lifted by two stages of energy and has more heat when flowing through the indoor heat exchanger 5 and the compressor 1, and when the high-temperature and high-pressure gas refrigerant exchanges heat with the outdoor heat exchanger 3, more heat can be released, so that a better defrosting effect is achieved to realize quick defrosting of the outdoor unit.
According to the air conditioner 100 of the embodiment of the invention, the switch valve 6 is controlled to be switched on or off according to the accumulated time and the temperature of the outdoor coil, so that targeted defrosting operation under different working conditions can be realized, when the switch valve 6 is switched on, the effective defrosting of the outdoor unit can be realized, the indoor unit can be ensured to be frosted, the comfort level of a user is improved, and when the switch valve 6 is controlled to be switched off, the outdoor unit can be quickly defrosted, and the unclean defrosting of the outdoor unit is avoided.
In some embodiments of the present invention, the controller 11 is further configured to determine if the accumulated time is above a second time threshold if the outdoor coil temperature is below a first temperature threshold.
The first temperature threshold may be set as required, for example, the first temperature threshold may be set to be less than or equal to 5 ℃, for example, the first time threshold may be set to be-2 ℃ or 0 ℃ or 1 ℃ or 5 ℃, and the like. When the outdoor coil temperature is detected to be lower than the first temperature threshold value, the outdoor coil temperature is in a relatively low state, which means that the outdoor unit has more frosting and a relatively thick frost layer. And a second time threshold value can be set according to the need, wherein the second time threshold value is set to be a value larger than the first time threshold value, for example, 3min is less than or equal to the second time threshold value is less than or equal to 8min, for example, the second time threshold value can be set to be 3min or 5min or 7min or 8min, and the like, and the defrosting effect under the condition that the control switch valve 6 is turned on is judged by accumulating the time of operating the defrosting mode and detecting the temperature of the outdoor coil in real time, so that the flow direction of the refrigerant in the pipeline can be adjusted according to the defrosting effect in time.
In other embodiments, if the accumulated time is above the second time threshold and below the third time threshold, the on-off valve 6 is controlled to be turned off until the accumulated time is above the third time threshold, and the air conditioner 100 is controlled to exit the defrost mode.
Wherein the third time threshold may be set as desired, in particular, the third time threshold > the second time threshold > the first time threshold needs to be satisfied. For example, a third time threshold value less than or equal to 6min may be set less than or equal to 12min, for example, the third time threshold value may be set to 6min or 8min or 10min or 12min, when it is determined that the accumulated time is higher than the second time threshold value and lower than the third time threshold value, the time for which the switch valve 6 is controlled to be turned on is longer, and the outdoor coil temperature is lower than the first temperature threshold value, which indicates that the defrosting is slower when the defrosting is performed by adopting the method, in order to avoid the overlong defrosting time, the defrosting force is required to be increased at this time, the switch valve 6 is controlled to be turned off, and the defrosting capability of the outdoor unit is improved, so as to implement the quick defrosting.
In addition, when defrosting is performed by adopting a mode of controlling the switch valve 6 to be turned off, the temperature of the outdoor coil pipe needs to be detected in real time, and when the temperature of the outdoor coil pipe is determined to be larger than the first temperature threshold value, the switch valve 6 can be controlled to be turned on again, so that the situation of indoor unit frosting caused by long-time defrosting by adopting the mode of controlling the switch valve 6 to be turned off is avoided.
Based on the above, when the outdoor unit is defrosted by controlling the on-off valve 6 to be turned off for a long time, the indoor unit is liable to be frosted, and the time for defrosting by the method is limited, and when the accumulated time is determined to be higher than the third time threshold, the defrosting time is considered to be long enough, and the frost layer in the outdoor unit can be completely removed, so that the air conditioner 100 is controlled to exit the defrosting mode.
According to the air conditioner 100 of the embodiment of the invention, in the defrosting mode, when the outdoor unit is defrosted by controlling the on/off valve 6 to be turned on and a period of time is reached, if the temperature of the outdoor coil is still at a lower level, the defrosting capacity of the outdoor unit is timely improved, so that the quick defrosting is realized.
In some embodiments of the present invention, the controller 11 is further configured to determine whether the accumulated time reaches a third time threshold if the outdoor coil temperature is above the first temperature threshold and below the second temperature threshold.
Wherein the second temperature threshold value can be set according to the requirement, and the second temperature threshold value should be larger than the first temperature threshold value, for example, the second temperature threshold value is not smaller than 0 ℃ and not larger than 10 ℃, for example, the first time threshold value can be set to be 0 ℃ or 5 ℃ or 8 ℃ or 10 ℃, and the like.
When the outdoor coil temperature is detected to be higher than the first temperature threshold and lower than the second temperature threshold, the amount of frost in the outdoor unit is considered to be normal, and the outdoor unit can be defrosted by controlling the on/off valve 6 to be on, but since the outdoor coil temperature is still in a relatively low state at this time, the time for defrosting in this way can be set to be relatively long.
In other embodiments of the present invention, the controller 11 is further configured to control the switch valve 6 to remain on until the integrated time reaches a third time threshold, wherein the second temperature threshold is greater than the first temperature threshold, and the third time threshold is greater than the first time threshold, if the integrated time does not reach the third time threshold.
The outdoor unit is defrosted by continuously adopting a mode of controlling the switch valve 6 to be connected, and the defrosting is determined to be completed until the accumulated time reaches the third time threshold value, and the air conditioner 100 is timely controlled to exit the defrosting mode, so that the outdoor unit is not only ensured to be defrosted cleanly, but also the indoor heat exchanger 5 is ensured not to be frosted in the defrosting process, and the situations of poor heating effect and the like caused by defrosting the indoor unit when the defrosting is completed and the indoor unit enters the heating mode again are avoided.
In some embodiments of the present invention, the air conditioner 100 is further configured to determine whether the accumulated time reaches the second time threshold or whether the outdoor coil temperature reaches the third temperature threshold if the outdoor coil temperature is above the second temperature threshold.
When the temperature of the outdoor coil is detected to be higher than the second temperature threshold, the outdoor coil is shown to be higher in temperature, frosting of the outdoor unit is less, the outdoor unit can be defrosted in a mode of controlling the on-off valve 6 to be connected, defrosting time can be limited to be shorter, and meanwhile, the temperature of the outdoor coil needs to be detected in real time to judge defrosting effects of the outdoor unit.
In other embodiments, the air conditioner 100 is controlled to exit the defrost mode if the accumulated time reaches a second time threshold or if the outdoor coil temperature reaches a third temperature threshold.
When the accumulated time is up to the second time threshold, the operation defrosting mode time is considered to be enough to completely defrost the outdoor unit, and it is determined that the defrosting operation is completed at this time. And, as can be seen from the above description, the third temperature threshold is higher, and when the temperature of the outdoor coil is detected to reach the third temperature threshold, it indicates that the outdoor unit is completely defrosted, and the air conditioner 100 needs to be controlled to exit the defrosting mode in time, so as to avoid the situation that the outdoor heat exchanger 3 is defrosted for a long time without frost, and the current of the compressor 1 is too large, and the compressor 1 is damaged.
Further, in the above defrosting situation, when the mode of controlling the switch valve 6 to be turned on is adopted to defrost, the outdoor coil temperature needs to be detected in real time, when the outdoor coil temperature is determined to be greater than the second temperature threshold, the defrosting speed is relatively high, the defrosting effect is relatively good, in order to avoid the situation that the defrosting mode is still continuously operated when the frost layer of the outdoor unit is cleaned, when the accumulated time is determined to reach the second time threshold or the outdoor coil temperature is higher than the second temperature threshold, the air conditioner 100 is timely controlled to exit the defrosting mode, and the situations that the compressor is jumped or damaged due to excessive current of the compressor caused by the fact that the outdoor heat exchanger 3 is frostless and is defrosted for a long time are avoided.
In summary, according to the air conditioner 100 provided by the embodiment of the invention, the outdoor coil temperature is detected in real time, the frosting or defrosting condition of the outdoor unit is known in time, and different defrosting modes are adaptively switched based on the frosting condition of the outdoor unit, so that the corresponding defrosting effect is achieved, the defrosting capacity of the outdoor unit can be improved, the quick defrosting can be realized, the defrosting cleanliness can be ensured even under the working conditions of low temperature, high humidity and the like, the indoor heat exchanger 5 can be ensured not to frost during the operation of the defrosting mode, the problem of poor heating effect caused by defrosting the indoor unit when the defrosting is completed and the indoor unit enters the heating mode again can be avoided, and the comfort level of a user is improved.
In some embodiments of the present invention, a defrosting control method for an air conditioner 100 of the above embodiment is also provided, where the air conditioner 100 of the embodiment of the present invention can be understood with reference to fig. 2 and 3, and details thereof are not repeated here. As shown in fig. 4, a flowchart of a defrosting control method for an air conditioner according to an embodiment of the present invention is shown, wherein the defrosting control method for an air conditioner at least includes steps S1 to S3, which are specifically described below.
S1, detecting that the air conditioner is switched to a defrosting mode.
In the heating mode, the outdoor heat exchanger is used as an evaporator to work for a long time, so that the outdoor unit is easy to frost, and at the moment, the air conditioner needs to be controlled to operate in a defrosting mode and defrost the outdoor unit in time. In defrost mode, the outdoor heat exchanger now acts as a condenser and the indoor heat exchanger acts as an evaporator. The high-temperature high-pressure gas refrigerant discharged from the exhaust port of the compressor passes through the four-way valve and then enters the outdoor heat exchanger, the high-temperature high-pressure gas refrigerant is condensed and radiated in the outdoor heat exchanger to become a medium-temperature medium-pressure liquid refrigerant, then enters the flash evaporator to cool and decompress and finally become a low-temperature low-pressure liquid refrigerant, and the on-off valve is arranged to distribute and control the flow direction of the low-temperature low-pressure liquid refrigerant, so that the defrosting effect of the outdoor unit is achieved.
S2, recording the accumulated time of the operation defrosting mode of the air conditioner.
When the air conditioner initially enters the defrosting mode, the compressor is started to operate, so that the operating state of the compressor may not be stable enough in an initial period of time, and the time of the air conditioner for operating the defrosting mode needs to be accumulated so as to determine the operating state of the compressor, and meanwhile, in the subsequent defrosting operation process, the defrosting mode is also convenient to adjust according to the accumulated time of the operating defrosting mode.
S3, determining that the accumulated time is lower than a first time threshold value, and controlling a switching valve between an air outlet pipe of the flash evaporator and an air suction port of the compressor to be switched on.
The first time threshold may be set as required, where the first time threshold should be set to a smaller value, for example, 1min less than or equal to the first time threshold less than or equal to 5min may be set, for example, 1min or 2min or 3min or 5min may be set.
Further, the on/off valves are controlled to be turned on within the first time threshold, and at this time, as can be seen from fig. 1, the refrigerant discharged from the compressor exhaust port includes two flow directions, where the first flow direction is: the exhaust port of the compressor 1, the D port of the four-way valve 2, the C port of the four-way valve 2, the outdoor heat exchanger 3, the second restrictor 10, the flash evaporator 4, the switch valve 6 and the air suction port of the compressor 1; the second path of flow direction is as follows: the exhaust port of the compressor 1, the D port of the four-way valve 2, the C port of the four-way valve 2, the outdoor heat exchanger 3, the second restrictor 10, the flash evaporator 4, the first one-way valve 7, the indoor heat exchanger 5, the E port of the four-way valve 2, the S port of the four-way valve 2 and the air suction port of the compressor 1.
According to the above, in the defrosting mode, the high-temperature and high-pressure gas refrigerant discharged by the compressor enters the outdoor heat exchanger to condense and release heat, then enters the second throttle to cool and reduce pressure to become low-temperature and low-pressure liquid refrigerant, and then the flash evaporator can distribute and control the flow direction of the low-temperature and low-pressure liquid refrigerant, wherein most of the low-temperature and low-pressure liquid refrigerant can be directly led into the compressor to avoid frosting of the indoor heat exchanger, and only a very small part of the low-temperature and low-pressure liquid refrigerant flows to the air suction port of the compressor according to the second flow direction, so that the indoor heat exchanger is not frosted when the outdoor machine is defrosted by controlling the switch valve, and the situation that the heating effect is poor due to the fact that the indoor machine needs to be frosted when the air conditioner reenters into the heating mode after defrosting is completed is avoided.
Further, as shown in fig. 1, in the defrosting mode, the compressor 1 is controlled to be turned on, the first check valve 7 is controlled to be turned on, the second check valve 9 is controlled to be turned off, the four-way valve 2 is controlled not to be powered on, and the air conditioner comprises an indoor fan and an outdoor fan, and the outdoor fan and the indoor fan are also controlled to be turned off.
According to the defrosting control method for the air conditioner, which is provided by the embodiment of the invention, in the defrosting mode, the switch valve is controlled to be switched on, so that most of liquid refrigerant which is cooled and depressurized by the second throttle device and becomes low-temperature low-pressure liquid refrigerant is directly led back to the compressor by the switch valve, and only very little low-temperature low-pressure liquid refrigerant can flow through the indoor heat exchanger, so that the indoor heat exchanger is ensured not to be frosted, the problem of poor heating effect caused by defrosting the indoor machine when defrosting is completed and the air conditioner enters a heating mode again is solved, and the comfort level of a user is improved.
In some embodiments of the present invention, as shown in fig. 5, a flowchart of a defrosting control method for an air conditioner according to another embodiment of the present invention is shown, wherein the defrosting control method for an air conditioner further includes step S4 and step S5, which are specifically described below.
S4, acquiring the temperature of the outdoor coil.
Wherein, as shown in fig. 3, a temperature sensor 12 may be provided in the coil of the outdoor heat exchanger 3 for sensing the outdoor coil temperature. The outdoor coil temperature can intuitively reflect the frosting condition in the outdoor unit, for example, when the outdoor coil temperature is lower, the frosting layer in the outdoor unit is thicker and frosted more, the defrosting capacity of the air conditioner needs to be improved, and when the outdoor coil temperature is higher, the frosting layer in the outdoor unit is thinner and frosted less, and the defrosting is easier.
S5, controlling the switch valve to be switched on or off according to the accumulated time and the temperature of the outdoor coil.
When the accumulated time of the operation defrosting mode of the air conditioner is higher than the first time threshold, the operation of the compressor 1 is confirmed to be stable, and the frosting condition in the outdoor unit is further judged at the moment, so that the air conditioner is controlled to perform targeted defrosting operation according to the amount of frost in the outdoor unit.
The bypass defrosting mode disclosed in the prior art is slower in defrosting, and the problems of uncleanness in defrosting and the like are easy to occur under some low-temperature high-humidity working conditions.
In the defrosting mode, when the switch valve is in an on state, most of low-temperature low-pressure liquid refrigerant can be directly led into the compressor 1 to avoid frosting of the indoor heat exchanger, the refrigerant does not pass through the indoor heat exchanger, which is equivalent to the condition that the heat of the refrigerant in the primary lifting pipeline is lacked, and the refrigerant is compressed by the compressor to be changed into high-temperature high-pressure gas, so that the heat in the refrigerant flowing through the outdoor heat exchanger 3 is less than that of the refrigerant subjected to the two-stage energy lifting at the moment, the defrosting effect is limited, and the device is suitable for the conditions that the frost layer in the outdoor unit is thinner and the frost amount is less. As shown in fig. 2 or 3, when the control switch valve is turned off, the flow direction of the refrigerant in the pipeline is: the air outlet of the compressor 1, the D port of the four-way valve 2, the C port of the four-way valve 2, the outdoor heat exchanger 3, the second restrictor 10, the flash evaporator 4, the first one-way valve 7, the indoor heat exchanger 5, the E port of the four-way valve 2, the S port of the four-way valve 2, the air suction port of the compressor 1, namely, the refrigerant in the pipeline is lifted by two stages of energy and has more heat when flowing through the indoor heat exchanger 5 and the compressor 1, and when the high-temperature and high-pressure gas refrigerant exchanges heat with the outdoor heat exchanger 3, more heat can be released, so that a better defrosting effect is achieved to realize quick defrosting of the outdoor unit.
From the above, when the temperature of the outdoor coil is higher, the switch valve can be controlled to be switched on, so that the effective defrosting of the outdoor unit can be realized, the frosting of the indoor unit can be ensured, and the comfort level of a user can be improved.
According to the defrosting control method for the air conditioner, the on/off valve is controlled according to the accumulated time and the temperature of the outdoor coil pipe, targeted defrosting operation under different working conditions can be achieved, when the on valve is controlled, effective defrosting of the outdoor unit can be achieved, indoor unit frosting can be guaranteed, user comfort is improved, and when the on valve is controlled to be off, the outdoor unit can be quickly defrosted, and the situation that the outdoor unit is not defrosted cleanly is avoided.
In some embodiments of the present invention, as shown in fig. 6, a flowchart of a defrosting control method of an air conditioner according to still another embodiment of the present invention, in which a switching valve is controlled to be turned on or off according to an accumulated time and an outdoor coil temperature, i.e., the above step S5 may include the steps S51 and S52, as follows.
S51, if the outdoor coil temperature is lower than the first temperature threshold, judging whether the accumulated time is higher than the second time threshold.
The first temperature threshold may be set as required, for example, the first temperature threshold may be set to be less than or equal to 5 ℃, for example, the first time threshold may be set to be-2 ℃ or 0 ℃ or 1 ℃ or 5 ℃, and the like. When the outdoor coil temperature is detected to be lower than the first temperature threshold value, the outdoor coil temperature is in a relatively low state, which means that the outdoor unit has more frosting and a relatively thick frost layer. And a second time threshold value can be set according to the need, wherein the second time threshold value is set to be a value larger than the first time threshold value, for example, the second time threshold value is set to be 3min or less and 8min or less, for example, the second time threshold value is set to be 3min or 5min or 7min or 8min or the like, and the defrosting effect under the condition that the control switch valve is turned on is judged by accumulating the time of operating the defrosting mode and detecting the temperature of the outdoor coil in real time, so that the flow direction of the refrigerant in the pipeline can be adjusted according to the defrosting effect in time.
And S52, if the accumulated time is higher than the second time threshold and lower than the third time threshold, the switch valve is controlled to be turned off until the accumulated time is higher than the third time threshold, and the air conditioner is controlled to exit the defrosting mode, wherein the third time threshold is larger than the second time threshold and larger than the first time threshold.
The third time threshold may be set as required, for example, the third time threshold may be set to be less than or equal to 6min and less than or equal to 12min, for example, the third time threshold may be set to be 6min or 8min or 10min or 12min, when the accumulated time is determined to be higher than the second time threshold and lower than the third time threshold and the temperature of the outdoor coil is lower than the first temperature threshold, it is indicated that the time of controlling the on-off valve to be on is longer at this time, but the defrosting effect is not ideal, in order to accelerate the defrosting speed, the defrosting force is required to be increased at this time, the on-off valve is controlled to be turned off, and the defrosting capability of the outdoor unit is improved, so as to realize rapid defrosting.
In addition, when defrosting is performed by adopting a mode of controlling the switch valve to be turned off, the temperature of the outdoor coil pipe is detected in real time, and when the temperature of the outdoor coil pipe is determined to be larger than a first temperature threshold value, the switch valve can be controlled to be turned on again, so that the situation of indoor unit frosting caused by long-time defrosting by adopting the mode of controlling the switch valve to be turned off is avoided.
Based on the above, when the outdoor unit is defrosted by adopting the mode of controlling the switch valve to be turned off for a long time, the indoor unit is easy to frost, the time for defrosting by adopting the mode is limited, and when the accumulated time is determined to be higher than the third time threshold value, the defrosting time is considered to be long enough, and the frost layer in the outdoor unit can be completely removed, so that the air conditioner is controlled to exit the defrosting mode.
In some embodiments of the present invention, as shown in fig. 7, a flowchart of a defrosting control method for an air conditioner according to still another embodiment of the present invention, in which the on/off valve is controlled to be turned on or off according to the accumulated time and the outdoor coil temperature, i.e., the above step S5 may further include the steps S53 and S54, as follows.
S53, if the outdoor coil temperature is higher than the first temperature threshold and lower than the second temperature threshold, judging whether the accumulated time reaches a third time threshold.
Wherein the second temperature threshold value can be set according to the requirement, and the second temperature threshold value should be larger than the first temperature threshold value, for example, the second temperature threshold value is not smaller than 0 ℃ and not larger than 10 ℃, for example, the first time threshold value can be set to be 0 ℃ or 5 ℃ or 8 ℃ or 10 ℃, and the like.
When the temperature of the outdoor coil is detected to be higher than the first temperature threshold and lower than the second temperature threshold, the amount of frost in the outdoor unit is considered to be basically in a normal state, and the outdoor unit can be defrosted by controlling the on-off valve to be on, but the time for defrosting in the mode can be set to be longer because the temperature of the outdoor coil is still in a comparatively low state.
And S54, if the accumulated time does not reach the third time threshold, controlling the switch valve to be kept on until the accumulated time reaches the third time threshold, and controlling the air conditioner to exit the defrosting mode, wherein the second temperature threshold is larger than the first temperature threshold, and the third time threshold is larger than the first time threshold.
And the outdoor unit is defrosted by continuously adopting a mode of controlling the switch valve to be switched on, and the defrosting is determined to be completed until the accumulated time reaches a third time threshold value, and the air conditioner is timely controlled to exit the defrosting mode, so that the outdoor unit is not only ensured to defrost cleanly, but also the indoor heat exchanger is ensured not to frost in the defrosting process, and the conditions of poor heating effect and the like caused by defrosting the indoor unit when the defrosting is completed and the heating mode is re-entered are avoided.
In some embodiments of the present invention, as shown in fig. 8, a flowchart of a defrosting control method for an air conditioner according to still another embodiment of the present invention is shown, in which the on/off valve is controlled to be turned on or off according to the accumulated time and the outdoor coil temperature, i.e., the above step S5 may further include the steps S55 and S56, as follows.
S55, if the outdoor coil temperature is higher than the second temperature threshold, judging whether the accumulated time reaches the second time threshold or whether the outdoor coil temperature is higher than the second temperature threshold, wherein the third time threshold is greater than the second time threshold and greater than the first time threshold.
When the temperature of the outdoor coil is detected to be higher than the second temperature threshold, the outdoor coil is shown to be higher in temperature, frosting of the outdoor unit is less, the outdoor unit can be defrosted in a mode of controlling the switch valve to be switched on, defrosting time can be limited to be shorter, and meanwhile, the temperature of the outdoor coil needs to be detected in real time to judge defrosting effects of the outdoor unit.
And S56, if the accumulated time reaches the second time threshold or the third time threshold, controlling the air conditioner to exit the defrosting mode.
When the accumulated time is up to the second time threshold, the operation defrosting mode time is considered to be enough to completely defrost the outdoor unit, and it is determined that the defrosting operation is completed at this time. And as can be seen from the above, the third temperature threshold is higher, and when the temperature of the outdoor coil is detected to reach the third temperature threshold, the outdoor unit is completely defrosted at this time, and the air conditioner needs to be controlled to exit the defrosting mode in time, so that the situations that the current of the compressor is too high, the compressor is jumped or damaged due to the fact that the outdoor heat exchanger is defrosted for a long time without frost are avoided.
Further, under the defrosting condition, when the mode of controlling the switch valve to be switched on is adopted for defrosting, the temperature of the outdoor coil pipe is required to be detected in real time, when the temperature of the outdoor coil pipe is determined to be larger than a second temperature threshold value, the defrosting speed is higher, the defrosting effect is better, in order to avoid the situation that the defrosting mode is still continuously operated when the frost layer of the outdoor unit is cleaned, when the accumulated time is determined to reach the second time threshold value or the temperature of the outdoor coil pipe is higher than the second temperature threshold value, the air conditioner is timely controlled to exit the defrosting mode, and the situations that the current of the compressor is overlarge, the compressor is jumped or the compressor is damaged due to the fact that the outdoor heat exchanger is frostless and is defrosted for a long time are avoided.
In some embodiments of the present invention, as shown in fig. 9, a flowchart of a defrosting control method of an air conditioner according to still another embodiment of the present invention is shown, wherein the defrosting control method of the air conditioner may include S101-S106, which is specifically described below.
S101, a user starts a heating mode.
S102, entering a heating mode.
S103, the compressor, the indoor fan and the outdoor fan are started, the switch valve is switched on, and the four-way valve is electrified.
S104, meeting the condition of entering the defrosting mode.
S105, entering a defrosting mode.
S106, the compressor, the indoor fan and the outdoor fan are started, the switch valve is switched on, and the four-way valve is powered down.
S107, accumulating the operation time N of the defrosting mode, judging whether N1 is less than or equal to N2 or not, if yes, executing step S108, and if no, returning to executing step S106. Wherein N1 is a first time threshold and N2 is a second time threshold.
S108, acquiring the outdoor coil temperature TC.
S109, in the step B, TC < T1 is detected, wherein T1 is a first temperature threshold.
S110, determining that N2 is not less than N and not more than N3, and turning off a switch valve, wherein N3 is a third time threshold.
S111, determining that N is larger than N3, exiting the defrosting mode, and returning to the execution step S102.
S112, in the step A, TC > T2 is detected, and the switching valve is switched on, wherein T2 is a second temperature threshold.
S113, determining that N is greater than N2 or detecting TC is greater than T3, exiting the defrosting mode, and returning to execute step S102, wherein T3 is a third temperature threshold.
S114, in the step C, detecting that T1 is not less than TC and not more than T2, and switching on the switch valve.
S115, determining that N is less than or equal to N3, and continuing to operate the defrosting mode.
S116, determining that N is more than N3, exiting the defrosting mode, and returning to execute the step S102.
In addition, when step S110 is executed, if T1 is detected to be equal to or less than TC, the control switch valve is turned on, that is, the execution of step B is changed to the execution of step C, and when step C is executed, TC > T2 is detected, the execution of step C is changed to the execution of step a.
According to the defrosting control method for the air conditioner, provided by the embodiment of the invention, the frosting or defrosting condition of the outdoor unit can be known in real time by detecting the temperature of the outdoor coil in real time, and different defrosting modes are adaptively switched based on the frosting condition of the outdoor unit, so that the corresponding defrosting effect is achieved, the defrosting capacity of the outdoor unit can be improved, the quick defrosting can be realized, the defrosting cleanliness can be ensured even under the working conditions of low temperature, high humidity and the like, the indoor heat exchanger can be ensured not to frost when the defrosting mode is operated, the problem of poor heating effect caused by defrosting the indoor unit when the defrosting is completed and the indoor unit enters the heating mode again can be avoided, and the comfort level of a user is improved.
Other constructions and operations of the air conditioner 100 and the like according to the embodiment of the present invention are known to those skilled in the art, and will not be described in detail herein.
In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples.
While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the invention, the scope of which is defined by the claims and their equivalents.

Claims (10)

1. An air conditioner, comprising:
the device comprises a compressor, a four-way valve, an outdoor heat exchanger, a flash evaporator and an indoor heat exchanger, wherein the flash evaporator is provided with a first liquid pipe, a second liquid pipe and an air outlet pipe, and the air outlet pipe is connected with an air suction port of the compressor;
The switch valve is arranged on a pipeline between the air outlet pipe and the air suction port of the compressor;
the first one-way valve and the first throttle are arranged in parallel between a first liquid pipe of the flash evaporator and the indoor heat exchanger, and a liquid inlet of the first one-way valve is connected with the first liquid pipe;
the second one-way valve and the second restrictor are arranged in parallel between a second liquid pipe of the flash evaporator and the outdoor heat exchanger, and a liquid inlet of the second one-way valve is connected with the second liquid pipe;
a controller connected to the on-off valve, the controller configured to: detecting that the air conditioner is switched to a defrosting mode, recording the accumulated time of the air conditioner in the defrosting mode, determining that the accumulated time is lower than a first time threshold, and controlling the switch valve to be switched on to form a first path flow direction and a second path flow direction, wherein the first path flow direction is an air outlet-four-way valve-outdoor heat exchanger-second restrictor-flash evaporator-switch valve-compressor air suction port of the compressor; the second flow direction is the exhaust port of the compressor, the four-way valve, the outdoor heat exchanger, the second restrictor, the flash evaporator, the first one-way valve, the indoor heat exchanger, the four-way valve and the air suction port of the compressor.
2. The air conditioner of claim 1, further comprising:
the temperature sensor is used for collecting the temperature of the outdoor coil;
the controller is connected to the temperature sensor and is further configured to: and determining that the accumulated time of the air conditioner in the defrosting mode is higher than the first time threshold, and controlling the switch valve to be switched on or off according to the accumulated time and the outdoor coil temperature.
3. The air conditioner of claim 2, wherein the controller is further configured to determine if the cumulative time is above a second time threshold if the outdoor coil temperature is below a first temperature threshold, and to control the on-off valve to turn off if the cumulative time is above the second time threshold and below a third time threshold until the cumulative time is above the third time threshold, wherein the third time threshold > the second time threshold > the first time threshold.
4. The air conditioner of claim 2, wherein the controller is further configured to determine whether the cumulative time reaches a third time threshold if the outdoor coil temperature is above a first temperature threshold and below a second temperature threshold, and to control the on-off valve to remain on until the cumulative time reaches the third time threshold if the cumulative time does not reach the third time threshold, and to control the air conditioner to exit the defrost mode, wherein the second temperature threshold is greater than the first temperature threshold and the third time threshold is greater than the first time threshold.
5. The air conditioner of claim 2, further configured to determine whether the cumulative time reaches a second time threshold or whether the cumulative time reaches a third time threshold if the outdoor coil temperature is above a second temperature threshold, and to control the air conditioner to exit the defrost mode if the cumulative time reaches the second time threshold or the third time threshold.
6. A defrosting control method for an air conditioner according to claim 1, comprising:
detecting that the air conditioner is switched to a defrosting mode;
recording the accumulated time of the air conditioner in the defrosting mode;
determining that the accumulated time is lower than a first time threshold value, and controlling a switching valve between an air outlet pipe of a flash evaporator and an air suction port of a compressor to be switched on to form a first path of flow direction and a second path of flow direction, wherein the first path of flow direction is an air suction port of the compressor, namely an air discharge port of the compressor, a four-way valve, an outdoor heat exchanger, a second restrictor, the flash evaporator, a switching valve and the air suction port of the compressor; the second flow direction is the exhaust port of the compressor, the four-way valve, the outdoor heat exchanger, the second restrictor, the flash evaporator, the first one-way valve, the indoor heat exchanger, the four-way valve and the air suction port of the compressor.
7. The defrosting control method of claim 6, further comprising:
acquiring the temperature of an outdoor coil;
and controlling the on/off of the switch valve according to the accumulated time and the outdoor coil temperature.
8. The defrosting control method of claim 7, wherein controlling the on/off of the on/off valve according to the accumulated time and the outdoor coil temperature comprises:
if the temperature of the outdoor coil is lower than a first temperature threshold, judging whether the accumulated time is higher than a second time threshold;
and if the accumulated time is higher than the second time threshold and lower than a third time threshold, controlling the switch valve to be turned off until the accumulated time is higher than the third time threshold, and controlling the air conditioner to exit the defrosting mode, wherein the third time threshold is larger than the second time threshold and larger than the first time threshold.
9. The defrosting control method of claim 7, wherein controlling the on/off of the on/off valve according to the accumulated time and the outdoor coil temperature comprises:
if the temperature of the outdoor coil is higher than the first temperature threshold and lower than the second temperature threshold, judging whether the accumulated time reaches a third time threshold;
And if the accumulated time does not reach the third time threshold, controlling the switch valve to be kept on until the accumulated time reaches the third time threshold, and controlling the air conditioner to exit the defrosting mode, wherein the second temperature threshold is larger than the first temperature threshold, and the third time threshold is larger than the first time threshold.
10. The defrosting control method of claim 7, wherein controlling the on/off of the on/off valve according to the accumulated time and the outdoor coil temperature comprises:
if the temperature of the outdoor coil is higher than a second temperature threshold, judging whether the accumulated time reaches a second time threshold or whether the accumulated time reaches a third time threshold, wherein the third time threshold is larger than the second time threshold and larger than the first time threshold;
and if the accumulated time reaches the second time threshold or the third time threshold, controlling the air conditioner to exit the defrosting mode.
CN202210757838.XA 2022-06-30 2022-06-30 Air conditioner and defrosting control method thereof Active CN115031350B (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5065584A (en) * 1990-07-30 1991-11-19 U-Line Corporation Hot gas bypass defrosting system
CN103363707A (en) * 2012-04-09 2013-10-23 珠海格力电器股份有限公司 Heat pump type air conditioning device
JP2020051667A (en) * 2018-09-26 2020-04-02 東芝キヤリア株式会社 Air conditioner
CN111692708A (en) * 2020-06-16 2020-09-22 珠海格力电器股份有限公司 Air conditioning system with frosting inhibition function and frosting inhibition control method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5065584A (en) * 1990-07-30 1991-11-19 U-Line Corporation Hot gas bypass defrosting system
CN103363707A (en) * 2012-04-09 2013-10-23 珠海格力电器股份有限公司 Heat pump type air conditioning device
JP2020051667A (en) * 2018-09-26 2020-04-02 東芝キヤリア株式会社 Air conditioner
CN111692708A (en) * 2020-06-16 2020-09-22 珠海格力电器股份有限公司 Air conditioning system with frosting inhibition function and frosting inhibition control method

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