KR20060065802A - Control method for air conditioner - Google Patents

Abstract

In order to reduce the power consumption by controlling the capacity of the refrigerant compressed in the compressor according to the state of the room, the present invention is a control method of an air conditioner equipped with a variable capacity compressor for air conditioning in the room, the cooling load of the room Initial operation step for determining; Providing a control method of an air conditioner including selectively performing an on-off operation for performing an on-off operation or a capacity-variable operation for performing a capacity variable operation according to the cooling load determined in the initial operation step. do.

Air Conditioning Control Method, Capacity Variable Compressor, Bypass Valve

Description

Control method of air conditioner {CONTROL METHOD FOR AIR CONDITIONER}

1 is a side cross-sectional view showing the structure of a rotary compressor according to the prior art.

Figure 2 is a cross-sectional view showing the structure of a cylinder of a rotary compressor according to the prior art.

3 is a view showing a control method of a rotary compressor according to the prior art

Figure 4 is a block diagram showing a variable displacement compressor assembly provided in the air conditioner according to the present invention.

5a and 5b is a cross-sectional view showing the bypass valve and the cylinder structure in a variable displacement compressor applied to the present invention.

Figure 6a and Figure 6b is a block diagram showing a change in the connection structure of the bypass pipe by the three-way valve in the variable displacement compressor applied to the present invention.

7 is a flowchart illustrating a control method of the air conditioner for cooling the room.

8 is a flowchart illustrating a control process performed in step A of FIG.

9 is a view showing an operating state of the variable displacement compressor according to the room temperature during the cooling of the room.

10 is a flowchart illustrating a control method of the air conditioner for heating the room.

FIG. 11 is a flowchart illustrating a control process performed in step B of FIG. 10.

12 is a view showing the operating state of the variable capacity compressor according to the room temperature when the room heating.

<Description of the symbols for the main parts of the drawings>

3: compressor 5: electric drive

6: compression section 17: rolling piston

18: vane 21: suction pipe

22: discharge pipe 31: bypass pipe

32: 1st piping 33: 2nd piping

41: accumulator 114: cylinder

124: bypass valve

The present invention relates to an air conditioner, and more particularly, to a control method of an air conditioner having a variable displacement compressor.

In general, an air conditioner is a device for cooling or heating indoor air through heat exchange between a refrigerant and indoor or outdoor air. At this time, the state of the refrigerant is changed according to the thermodynamic cycle while passing through the compressor-condenser-expansion device-evaporator, and in particular, the indoor air is cooled or heated by heat transfer through the phase change of the refrigerant generated in the evaporator and the condenser.

On the other hand, the compressor is a device that is supplied from the outside to circulate the thermodynamic cycle as described above. Here, the compressor is a device for compressing a fluid such as refrigerant gas, and is classified into a rotary compressor, a reciprocating compressor, a scroll compressor, and the like according to the method of compressing the fluid.

1 is a side sectional view showing a configuration of a rotary compressor according to the prior art.

As shown in FIG. 1, the rotary compressor 3 includes the transmission part 5 and the compression part 6 together in the case 10, and the transmission part 5 and the compression part 6 include the rotary shaft 13. ) Are coupled to both ends to transmit the rotational force of the transmission part 5 to the compression part 6.

In more detail, the transmission part 5 includes a stator 11 mounted on an inner circumferential surface of the case 10 and a rotor 12 rotatably provided inside the stator, wherein the rotor 12 has a rotating shaft. Combined with (13). Accordingly, when power is supplied to the transmission part 5, the rotor 12 and the rotation shaft 13 are rotated together by a rotor field formed between the stator 11 and the rotor 12.

Meanwhile, the compression unit 6 includes a cylinder 14 and a rolling piston 17 connected to the rotating shaft, and the rolling piston 17 is eccentrically coupled with the rotating shaft 13 to rotate.

Figure 2 is a cross-sectional view showing the internal configuration of the cylinder of the rotary compressor according to the prior art.

As shown in FIG. 2, a cylindrical compression space is formed inside the cylinder 14, and the rolling piston 17 is eccentrically connected to the rotating shaft 13 so that one side of the outer circumferential surface is in contact with the inner circumferential surface of the cylinder 14. .                         

In addition, a vane for advancing and reversing along the radial direction on one inner side of the cylinder 14 and contacting the outer circumferential surface of the rolling piston 17 to partition the inner space into the suction chamber S and the compression chamber C ( 18) is provided. Here, the vanes 18 are slid along the vane accommodating portion 18a formed at one side of the cylinder 14, and the rear of the vanes 18 are elastically supported by the springs 18b.

In addition, an inlet port 14a through which the refrigerant is sucked is formed at one side of the vane 18, and a discharge port 14b through which the compressed refrigerant is discharged is formed at the other side. Here, the suction port 14a is connected to the suction pipe 21 and the discharge port 14b is connected to the discharge port 15a. The upper end of the discharge port (15a) is provided with a discharge valve 19 which is opened and closed elastically toward the upper side.

Hereinafter, the operation of the rotary compressor will be described.

First, when power is applied to the transmission part 5, the rotating shaft 13 is rotated in the clockwise direction, and thus the rolling piston 17 connected to the rotating shaft 13 is eccentrically rotated in the inner space of the cylinder 14. . At this time, the refrigerant flows into the suction chamber S partitioned by the vanes 18 through the suction port 14a, and the refrigerant in the compression chamber C is compressed and discharged through the discharge port 14b. . The discharged refrigerant is moved upwards through the discharge port 15a and moved to the discharge pipe 22 provided in the upper portion of the case 10. Thereafter, the compressed refrigerant is guided to the condenser through the discharge pipe 22.

On the other hand, the air conditioner equipped with a compressor according to the prior art harmonizes the indoor air by operating or stopping the compressor according to the room temperature.                         

3 is a view showing the operating state of the compressor according to the prior art and the temperature change of the room according to it.

As shown in FIG. 3, after the air conditioner is operated to cool the room, the compressor is stopped when the actual temperature T _in of the room falls below the desired temperature T _d and reaches a set temperature. In addition, when the temperature of the room is raised again because the compressor is not operated and exceeds the set temperature, the compressor is operated again to cool the air in the room. By repeating the above process, the room temperature is maintained at an appropriate level.

On the other hand, in order to stop the operation of the compressor in the conventional air conditioner to operate again, there is a problem that consumes a lot of power because it must be rotated to overcome the inertia of the motor shaft for the compressor initially.

In addition, there is a problem in that the risk of damage to the motor and its rotating shaft is increased when the compressor is repeatedly driven and stopped.

In order to solve the above problems, it is an object of the present invention to provide an air conditioner equipped with a variable displacement compressor to reduce the power consumption and to drive stably.

In order to achieve the above object, the present invention provides a control method of an air conditioner having a variable displacement compressor for air conditioning in the room, the initial operation step for determining the cooling load of the room; Providing a control method of an air conditioner including selectively performing an on-off operation for performing an on-off operation or a capacity-variable operation for performing a capacity variable operation according to the cooling load determined in the initial operation step. do.

Hereinafter, with reference to the accompanying drawings will be described in detail with an air conditioner and a control method provided with a variable displacement compressor according to a preferred embodiment of the present invention.

4 is a configuration diagram of a variable displacement compressor applied to a control method of an air conditioner according to the present invention, and FIGS. 5A and 5B are cross-sectional views illustrating a cylinder structure according to an operation process of the variable displacement compressor.

As shown in Figure 4 to 5b, the case 10 of the variable-capacity compressor (3) is provided with a transmission unit 5 consisting of a rotor 12 and the stator 11 and the lower side of the transmission unit The compression section 6 is provided. The compression unit 6 includes a cylinder 114 having a cylindrical compression space therein and a rolling piston 17 which is eccentrically rotated in the compression space.

The rolling piston 17 is eccentrically connected to the rotating shaft 13 connected to the rotor 12, and is formed between the rotor 12 and the stator 11 when power is supplied to the transmission part 5. The rotor 12 and the rotating shaft 13 are rotated together by the rotating magnetic field. At this time, the rolling piston 17 connected to the lower portion of the rotating shaft 13 is also rotated together. Here, the rotor 12 is mounted so that one side is in contact with the inner peripheral surface of the cylinder (14).

In addition, a vane for advancing and reversing along the radial direction and contacting the outer circumferential surface of the rolling piston 17 on one side of the cylinder 14 to partition the inner space into the suction chamber S and the compression chamber C is provided. 18 is provided. Here, the vanes 18 are slid along the vane receiving portion 18a formed at one side of the cylinder, and the back of the vanes 18 are elastically supported by the springs 18b.

In addition, one side of the vane 18 is connected to the suction pipe 21 to form a suction port 14a through which the refrigerant is sucked, and a discharge port 14b through which the compressed refrigerant is discharged. Here, the discharge port 14b is connected to the discharge port 15a, and the discharge valve 19 is provided at the upper end of the discharge port 15a to be elastically opened and closed upward. The refrigerant discharged through the discharge port 14b is discharged through the discharge pipe 22 provided in the upper portion of the case 10.

As shown in FIG. 4, a low pressure refrigerant flows into the compressor from the first heat exchanger 51 through the suction pipe 21, and the second heat exchanger 53 from the compressor through the discharge pipe 22. The high pressure refrigerant is discharged. In addition, the refrigerant discharged from the second heat exchanger 53 is introduced into the first heat exchanger 51 through the expansion valve 52 so that the refrigerant passing through the devices as a whole changes state along the thermodynamic cycle.

The first heat exchanger 51 connected to the discharge side of the compressor functions as a condenser, and the second heat exchanger 53 connected to the suction side of the compressor functions as an evaporator. At this time, when cooling the room, the evaporator is located on the indoor side, whereas when heating the room, the condenser should be located in the room. To this end, the air conditioner may be configured as a heat pump for selectively cooling or heating the room by selectively connecting the compressor discharge side with either the first heat exchanger or the second heat exchanger by switching a four-way valve. .

Meanwhile, a bypass hole 31a is formed at a position separated by a predetermined angle from a portion where the vanes 18 are positioned, and a bypass pipe 31 is connected to the bypass hole 31a. The bypass pipe 31 and the space inside the cylinder 114 are selectively communicated with each other by the bypass valve 124.

A process of varying the capacity of the refrigerant to be compressed through the configuration in which a part of the refrigerant sucked into the cylinder 114 in the compressor assembly is selectively introduced into the compressor inlet 14a through the bypass pipe 31 will be described. Is as follows.

First, a process of compressing a refrigerant of full capacity will be described.

The capacity of the refrigerant initially sucked into the cylinder 114 is a portion hatched inside the cylinder 114, as shown in FIG. 5A. Assuming that the rolling piston 17 rotates in the clockwise direction, a vacuum pressure is formed in the suction chamber S to suck the refrigerant through the suction port 14a, and at the same time, the refrigerant already sucked in the compression chamber C It is compressed between the rolling piston 17 and the inner wall of the cylinder 114.

That is, when the bypass pipe 31 is in a closed state, the refrigerant of the first suction capacity described above is compressed to the volume of the compression chamber C on the right side as shown in 5b. In this way, the refrigerant compressed above a predetermined pressure is discharged through the discharge port 14b.

Meanwhile, a process of compressing a small amount of refrigerant by varying the capacity will be described below. When the bypass pipe 31 is in communication with the in-cylinder compression chamber C, the refrigerant is not compressed while the rolling piston 17 is rotated from the state shown in Fig. 5A to the state shown in Fig. 5B. It flows out through the pipe 31.

Thereafter, since the rolling piston 17 is further rotated to come into contact with the bypass hole 31a, the compression chamber C does not communicate with the bypass pipe 31a, so the refrigerant starts to be compressed. Therefore, only the refrigerant having a small capacity other than the refrigerant flowing out through the bypass pipe 31a is actually compressed among the refrigerant sucked first. In this case, instead of reducing the capacity of the compressed refrigerant discharged from the compressor, there is an advantage that can reduce the power consumption than when compressing the entire capacity.

As described above, the capacity of the refrigerant compressed in the compressor can be adjusted by selectively communicating the bypass pipe 31 and the compression space inside the cylinder 114. To this end, a bypass valve 124 is provided at a boundary point between the bypass pipe 31 and the cylinder 114 to selectively open and close the bypass hole 31a.

As shown in FIGS. 5A and 5B, the bypass valve 124 includes an opening and closing member 124a and a body 124b for guiding the movement of the opening and closing member 124a. Here, the opening and closing member (124a) is preferably made of a plate or sphere shape to selectively block the hole (31a). In addition, the opening and closing member 124a is moved by the pressure difference between the cylinder side and the bypass tube side to selectively block the bypass hole 31a to selectively select the interior of the bypass pipe 31 and the cylinder 114. Communicate with Further, the rear of the opening and closing member 124a is preferably supported by an elastic spring 124c that provides a recovery force in the direction of closing the bypass hole 31a.

Here, when the cylinder-side pressure is higher than the bypass tube pressure based on the opening / closing member 124a, the bypass hole 31a is opened. On the contrary, the cylinder-side pressure is bypass-passing based on the opening / closing member 124a. If the pressure is lower than the bypass hole 31a is closed.

Hereinafter, a process of selectively opening and closing the bypass valve 124 by effectively regulating pressure on both sides of the opening and closing member 124a will be described.

As shown in FIG. 4, the bypass pipe 31 is connected to the first pipe 33 and the second pipe 32, and the first pipe 33 is connected to the discharge pipe 22 of the compressor. The second pipe 32 is connected to the suction pipe 21 of the compressor. The bypass pipe 31 is selectively communicated with the first pipe 33 or the second pipe 32 in accordance with the operation of the switching means. Here, the switching means includes a first valve 33a and a second valve 32a provided in the first pipe 33 and the second pipe 32, respectively, and the valves 33a and 32a of the Through the operation, the flow of the refrigerant flowing through the pipes 32 and 33 is selectively blocked. To this end, the valves 32a and 33a preferably consist of an electrically controlled two-way solenoid valve. Of course, if the first pipe 33 and the second pipe 32 is configured to selectively communicate with the bypass pipe 31, in the case of using a three-way or four-way valve in addition to using the two-way valve It is also possible.                     

Here, the suction pipe 21 is preferably provided with an accumulator 41 for separating the refrigerant sucked by the compressor (3) into the gas phase and the liquid phase to flow only the refrigerant in the gas phase into the compressor. This prevents the liquid refrigerant from entering the compressor and damaging the compressor.

6a and 6b is a schematic configuration diagram showing the operation of the variable displacement compressor according to the operation of the valves.

Referring to FIG. 6A, a process in which the bypass valve 124 is closed to compress the refrigerant of the full capacity will be described below. First, when the first valve 33a is closed and the second valve 32a is opened, the high pressure refrigerant at the compressor discharge side flows into the bypass pipe 31 through the first pipe 33. At this time, as shown in Figure 5a or 5b, since the pressure on the bypass tube side of the opening and closing member 124a provided in the bypass valve 124 is high, the opening and closing member 124a is the pressure of both front and rear sides Due to the difference, the bypass hole 31a is moved in the direction of closing.

Therefore, the bypass valve 124 is in a closed state, and as a result, the refrigerant of the full capacity can be compressed by not flowing out through the bypass pipe 31 in the process of compressing the refrigerant as described above.

Meanwhile, referring to FIG. 6B, the bypass valve 124 is opened to describe a process of compressing only a part of the refrigerant in the compressor's total capacity as follows. First, when the first valve 33a is opened and the second valve 32a is closed, the bypass pipe 31 is connected to the suction pipe through which the refrigerant of low pressure flows through the second pipe 32. At this time, the pressure in the cylinder 114 is higher than the pressure in the bypass pipe 31. Therefore, referring to FIG. 5A or 5B, since the pressure on the cylinder side of the opening / closing member 124a provided inside the bypass valve 124 is higher, the opening / closing member 124a may have a pressure difference between the two sides. It moves by the direction which opens the bypass hole 31a by this.

Therefore, the bypass valve 124a is in an open state, and part of the bypass valve 124a flows out through the bypass pipe 31 in the process of compressing the refrigerant in the cylinder 114, so that only a small amount of refrigerant is compressed. Here, the refrigerant flowing out through the bypass pipe 31 flows into the suction valve 21 through the first pipe 32 and is supplied into the cylinder 114 again.

As described above, the variable displacement compressor according to the present invention may selectively perform a compression process of a compressible total capacity or a compression process of a small capacity refrigerant that is part of the total capacity. The control method of the air conditioner equipped with the variable displacement compressor as described above, while controlling the operation-stop of the compressor 3, that is, on-off as well as opening / closing of the bypass valve 124 according to the temperature change of the room. Is performed. Hereinafter, a control method of an air conditioner according to the present invention will be described.

7 is a flowchart illustrating a control method of the air conditioner according to the present invention for cooling the room, and FIG. 8 is a flowchart illustrating the control method performed in step A of FIG. 7.

As shown in FIG. 7, the control method according to the present invention includes a step of selectively performing on-off operation and variable capacity operation according to the initial operation step and the cooling load of the room determined in the initial operation step. Here, the variable displacement compressor is preferably a rotary compressor for varying the capacity of the refrigerant to be compressed by selectively opening and closing the bypass pipe provided in the above-described cylinder.

First, an air conditioner is turned ON (S1), and it is determined whether the air conditioner requires an initial operation for determining a cooling load of the compressor (SA).

When it is necessary to determine the cooling load through the initial operation, as shown in FIG. 8, the initial operation step is performed. First, the indoor temperature T _in is measured in real time by a temperature sensor provided at one side of the air conditioner, and the measured temperature is transmitted to a microcomputer that controls the operation of the air conditioner. At this time, the microcomputer selectively turns on / off the compressor according to the detected room temperature T _in .

Here, in the initial operation step, if the room temperature (T _in ) is greater than or exceeds the temperature (T _d + a ℃) plus the value set in the desired temperature (T _d ), operating the compressor at a large capacity (S6). And, if the room temperature (T _in ) is less than or less than the temperature (T _d -a ℃) minus the value set in the desired temperature (T _d ) is performed by repeating the step (S7) to stop the compressor. Here, the operation and the stop of the compressor are repeated at least two or more predetermined times.

Stopping the compressor preferably lasts for at least a predetermined time T1. This is because the compressor is prevented from being damaged when it is frequently turned on and off, and the time required for the cold air discharged from the indoor heat exchanger of the air conditioner equipped with the compressor to diffuse into the room is required. Therefore, the set time T1 is set in consideration of the time for spreading the cold air into the room.

On the other hand, the cooling load can be determined through the calculation of the operation rate. Here, the operation rate is calculated through calculation of (the total operation time of the compressor / the total operation time of the air conditioner) when the operation and the stop of the compressor is repeated a predetermined number of times, the calculated operation rate is the set value and Compared (S2). Here, the total operating time of the air conditioner is a state in which power is supplied to the air conditioner, and refers to a time obtained by adding both an operation time and a stop time of the compressor.

The high operation rate occurs when the time for stopping the compressor is minimized, which occurs when the cooling load in the room is very large. On the other hand, the low operation rate means that the cooling load in the room is low or the compressor frequently starts and stops repeatedly. Therefore, when the operation rate is low, power consumption is increased due to frequent operation and stop of the compressor, and the risk of damage to the compressor is increased. Therefore, it is preferable to change the operation method of the compressor in response to a low cooling load.

Therefore, when the operation rate is above or above the set value M, on-off operation is performed in the same manner as the initial operation step described above, and when the operation rate is below or below the set value M, the variable capacity operation is performed. Let this be done. Through this, when the cooling load of the room is large, the air conditioner performs more heat exchange per unit time by performing on-off operation, and when the cooling load of the room is below a certain level, the variable capacity operation is performed to perform the air. Ensure that the conditioner performs an adequate level of heat exchange.

In other words, the greater the amount of refrigerant compressed and discharged from the compressor, the more heat can be absorbed, thereby satisfying a large cooling load in the room. On the other hand, when the cooling load of the room is small, an appropriate level of cooling load can be satisfied without stopping the compressor by reducing the amount of the compressed and discharged refrigerant.

On the other hand, the on-off operation performed when the operation rate is greater than or equal to the set value (M) will be described as follows.

Referring to FIG. 8, the on-off operation operates the compressor at a large capacity when the indoor temperature T _in is equal to or exceeds the temperature T _d + a ° C. plus the set value of the desired temperature T _d . Step (S6) and the step (S7) of stopping the compressor when the room temperature (T _in ) is less than or below the temperature (T _d -a ℃) minus the value set in the desired temperature (T _d ) It is carried out including.

In this case, the step of stopping the compressor preferably lasts for at least a predetermined time (T1). This is because the compressor is prevented from being damaged when the compressor is frequently turned on and off, and the time required for the cold air discharged from the indoor heat exchanger of the air conditioner equipped with the compressor to diffuse into the room is required. Therefore, the set time T1 is set in consideration of the time for spreading the cold air into the room.

On the other hand, the capacity-variable operation performed when the operation rate is greater than or equal to the set value will be described.                     

9 is a view showing a change in the room temperature when the compressor of the air conditioner performs a variable capacity operation.

As shown in Figure 9, when the room temperature (T _in ) is lowered by the operation of the air conditioner for cooling the room reaches the desired temperature (T _d ), the variable displacement compressor is a small amount of refrigerant that is part of the total compression capacity Only the process of compressing. Then, because the decrease rate of the room temperature is slow, the time to reach the room temperature (T _in) is obtained by subtracting a value set in said desired temperature (T _d) temperature (T _d -a ℃) becomes long. Therefore, since the on-off cycle of the compressor can be lengthened, it is possible to reduce excessive power consumption when starting the compressor. In the variable capacity operation, the opening and closing of the bypass valve provided in the rotary compressor as well as the on-off of the compressor are controlled according to the change _{in the} room temperature T _in as described below.

First, when the room temperature T _in exceeds the temperature (T _d + a ° C.) plus the value a set to the desired temperature T _d , the compressor is controlled to compress a large amount of refrigerant. To this end, as shown in Figure 6a, the bypass valve 124 provided on one side of the cylinder 114 of the rotary compressor by the operation of the switching means is closed. When the bypass valve 124 is closed, the total capacity that can be compressed by the compressor 3, that is, a large amount of refrigerant is compressed and discharged.

In addition, when the room temperature T _in is lowered and the desired temperature T _d is reached, the compressor 3 controls to compress a small amount of refrigerant. To this end, as shown in Figure 6b, the bypass valve 124 provided on one side of the cylinder (3) of the rotary compressor is closed. As the bypass valve 124 is closed, a part of the total capacity that the compressor 3 can compress, that is, only a small amount of cold, is compressed and discharged.

Here, the control of the first valve 33a and the second valve 32a used as the switching means to open and close the bypass valve 124 is as described above with reference to FIGS. 4 to 6B.

In addition, the compressor is stopped when the indoor temperature is equal to or less than the temperature (T _d -a ° C) minus the set value (a) from the desired temperature (T _d ). At this time, the step of stopping the compressor is preferably continued for at least a predetermined time (T1).

On the other hand, the control method of the air conditioner in the case of heating the room is as follows.

10 is a flowchart illustrating a control method of the air conditioner when heating the room, and FIG. 11 is a flowchart illustrating a control process performed in step B of FIG. 10.

As shown in FIG. 10 and FIG. 11, in the case of heating the room, the initial operation step for determining the heating load of the compressor and the on-off operation are performed according to the determined cooling load as in the above-described control for cooling. The capacitive variable operation that performs the on-off operation and the variable variable operation is selectively performed.

In the initial operation step, it is possible to determine the heating load by calculating the operation rate. Here, the operation rate is calculated through calculation of (the total operation time of the compressor / the total operation time of the air conditioner) when the operation and stop of the compressor is repeated a predetermined number of times based on the result performed in the initial operation step. .

The high operation rate occurs when the time for stopping the compressor is minimized, which occurs when the heating load in the room is very large. On the other hand, the low operation rate means that the heating load in the room is low or the compressor frequently starts and stops repeatedly. Therefore, when the operation rate is low, power consumption is increased due to frequent operation and stop of the compressor, and the risk of damage to the compressor is increased. Therefore, it is preferable to change the operation method of the compressor in response to a low heating load.

Thereafter, when the calculated operation rate is equal to or greater than the set value M, on-off operation is performed in the same manner as in the initial operation step described above, while the calculated operation rate is equal to or less than the set value M. If the value is equal to or less than the capacity variable operation is performed. The variable capacity operation may be performed by selectively changing the capacity of the refrigerant compressed by the compressor as well as on / off of the compressor.

Here, when the operation rate calculated through the initial operation step and the initial operation step exceeds a set value, that is, when the on-off operation is performed when the heating load is large, on-off of the compressor is performed according to the room temperature. Controlled.

As shown in Figure 11, when the room temperature (T _in ) is less than or less than the temperature (T _d -a ℃) minus the value set in the desired temperature (T _d ) operating the compressor in a large capacity (S15) And a step (S16) of stopping the compressor when the room temperature T _in is equal to or greater than the temperature T _d + a ° C. plus the value set in the desired temperature T _d . In this case, as in the case of cooling, the step of stopping the compressor in consideration of the time when the warmth discharged from the indoor unit of the air conditioner is diffused into the room is preferably at least longer than the set time (T2).

As shown in FIG. 10, in the capacity varying step, when the room temperature T _in is less than the temperature (T _d -a ° C.) minus a value set in the desired temperature T _d , the compressor is configured to supply a large amount of refrigerant. Controlling to compress (S12), and when the desired temperature (T _d ) is reached while the room temperature (T _in ) is increased, controlling the compressor to compress a small amount of refrigerant (S13), and an indoor temperature. If (T _in ) is equal to or more than the temperature (T _d + a ° C.) plus the value set in the desired temperature (T _d ), the step of stopping the compressor is performed. At this time, the step of stopping the compressor as in the case of the cooling of the room described above preferably lasts for at least a predetermined time.

12 is a view showing a change in the room temperature when the compressor performs a variable capacity operation.

As shown in FIG. 12, when the room temperature T _in is increased by the operation of the air conditioner for heating the room and the desired temperature T _d is reached, the variable displacement compressor is a small amount of refrigerant that is a part of the total compression capacity. Only the process of compressing. Then, because the slow rising speed of the indoor temperature, the time to reach the room temperature (T _in) is obtained by adding a value set in said desired temperature (T _d) temperature (T _d + a ℃) becomes long. Therefore, since the on-off cycle of the compressor can be lengthened, it is possible to reduce excessive power consumption when starting the compressor.

In more detail, in the variable displacement operation, the opening and closing of the bypass valve and the on-off of the compressor are controlled according to the change in the temperature of the room.

First, when the indoor temperature T _in is equal to or less than or equal to or lower than the temperature (T _d -a ° C) minus the value (a) set in the desired temperature (T _d ), the compressor is controlled to compress a large amount of refrigerant. For this purpose, as shown in Figure 6a, the bypass valve 124 provided on one side of the cylinder 114 of the rotary compressor by the operation of the switching means is closed. When the bypass valve 124 is closed, the total capacity that can be compressed by the compressor 3, that is, a large amount of refrigerant is compressed and discharged.

As the room is heated by the operation of the air conditioner performing the above operation, when the room temperature T _in is raised to reach the desired temperature T _d , the compressor compresses a small amount of refrigerant. Controlled. To this end, as shown in Figure 6b, the bypass valve 124 provided on one side of the cylinder 114 of the rotary compressor is opened. When the bypass valve 124 is opened, only a part of the total capacity that the compressor 3 can compress, that is, a small amount of refrigerant, is compressed and discharged.

Here, the control of the first valve 33a and the second valve 32a used as the switching means to open and close the bypass valve 124 is as described above with reference to FIGS. 4 to 6B. In addition, the compressor 3 is stopped when the room temperature T _in is equal to or higher than the temperature T _d + a ° C. plus the value set to the desired temperature T _d . At this time, the step of stopping the compressor is preferably continued for at least a predetermined time (T2).

Although the preferred embodiments of the present invention have been described above by way of example, the scope of the present invention is not limited to these specific embodiments, and may be modified and implemented appropriately within the scope described in the claims.

As described above, the control method of the air conditioner with a variable displacement compressor according to the present invention provides the following effects.

First, by controlling the compressor to fit the indoor air conditioning environment by reducing the on-off operation or variable capacity operation of the compressor according to the cooling or heating load of the room can reduce the power consumption.

Second, it is possible to improve the operation rate of the compressor by changing the refrigerant compression capacity of the compressor according to the room temperature. In other words, when the cooling or heating load is small, only a small amount of refrigerant is compressed to reduce the rate of change in the room temperature, thereby delaying the timing of stopping the compressor. Thus, power consumed by frequent on-off can be reduced, and damage to the compressor can be prevented.                     

Third, the bypass pipe can be selectively opened and closed by simple operation of the switching means provided in the pipes connected to the compressor without the complicated circuit arrangement, thereby making it easier to change the capacity of the refrigerant to be compressed. It is possible to implement a control method of the compressor and the air conditioner.

Claims (17)

In the control method of the air conditioner equipped with a variable capacity compressor for cooling the room, An initial operation step for determining an indoor cooling load; And selectively performing an on-off operation for performing an on-off operation or a capacity-variable operation for performing a capacity variable operation according to the cooling load determined in the initial operation step. The method of claim 1, The initial operation step And calculating an operation rate for determining a cooling load as the compressor is turned on and off according to the difference between the set temperature and the room temperature. The method of claim 1, The on-off operation is, Operating the compressor when a room temperature exceeds a temperature obtained by adding a value set to a desired temperature; And And stopping the compressor when the room temperature is equal to or lower than the temperature set to the desired temperature. The method of claim 3, And stopping the compressor lasts at least a predetermined time. The method of claim 1, The capacity variable operation, Controlling the compressor to compress a large amount of refrigerant when a room temperature exceeds a temperature obtained by adding a value set to a desired temperature; Controlling the compressor to compress a small amount of refrigerant when a room temperature is lowered and the desired temperature is reached; And And controlling the compressor when the room temperature is equal to or lower than the temperature set to the desired temperature. The method of claim 5, And stopping the compressor lasts at least a predetermined time. In the control method of an air conditioner equipped with a variable capacity compressor for heating the room, Initial operation step for determining the heating load of the room; And selectively performing an on-off operation for performing an on-off operation or a variable-variable operation for performing a capacity variable operation according to the heating load determined in the initial operation step. The method of claim 7, wherein The initial operation step And calculating an operation rate for determining a heating load as the compressor is turned on and off according to the difference between the set temperature and the room temperature. The method of claim 7, wherein The on-off operation is, Operating the compressor when the room temperature is lower than the temperature minus the value set in the desired temperature; And And stopping the compressor when the room temperature is equal to or greater than the temperature set to the desired temperature. The method of claim 9, And stopping the compressor lasts at least a predetermined time. The method of claim 7, wherein The capacity variable operation, Controlling the compressor to compress a large amount of refrigerant when the indoor temperature is lower than a temperature obtained by subtracting a value set to a desired temperature; Controlling the compressor to compress a small amount of refrigerant when an indoor temperature is raised and the desired temperature is reached; And And stopping the compressor when the room temperature is equal to or greater than the value set to the desired temperature. The method of claim 11, And stopping the compressor lasts at least a predetermined time. A rotary compressor for compressing and discharging the sucked refrigerant inside the cylinder; A bypass tube selectively communicating with the inside of the cylinder; A bypass valve provided between the bypass pipe and the cylinder and opened and closed by a pressure difference between the cylinder side and the bypass pipe side; And In the control method of the air conditioner comprising a switching means for selectively connecting the bypass pipe to the compressor suction side or discharge side, The control method of the air conditioner for controlling the opening and closing of the bypass valve and the on-off of the compressor in accordance with the change in the temperature of the room. The method of claim 13, In order to cool the room, Controlling the switching means to close the bypass pipe when the room temperature exceeds the temperature plus the value set in the desired temperature; Controlling the switching means to open the bypass pipe when the room temperature is lowered and the desired temperature is reached; And And controlling the compressor when the room temperature is equal to or lower than the temperature set to the desired temperature. The method of claim 13, If you want to heat the room, Controlling the switching means to close the bypass pipe when the indoor temperature is lower than the temperature minus the value set in the desired temperature; Controlling the switching means to open the bypass pipe when the desired temperature is reached while the temperature of the room is increased; And And stopping the compressor when the room temperature is equal to or greater than the value set to the desired temperature. When cooling the room using an air conditioner equipped with a variable displacement compressor, Controlling the compressor to compress a large amount of refrigerant when the room temperature is equal to or greater than a temperature set to a desired temperature; Controlling the compressor to compress a small amount of refrigerant when a room temperature is lowered and the desired temperature is reached; And And stopping the compressor for at least a predetermined time when the room temperature is less than the temperature minus the value set in the desired temperature. When heating the room using an air conditioner equipped with a variable displacement compressor, Controlling the compressor to compress a large amount of refrigerant when the room temperature is equal to or less than the temperature minus the desired value; Controlling the compressor to compress a small amount of refrigerant when an indoor temperature is raised and the desired temperature is reached; And And stopping the compressor for at least a predetermined time when the room temperature is equal to or higher than a temperature set to a desired temperature.

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