KR20060034148A - Air conditioner with sub compression loop - Google Patents

Abstract

The present invention relates to an air conditioner having an auxiliary compression circuit, comprising: a main compressor for compressing a refrigerant; A four-way valve disposed on the discharge side of the main compressor; An outdoor heat exchanger having one side connected to the four-way valve; An indoor heat exchanger having one side connected to the outdoor heat exchanger and the other side connected to the four-way valve; An expansion device disposed between the outdoor heat exchanger and the indoor heat exchanger; One side is connected to the discharge side of the main compressor and the other side is connected to the upstream side of the four-way valve, and an auxiliary compressor disposed in the auxiliary passage for compressing the refrigerant, respectively, on the inlet and outlet side of the auxiliary passage It is characterized in that it comprises a secondary compression circuit having an inlet side opening valve and an outlet side opening and closing valve disposed to open and close the auxiliary flow path. Thereby, an air conditioner having an auxiliary compression circuit capable of suppressing a sudden increase in noise during high compression ratio operation and improving the efficiency and reliability of the compressor is provided.

Description

Air conditioner with auxiliary compression circuit {AIR CONDITIONER WITH SUB COMPRESSION LOOP}

1 is a configuration of a refrigeration cycle of a conventional air-conditioning combined air conditioner,

2 is a pressure-enthalpy diagram in high compression ratio operation,

3 is a configuration diagram of a refrigeration cycle of an air conditioner having an auxiliary compression circuit according to an embodiment of the present invention;

4 is a view for explaining the operation of the auxiliary compression circuit of FIG.

FIG. 5 is a control block diagram of the air conditioner of FIG. 3.

Explanation of symbols on the main parts of the drawings

11: main compressor 12: suction pressure sensor

13 four-way valve 14 discharge pressure sensor

15: outdoor heat exchanger 17: indoor heat exchanger

19: expansion device 20: auxiliary compression circuit

21: auxiliary flow path 23: inlet opening and closing valve

24: outlet side open and close valve 25: auxiliary compressor

27: equalization tank 28: oil return passage

29: oil return pipe 30: return pipe opening and closing valve

31: control unit 33: pressure difference calculation unit

The present invention relates to an air conditioner having an auxiliary compression circuit. More particularly, the present invention relates to an air conditioner including an auxiliary compression circuit. It relates to an air conditioner.

1 is a configuration of a refrigeration cycle of a conventional air-conditioning combined air conditioner, Figure 2 is a pressure-enthalpy diagram in the high compression ratio operation. As shown in FIG. 1, the combined air-conditioning and air conditioner includes a compressor 101 for compressing a refrigerant, a four-way valve 103 arranged to switch a flow path of the refrigerant on the discharge side of the compressor 101, and a four-way valve 103. ) Is connected to the outdoor heat exchanger 105 and the refrigerant is heat-exchanged, one side is connected to the four-way valve 103, the other side is connected to the outdoor heat exchanger 105 and the indoor heat exchanger 107, the outdoor heat exchanger 105 ) And an expansion device (109) disposed between the indoor heat exchanger (107).

In the cooling operation, the four-way valve 103 switches the flow path so that the refrigerant compressed in the compressor 101 flows to the outdoor heat exchanger 105, and the refrigerant compressed in the compressor 101 is transferred to the outdoor heat exchanger 105. The heat exchanger condenses, expands under reduced pressure in the expansion device 109, and performs a cooling operation to absorb latent heat of evaporation while heat-exchanging in the indoor heat exchanger 107.

In the heating operation, the four-way valve 103 switches the flow path so that the refrigerant compressed by the compressor 101 flows to the indoor heat exchanger 107, and the refrigerant that has undergone the heating operation by heat exchange in the indoor heat exchanger 107 condenses. After the expansion device 109 is expanded under reduced pressure. The expanded pressure refrigerant absorbs latent heat from the outdoor heat exchanger 105 and evaporates. At this time, the cycle of the refrigerant is formed in the order of loop 1 → 2 → 3 → 4 in which the pressure difference on the high pressure side and the pressure difference on the low pressure side form the first value ΔP, as shown in FIG. When is very low, the pressure difference on the high pressure side and the pressure on the low pressure side are formed in the order of loop 1 '→ 2' → 3 → 4, which makes the second value ΔP 'larger than the first value ΔP.

By the way, in the conventional air-conditioning combined air conditioner, when the outside air temperature is very low during the heating operation, the pressure difference between the suction side and the discharge side becomes large, which causes the compressor 101 to perform a high compression ratio operation. Not only is the noise of 101 increased dramatically, but also the efficiency and reliability of the compressor 101 are deteriorated.

Accordingly, an object of the present invention is to provide an air conditioner having an auxiliary compression circuit capable of suppressing a sudden increase in noise during high compression ratio operation and improving the efficiency and reliability of the compressor.

The object is, according to the present invention, a main compressor for compressing a refrigerant; A four-way valve disposed on the discharge side of the main compressor; An outdoor heat exchanger having one side connected to the four-way valve; A chamber heat exchanger having one side connected to the outdoor heat exchanger and the other side connected to the four-way valve; An expansion device disposed between the outdoor heat exchanger and the indoor heat exchanger; One side is connected to the discharge side of the main compressor and the other side is connected to the upstream side of the four-way valve, and an auxiliary compressor disposed in the auxiliary passage for compressing the refrigerant, respectively, on the inlet and outlet side of the auxiliary passage It is achieved by an air conditioner having an auxiliary compression circuit, characterized in that it comprises an auxiliary compression circuit disposed and provided with an inlet side opening and closing valve for opening and closing the auxiliary passage.

Here, it is preferable to further include a pressure equalizing tank disposed downstream of the inlet-side opening and closing valve of the auxiliary flow passage to temporarily receive the refrigerant compressed by the main compressor.

It is effective to further include an oil return flow passage formed to connect the suction side of the pressure equalizing tank and the main compressor so that the oil in the pressure equalizing tank is returned to the main compressor.

The oil return passage, one side is connected to the equalization tank and the other side is configured to include an oil return pipe connected to each other in communication with the suction side of the main compressor, and a return pipe opening and closing valve for opening and closing the oil return pipe. It is preferable.

The oil return passage is effective to include a capillary tube.

It is preferable to further include a control unit for controlling the inlet side open valve and the outlet side open valve according to the operation mode.

And a suction side pressure sensor and a discharge side pressure sensor for detecting pressures on the suction side and the discharge side of the main compressor, and a pressure difference calculation unit for calculating a pressure difference between the suction side and the discharge side of the main compressor, wherein the control unit is a heating operation. In this case, it is effective to control the inflow side opening valve and the outflow side opening valve to be opened based on the calculation result of the pressure difference calculating section.

The air temperature sensor may further include an outside air temperature sensor configured to detect an outside air temperature, and the controller may control the inflow side opening valve and the outflow side opening valve to be opened, respectively, based on the detection result of the outside air temperature sensor during heating operation.

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

3 is a configuration diagram of a refrigeration cycle of an air conditioner having an auxiliary compression circuit according to an embodiment of the present invention, FIG. 4 is a view for explaining the operation of the auxiliary compression circuit of FIG. 3, and FIG. 5 is FIG. 3. Is a control block diagram of an air conditioner. As shown in these figures, the air conditioner provided with the auxiliary compression circuit includes a main compressor 11 for compressing a refrigerant, a four-way valve 13 disposed on the discharge side of the main compressor 11, and one side of the air conditioner. Outdoor heat exchanger 15 connected to the valve 13, one side is connected to the outdoor heat exchanger 15, the other side is connected to the four-way valve 13, the indoor heat exchanger 17, the outdoor heat exchanger 15 And an expansion device 19 disposed between the indoor heat exchangers 17, one side connected to the discharge side of the main compressor 11, and the other side connected to an upstream side of the four-way valve 13; An auxiliary compressor (25) arranged in the auxiliary passage (21) to compress the refrigerant, an inlet side opening / closing valve (23) for opening and closing the auxiliary passage (21) disposed at the inlet and outlet sides of the auxiliary passage (21), and And an auxiliary compression circuit 20 having an outlet side opening and closing valve 24.

On the discharge side and the suction side of the main compressor 11, the discharge side pressure sensor 14 and the suction side pressure sensor 12 are respectively provided so as to detect the pressure. The four-way valve 13 is installed on the discharge side of the main compressor 11 so as to switch the flow path of the refrigerant according to the operation mode, and the outdoor heat exchanger 15 is connected to one side of the four-way valve 13. The other side of the four-way valve 13 is connected to the indoor heat exchanger 17, an expansion device 19 is provided between the outdoor heat exchanger 15 and the indoor heat exchanger 17 to expand the refrigerant under reduced pressure. .

On the other hand, the auxiliary compressor circuit 20 is formed between the main compressor 11 and the four-way valve 13 to selectively compress the refrigerant during the heating operation.

The auxiliary compression circuit 20 is arranged in the auxiliary flow passage 21 and one side connected to the discharge side of the main compressor 11 and the other side upstream of the four-way valve 13, and the auxiliary compressor 21 is arranged in the main compressor An auxiliary compressor 25 for compressing the refrigerant compressed in 11 is provided.

Inlet and outlet valves 23 and outlet side opening and closing valves 24 are respectively installed on the inlet and outlet sides of the auxiliary passage 21 so as to open and close the flow path, respectively. On the downstream side of 23, there is provided a pressure equalizing tank 27 which forms a temporary receiving space of the refrigerant therein. An oil return flow path 28 is formed at the bottom of the pressure equalizing tank 27 so that the oil inside can be returned to the main compressor 11. The oil return flow path 28 includes an oil return pipe 29 having one end connected to the bottom of the equalization tank 27 and the other end connected to the suction side of the main compressor 11, and an oil return pipe. A return irrigation valve 30 is provided to open and close the valve 29. Here, the oil return passage 28 may be formed of a capillary tube whose one end is connected to the bottom of the equalization tank 27 and the other end is connected to the suction side of the main compressor (11).

On the other hand, the control unit 31 is implemented in the form of a microcomputer with a built-in control program, the pressure difference calculation unit 33 to calculate the pressure difference by detecting the suction and discharge side pressure of the main compressor 11 during the heating operation And a suction side pressure sensor 12 and a discharge side pressure sensor 14 so that the refrigerant can be compressed by the auxiliary compressor 25 when the pressure difference calculated by the pressure difference calculating unit 33 is equal to or larger than a set value. The inlet side open valve 23 and the outlet side open valve 24 are electrically connected to each other.

By such a configuration, the control unit 31 controls the four-way valve 13 so that the flow path is switched so that the refrigerant compressed in the main compressor 11 flows to the indoor heat exchanger 17 during the heating operation, and the indoor heat exchanger 17 The refrigerant flowed into) expands under reduced pressure while performing heating and passing through the expansion device 19. The refrigerant passing through the expansion device (19) absorbs latent heat in the outdoor heat exchanger (15) and evaporates, and is sucked into the main compressor (11) via the four-way valve (13). At this time, the pressure difference calculation unit 33 calculates the difference between the suction side pressure and the discharge side pressure detected by the suction side pressure sensor 12 and the discharge side pressure sensor 14, respectively, and the control unit 31 calculates the calculated pressure. When the difference is less than the set value, the inlet side opening valve 23 and the outlet side opening and closing valve 24 are controlled to maintain the auxiliary flow passage 21 in a blocked state so that the refrigerant can be compressed in the main compressor 11.

On the other hand, when the result of the pressure difference calculated by the pressure difference calculation unit 33 is greater than or equal to the set value, the control unit 31 is the inlet side opening valve 23 and the outlet side opening and closing valve (23) so that the refrigerant flows into the auxiliary flow passage 21 ( In addition to controlling 24, the auxiliary compressor 25 is controlled to be driven. Accordingly, some of the refrigerant discharged from the main compressor 11 flows along the auxiliary flow path 21 and is temporarily accommodated in the equalization tank 27. At this time, the equalization tank 27 is to reduce the discharge pulsation of the refrigerant discharged from the main compressor 11 and to reduce the problems caused by the difference in the mass flow per unit time between the main compressor 11 and the auxiliary compressor (25). .

The refrigerant temporarily contained in the equalization tank 27 is sucked into the auxiliary compressor 25, compressed, flowed along the auxiliary flow path 21, joined with the refrigerant discharged from the main compressor 11, and then passed through the four-way valve 13. To the indoor heat exchanger (17). The refrigerant that has been heated in the indoor heat exchanger (17) is again sucked into the main compressor (11) through the expansion device (19) and the outdoor heat exchanger (15) via the four-way valve (13), and compressed and discharged. The heating process is performed while repeating the process.

On the other hand, if oil accumulates in the equalization tank 27 or more, the control unit 31 controls the return pipe opening and closing valve 30 to open the oil return pipe 29, and when the oil return pipe 29 is opened The oil inside the pressure equalizing tank 27 flows along the oil return pipe 29 and is sucked to the suction side of the main compressor 11 to be returned to the inside of the main compressor 11.

In the above-described and illustrated embodiments, for example, a case in which the pressure between the suction side and the discharge side of the main compressor is detected to calculate the difference between the high pressure and the low pressure, and the auxiliary compressor is configured to be compressed based on the calculation result during the heating operation. However, it may be configured to detect the outside temperature and to be compressed in the auxiliary compressor when the detected outside temperature is below the set temperature.

As described above, according to the present invention, a main compressor for compressing a refrigerant, a four-way valve disposed on the discharge side of the main compressor, an outdoor heat exchanger one side is connected to the four-way valve, one side is connected to the outdoor heat exchanger and the other side is four sides An indoor heat exchanger connected to the valve, an expansion device disposed between the outdoor heat exchanger and the indoor heat exchanger, an auxiliary flow path connected to the discharge side of the main compressor and the other side connected to an upstream side of the four-way valve, and disposed in the auxiliary flow path. And an auxiliary compressor for compressing the refrigerant, and an auxiliary compression circuit having an inlet opening / closing valve and an outlet side opening / closing valve disposed at each of the inlet and outlet sides of the auxiliary passage to open and close the auxiliary passage. Refrigerant is compressed by the main compressor and the sub-compressor to suppress the sudden increase in noise, and improve the efficiency and reliability of the compressor. An air conditioner with a subcompressible compression circuit is provided.

Claims (8)

A main compressor for compressing the refrigerant; A four-way valve disposed on the discharge side of the main compressor; An outdoor heat exchanger having one side connected to the four-way valve; An indoor heat exchanger having one side connected to the outdoor heat exchanger and the other side connected to the four-way valve; An expansion device disposed between the outdoor heat exchanger and the indoor heat exchanger; One side is connected to the discharge side of the main compressor and the other side is connected to the upstream side of the four-way valve, and an auxiliary compressor disposed in the auxiliary passage for compressing the refrigerant, respectively, on the inlet and outlet side of the auxiliary passage And an auxiliary compression circuit disposed at an opening side opening and closing valve to open and close the auxiliary passage. The method of claim 1, And an equalization tank disposed on a downstream side of the inlet-side opening / closing valve of the auxiliary passage to temporarily receive the refrigerant compressed by the main compressor. The method of claim 2, And an oil return passage configured to connect the suction tank of the equalization tank and the suction side of the equalization tank so that the oil of the equalization tank is returned to the main compressor. The method of claim 3, The oil return passage, one side is connected to the equalization tank and the other side is an oil return pipe connected to each other in communication with the suction side of the main compressor, and the return pipe opening and closing valve for opening and closing the oil return pipe An air conditioner having an auxiliary compression circuit. The method of claim 3, The oil return passage is an air conditioner having an auxiliary compression circuit, characterized in that it comprises a capillary tube. The method according to any one of claims 1 to 5, And a control unit for controlling the inflow side open valve and the outflow side open valve according to an operation mode. The method of claim 6, And a suction side pressure sensor and a discharge side pressure sensor for detecting pressures on the suction side and the discharge side of the main compressor, and a pressure difference calculation unit for calculating a pressure difference between the suction side and the discharge side of the main compressor, wherein the control unit is a heating operation. And an inlet-side open / close valve based on the calculation result of the pressure difference calculation unit. The method of claim 6, And an outside air temperature sensor for detecting an outside air temperature, wherein the control unit controls the inflow side opening valve and the outflow side opening valve to be opened, respectively, based on the detection result of the outside air temperature sensor during heating operation. Air conditioner with a compression circuit.

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