KR20050105743A - An apparatus and method for control of heat pump system using two compressors - Google Patents

Abstract

Compressor control apparatus and control method of the air conditioner according to the present invention, in an air conditioner to which a plurality of compressors are applied, immediately with an on signal without the standby mode of the compressor or the off function of the compressor in operation A compressor control apparatus and a control method of an air conditioner for starting a compressor, the compressor control method using a compressor control device according to the present invention, the control step of generating a control signal in the control unit; A second step of opening a solenoid valve in response to the control signal; A third step of bypassing the discharge gas to the low pressure side of the compressor through an open solenoid valve; And a fourth step of restarting an off compressor by the control signal.

In the compressor control apparatus of the air conditioner according to the present invention, the discharge gas is bypassed when the off compressor is restarted in a cycle to which a plurality of compressors are applied, so that the restart failure or the pressure of the off compressor is lost. By restarting the car without waiting for the car to dissipate, there is an immediate response to changes in the indoor load.

In addition, the present invention, by bypassing the discharge gas by a certain amount without turning off (compressor), a certain cooling capacity can be secured even during overload, frequent frequent on-off (off / on) of the compressor By this avoidance, there is another effect that the long-term reliability of the compressor can be ensured.

Description

An apparatus and method for control of heat pump system using two compressors}

The present invention relates to a compressor control apparatus and a control method of an air conditioner to which two compressors are applied, and in particular, restarts an off compressor without a waiting time for eliminating a restart failure or a pressure difference of the off compressor. In addition, it is possible to immediately respond to fluctuations in the indoor load, and at the same time, a certain level of cooling capacity can be secured even during overload, and frequent on / off repetition of the compressor is avoided, thereby ensuring long-term reliability of the compressor. The present invention relates to a compressor control apparatus and a control method of an air conditioner.

In general, an air conditioner system includes a compressor in which a gaseous refrigerant of low temperature and low pressure is changed into a gaseous refrigerant of high temperature and high pressure, and a gaseous refrigerant of high temperature and high pressure changed in the compressor is converted into a liquid refrigerant of medium temperature and high pressure. A condenser, an expansion device in which the medium-temperature high-pressure liquid state changed in the condenser is converted into a low-temperature low-pressure liquid state refrigerant, and a four-way valve for changing the flow path of the refrigerant according to the cooling and heating mode.

In the air conditioner system, the indoor heat exchanger and the outdoor heat exchanger have different roles depending on the cooling and heating modes. In the heating mode, the indoor heat exchanger performs the role of a condenser, the outdoor heat exchanger performs the role of an evaporator, and the indoor heat exchange in the cooling mode. The gas serves as the evaporator and the outdoor heat exchanger serves as the condenser.

In addition, recently, a plurality of compressors having different capacities are employed so that the compression capacity of the refrigerant can be varied according to the cooling load or the heating load, thereby optimizing the cooling and heating efficiency.

1 is a block diagram showing the main configuration of an air conditioner according to the prior art.

Referring to FIG. 1, a main configuration of a refrigerant structure of a general air conditioner system is illustrated, and a plurality of compressors in which a low temperature low pressure refrigerant is changed into a high temperature high pressure gaseous refrigerant has a different capacity. It consists of the 1st compressor 6 and the 2nd compressor 7. The first and second compressors 6 and 7 have a capacity determined for each compressor so as to be set by the producer and compressed by a predetermined ratio of the total refrigerant capacity. Hereinafter, in the present specification, the first compressor 6 is It is a small capacity compressor, and the 2nd compressor 7 is illustrated as a large capacity compressor.

Accordingly, in the air conditioner to which two compressors are applied, the compression capacity of the refrigerant is variable by selectively operating or fully operating the first compressor 6 and the second compressor 7 according to a heating and cooling load. It is a structure.

In general, an air conditioner system includes a check valve (8, 9) and the first, second compressor (6, 7) to prevent backflow of refrigerant compressed by the first and second compressor (6,7). Four-way valve (3) to switch the flow path of the refrigerant passing through to change the role of the heat exchanger, an outdoor heat exchanger (5) in which the refrigerant is heat-exchanged with the outdoor air to condense into a liquid refrigerant of medium temperature and high pressure, and the outdoor heat exchanger (5 Expansion device 2 in which the refrigerant having passed through) is decompressed to a liquid refrigerant of low temperature and low pressure, an indoor heat exchanger 10 in which the refrigerant passing through the expansion device 2 exchanges heat with indoor air, and the indoor heat exchanger 10 The liquid refrigerant is separated from the liquid and gaseous two-phase refrigerant passing through the) and the accumulator 4 for supplying only the gas refrigerant to the first and second compressors 6 and 7 is included. As the refrigerant passes, the cooling cycle is completed.

In the air conditioner system as described above, when the cooling or heating load is small, the first compressor 6 having the smaller capacity among the first and second compressors 6 and 7 is selectively operated, and the second compressor 7 Is not operated, and the check valve 9 of the second compressor 7 is locked.

Therefore, the compressed high-pressure gas refrigerant discharged from the refrigerant discharge port of the second compressor 7 and raised to the second check valve 9 is isolated, and the refrigerant discharge port of the second compressor 7 is maintained at a high pressure. do. In addition, since the refrigerant intake port of the second compressor 7 is before the gas refrigerant is compressed, a pressure difference is generated between the refrigerant intake port and the refrigerant discharge port of the second compressor 7 as it is maintained at a low pressure.

That is, when the pressure difference between the refrigerant intake port and the refrigerant discharge port of the second compressor 7 is solved and is pressured, the second compressor 7 is restarted, and the atmosphere for restarting the second compressor 7 in the stopped state is restarted. The time is equal to the time required for the pressure between the refrigerant suction port and the refrigerant discharge port of the second compressor 7 to be equalized.

In addition, when the cooling or heating load is rather large, the second compressor 7 having a large capacity among the first and second compressors 6 and 7 is selectively operated, and the first compressor 6 is not operated. The check valve 8 of the first compressor 6 is locked. That is, the first compressor 6 and the second compressor 7 are selectively operated or full driven according to the heating and cooling load.

2 is a flow chart showing a compressor control method of the air conditioner according to the prior art.

Referring to FIG. 2, when the cooling or heating load is small, the small capacity first compressor 6 is turned on and the large capacity second compressor 7 is turned off. When the compressor 7 is restarted, it is kept in the standby mode until the pressure difference between the working compressor 6 and the off compressor 7 is resolved, or the working compressor is turned off to 3 It will be restarted in minutes.

As described above, in order to restart the off-compressor in a stopped state, there is a problem in that it does not respond quickly to changes in the heating and cooling load due to the waiting time.

 Further, the off compressor is started before a waiting time for restarting the off compressor in the stopped state, that is, a time required for the pressure between the refrigerant suction port and the refrigerant discharge port of the off compressor to be leveled off. If you want to do that, there was a problem that will fail to restart.

The present invention has been made in view of the above problems, and the discharge gas is bypassed when the off compressor is restarted in a cycle to which a plurality of compressors are applied, so that the restart failure or the pressure difference of the off compressor is reduced. It is an object of the present invention to provide a compressor control apparatus and a control method of an air conditioner to restart immediately without waiting time to be eliminated, so as to respond immediately to the changes in the indoor load.

In addition, by bypassing the discharged gas by a certain amount without turning off the compressor, a cooling capacity of a certain level or more can be secured even when overloaded, and frequent on / off repetition of the compressor is avoided. It is another object of the present invention to provide a compressor control device and a control method of an air conditioner to ensure long-term reliability of the compressor.

Compressor control apparatus of the air conditioner according to the present invention, the control unit for generating a control signal; Opening and closing means for selectively opening a flow path of discharge gas according to the control signal; Two or more compressors restarted in an off state by the control signal; And a capillary tube connected between the opening and closing means and the plurality of compressors.

In addition, the compressor control method of the air conditioner according to the present invention comprises a first step of generating a control signal from the control unit; A second step of opening and closing means by the control signal; A third step of bypassing the discharge gas to the low pressure side of the compressor through an open opening / closing means; And a fourth step of restarting an off compressor by the control signal.

In the compressor control method of the air conditioner according to the present invention, the discharge gas is bypassed when the off compressor is restarted in a cycle to which a plurality of compressors are applied, so that the restart failure or the pressure of the off compressor is lost. By restarting the car without waiting for the car to dissipate, there is an immediate response to changes in the indoor load.

In addition, the present invention, by bypassing the discharge gas by a certain amount without turning off (compressor), a certain cooling capacity can be secured even during overload, frequent frequent on-off (off / on) of the compressor By this avoidance, there is another effect that the long-term reliability of the compressor can be ensured.

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

However, the spirit of the present invention is not limited to the embodiments presented, and those skilled in the art who understand the spirit of the present invention can easily suggest other embodiments within the scope of the same idea.

3 is a block diagram showing the main configuration of an air conditioner according to the present invention.

Referring to FIG. 3, the main structure of the air conditioner system according to the present invention is illustrated, and the air conditioner to which two compressors are applied is provided in the first and second compressors 21 and 22. Check valves 18 and 19 to prevent backflow of the compressed refrigerant and four-way valves 14 through which the flow paths of the refrigerant passing through the first and second compressors 21 and 22 are switched to change the role of the heat exchanger. , An outdoor heat exchanger (20) in which the refrigerant is heat-exchanged with outdoor air to condense into a medium-temperature high-pressure liquid refrigerant, an expansion device (13) in which the refrigerant passing through the outdoor heat exchanger (20) is decompressed to a low-temperature low-pressure liquid refrigerant, and Liquid refrigerant from an indoor heat exchanger (24) in which the refrigerant passing through the expansion device (13) exchanges heat with indoor air, and a liquid and gaseous two-phase refrigerant passing through the indoor heat exchanger (24). Is separated and accumulate to supply only the gas refrigerant to the first and second compressors 21 and 22. It includes a locator (17).

In addition, the air conditioner according to the present invention, in particular, the solenoid valve 16 to regulate the discharge refrigerant is not bypassed or bypassed, and the amount of the discharged refrigerant to be bypassed (by pass) Capillary 15 is further included to allow adjustment.

In the air conditioner system as described above, when the cooling or heating load is small, the first compressor 21 having the smaller capacity among the first and second compressors 21 and 22 is selectively operated, and the second compressor 22 is operated. Is not operated, and the check valve 19 of the second compressor 22 is locked.

In addition, when the cooling or heating load is rather large, the second compressor 22 having a large capacity among the first and second compressors 21 and 22 is selectively operated, and the first compressor 21 is not operated. The check valve 18 of the first compressor is locked, and when the cooling or heating load is very large, the first and second compressors 21 and 22 are operated simultaneously, and the first and second compressors 21, The check valves 18 and 19 of 22 are all opened.

In addition, the solenoid valve on the discharge port side of the first and second compressors 21 and 22 controls the discharge refrigerant to not bypass or bypass by a control signal of a controller (not shown). (16) is coupled, and between the solenoid valve 16 and the check valves (18, 19), a capillary tube (15) is provided so that the amount of discharged refrigerant that is bypassed is adjusted.

4 is a flowchart illustrating a compressor control method of the air conditioner according to the present invention.

Looking at the process of controlling the compressor of the air conditioner according to the present invention with reference to Figure 4, the present invention is to restart the off compressor in the air conditioner (ie, variable cycle) to which a plurality of compressor is applied The present invention relates to an apparatus and a method for smoothing, in particular, a device for bypassing a hot discharge gas, that is, a capillary tube and a solenoid valve selectively opened, and a control unit for controlling the same. The solenoid valve is selectively opened in response to a control signal of, so that the hot discharge gas is bypassed to the low pressure side of the compressor.

That is, after one compressor is turned off among two (or three) compressors according to the operating conditions set by inputting to the control unit (microcomputer) first, that is, the indoor temperature setting, the indoor unit operation combination number in the multi air conditioner, and the like. For example, when the off compressor is restarted, a signal for restarting the off compressor from the microcomputer by selecting a button on the operation unit is generated, and the control signal bypasses the hot discharge gas. The solenoid valve is opened to pass by. At this time, the hot discharge gas is supplied to the low pressure side of the compressor, that is, the inlet side of the accumulator through a capillary tube and a solenoid valve connected to the front end of the solenoid valve, so that the start of the off compressor is smoothly performed.

This is a method for reducing the starting load when the off compressor is started by the control signal so that the starting resistance is reduced upon restart.

That is, the compressor control method of the air conditioner according to the present invention includes a first step of generating a control signal from the control unit; A second step of opening and closing means by the control signal; A third step of bypassing the discharge gas to the low pressure side of the compressor through an open opening / closing means; And a fourth step of restarting the off compressor in response to the control signal.

In addition, when the off compressor is turned on by the control signal of the controller as described above, when a predetermined time (about 1 minute) has elapsed, the solenoid valve is closed again to obtain a high temperature discharge gas. A fifth step is further included to allow the card to be circulated normally without being passed by.

In the overload operation, the solenoid valve for the discharge gas bypass is opened before the compressor OLP is operated due to the increase in the discharge gas temperature and the current value. Allow the compressor to run continuously without operation. And, the temperature of the discharge gas, the current value and the outdoor temperature just before the operation, the value is derived by the experiment.

In the present invention, when the off compressor is restarted, the discharge gas is bypassed so that the restart can be restarted without waiting time for the failure of restart or the pressure difference of the off compressor to be eliminated.

In the compressor control method of the air conditioner according to the present invention, the discharge gas is bypassed when the off compressor is restarted in a cycle to which a plurality of compressors are applied, so that the restart failure or the pressure of the off compressor is lost. By restarting the car without waiting for the car to dissipate, there is an immediate response to changes in the indoor load.

In addition, the present invention, by bypassing the discharge gas by a certain amount without turning off (compressor), a certain cooling capacity can be secured even during overload, frequent frequent on-off (off / on) of the compressor By this avoidance, there is another effect that the long-term reliability of the compressor can be ensured.

1 is a block diagram showing the main configuration of an air conditioner according to the prior art.

Figure 2 is a flow chart showing a compressor control method of the air conditioner according to the prior art.

Figure 3 is a block diagram showing the main configuration of the air conditioner according to the present invention.

Figure 4 is a flow chart showing a compressor control method of the air conditioner according to the present invention.

Explanation of symbols on the main parts of the drawings

12 connection pipe 13 expansion device 14 4-way valve

15: capillary 16: solenoid valve 17: accumulator

18, 19: valve 20: outdoor heat exchanger 21: first compressor

22: second compressor 23: service valve 24: indoor unit

Claims (6)

A first step of generating a control signal from the controller; A second step of opening and closing means by the control signal; A third step of bypassing the discharge gas to the low pressure side of the compressor through an open opening / closing means; And And a fourth step of restarting an off compressor according to the control signal. The method of claim 1, After a certain time has passed after the off compressor is turned on by the control signal, the solenoid valve is closed again so that the hot discharge gas is not bypassed and is circulated normally. Compressor control method of the air conditioner further comprises a fifth step. The method of claim 1, The opening and closing means is a compressor control method of the air conditioner, characterized in that the solenoid valve. A control unit for generating a control signal; Opening and closing means for selectively opening a flow path of discharge gas according to the control signal; Compressor control device of the air conditioner including two or more plurality of compressors restarted in the off (off) state by the control signal. The method of claim 4, wherein Compressor control device of the air conditioner further comprises a capillary tube connected between the opening and closing means and a plurality of compressors. The method of claim 4, wherein Compressor control device of the air conditioner, characterized in that the opening and closing means is a solenoid valve.