CN114440392B

CN114440392B - Air conditioner and air conditioner control method

Info

Publication number: CN114440392B
Application number: CN202210180385.9A
Authority: CN
Inventors: 丁帮海
Original assignee: Hisense Air Conditioning Co Ltd
Current assignee: Hisense Air Conditioning Co Ltd
Priority date: 2022-02-25
Filing date: 2022-02-25
Publication date: 2023-10-27
Anticipated expiration: 2042-02-25
Also published as: CN114440392A

Abstract

The invention discloses an air conditioner and an air conditioner control method, wherein the air conditioner comprises a compressor, a four-way valve, an outdoor heat exchanger, a first throttling element, an indoor heat exchanger, a second throttling element, a temperature sensor and a controller. The second throttling element is arranged at the branch pipe pipeline of the indoor heat exchanger; the temperature sensor is used for collecting outdoor environment temperature; the controller is connected with the second throttling element and the temperature sensor and is configured to: and detecting a heating stop instruction, acquiring the outdoor environment temperature, and controlling the second throttling element to be closed when the outdoor environment temperature is lower than a preset temperature threshold value. The air conditioner provided by the embodiment of the invention can seal most refrigerants in an indoor heat exchanger in a stop state, prevent the refrigerants from migrating and accumulating in a crankcase of a compressor when the temperature is low, and rapidly improve the suction pressure during heating operation, so that the operation reliability of the compressor is improved.

Description

Air conditioner and air conditioner control method

Technical Field

The invention relates to the technical field of air conditioners, in particular to an air conditioner and an air conditioner control method.

Background

With the improvement of living standard of people, the popularity of air conditioners is higher, various air conditioner problems in the market are endless, and the problem of refrigerant backflow in the stop state of the air conditioner is emphasized. Aiming at the problem that the low-temperature heating suction pressure of an air conditioning system is too low, the prior art mostly adopts a mode of increasing the power of a crankcase heating belt of a compressor and improving the temperature in the crankcase, so that the situation that excessive liquid refrigerant migrates to the crankcase and invades into engine oil of the compressor 1 and reduces the flow resistance of the refrigerant in a pipeline due to low temperature is avoided. However, the scheme increases the standby power consumption of the air conditioner, and the compressor heating belt needs to be powered in advance before starting up, so that the energy conservation is not achieved. In the prior art, another scheme is also provided, when the air conditioner is in heating operation, the air conditioner is controlled to operate for a period of time to drive the refrigerant into the outdoor heat exchanger rapidly, and then the four-way valve is electrified to operate for heating the mode after the refrigerant is operated for a period of time, however, the scheme can lead to slow temperature rise of air outlet temperature when the air conditioner heats, the air outlet effect is affected, and the user experience is poor.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems existing in the prior art.

Therefore, one of the purposes of the present invention is to provide an air conditioner, which can seal most of the refrigerant in the indoor heat exchanger in the stop state, prevent the refrigerant from migrating and accumulating in the crankcase of the compressor when the temperature is low, and rapidly raise the suction pressure during the heating operation, so as to improve the operation reliability of the compressor.

The second objective of the present invention is to provide a 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 first throttling element and an indoor heat exchanger; the second throttling piece is arranged at the branch pipe pipeline of the indoor heat exchanger. The second throttling element is arranged at the branch pipe pipeline of the indoor heat exchanger, and the control of the refrigerant flow can be further realized on the basis of being provided with the first throttling element.

The temperature sensor is used for collecting outdoor environment temperature; a controller coupled to the second throttle and the temperature sensor configured to: and detecting a heating stop instruction, acquiring the outdoor environment temperature, and controlling the second throttling element to be closed when the outdoor environment temperature is lower than a preset temperature threshold value. After the compressor is heated and stopped, the controller controls the second throttling element to be closed, so that most of refrigerant in the system can run to the indoor heat exchanger and be stored in the indoor heat exchanger.

According to the air conditioner provided by the embodiment of the invention, the second throttling element is arranged at the branch pipe pipeline of the indoor heat exchanger, when the compressor is stopped and the outdoor environment temperature is lower than the preset temperature threshold value, the controller controls the second throttling element to be closed, so that most of refrigerant is sealed in the indoor heat exchanger after heating and stopping, the refrigerant is prevented from migrating and accumulating in the crankcase of the compressor when the temperature is lower in the stopped state, the refrigerant can be quickly pumped into the air return ports of the outdoor heat exchanger and the compressor from the indoor heat exchanger when the system is restarted for heating operation, the problem that the air suction pressure of the compressor is built slowly when the low-temperature heating is started is solved, the operation reliability of the compressor is improved, the air outlet effect is not influenced when the air conditioner is restarted for heating operation, and the user experience is improved.

In some embodiments of the invention, the D port of the four-way valve is connected to the exhaust port of the compressor, the S port of the four-way valve is connected to the return air port of the compressor, the C port of the four-way valve is connected to the outdoor heat exchanger, and the E port of the four-way valve is connected to the indoor heat exchanger. The connection state of the C port and the E port of the four-way valve can be directly adjusted in the original hardware architecture, so that the controller can conveniently control the power on/off of the four-way valve after refrigeration/heating and stopping.

In some embodiments, the controller is further configured to: and when a refrigerating instruction is detected, controlling the S port and the E port of the four-way valve to be communicated, or when a heating instruction is detected, controlling the S port and the C port of the four-way valve to be communicated. Because the S port is communicated with the E port when the four-way valve is electrified and the S port is communicated with the C port when the four-way valve is in a power-off state, the controller controls the four-way valve to be electrified in a refrigerating mode, and the controller controls the four-way valve to be powered off in a heating mode, so that the situation that high pressure cannot be established due to the fact that the E port and the S port of the four-way valve are communicated in series due to the reset of a valve body sliding block in the four-way valve after the heat of a compressor in a conventional facility is stopped is avoided.

In addition, after the compressor is stopped in a heating mode, an E port and an S port of the four-way valve cannot be connected with the indoor heat exchanger and are matched with each other in a closing mode, so that the refrigerant is sealed in the indoor heat exchanger as much as possible, and the situation that excessive liquid refrigerant migrates to a crankcase of the compressor and even invades engine oil of the compressor 1 when the temperature is low can be more effectively avoided.

In some embodiments of the invention, the controller, when controlling the second throttle to close, is specifically configured to: and acquiring the operation frequency before the compressor is stopped, and controlling the closing rate of the second throttling element according to the operation frequency before the compressor is stopped. The proper closing rate is set based on the operation frequency before the compressor is stopped, and the controller controls the second throttling element to be closed at the preset closing rate, so that the safety of the system pressure can be ensured, the refrigerant can be rapidly sealed in the indoor heat exchanger, and the stability and the reliability of the system operation are ensured.

In some embodiments of the invention, the controller, when controlling the closing rate of the second throttle, is specifically configured to: the smaller the operating frequency before the compressor is stopped, the larger the closing rate of the second throttling element is controlled.

In some embodiments of the invention, the controller is further configured to: and when the operation frequency before the compressor is stopped is lower than a first frequency threshold value, controlling the second throttling element to be closed at a first speed, when the operation frequency before the compressor is stopped is higher than the first frequency threshold value and lower than a second frequency threshold value, controlling the second throttling element to be closed at a second speed, wherein the second speed is lower than the first speed, and when the operation frequency before the compressor is stopped is higher than the second frequency threshold value, controlling the second throttling element to be closed at a third speed, and the third speed is lower than the second speed. Therefore, when the operation frequency of the compressor before stopping is smaller, the controller controls the second throttling element to be quickly closed at a larger speed, so that the refrigerant can be timely sealed in the indoor heat exchanger, and when the operation frequency of the compressor before stopping is larger, the controller controls the second throttling element to be quickly closed at a smaller speed, so that the pressure safety of the system can be ensured, and the refrigerant can be quickly sealed in the indoor heat exchanger, so that the stability and the reliability of the operation of the system are ensured.

In some embodiments of the invention, the air conditioner further comprises: the check valve is arranged between the exhaust port of the compressor and the D port of the four-way valve and is used for enabling the refrigerant to flow unidirectionally from the exhaust port of the compressor to the D port of the four-way valve. The one-way valve has one-way conduction function and is used for controlling the flow direction of the refrigerant. Therefore, by arranging the one-way valve, the refrigerant can be effectively prevented from flowing back to the compressor when the compressor is in operation and after the compressor is stopped.

In addition, through setting up the check valve to after the compressor shut down under the heating mode, control its control four way valve E port and S port can not switch on, and control indoor heat exchanger connection and control second throttling element close, mutually support between the three, can furthest seal the refrigerant in indoor heat exchanger, prevent that the refrigerant from flowing back to the compressor, promote the reliability of compressor, can also prolong the life of compressor to a certain extent.

In order to achieve the above object, a second aspect of the present invention provides a control method of an air conditioner, where the air conditioner includes a compressor, a four-way valve, an outdoor heat exchanger, a refrigerant circuit formed by combining a first throttling element and an indoor heat exchanger, a second throttling element, a controller, and a temperature sensor, the second throttling element is disposed at a shunt pipe of the indoor heat exchanger, the temperature sensor is used for collecting outdoor ambient temperature, and the controller is used for controlling the four-way valve and the second throttling element; the air conditioner control method comprises the following steps: detecting a heating stop instruction, and acquiring the outdoor environment temperature; and when the outdoor environment temperature is lower than a preset temperature threshold value, controlling the second throttling element to be closed, wherein the second throttling element is arranged at the branch pipe line of the indoor heat exchanger of the air conditioner.

According to the air conditioner control method provided by the embodiment of the invention, when the air conditioner is stopped and the outdoor environment temperature is lower than the preset temperature threshold value, the second throttling element is controlled to be closed, so that most of refrigerant can be sealed in the indoor heat exchanger after the compressor is stopped in a heating mode, the refrigerant is prevented from migrating and accumulating in the crankcase of the compressor when the temperature is lower in the stopped state, the refrigerant can be quickly pumped into the outdoor heat exchanger and the air return port of the compressor from the indoor heat exchanger when the system is restarted for heating operation, the problem that the air suction pressure of the compressor is built slower when the low-temperature heating operation is started is solved, the operation reliability of the compressor is improved, the air outlet effect is not influenced when the air conditioner is restarted for heating operation, and the user experience is improved.

In some embodiments of the present invention, a D port of a four-way valve of the air conditioner is connected to an exhaust port of a compressor, an S port of the four-way valve is connected to a return air port of the compressor, a C port of the four-way valve is connected to the outdoor heat exchanger, and an E port of the four-way valve is connected to the indoor heat exchanger; the air conditioner control method further comprises the following steps: when a refrigerating instruction is detected, an S port and an E port of the four-way valve are controlled to be communicated; or when the heating instruction is detected, controlling the S port and the C port of the four-way valve to be communicated. Because the S port is communicated with the E port when the four-way valve is electrified and the S port is communicated with the C port when the four-way valve is powered off, the four-way valve is controlled to be electrified in a refrigerating mode, the four-way valve is controlled to be powered off in a heating mode, and the situation that high pressure cannot be established due to serial communication of the E port and the S port of the four-way valve caused by resetting of a valve body sliding block in the four-way valve after a compressor machine under conventional facilities is heated and stopped is avoided.

In some embodiments of the invention, the controlling the second restriction to close includes: acquiring the operation frequency of the compressor before stopping; and controlling the closing rate of the second throttling element according to the operation frequency before the compressor is stopped, wherein the smaller the operation frequency before the compressor is stopped is, the larger the closing rate of the second throttling element is controlled. Therefore, when the operation frequency of the compressor before the shutdown is determined to be smaller, the controller controls the second throttling element to be quickly closed at a larger speed, so that the refrigerant can be ensured to be timely sealed in the indoor heat exchanger, and when the operation frequency of the compressor before the shutdown is determined to be larger, the controller controls the second throttling element to be quickly closed at a smaller speed, so that the pressure safety of the system can be ensured, and the refrigerant can be quickly sealed in the indoor heat exchanger, so that the stability and the reliability of the operation of the system are ensured.

In some embodiments of the invention, controlling the closing rate of the second restriction according to the operating frequency before the compressor is shut down comprises: controlling the second restriction to close at a first rate when the operating frequency of the compressor prior to shutdown is below a first frequency threshold; controlling the second restriction to close at a second rate when the operating frequency before the compressor is shut down is above the first frequency threshold and below a second frequency threshold, the second rate being less than the first rate; and when the operation frequency before the compressor is stopped is higher than the second frequency threshold value, controlling the second throttling element to be closed at a third speed, wherein the third speed is smaller than the second speed. Therefore, the second throttling element is controlled to be closed based on the proper closing rate selected by the operation frequency before the compressor is stopped, so that the pressure safety of the system can be ensured, the refrigerant can be rapidly sealed in the indoor heat exchanger, and the stability and the reliability of the operation of the system are ensured.

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 schematic view of an air conditioner according to still another embodiment of the present invention;

FIG. 5 is a schematic diagram of a four-way valve according to one embodiment of the invention;

FIG. 6 is a schematic diagram of a four-way valve according to another embodiment of the present invention;

fig. 7 is a flowchart of an air conditioner control method according to an embodiment of the present invention;

fig. 8 is a flowchart of an air conditioner control method according to another embodiment of the present invention;

fig. 9 is a flowchart of an air conditioner control method according to still another embodiment of the present invention;

fig. 10 is a flowchart of an air conditioner control method 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 first throttling element 4, the indoor heat exchanger 5, the second throttling element 6, the temperature sensor 7, the controller 8, the one-way valve 9, the first stop valve 10, the second stop valve 11, the high-pressure switch HP and the low-pressure switch LP;

pilot valve 21, main valve 22, solenoid 23, control valve 24, valve body slider 25.

Detailed Description

Embodiments of the present invention will be described in detail below, by way of example with reference to the accompanying drawings.

When the temperature inside the compressor is lower than that inside the indoor/outdoor heat exchanger after the air conditioner compressor is stopped for a period of time, the temperature difference between the compressor and the indoor/outdoor heat exchanger can cause pressure difference between the compressor and the indoor/outdoor heat exchanger, and the refrigerant migrates and accumulates into the crankcase of the compressor under the driving action of the pressure difference, so that the phenomenon is more easy to happen especially in cold weather. And the longer the compressor downtime, the more refrigerant will migrate to the interior of compressor crankcase, and when the air conditioner starts the operation, refrigerant flow can take very big part of compressor lubricating oil out of the compressor crankcase, and the lubricating oil of taking out can increase the flow resistance of refrigerant in the pipeline for the suction pressure when the compressor starts the operation sets up slower, seriously influences the operational reliability of compressor. The lower suction pressure also can lead to that the lubricating oil carried out by the refrigerant can not timely return to the compressor, and the moving parts in the crankcase of the compressor lack lubrication, so that the service life of the compressor is influenced. And for some indoor heat exchangers and outdoor heat exchangers which are installed by long connecting pipes, the pressure loss of the refrigerant in the pipeline is larger, so that the reduction of suction pressure can be further aggravated, and the use reliability of the compressor is reduced.

In order to solve the problems that after the air conditioner is stopped in a heating mode, refrigerant migrates and accumulates in a crankcase of the compressor due to low ambient temperature, the suction pressure of the compressor is too low when the air conditioner is started to run in a heating mode again, and the like, the embodiment of the application provides the air conditioner and an air conditioner control 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, in which a basic structure of the air conditioner can be understood in conjunction with fig. 1, and in the present application, the air conditioner performs a cooling/heating cycle of the air conditioner by using a compressor, a condenser (outdoor heat exchanger), an expansion valve, and an evaporator (indoor heat exchanger). 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 refrigeration 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 can be provided with a compressor, an outdoor heat exchanger, an outdoor fan, an expander and similar components of refrigeration cycle, and the air conditioner indoor unit can also 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. Fig. 2 is a schematic view of an air conditioner according to an embodiment of the present application; fig. 3 is a schematic view of an air conditioner according to another embodiment of the present application.

As shown in fig. 2, the air conditioner 100 includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, a first throttle 4, an indoor heat exchanger 5, a second throttle 6, a temperature sensor 7, and a controller 8.

As shown in fig. 3, the first throttling element 4 may be an expansion valve, and specifically, the first throttling element 4 is disposed in a pipe connecting the indoor heat exchanger 3 and the outdoor heat exchanger 4 for playing a role of throttling and reducing pressure.

Four ports are arranged in the four-way valve 2 and are respectively connected with a return air port and an exhaust port of the compressor 1, the indoor heat exchanger 5 and the outdoor heat exchanger 3, and the four ports are used for changing the flow direction of a refrigerant in a system pipeline to realize the mutual conversion between refrigeration and heating.

Wherein the second throttling element 6 is arranged at the branch pipe of the indoor heat exchanger 5. The second throttling element 6 may be an electronic expansion valve, and specifically, the second throttling element 6 may also be disposed in a pipeline connecting the indoor heat exchanger 5 and the outdoor heat exchanger 3, and located between the first throttling element 4 and the indoor heat exchanger 5 and located at a shunt pipe pipeline of the indoor heat exchanger 5.

In some embodiments, the temperature sensor 7 may be disposed in the outdoor unit, or the temperature sensor 7 may be disposed separately outdoors for collecting outdoor ambient temperature.

As shown in fig. 2, the controller 8 is connected to the second throttle 6 and the temperature sensor 7, and can acquire the outdoor ambient temperature detected by the temperature sensor 7 in real time. Wherein the controller 8 is not shown in fig. 3.

In some embodiments, the controller 8 is configured to: and detecting a heating stop instruction, acquiring the outdoor environment temperature, and controlling the second throttling element 6 to be closed when the outdoor environment temperature is lower than a preset temperature threshold value.

The preset temperature threshold may be set under laboratory conditions or according to actual needs, for example, for an intelligent air conditioner, a variable frequency air conditioner, etc. with an autonomous operation heating mode, for example, when it is detected that the outdoor ambient temperature is lower than a certain temperature set value, the air conditioner 100 may autonomously operate the heating mode, and the preset temperature threshold may be set to be lower than the temperature set value corresponding to the autonomous entry heating mode.

As shown in fig. 4, a schematic view of an air conditioner according to still another embodiment of the present invention is shown, wherein a direction indicated by a straight arrow indicates a flow direction of a refrigerant when the air conditioner 100 operates in a cooling mode; the direction indicated by the dotted arrow indicates the flow direction of the refrigerant when the air conditioner 100 operates in the heating mode.

It can be understood that when the air conditioner operates in the heating mode, the flow direction of the refrigerant is as follows: the compressor 1-the four-way valve 2-the indoor heat exchanger 5-the second throttling element 6-the first throttling element 4-the outdoor heat exchanger 3-the four-way valve 2-the compressor 1. Specifically, in the heating mode, the second throttling element 6 is in an open state, the high-temperature and high-pressure gaseous refrigerant sprayed out of the air outlet of the compressor 1 enters the indoor heat exchanger 5 through the port D and the port E of the four-way valve 2, and completes condensation heat release in the indoor heat exchanger 5, then passes through the first throttling element 4 and becomes low-temperature and low-pressure liquid refrigerant to enter the outdoor heat exchanger 3, the liquid refrigerant evaporates and absorbs heat in the outdoor heat exchanger 3 to become low-temperature and low-pressure gaseous refrigerant, the gaseous refrigerant flows back to the air return port of the compressor 1 through the port C and the port S of the four-way valve 2, and then is compressed again in the compressor 1, and the next refrigerant circulation process is re-entered. When the controller 8 detects a heating stop command, it indicates that the compressor 1 is stopped when the heating mode is operated, and the second throttling element 6 is controlled to be closed at this time, so that the refrigerant in the pipeline cannot pass through the second throttling element 6 and is finally sealed in the indoor heat exchanger 5.

Based on the configuration of the controller 8, after the compressor 1 is stopped in the heating mode, the refrigerant is sealed in the indoor heat exchanger 5, and even if the outdoor environment temperature is relatively low during the stop of the air conditioner 100, the refrigerant will not flow back to the air return port of the compressor 1, so that the situation that excessive liquid refrigerant migrates to the crankcase of the compressor 1 and even invades into the engine oil of the compressor 1 caused by low temperature can be effectively avoided.

According to the air conditioner 100 provided by the embodiment of the invention, the second throttling element 6 is arranged at the branch pipe pipeline of the indoor heat exchanger 5, when the compressor 1 is stopped and the outdoor environment temperature is lower than the preset temperature threshold value, the controller 8 controls the second throttling element 6 to be closed, so that most refrigerant can be sealed in the indoor heat exchanger 5 after the compressor 1 is heated and stopped, the refrigerant is prevented from migrating and accumulating in the crankcase of the compressor 1 when the temperature is lower in the stopped state, and then the refrigerant can be quickly pumped into the air return ports of the outdoor heat exchanger 3 and the compressor 1 from the indoor heat exchanger 5 when the system is restarted for heating, the problem that the establishment of the suction pressure of the compressor 1 is slower when the low-temperature heating is started is solved, the operation reliability of the compressor 1 is improved, the air outlet effect is not influenced when the air conditioner 100 is restarted for heating operation, and the user experience is improved.

Wherein, the structure of the four-way valve 2 and the port connection condition of the four-way valve 2 according to the embodiment of the present invention can be described with reference to fig. 4, 5 and 6, fig. 5 is a schematic diagram of the four-way valve according to an embodiment of the present invention; fig. 6 is a schematic view of a four-way valve according to another embodiment of the present invention.

In some embodiments of the present invention, as shown in fig. 4, the D port of the four-way valve 2 is connected to the discharge port of the compressor 1, and the S port of the four-way valve 2 is connected to the return air port of the compressor 1.

Specifically, as shown in fig. 5, the four-way valve 2 may be a conversion component commonly used in an air conditioner, the four-way valve 2 may include four ports including a D port, an S port, an E port, and a C port, and further includes a pilot valve 21, a main valve 22, an electromagnetic coil 23, a control valve 24, and other structures, a valve body slider 25 is further disposed in the four-way valve 2, the valve body slider 25 may be a movable slider, and when the valve body slider 25 moves at the S port, the E port, and the C port, the S port and the C port may be turned on, or the E port and the C port may be turned on. It will be appreciated that when the four-way valve 2 is not powered on, the valve body slide block 25 is in a position capable of switching on the C port and the S port by default, wherein the state of the valve body slide block 25 shown in fig. 5 is the position of the valve body slide block 25 and the state in which the S port and the C port are switched on when the four-way valve 2 is not powered on. When the four-way valve 2 is powered on, the electromagnetic coil 23 is electrified, and the valve body sliding block 25 slides to connect the E port and the C port. The state of the valve body slide block 25 shown in fig. 6 is that the position of the valve body slide block 25 and the S port and the E port are connected after the four-way valve 2 is powered on.

In some embodiments, as shown in fig. 4, the C port of the four-way valve 2 is connected to the outdoor heat exchanger 3. Based on the characteristics of the four-way valve 2, when the four-way valve 2 is not electrified, the S port and the C port are communicated, namely, a pipeline between the air return port of the compressor 1 and the outdoor heat exchanger 3 is communicated, and then the refrigerant flows back to the air return port of the compressor 1 from the outdoor heat exchanger 3.

And, in some embodiments, the E port of the four-way valve 2 is connected to the indoor heat exchanger 5, as can be seen from the above embodiments, after the four-way valve 2 is powered on, the valve body slider 25 moves to connect the S port and the E port, that is, connect the return port of the compressor 1 with the pipeline between the indoor heat exchanger 5, and then the refrigerant flows back from the indoor heat exchanger 5 to the return port of the compressor 1.

Wherein, in some embodiments, the controller 8 is further configured to: when a refrigerating instruction is detected, the S port and the E port of the four-way valve 2 are controlled to be communicated, or when a heating instruction is detected, the S port and the C port of the four-way valve are controlled to be communicated.

Specifically, in the refrigeration mode, the second throttling element 6 is also in an open state, the high-temperature and high-pressure gaseous refrigerant sprayed out of the air outlet of the compressor 1 enters the outdoor heat exchanger 3 through the port D and the port C of the four-way valve 2, and completes condensation and heat release in the outdoor heat exchanger 3, then passes through the first throttling element 4 and becomes low-temperature and low-pressure liquid refrigerant to enter the indoor heat exchanger 5, the liquid refrigerant is evaporated and absorbs heat in the indoor heat exchanger 5 to become low-temperature and low-pressure gaseous refrigerant, the gaseous refrigerant flows back to the air return port of the compressor 1 through the port E and the port S of the four-way valve 2, and then is compressed again in the compressor 1, and the next refrigerant circulation process is re-entered.

The E port and S port of the four-way valve 2 need to be controlled to be turned on according to the refrigerant circulation process in the cooling mode, and thus the four-way valve 2 needs to be powered on, and the C port and S port of the four-way valve 2 need to be controlled to be turned on according to the refrigerant circulation process in the heating mode, and thus the four-way valve 2 needs to be powered off. Based on the above, the controller 8 can control the four-way valve 2 to be electrified in the cooling mode and control the four-way valve 2 to be powered off in the heating mode.

In addition, after the compressor 1 is stopped, the four-way valve 2 is still in the power-off state, that is, the heating state and the four-way valve 2 is in the power-off state after the heating and stopping, and the valve body valve block 25 cannot move in the power-off state, that is, the C port and the S port of the four-way valve 2 are always connected in the two states. Since the controller 8 also controls the second throttling element 6 to be closed after the compressor 1 is stopped in the heating mode, the refrigerant in the system pipeline cannot pass through the second throttling element 6 and finally is sealed in the indoor heat exchanger 5, in this case, the C port and the S port are always connected, that is, the E port and the S port cannot be connected, so that the refrigerant stored in the indoor heat exchanger 5 can be prevented from flowing back to the air return port of the compressor 1 along the pipeline from the E port of the four-way valve 2.

Further, after the compressor 1 is stopped in the heating mode, the E port and the S port of the four-way valve 2 cannot be connected with the indoor heat exchanger 5 and are matched with each other in a closing manner to control the second throttling element 6, so that the refrigerant is sealed in the indoor heat exchanger 5 as much as possible, and the situation that excessive liquid refrigerant migrates to the crankcase of the compressor 1 and even invades into engine oil of the compressor 1 caused by low temperature can be more effectively avoided.

In some embodiments of the invention, the controller 2, when controlling the closing of the second restriction 6, is specifically configured to: the operation frequency before the stop of the compressor 1 is obtained, and the closing rate of the second throttle 6 is controlled according to the operation frequency before the stop of the compressor 1.

When the air conditioner 1 is operated in the heating mode, the operation frequency of the compressor 1 is different due to different parameters such as the user set temperature, the outdoor environment temperature, the indoor environment temperature, and the like. It can be understood that when the operation frequency of the compressor 1 is high, the circulation flow rate of the refrigerant in the system is relatively fast, the flow rate is relatively large, when the operation frequency of the compressor 1 is relatively low, the circulation flow rate of the refrigerant in the system is relatively slow, the flow rate is relatively small, and after the compressor 1 is stopped, a certain time is required for the refrigerant in the system to be stationary from flowing. Therefore, after the compressor 1 is stopped, if the controller 8 immediately controls the second throttling element 6 to be quickly closed, the pressure in the system pipeline may be high and even the indoor heat exchanger 5 may be failed because the refrigerant circulation flow rate is still in a state of high flow rate and high flow rate, if the second throttling element 6 is controlled to be very slowly closed or even to be delayed to be closed, a part of the refrigerant may already flow through the second throttling element 6 and cannot flow back to the indoor heat exchanger 5 before stopping the flow, and therefore the refrigerant may not be sealed in the indoor heat exchanger 5 as much as possible, so that the sealing effect may not be achieved.

The controller 8 can adapt to different operation conditions of the compressor 1 by controlling the closing rate of the second throttling element 6 according to the operation frequency before the compressor 1 is stopped, so that the refrigerant can be rapidly sealed in the indoor heat exchanger 5, the system pressure is not too high, and the stability and the reliability of the system operation are ensured.

Specifically, in some embodiments, the controller 8, when controlling the closing rate of the second throttle 6, is specifically configured to: the smaller the operating frequency before the compressor 1 is stopped is determined, the greater the closing rate at which the second throttle 6 is controlled to be closed.

The smaller the operation frequency of the compressor 1 is, the slower the refrigerant circulation flow rate is, and the smaller the flow rate is, the refrigerant in the system can stop flowing very quickly after the compressor 1 is stopped, at the moment, the second throttling element 6 is controlled to be closed at a larger closing rate, so that the refrigerant can be rapidly sealed in the indoor heat exchanger 5 as much as possible while the safety of the system pressure is ensured, and the stability and the reliability of the system operation are ensured.

Further, in some embodiments, the controller 8 is further configured to: and when the operation frequency before the compressor is stopped is lower than a first frequency threshold value, controlling the second throttling element to be closed at a first rate, when the operation frequency before the compressor is stopped is higher than the first frequency threshold value and lower than a second frequency threshold value, controlling the second throttling element to be closed at a second rate, wherein the second rate is lower than the first rate, and when the operation frequency before the compressor is stopped is higher than the second frequency threshold value, controlling the second throttling element to be closed at a third rate, and the third rate is lower than the second rate.

In some embodiments of the present invention, as shown in fig. 3, the air conditioner 100 further includes a check valve 9, wherein the check valve 9 is disposed between the discharge port of the compressor 1 and the D port of the four-way valve 2, for unidirectional flow of the refrigerant from the discharge port of the compressor 1 to the D port of the four-way valve 2.

Specifically, the check valve 9 has a one-way conduction function for controlling the flow direction of the refrigerant. When the air conditioner 100 is operating normally, the refrigerant flows unidirectionally from the exhaust port of the compressor 1 to the D port of the four-way valve 2, and the check valve is provided to prevent the refrigerant from flowing back into the compressor 1. And, after the compressor 1 stops operating, although most of the refrigerant in the system has been blocked into the indoor heat exchanger 5, there may be a portion of the refrigerant that does not flow to the indoor heat exchanger 5 in time and remains in the pipe. For example, after the compressor 1 is stopped, a part of the high-temperature and high-pressure refrigerant ejected from the exhaust port of the compressor 1 remains in a pipeline between the exhaust port of the compressor 1 and the D port of the four-way valve 2, and the refrigerant in the pipeline has a higher pressure ratio and is likely to flow back into the compressor 1 from the exhaust port of the compressor 1, and by arranging the one-way valve at the exhaust port of the compressor 1, the part of the refrigerant cannot flow back, and the refrigerant remaining in the four-way valve 2 can be prevented from flowing back.

Therefore, by arranging the check valve 9 and after the compressor 1 is stopped in the heating mode, the E port and the S port of the four-way valve 2 cannot be connected with the indoor heat exchanger 5 and the second throttling element 6 is controlled to be closed, and the three are matched with each other, so that the refrigerant can be sealed in the indoor heat exchanger 5 to the greatest extent, the refrigerant is prevented from flowing back to the compressor 1, the reliability of the compressor 1 is improved, and the service life of the compressor 1 can be prolonged to a certain extent.

Further, as shown in fig. 3, the air conditioner 100 further includes a first stop valve 10 and a second stop valve 11, and the first stop valve 10 and the second stop valve 11 may be used to connect the indoor heat exchanger 5 and the outdoor heat exchanger 3, close or open the refrigerant circuit, so as to achieve the effect of cutting off the refrigerant circuit or adjusting the flow rate of the refrigerant, wherein the first stop valve 10 may be disposed in a pipeline between the first throttling element 4 and the second throttling element 6, and the second stop valve 12 may be disposed in a pipeline between the indoor heat exchanger 5 and the E port of the four-way valve 2.

The air conditioner 100 may further include a high pressure switch HP provided at the discharge port of the compressor 1, wherein the high pressure switch HP may be provided in a line between the check valve 9 and the D port of the four-way valve 2 to achieve protection of the high pressure side of the compressor 1. The air conditioner 100 may further include a low pressure switch LP provided at the return port of the compressor 1 to achieve protection of the low pressure side of the compressor 1.

In addition, the air conditioner 100 may further include a plurality of sensors (not shown) such as a temperature sensor, a pressure sensor, etc. for collecting control signals and operation parameters of various components of the air conditioner 100 in real time.

In some embodiments of the present invention, a control method of an air conditioner is also provided, which is applied to the air conditioner 100 of any one of the above embodiments, wherein, as shown in fig. 2, the air conditioner 100 includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, a refrigerant circuit combined by a first throttling element 4 and an indoor heat exchanger 5, a second throttling element 6, a controller 8, and a temperature sensor 7, the second throttling element 6 is disposed at a shunt pipe line of the indoor heat exchanger 5, the temperature sensor 7 is used for collecting outdoor environment temperature, and the controller 8 is used for controlling the four-way valve 2 and the second throttling element 6.

Specifically, the hardware architecture of the air conditioner 100 according to the embodiment of the present invention can be understood by referring to fig. 2-4 and combining the above descriptions are omitted herein.

As shown in fig. 7, a flowchart of an air conditioner control method according to an embodiment of the present invention is shown, wherein the air conditioner control method includes step S1 and step S2, which are specifically as follows.

S1, detecting a heating stop instruction and acquiring the outdoor environment temperature.

The temperature sensor may be provided to collect the outdoor ambient temperature, for example, the temperature sensor may be provided in the outdoor unit or may be provided separately outdoors.

When the air conditioner operates in a heating mode, the flow direction of the refrigerant in the system is as follows: compressor-four-way valve-indoor heat exchanger-second throttling element-first throttling element-outdoor heat exchanger-four-way valve-compressor.

And S2, when the outdoor environment temperature is lower than a preset temperature threshold value, controlling the second throttling element to be closed. The second throttling element is arranged at the branch pipe of the indoor heat exchanger of the air conditioner.

For example, for an intelligent air conditioner, a variable frequency air conditioner, etc. that can autonomously operate a heating mode when it is detected that the outdoor ambient temperature is lower than certain temperature set values, a preset temperature threshold may be set lower than a temperature set value corresponding to the autonomous entering heating mode. The preset temperature threshold may be set under laboratory conditions or according to actual needs, which is not limited herein.

Through setting up the second throttling element in the indoor heat exchanger shunt tubes pipeline department of air conditioner, when outdoor ambient temperature is less than and predetermines temperature threshold value and after the compressor is shut down, control the second throttling element and close, after compressor heat shut down, make refrigerant in the pipeline can not pass through the second throttling element and finally be sealed in indoor heat exchanger. At this time, even if the outdoor ambient temperature is relatively low during the shutdown of the air conditioner, the refrigerant will not flow back to the air return port of the compressor through the pipeline, so that the situation that excessive liquid refrigerant migrates to the crankcase of the compressor and even invades engine oil of the compressor due to low temperature can be effectively avoided.

According to the air conditioner control method provided by the embodiment of the invention, when the air conditioner is stopped and the outdoor environment temperature is lower than the preset temperature threshold value, the second throttling element is controlled to be closed, so that most of refrigerant can be sealed in the indoor heat exchanger after the compressor is stopped in a heating mode, the refrigerant is prevented from migrating and accumulating in the crankcase of the compressor when the temperature is lower in the stopping mode, the refrigerant can be quickly pumped into the outdoor heat exchanger and the air return port of the compressor from the indoor heat exchanger when the system is restarted for heating operation, the problem that the air suction pressure of the compressor is built slowly when the compressor is started for low-temperature heating is solved, the operation reliability of the compressor is improved, and the user experience is improved.

In some embodiments of the present invention, as shown in fig. 3, the D port of the four-way valve 2 of the air conditioner 100 is connected to the exhaust port of the compressor 1, the S port of the four-way valve 2 is connected to the return air port of the compressor 1, the C port of the four-way valve 2 is connected to the outdoor heat exchanger 3, and the E port of the four-way valve 2 is connected to the outdoor heat exchanger 5. The structure of the four-way valve 2 and the port connection condition of the four-way valve 2 in the embodiment of the present invention may be understood by referring to the contents of the above embodiments in conjunction with fig. 4, 5 and 6, and will not be described herein.

As shown in fig. 8, a flowchart of an air conditioner control method according to another embodiment of the present invention is shown, wherein the air conditioner control method further includes step S3 or step S4, which are specifically described below.

And S3, when a refrigerating instruction is detected, controlling the S port and the E port of the four-way valve to be communicated.

When the four-way valve is not electrified, the S port and the C port are communicated, namely a pipeline between the air return port of the compressor and the outdoor heat exchanger is communicated, and then the refrigerant flows back to the air return port of the compressor from the outdoor heat exchanger.

Specifically, when the air conditioner operates in the heating mode, the second throttling element is also in an open state, and the flow direction of the refrigerant in the system is as follows: compressor-four-way valve-outdoor heat exchanger-first throttling element-second throttling element-indoor heat exchanger-four-way valve-compressor. According to the refrigerant circulation process in the refrigeration mode, the E port and the S port of the four-way valve are required to be controlled to be connected, and after the four-way valve is electrified, the E port and the S port of the four-way valve can be connected, so that the four-way valve is required to be electrified in the refrigeration mode.

And S4, when a heating instruction is detected, controlling the S port and the C port of the four-way valve to be communicated.

According to the refrigerant circulation process in the heating mode, the C port and the S port of the four-way valve are required to be controlled to be connected, and after the four-way valve is powered off, the S port and the C port of the four-way valve can be connected, so that the four-way valve is required to be controlled to be powered off in the heating mode.

In addition, after the compressor is stopped, the four-way valve is still in a power-off state, namely, the four-way valve is in a power-off state after the heating state and the heating stopping state, and a valve body valve block in the four-way valve cannot move in the power-off state, namely, a C port and an S port of the four-way valve are always connected in the two states. Because the second throttling element needs to be controlled to be closed after the compressor is stopped in the heating mode, the refrigerant in the system pipeline cannot pass through the second throttling element and finally is sealed in the indoor heat exchanger, and in the case, the C port and the S port are always connected, namely the E port and the S port cannot be connected, so that the refrigerant stored in the indoor heat exchanger can be prevented from flowing back to the air return port of the compressor along the pipeline from the E port of the four-way valve.

Further, after the compressor is stopped in a heating mode, an E port and an S port of the four-way valve cannot be connected with the indoor heat exchanger and are matched with each other in a closing mode, so that the refrigerant is sealed in the indoor heat exchanger as much as possible, and the situation that excessive liquid refrigerant migrates to a crankcase of the compressor and even invades engine oil of the compressor when the temperature is low can be more effectively avoided.

In some embodiments of the present invention, as shown in fig. 9, a flowchart of a control method of an air conditioner according to still another embodiment of the present invention is shown, wherein the controlling the second throttle closing in the above step S2 specifically includes step S21 and step S22.

S21, acquiring the operation frequency of the compressor before stopping.

When the air conditioner operates in the heating mode, the operating frequency of the compressor is different due to different parameters such as the user set temperature, the outdoor environment temperature, the indoor environment temperature and the like. It can be understood that when the operating frequency of the compressor is high, the circulating flow rate of the refrigerant in the system is relatively high, the flow rate is relatively high, when the operating frequency of the compressor is relatively low, the circulating flow rate of the refrigerant in the system is relatively low, the flow rate is relatively low, and after the compressor is stopped, a certain time is required for the refrigerant in the system to be changed from flowing to static.

S22, controlling the closing rate of the second throttling element according to the operation frequency before the compressor is stopped, wherein the smaller the operation frequency before the compressor is stopped is, the larger the closing rate of the second throttling element is controlled.

After the compressor is stopped, if the second throttling element is immediately controlled to be closed, the pressure in the system pipeline is high and even the indoor heat exchanger is failed because the refrigerant circulation flow rate is still in a state of high flow rate and high flow rate, if the second throttling element is controlled to be closed very slowly and even after being closed, a part of refrigerant can flow through the second throttling element and cannot flow back to the indoor heat exchanger before stopping flowing, and the refrigerant cannot be sealed in the indoor heat exchanger as much as possible, so that the sealing effect cannot be achieved.

It can be understood that the smaller the operation frequency of the compressor is, the slower the circulation flow rate of the refrigerant is, and the smaller the flow rate is, the refrigerant in the system can stop flowing very fast after the compressor is stopped, at this time, the second throttling element is controlled to be closed at a larger closing rate, so that the refrigerant can be rapidly sealed in the indoor heat exchanger as much as possible while the pressure safety of the system is ensured, and the stability and the reliability of the operation of the system are ensured. The closing rate of the second throttling element is controlled according to the operation frequency before the compressor is stopped, so that the device can adapt to different operation conditions of the compressor, can rapidly seal the refrigerant in the indoor heat exchanger, is not too high in system pressure, and ensures the stability and reliability of system operation.

In some embodiments of the present invention, as shown in fig. 10, a flowchart of a control method of an air conditioner according to still another embodiment of the present invention, in which a closing rate of a second throttling element is controlled according to an operation frequency before a compressor is stopped, that is, the above step S22 may include steps S221 to S223, as follows.

S221, when the operation frequency before the compressor is stopped is lower than a first frequency threshold value, controlling the second throttling element to be closed at a first speed.

Wherein the detected frequency of operation before the compressor is shut down may be noted Fr.

S222, when the operation frequency before the compressor is stopped is higher than a first frequency threshold value and lower than a second frequency threshold value, controlling the second throttling element to be closed at a second speed, wherein the second speed is smaller than the first speed.

And S223, when the operation frequency before the compressor is stopped is higher than a second frequency threshold value, controlling the second throttling element to be closed at a third speed, wherein the third speed is smaller than the second speed.

Wherein the detected frequency of operation before the compressor is shut down may be noted Fr. When the second restriction is an electronic expansion valve, the first rate, the second rate, and the third rate may be rates of movement of a valve stem in the electronic expansion valve. The first frequency threshold, the second frequency threshold, the first rate, the second rate, the third rate, etc. may be set under laboratory conditions or according to actual needs, and are not limited herein.

For example, a first frequency threshold may be set at 50Hz, a second frequency threshold may be set at 50Hz, a first rate may be set at A steps/s, a second rate may be set at B steps/s, and a third rate may be set at C steps/s.

That is, when the operation frequency Fr before the compressor is stopped is less than or equal to 50Hz, the second throttling element is controlled to be closed at a first speed A step/s, when the operation frequency Fr before the compressor is stopped is detected to be less than or equal to 50Hz and less than 70Hz, the second throttling element is controlled to be closed at a first speed B step/s, and when the operation frequency Fr before the compressor is detected to be more than or equal to 70Hz, the second throttling element is controlled to be closed at a first speed C step/s, wherein A is less than B and less than C.

Based on the above, when the operation frequency of the compressor before stopping is determined to be smaller, the controller controls the second throttling element to be quickly closed at a larger speed, so that the refrigerant can be ensured to be timely sealed in the indoor heat exchanger, and when the operation frequency of the compressor before stopping is determined to be larger, the controller controls the second throttling element to be quickly closed at a smaller speed, so that the pressure safety of the system can be ensured, and the refrigerant can be quickly sealed in the indoor heat exchanger, so that the stability and the reliability of the operation of the system are ensured.

Other constructions and operations of the vehicle air conditioner 100 and the like according to the embodiment of the present invention are known to those of ordinary skill 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

1. An air conditioner, comprising:

the device comprises a compressor, a four-way valve, an outdoor heat exchanger, a first throttling element and an indoor heat exchanger;

the second throttling piece is arranged in a pipeline for connecting the indoor heat exchanger and the outdoor heat exchanger, is positioned between the first throttling piece and the indoor heat exchanger and is positioned at the branch pipeline of the indoor heat exchanger;

The temperature sensor is used for collecting outdoor environment temperature;

a controller coupled to the second throttle and the temperature sensor configured to:

detecting a heating stop instruction, acquiring the outdoor environment temperature, and controlling the second throttling element to be closed when the outdoor environment temperature is lower than a preset temperature threshold value;

the controller is specifically configured to, when controlling the second throttle to close: acquiring the operation frequency of the compressor before stopping, and controlling the closing rate of the second throttling element according to the operation frequency of the compressor before stopping;

the controller, when controlling the closing rate of the second throttle, is specifically configured to: the smaller the operating frequency before the compressor is stopped, the larger the closing rate of the second throttling element is controlled.

2. An air conditioner according to claim 1, wherein,

the port D of the four-way valve is connected with the exhaust port of the compressor, the port S of the four-way valve is connected with the air return port of the compressor, the port C of the four-way valve is connected with the outdoor heat exchanger, and the port E of the four-way valve is connected with the indoor heat exchanger;

wherein the controller is further configured to: and when a refrigerating instruction is detected, controlling the S port and the E port of the four-way valve to be communicated, or when a heating instruction is detected, controlling the S port and the C port of the four-way valve to be communicated.

3. The air conditioner of claim 1, wherein the controller is further configured to: and when the operation frequency before the compressor is stopped is lower than a first frequency threshold value, controlling the second throttling element to be closed at a first speed, when the operation frequency before the compressor is stopped is higher than the first frequency threshold value and lower than a second frequency threshold value, controlling the second throttling element to be closed at a second speed, wherein the second speed is lower than the first speed, and when the operation frequency before the compressor is stopped is higher than the second frequency threshold value, controlling the second throttling element to be closed at a third speed, and the third speed is lower than the second speed.

4. The air conditioner according to claim 1 or 2, further comprising:

the check valve is arranged between the exhaust port of the compressor and the D port of the four-way valve and is used for enabling the refrigerant to flow unidirectionally from the exhaust port of the compressor to the D port of the four-way valve.

5. The control method of the air conditioner is characterized in that the air conditioner comprises a compressor, a four-way valve, an outdoor heat exchanger, a refrigerant loop formed by combining a first throttling element and an indoor heat exchanger, a second throttling element, a controller and a temperature sensor, wherein the second throttling element is arranged in a pipeline connected with the indoor heat exchanger and the outdoor heat exchanger, is positioned between the first throttling element and the indoor heat exchanger and is positioned at a branch pipeline of the indoor heat exchanger, the temperature sensor is used for collecting outdoor environment temperature, and the controller is used for controlling the four-way valve and the second throttling element;

The air conditioner control method comprises the following steps:

detecting a heating stop instruction, and acquiring the outdoor environment temperature;

when the outdoor environment temperature is lower than a preset temperature threshold value, controlling the second throttling element to be closed, including:

acquiring the operation frequency of the compressor before stopping;

and controlling the closing rate of the second throttling element according to the operation frequency before the compressor is stopped, wherein the smaller the operation frequency before the compressor is stopped is, the larger the closing rate of the second throttling element is controlled.

6. The method for controlling an air conditioner according to claim 5, wherein,

the port D of the four-way valve of the air conditioner is connected with an exhaust port of the compressor, the port S of the four-way valve is connected with an air return port of the compressor, the port C of the four-way valve is connected with the outdoor heat exchanger, and the port E of the four-way valve is connected with the indoor heat exchanger;

the air conditioner control method further comprises the following steps:

when a refrigerating instruction is detected, an S port and an E port of the four-way valve are controlled to be communicated;

or when the heating instruction is detected, controlling the S port and the C port of the four-way valve to be communicated.

7. The air conditioner control method as set forth in claim 5, wherein controlling a closing rate of the second throttle according to an operation frequency before the compressor is stopped, includes:

Controlling the second restriction to close at a first rate when the operating frequency of the compressor prior to shutdown is below a first frequency threshold;

controlling the second restriction to close at a second rate when the operating frequency before the compressor is shut down is above the first frequency threshold and below a second frequency threshold, the second rate being less than the first rate;

and when the operation frequency before the compressor is stopped is higher than the second frequency threshold value, controlling the second throttling element to be closed at a third speed, wherein the third speed is smaller than the second speed.