KR20070078194A - Air conditioner and the method for controlling the operation thereof - Google Patents

Abstract

An air conditioner and a method of controlling the operation thereof are provided to reduce manufacturing cost by not needing to add a separate mixing device. A method of controlling an electronic opening/closing valve includes the steps of starting a heating operation(S710), determining whether the operation of the air conditioner is a cooling operation or the heating operation by a controlling unit if the air conditioner is operated(S720), determining whether the stop time of a compressor is over a predetermined time by the controlling unit in case of the heating operation(S730), determining whether the temperature of external air is below a predetermined temperature by a temperature sensor in case that the stop time of the compressor is over the predetermined time(S740), turning on the electronic opening/closing valve by the controlling unit in case that the temperature of external air is below the predetermined temperature(S750), determining whether the on time of the electronic opening/closing valve is over a predetermined time by a timer(S760), and turning off the electronic opening/closing valve by the controlling unit in case that the on time of the electronic opening/closing valve is over the predetermined time or the temperature of a discharge pipe is over a predetermined temperature(S770).

Description

Air conditioner and the method for controlling the operation

1 is a view for explaining a cold half cycle of a conventional general air conditioner.

2 is a structural diagram of a typical accumulator.

3 is a structural diagram of an accumulator provided with mixing means.

4 is a view for explaining a heating cycle of the heat pump type air conditioner according to the present invention.

5 is a structural diagram of the accumulator and the branch pipe according to the present invention.

Figure 6 is a block diagram for explaining the opening and closing operation of the solenoid valve according to the invention.

7 is a flowchart illustrating a control method of the electromagnetic open / close valve according to the present invention.

* Short description for the drawing symbols *

41: branch piping 42: electromagnetic opening and closing valve

43, 44: temperature sensor 45: timer

46: control unit 410: compressor

420: first heat exchanger 430: second heat exchanger

440: Inflator 450: Four sides

460: accumulator

The present invention relates to an air conditioner, and more particularly, to an air conditioner capable of recovering oil in an accumulator to a compressor and a method of controlling the operation thereof.

In general, an air conditioner is a cooling / heating device that is installed in a room or a wall of a vehicle, an office, or a home, to cool or heat a room. A separate type of air conditioner that is separated from an outdoor side installed outdoors and an indoor side installed indoors The air conditioner is largely divided into an integrated air conditioner in which the outdoor unit and the indoor side are integrated.

Such an air conditioner basically includes a component consisting of a compressor, a condenser, an expander, and an evaporator, and the working fluid, the refrigerant, is circulated while continuing to change the compression, condensation, expansion, and evaporation.

More specifically, the low temperature low pressure dry saturated refrigerant (low temperature low pressure gas phase refrigerant), which is discharged from the evaporator, is adiabatically compressed in a compressor and compressed into a high temperature high pressure superheated steam refrigerant (high temperature high pressure gas phase refrigerant). .

The high temperature and high pressure superheated steam refrigerant (high temperature and high pressure gaseous refrigerant) introduced from the compressor to the condenser dissipates the latent heat of condensation and is introduced into the expander as a high temperature and high pressure saturated liquid refrigerant (high temperature and high pressure liquid refrigerant).

The high-temperature, high-pressure saturated liquid refrigerant (high-temperature, high-pressure liquid refrigerant) is expanded into isotropic low-temperature liquid refrigerant by isenthalpy expansion in the expander and then flows into the evaporator.

The low-temperature liquid phase refrigerant flowing into the evaporator from the expander is converted into a low-temperature low-pressure dry saturated vapor (low-temperature low-pressure gas phase refrigerant) through the endothermic process, the circulation process is repeated repeatedly.

As described above, an air conditioner that performs compression, condensation, expansion, and evaporation cycles of a refrigerant may be used as a heating and cooling device. The use of a heating device means that the high temperature and high pressure gaseous refrigerant introduced into the condenser is a high temperature and high pressure liquid refrigerant. It is a case of using the latent heat of condensation that is radiated to the surroundings while radiating, and to use as a cooler is to take away the heat of the surroundings while the low-temperature low-pressure liquid refrigerant flowing into the evaporator is converted into a low-temperature low-pressure gaseous refrigerant.

Hereinafter, a cooling and heating cycle of the air conditioner will be described in detail with reference to FIG. 1.

1 is a view for explaining the cold half cycle of a conventional general air conditioner.

As can be seen in Figure 1, the air conditioner is a compressor 110 for performing the basic operations of compression, condensation, expansion, evaporation, the first heat exchanger 120, the expander 140, and the second heat exchanger ( 130, and further includes a four-way valve (150) for changing the circulation path of the refrigerant in accordance with the air-conditioning selection and the accumulator 160 for filtering the liquid refrigerant.

Hereinafter, the operation according to the heating and cooling will be described.

First, the heating operation will be described. The solid line of FIG. 1 shows the moving direction of the refrigerant during the heating operation.

In the heating operation, the compressor 110 compresses and converts the gaseous refrigerant of low temperature and low pressure into a gaseous refrigerant of high temperature and high pressure. The high temperature and high pressure gaseous refrigerant compressed by the compressor 110 flows into the four sides 150. The high temperature and high pressure gaseous refrigerant introduced into the four sides 150 is guided to the first heat exchanger 120 through the valve 153 to be introduced.

The high temperature and high pressure gaseous refrigerant introduced into the first heat exchanger 120 is condensed by causing a phase change into a liquid refrigerant having a high temperature and high pressure while contacting cold indoor air. Do it.

The high temperature and high pressure liquid refrigerant condensed in the first heat exchanger 120 is introduced into the expander. The expander 140 is a device for supplying a suitable refrigerant according to a load change to the second heat exchanger 130. The inflator 140 converts the high temperature and high pressure liquid refrigerant supplied from the first heat exchanger 120 into a low temperature low pressure liquid refrigerant. After the transfer to the second heat exchanger (130).

The low-temperature low-pressure liquid refrigerant supplied from the expander 140 to the second heat exchanger 130 absorbs heat from the outside air, changes into a low-temperature voltage gaseous refrigerant, and evaporates.

Next, the low-temperature low-pressure gas phase refrigerant supplied from the second heat exchanger 130 to the four sides 150 is introduced into the valve 151 and then supplied to the accumulator 160 through the valve 152.

The accumulator 160 is a device that separates and receives the low-temperature low-pressure liquid refrigerant from the refrigerant supplied from the second heat exchanger 130. In general, when the liquid refrigerant directly flows into the compressor 110, since it may cause damage to the compressor, the liquid refrigerant serves to separate the liquid refrigerant from the accumulator 160.

The low-temperature, low-pressure gas phase refrigerant passing through the accumulator 160 flows into the compressor 110 and circulates according to the aforementioned cycle.

In particular, the air conditioner capable of the above heating operation is also referred to as a heat pump type air conditioner.

Next, the cooling operation will be described. In FIG. 1, the dotted line indicates the movement of the refrigerant during the cooling operation.

As shown, the cooling operation reverses only the roles of the first and second heat exchangers 120 and 130, and the overall operation is the same. That is, in the cooling operation, the second heat exchanger 130 serves as a condenser and the first heat exchanger 120 serves as an evaporator. The apparatus for controlling this is the four sides 150, the refrigerant passing through the compressor 110 is the second heat exchanger 130-expander 140-the first heat exchanger 120-(accumulator 160). It is subjected to a process of condensation-expansion-evaporation-compression while circulating along the compressor (110).

As in the heating operation, the accumulator 160 has a liquid refrigerant that is not evaporated in the first heat exchanger 120 among the refrigerant flowing from the first heat exchanger 120 through the four sides 150. To prevent ingress.

Hereinafter, the structure of a conventional accumulator will be described.

2 shows a cross-sectional view of an accumulator commonly used in air conditioners.

As shown in Fig. 2, the conventional accumulator is composed of a sealed cylindrical container 201. The pipe (a) entering the inside of the container 201 through a hole formed in the upper side of the container 201 is for guiding the refrigerant flowing from the heat exchanger functioning as an evaporator into the container, and the upper part of the container 201. Pipe (b) is connected to the hole formed on the other side of the to supply the gaseous refrigerant in the container 201 to the compressor (110). One side of the pipe (b) is formed with an oil recovery hole 202 for recovering the oil described below.

The oil is introduced into the container 201 by being mixed with a refrigerant that is a working fluid, and used to smoothly operate the compressor 110. Therefore, the oil mixed with the refrigerant and supplied to the container 201 should be supplied to the compressor, and the compressor may be worn when the oil is not properly supplied to the compressor.

As can be seen from the above description, it can be seen that the liquid refrigerant, the gaseous refrigerant, and the oil are mixed in the container 201 forming the accumulator 160.

By the way, the accumulator of such a structure has the following problems in an air-conditioning operation, especially a heating operation.

When the temperature of the outside air is below the predetermined temperature during the heating operation, and the stop time of the compressor has passed a predetermined time (that is, when the time when the air conditioner temporarily stops during the heating operation has elapsed a certain time), the accumulator 160 The liquid refrigerant, gaseous refrigerant, and oil, which are mixed in each other, are separated from each other and distributed as shown in FIG. 2 according to specific gravity.

That is, as shown in Figure 2, the lower portion of the container 201 is a liquid refrigerant having the highest specific gravity, the oil in the middle portion of the container 201, the gaseous phase refrigerant having the lowest specific gravity in the upper portion of the container 201 They will be separated from each other.

In this state, when the compressor 150 is operated while the air conditioner is restarted, oil may not be properly recovered through the oil recovery hole 202.

As such, if the oil is not properly recovered, the oil supplied to the compressor 110 may be insufficient, resulting in problems such as wear of the compressor 150 and deterioration of compression performance.

In order to solve this problem, conventionally, the liquid refrigerant, the gaseous refrigerant, and the oil in the accumulator 160 are mixed with each other to recover the oil through the oil recovery hole 202 and to supply the compressor 110.

3 is an example of a conventional accumulator provided with mixing means for intermixing liquid refrigerant, gaseous refrigerant, and oil in the accumulator 160.

3 is provided with mixing means 300 for intermixing refrigerant and oil in accumulator 160.

Mixing means 300 is a refrigerant storage unit 301 for storing the refrigerant and the electric heater 302 for heating the outside of the refrigerant storage unit 301 to change the refrigerant stored in the refrigerant storage unit 301 to a high temperature and high pressure ), A connection pipe 303 connected between a hole formed at one side of the refrigerant storage unit 301 and a hole formed at a lower side of the accumulator 160 to enable movement of the refrigerant, and a connection pipe 303. Is formed on one side of the electromagnetic opening and closing valve 304 for controlling the movement of the refrigerant.

In connection with the operation, when the liquid and gaseous refrigerant and the oil in the accumulator 160 is to be mixed, the refrigerant in the refrigerant storage unit 301 phase-changed into the high-temperature and high-pressure gaseous refrigerant by the electric heater 302 is connected to the connection pipe. It is supplied to the accumulator 160 through 303. When the high temperature and high pressure gaseous refrigerant is supplied into the accumulator 160 under low temperature and low pressure through the connection pipe 303, refrigerant and oil separated from each other according to specific gravity are mixed with each other as shown in FIG. 2. Therefore, the oil is recovered through the oil recovery pipe 202.

However, when the oil is recovered by the conventional method as shown in FIG. 3, there is a problem in that the mixing means 300 is additionally provided.

In addition, when the mixing means 300 is provided, a problem arises in that the manufacturing cost of the air conditioner increases.

The present invention has been proposed to solve the above-mentioned problems of the prior art, and is intended to provide an air conditioner and a method of controlling the operation of the refrigerant having a high temperature and high pressure can be directly supplied to the accumulator by the pressure difference.

To this end, the present invention is to provide an air conditioner to form a branch pipe on one side of the discharge pipe of the compressor and directly connect the branch pipe to the accumulator.

In the air conditioner operation control method according to an embodiment of the present invention, the liquid refrigerant and the gaseous phase present inside the accumulator when the stop time of the compressor exceeds a predetermined time and the ambient air temperature around the accumulator is lower than a predetermined temperature during the heating operation. It is characterized by having a mixing process for mixing the refrigerant and oil.

In one embodiment according to the invention, the mixing process is characterized in that the block is performed after a predetermined time.

In one embodiment according to the present invention, the mixing process is characterized in that by injecting the refrigerant of the high temperature and high pressure state of the refrigerant which is the working fluid of the air conditioner to the accumulator.

In one embodiment according to the invention, the refrigerant in the high temperature and high pressure state is characterized in that part of the refrigerant discharged from the compressor.

In one embodiment according to the invention, the refrigerant in the high temperature and high pressure state is characterized in that part of the refrigerant discharged from the condenser of the air conditioner.

In one embodiment according to the present invention, the mixing process is blocked if the temperature of the discharge pipe for guiding the flow of the refrigerant discharged from the compressor is a predetermined temperature or more.

An air conditioner according to a second embodiment of the present invention includes a compressor for compressing a refrigerant, a first heat exchanger for condensing the refrigerant flowing from the compressor, an expander for reducing the refrigerant supplied from the first heat exchanger, and A second heat exchanger for evaporating an incoming refrigerant, an accumulator for supplying the gaseous refrigerant to the compressor by separating a liquid refrigerant and a gaseous refrigerant, which are refrigerants supplied from the second heat exchanger, and a refrigerant discharged from the compressor And a branch pipe branched from one side of the discharge pipe for guiding the flow, wherein the branch pipe is extended to be inserted into one side of the accumulator.

In the second embodiment according to the present invention, one side of the branch pipe is provided with an electromagnetic opening and closing valve for controlling a portion of the refrigerant discharged from the discharge pipe of the compressor is injected into the accumulator do.

In a second embodiment according to the present invention, a control unit for controlling the operation of the electromagnetic opening and closing valve is further provided.

In the second embodiment according to the present invention, during the heating operation, when the stop time of the compressor exceeds a predetermined time and the outside air temperature around the accumulator is less than a predetermined temperature, the control valve is opened by the control unit. It is characterized in that (on).

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a view for explaining a heating cycle of the heat pump type air conditioner according to an embodiment of the present invention. For reference, the structure and function of the compressor 110, the first and second heat exchangers 120 and 130, the expander 140, and the four sides 150 described in FIG. 1 are described in the present invention. 410, first and second heat exchangers 420 and 430, expander 440 and four sides 450 are substantially the same in structure and function. And, like FIG. 1, FIG. 4 is shown to schematically illustrate the components in order to explain the basic operation of the air conditioner.

Hereinafter, a case in which the heat pump type air conditioner shown in FIG. 4 is used for heating will be described.

In the heating operation, the compressor 410 compresses and converts the low-temperature low-pressure gas phase refrigerant introduced through the pipe b connected to the accumulator 460 into a high-temperature high-pressure gas phase refrigerant.

The high temperature and high pressure gaseous refrigerant compressed by the compressor 310 flows into the four sides 450. The high temperature and high pressure gaseous refrigerant introduced into the four sides 450 is guided and introduced into the first heat exchanger 420 through the valve 453.

The high temperature and high pressure gaseous refrigerant introduced into the first heat exchanger 420 is condensed by causing a phase change to a liquid refrigerant having a high temperature and high pressure while contacting cold indoor air. Do it.

The high temperature and high pressure liquid refrigerant condensed in the first heat exchanger 420 flows into the expander 440. The expander 440 is a device for supplying a suitable refrigerant according to a load change to the second heat exchanger 430. The expander 440 converts the high temperature and high pressure liquid refrigerant supplied from the first heat exchanger 420 into a low temperature low pressure liquid refrigerant. After the transfer to the second heat exchanger (430).

The low temperature low pressure liquid refrigerant supplied from the expander 440 to the second heat exchanger 430 absorbs heat from the outside air and changes into a low temperature low pressure gas phase refrigerant to evaporate.

Next, the low-temperature low-pressure gas phase refrigerant supplied from the second heat exchanger 430 to the four sides 450 is introduced into the valve 451 and then supplied to the accumulator 460 through the valve 452. The accumulator 460 separates the liquid phase refrigerant supplied from the second heat exchanger 430 and the gaseous refrigerant, and the separated gaseous refrigerant is supplied to the compressor 410 to repeat the above-described series of cycles.

The following is one of the features of the present invention, a hole formed in one side of the discharge pipe (c) for discharging the high-temperature, high-pressure gas phase refrigerant from the compressor 401 and on one side of the lower part of the container 601 constituting the accumulator 460 Branch pipes 41 are provided which connect between the formed holes.

One side of the branch pipe 41 in the longitudinal direction is provided with an electromagnetic opening and closing valve 42 for controlling the opening and closing of the branch pipe (41). Whether or not to open or close the electronic open / close valve 42 is made by a controller (not shown), which will be described below.

On the other hand, the temperature sensor 43 attached to one side of the discharge pipe (c) of the compressor 401 is for measuring the temperature of the discharge pipe (c).

FIG. 5 shows a detailed configuration diagram of the accumulator 460 and the branch pipe 41 described with reference to FIG. 4.

As shown in FIG. 5, the accumulator 460 consists of a sealed cylindrical container 601. The pipe (a) entering the inside of the container 601 through a hole formed in the upper side of the container 601 is for guiding the refrigerant flowing from the heat exchanger functioning as an evaporator into the container 601. At this time, in addition to the refrigerant, the oil to be used in the compressor 410 is also introduced.

The pipe b inserted into the hole formed at the other side of the upper part of the container 601 and having a U shape inside the container 601 is for supplying the gaseous refrigerant in the container 601 to the compressor 410. . An oil recovery hole 602 for recovering oil accumulated in the container 601 is formed at one side of the lower portion of the U-shaped pipe b.

On the other hand, the branch pipe 41 branched from one side of the discharge pipe (c) of the compressor 410 is extended to pass through the hole formed in the lower one side of the container (601). On the one side of the branch pipe 41 in the longitudinal direction, an electromagnetic opening and closing valve 42 for controlling the opening and closing of the branch pipe 41 is provided.

In operation, when the liquid and gaseous refrigerants and oil in the accumulator 460 are to be mixed or when such conditions are met, the solenoid valve 42 is opened by a control unit to be described below.

When the electromagnetic opening and closing valve 42 is opened, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 410 through the branch pipe 41 flows into the accumulator 460 at a high speed, thereby allowing the liquid and gaseous refrigerant in the accumulator 460 to flow. And oil are mixed together. This mixing process is voluntary. Here, the expression spontaneous is used because the phenomenon in which the high-temperature and high-pressure gaseous refrigerant is injected into the accumulator 460 in the low-temperature low-pressure state through the branch pipe 41 is caused by a pressure difference. When the high-temperature, high-pressure gaseous refrigerant is injected into the accumulator 460 at high speed by the pressure difference, the liquid refrigerant, oil, and gaseous refrigerant, which are separated from each other according to specific gravity, are mixed in the accumulator 460.

When the mixing process is performed, the oil remaining in the intermediate position of the accumulator 460 is moved to the lower part of the accumulator 460, and as a result, the oil can be recovered through the oil return pipe 602. Opening and closing conditions and the oil mixing process of the electromagnetic opening and closing valve 42 will be described in detail below.

FIG. 6 is a block diagram illustrating the opening and closing operation of the electromagnetic opening and closing valve 42 described with reference to FIGS. 4 and 5.

6, the temperature sensor 43 is attached to one side of the discharge pipe (c) of the compressor 410 to measure the temperature of the discharge pipe (c), the temperature sensor 44 is installed at a predetermined position of the air conditioner The temperature of the outside air is measured, and the timer 45 measures the opening and closing time of the solenoid valve 42.

The control unit 46 functions to control the operation of the electronic opening and closing valve 42 by using information transmitted from the temperature sensors 43 and 44 and the timer 45.

7 is a flowchart for explaining a method of controlling the electromagnetic open / close valve 42.

First, the heating operation is started by the heat pump type air conditioner according to the present invention described in FIG. 4 (step S710).

When the heating operation is started, the compressor 410 compresses the low-temperature low-pressure gaseous refrigerant supplied from the accumulator 460 and then supplies it to the first heat exchanger 420 through the four sides 450.

In the first heat exchanger 420, the supplied refrigerant is condensed, converted into a liquid refrigerant having a high temperature and high pressure, and supplied to the expander 440.

The expander 440 converts the liquid refrigerant of high temperature and high pressure into a liquid refrigerant of low temperature and low pressure and supplies the same to the second heat exchanger 430.

The low temperature low pressure liquid refrigerant supplied to the second heat exchanger 430 is converted into a low temperature low pressure gas phase refrigerant after being heat-exchanged with the outside air, and then supplied to the four sides 450.

The refrigerant supplied to the four sides 450 is supplied to the compressor 410 via the accumulator 460 to repeat the series of cycles.

When the target heating temperature is reached by the heating operation according to the cycle as described above, the air conditioner stops the operation for a predetermined time, and then performs the heating operation by restarting when the indoor temperature drops below the predetermined temperature. .

That is, during the heating operation, the air conditioner does not always operate, but performs the heating operation while repeating the operation for a predetermined time and stopping the operation for a predetermined time.

Next, when the air conditioner operates as described above, the controller 46 basically determines whether the operation of the air conditioner is a cooling operation or a heating operation (step S720).

As a result of the determination in step S720, in the case of the cooling operation, the controller 46 maintains the current state of the electromagnetic open / close valve 42 in the off state (step S780).

On the other hand, as a result of the determination in step S720, in the case of the heating operation, the controller 46 further determines whether the stop time of the compressor 410 has elapsed a predetermined time (step S730). At this time, the timer 45 determines whether the stop time of the compressor 410 has elapsed. Here, the reason for determining whether the stop time of the compressor 410 has elapsed for a predetermined time is that the liquid and gaseous refrigerant in the accumulator 460 when the operation of the air conditioner is temporarily suspended for a long time, and This is because the oil is separated by specific gravity. Therefore, the predetermined time means the minimum time that the liquid and gaseous refrigerant and the oil in the accumulator 460 are separated according to specific gravity.

As a result of the determination in step S730, when the stop time of the compressor 410 does not pass a predetermined time, the control unit 46 maintains the current state of the electromagnetic opening and closing valve 42 in the off state (step S780). That is, when the stop time of the compressor 410 does not pass a predetermined time, the reason why the solenoid valve 42 is kept off is that the liquid, gaseous refrigerant, and oil inside the accumulator 460 are not mixed. This is because it is judged that there is no big crowd in operation.

On the other hand, as a result of the determination in step S730, when the stop time of the compressor 410 has passed a predetermined time, the controller 46 determines whether the temperature of the outside air measured by the temperature sensor 44 is below a predetermined temperature. Determine (step S740). Here, the temperature of the outside air means the ambient temperature of the accumulator 460.

As a result of the determination in step S740, when the temperature of the outside air is higher than the predetermined temperature, the control unit 46 maintains the current state of the electromagnetic opening and closing valve 42 in the off state (step S780).

On the other hand, as a result of the determination in step S740, when the temperature of the outside air is lower than the predetermined temperature, the controller 46 turns on the solenoid valve 42 (step S750). This is because, if the temperature of the outside air is less than or equal to the predetermined temperature, it is determined that the liquid phase and the gaseous refrigerant and the oil in the accumulator 460 are separated according to the specific gravity within a short time.

When the solenoid valve 42 is turned on, the high-temperature, high-pressure gaseous refrigerant discharged through the discharge pipe c of the compressor 410 is strongly injected into the accumulator 460 through the branch pipe 41. Therefore, the refrigerant and the oil which are separated into the liquid refrigerant, the oil, and the gaseous refrigerant in the accumulator 460 are mixed by the high temperature and high pressure gaseous refrigerant injected through the branch pipe 41. As a result, oil recovery through the oil recovery pipe 602 becomes possible, and the recovered oil starts to be injected into the compressor 410 through a pipe b connected to the compressor 410.

Next, the control unit 46 determines whether the on time of the electromagnetic shutoff valve 42 has elapsed by a predetermined time (for example, about 3 minutes) using the timer 45 (step S760). At the same time, using the temperature sensor 43 attached to one side of the discharge pipe (c) of the extruder 410, it is determined whether the temperature of the discharge pipe (c) is above a predetermined temperature (step S760).

As a result of the determination in step S760, when the on time of the electromagnetic opening and closing valve 42 has passed a predetermined time (for example, about 3 minutes) or when the temperature of the discharge pipe c is higher than or equal to the predetermined temperature, the controller ( 46 turns off the solenoid valve 42. When the on time of the solenoid valve 42 has elapsed for a predetermined time (for example, about 3 minutes) or if the temperature of the discharge pipe c is greater than or equal to the predetermined temperature, the solenoid valve 42 of the controller 46 The reason for turning off) is because it is determined that the oil is sufficiently mixed in the accumulator 460 under the above conditions.

On the other hand, as a result of the determination in step S760, the on time of the solenoid valve 42 has not elapsed for a predetermined time (for example, about 3 minutes), and the temperature of the discharge pipe c is also below the predetermined temperature. In case it returns to step S750. The reason for this is to sufficiently mix the oil in the accumulator 460.

The oil mixing method inside the accumulator 460 described above is just one example for implementing the technical idea of the present invention.

That is, in one embodiment of the present invention, a portion of the high-temperature, high-pressure gaseous refrigerant, which is a refrigerant discharged from the compressor 410, is strongly injected into the accumulator 460 through the branch pipe 41 to mix the oil in the accumulator 460. Although the method of the present invention has been described, the technique of the present invention includes all methods of injecting the high temperature and high pressure refrigerant of the operating refrigerant of the air conditioner into the accumulator 460.

Therefore, a method of injecting the high temperature and high pressure refrigerant supplied to the first heat exchanger 420 through the valve 453 of the four sides 450 to the accumulator 460 may be adopted. A method of injecting the high temperature and high pressure refrigerant discharged from the heat exchanger 420 into the accumulator 460 may be adopted.

As described above, in the present invention, a method of recovering oil in the accumulator by directly injecting a high temperature and high pressure refrigerant in the operating refrigerant of the air conditioner into the accumulator.

Therefore, in the case of the present invention, there is an advantage that it is unnecessary to add a separate mixing means as in the prior art, there is an economic advantage that can lower the manufacturing cost of the air conditioner.

Claims (12)

As an operation control method of an air conditioner, In the heating operation, if the stop time of the compressor exceeds a predetermined time and the outside air temperature around the accumulator is less than a predetermined temperature, air having a mixing process of mixing the liquid refrigerant, gaseous refrigerant and oil present in the accumulator How to control the operation of the harmonizer. The method of claim 1, wherein the mixing is interrupted after being performed for a predetermined time. The method of claim 1, wherein the mixing is performed by injecting a refrigerant at a high temperature and high pressure into the accumulator from a refrigerant that is a working fluid of the air conditioner. 4. The method of claim 3, wherein the refrigerant in the high temperature and high pressure state is a part of the refrigerant discharged from the compressor. 4. The method of claim 3, wherein the refrigerant in the high temperature and high pressure state is part of the refrigerant discharged from the condenser of the air conditioner.  The method of claim 4, wherein the mixing process is interrupted when the temperature of the discharge pipe guiding the flow of the refrigerant discharged from the compressor is higher than or equal to a predetermined temperature. A compressor for compressing the refrigerant, A first heat exchanger for condensing the refrigerant flowing from the compressor; An expander for depressurizing the refrigerant supplied from the first heat exchanger; A second heat exchanger for evaporating a refrigerant flowing from the expander; An accumulator for supplying the gas phase refrigerant to the compressor by separating the liquid phase refrigerant and the gas phase refrigerant, which are refrigerants supplied from the second heat exchanger, from each other; It is provided with a branch pipe branched from one side of the discharge pipe for guiding the flow of the refrigerant discharged from the compressor, And the branch pipe is extended to be inserted into one side of the accumulator. The method of claim 7, wherein And one side of the branch pipe is provided with an electromagnetic opening and closing valve for controlling a portion of the refrigerant discharged from the discharge pipe of the compressor to be injected into the accumulator. The method of claim 8, Air conditioner further comprises a control unit for controlling the operation of the electromagnetic opening and closing valve. The method of claim 9, During the heating operation, when the stop time of the compressor exceeds a predetermined time and the outside air temperature around the accumulator is less than a predetermined temperature, the air opening and closing valve is turned on by the controller. group. The method of claim 10, And when the on time of the solenoid valve is elapsed for a predetermined time, the solenoid valve is turned off by the controller. The method of claim 10, When the temperature of the discharge pipe for guiding the flow of the refrigerant discharged from the compressor in the state that the electromagnetic opening valve is on (on), the electronic opening and closing valve is turned off by the controller if the temperature of the discharge pipe is above a predetermined temperature. Air conditioner.

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