KR102256588B1 - Air conditioning system using heat pump - Google Patents

Abstract

The present invention provides an air conditioning system using a heat pump, which comprises: a compression unit which compresses low-temperature and low-pressure gaseous refrigerant into high-temperature and high-pressure gaseous refrigerant and provides the compressed refrigerant; a first coil which is connected to the compression unit and a flow path through which the refrigerant flows, and condenses or evaporates the refrigerant flowing according to a flow direction of the refrigerant changed by a cooling operation or a heating operation; a second coil which is connected in parallel with the first coil and the flow path through which the refrigerant flows, and reheats supply air with condensation heat of the refrigerant selectively introduced according to a cooling load and the humidity of the supply air; a third coil which is connected to the first coil and the second coil by the flow path through which the refrigerant flows, and condenses or evaporates the refrigerant flowing according to the flow direction of the refrigerant changed by the cooling operation or the heating operation; an expansion valve which is provided at one side of the third coil to expand the condensed refrigerant to a low temperature and low pressure, and provides the refrigerant to the third coil; a four-way flow path switching valve which is connected to refrigerant paths connected to inlet and discharge sides of the compression unit, and refrigerant paths connected to one side of the first coil and the other side of the third coil, and changes the flow direction of the refrigerant according to the cooling operation and the heating operation; and a three-way control valve which is provided at a branch point at which a fourth refrigerant path branches in the first refrigerant path, and controls the opening degree of the fourth refrigerant path according to the required amount of reheat of the supply air. Therefore, precise temperature control is possible.

Description

Air conditioning system using heat pump

The present invention relates to an air conditioning system, and more particularly, by controlling the flow amount of the refrigerant flowing to the second coil in stages according to the reheat amount of supply air, it is possible to precisely cope with the reheating load, and separate separate for defrosting. It relates to an air conditioning system using a heat pump in which defrost is eliminated by heat of a refrigerant compressed without a heat source.

In general, a thermo-hygrostat maintains indoor temperature, humidity, airflow, etc. in a state suitable for the purpose of use, and performs cooling operation, cooling dehumidification and reheat operation, constant temperature heating and humidification operation according to the necessity. In order to maintain the indoor space at the desired temperature and humidity, the thermo-hygrostat includes a cooling coil, a heating coil, and a humidifier. How precisely controls the indoor temperature and humidity depending on how each method is combined and operated. And driving costs are different.

Common methods are a cooling operation method using an air-cooled and water-cooled refrigeration system, a heating and reheating method using an electric heater or hot water coil, and a humidification method using electricity or steam.

In addition, in order to save energy during reheating, a hot gas reheating method using high temperature and high pressure refrigerant gas sent from the compressor to the condenser is also used. The conventional hot gas reheating method closes the refrigerant flow path sent to the condenser at the same time as reheating, so that when the electronic valve is operated, a shock occurs due to a rapid change in the flow of refrigerant in the refrigerant flow path, and the electronic valve and the compressor are frequently burned out by such shock. .

Recently, there are many cases of cooling and heating buildings using a cooling and heating method using a heat pump refrigeration cycle. However, in the constant temperature and humidity field, it is difficult to operate continuous constant temperature heating during defrost operation due to the frost of the outdoor unit in the case of winter heating operation in the constant temperature and humidity field. In the field of humidity and humidity, the heat pump heating method was not adopted.

In order to solve the above problems, a compressor that compresses the refrigerant to high temperature and high pressure, a condenser that condenses the refrigerant compressed by the compressor to high temperature and high pressure, and expands the refrigerant condensed by the condenser to expand to low temperature and low pressure. An expansion valve to allow cooling, an evaporator for cooling by absorbing external heat by the low-temperature and low-pressure refrigerant expanded by the expansion valve, and an evaporator receiving direct supply of the high-temperature and high-pressure refrigerant compressed by the compressor. In a heat pump having a reheating coil for reheating cooled and dehumidified indoor discharge air, the reheating coil is divided into a plurality of reheating coils and has an electromagnetic valve for each reheating coil, and has an electromagnetic valve in a refrigerant flow path connected from the compressor to the condenser, When the temperature of the indoor discharged air cooled and dehumidified by the evaporator is lower than the required indoor discharge temperature and reheating operation, the hot gas refrigerant discharged from the compressor is opened through a refrigerant flow channel among a plurality of parallel divided reheat coils to discharge indoor discharged air. At this time, the hot gas refrigerant flow path discharged to the condenser is kept open, and then the remaining refrigerant flow paths installed in the reheating coil are opened so that the hot gas refrigerant is discharged to all of the plurality of reheating coils to heat the indoor discharged air, When the refrigerant passage is switched and controlled to close the refrigerant passage discharged to the condenser, and the refrigerant passages of the reheating coil are sequentially opened during the cooling dehumidification and reheat operation, when all of the refrigerant passages of the plurality of reheat coils are opened. A thermo-hygrostat using a heat pump, characterized in that the refrigerant flow path discharged from the compressor to the condenser is closed in stages, thereby controlling the shock applied to the device to be relieved.

However, in the prior art, a plurality of reheating coils are arranged and each reheating coil has an electronic valve, so when manufacturing and assembling work is inferior due to the complicated structure, the manufacturing cost is increased, and the precise temperature according to the required amount of reheating is not achieved, causing a fire. There was a possibility that it could happen.

As a conventional technique, Korean Laid-Open Patent Publication No. 10-2010-0137050 (2010.12.30) may be referred to.

The present invention controls the flow amount of the refrigerant flowing to the second coil in stages according to the reheat amount of the supply air, so that it is easy to cope with the precise reheat load, and the defrost is solved by the heat of the compressed refrigerant without a separate heat source for defrost. Its purpose is to provide an air conditioning system using a heat pump.

The air conditioning system using a heat pump according to the present invention includes a first compressor that constantly compresses and discharges a low-temperature and low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant, and selectively converts a low-temperature and low-pressure gaseous refrigerant to a high-temperature and high-pressure gaseous refrigerant according to cooling and heating loads. A compression unit including a second compressor that compresses and discharges the gaseous refrigerant in the compressed air, and a refrigerant flowing according to the flow direction of the refrigerant changed by a cooling operation or a heating operation, which is connected to a flow path through which the compression unit and the refrigerant flow. A first coil that condenses or evaporates, and a second coil that is connected to a flow path through which the first coil and the refrigerant flow, and reheats the supply air with condensation heat of the refrigerant selectively introduced according to the cooling load and the humidity of the supply air, and the second coil. A third coil that is connected to the first coil and the second coil through a flow path through which the refrigerant flows, condenses or evaporates the refrigerant flowing according to the flow direction of the refrigerant changed by the cooling operation or the heating operation, and one side of the third coil An expansion valve provided to expand the condensed refrigerant to reduce pressure to low temperature and low pressure, and provide the third coil, a first refrigerant passage connecting the discharge side of the compression unit to one side of the first coil, and the first A second refrigerant passage connecting the other side of the coil and one side of the third coil, a third refrigerant passage connecting the other side of the third coil and the inlet side of the compression unit, and branching from the first refrigerant passage, the A fourth refrigerant passage connecting one side of the second coil, a fifth refrigerant passage connecting the other side of the second coil and the second refrigerant passage, and a first refrigerant passage on the discharge side of the compressor are connected to the first port, The first refrigerant flow path on one side of the first coil is connected to the fourth port, the third refrigerant flow path is connected to the second port, and the fourth refrigerant flow path is connected to the third port. It is connected to a four-way flow path switching valve that selectively changes the flow direction of the refrigerant, and a fifth refrigerant flow path through which the refrigerant flows through the first coil and a fifth refrigerant flow path through which the refrigerant flows through the first coil. And a three-way control valve that allows the refrigerant to flow into the second coil in stages according to the amount of reheating.

delete

And an oil separator provided on the discharge side of the compression part of the first refrigerant flow path according to the present invention, and resupply to the compression part after filtering and recovering the compressor oil from the refrigerant by introducing the refrigerant discharged from the compression part. have.

In addition, while branching from the outlet side of the compression unit of the first refrigerant flow channel according to the present invention, it is connected to the other side of the first coil of the second refrigerant flow channel, and is disposed close to the first coil, and selectively the compression unit It may include a sixth refrigerant passage for defrosting the first coil with the heat of the refrigerant discharged from.

In addition, it may include a liquid separator that is provided at the inlet end of the compression unit of the third refrigerant flow path according to the present invention to allow only gaseous refrigerant to flow into the compression unit.

The air conditioning system using the heat pump according to the present invention has the following effects.

First, the amount of refrigerant flowing to the reheated coil is controlled step by step by a three-way control valve, enabling precise temperature control, and there is no need to have a plurality of coils and valves as in the prior art for stepwise temperature control. In addition to reducing manufacturing cost, workability is improved.

Second, during the heating operation, defrost is performed by the heat of the high-temperature gas phase refrigerant discharged from the compression unit by the outdoor unit coil, so that a separate heating unit for defrosting the outdoor unit coil is not required.

1 is an exemplary view showing a refrigerant circulation flow path of an air conditioning system using a heat pump according to an embodiment of the present invention.
2 is an exemplary view showing a circulation path of a refrigerant in a cooling operation mode of an air conditioning system using a heat pump according to an embodiment of the present invention.
3 is an exemplary view showing a circulation path of a refrigerant in a heating operation mode of an air conditioning system using a heat pump according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventors appropriately explain the concept of terms in order to explain their own invention in the best way. Based on the principle that it can be defined, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention.

Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and do not represent all the technical ideas of the present invention. It should be understood that there may be variations.

The present invention controls the flow amount of the refrigerant flowing to the second coil in stages according to the reheat amount of the supply air, enabling precise coping with the reheat load, and defrosting by heat of the compressed refrigerant without a separate heat source for defrosting. It relates to an air conditioning system using a heat pump, and its implementation will be described in more detail with reference to the drawings as follows.

An air conditioning system using a heat pump according to an embodiment of the present invention with reference to FIG. 1 includes a compression unit 10, a first coil 20, a second coil 30, a third coil 40, and a four-way flow path switching valve. 60 and a three-way control valve 70, wherein the compression unit 10 compresses and discharges a gaseous refrigerant having a low temperature and low pressure to a high temperature and high pressure.

At this time, the compression unit 10 according to an embodiment of the present invention includes a first compressor 11 for compressing and discharging a low temperature and low pressure gaseous refrigerant into a high temperature and high pressure gaseous refrigerant at all times while driving the air conditioning system, and cooling and And a second compressor 12 for selectively compressing and discharging a low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant according to the amount of heating load.

The first compressor 11 and the second compressor 12 of the compression unit 10 are preferably operated by an inverter method, and the first compressor 11 or the second compressor 12 is performed during the period when the load is relatively small. It can be operated independently, and both the first compressor 11 and the second compressor 12 can be operated in summer and winter seasons with relatively high loads.

In addition, the first coil 20 is provided in an outdoor unit to condense or evaporate the refrigerant according to the flow direction of the refrigerant that is changed by a cooling operation or a heating operation. The refrigerant flowing along with the outside air passing through the coil is exchanged with each other, so that the heat of condensation or evaporation of the refrigerant is conducted to the outside air, and the refrigerant is condensed or evaporated.

The second coil 30 is connected to one side of the first coil 20 through a flow path through which the refrigerant flows, and is preferably connected by a three-way control valve 70, and the second coil 30 is optional. The refrigerant is introduced into the room to exchange heat with the refrigerant with the air supply supplied to the room, and the air supply is heated with the heat of condensation of the refrigerant.

At this time, the second coil 30 is preferably provided in the indoor unit, and as some of the refrigerant flowing through the first coil 20 diverges and flows into the second coil 30, the third coil 40 By cooling, condensation heat of the refrigerant is provided to the air supply air supplied to the room to heat the air supply, thereby enabling precise cooling operation.

The refrigerant flowing into the second coil 30 flows through the opening and closing of the three-way control valve 70, and a description of the three-way control valve 70 will be described in more detail below.

In addition, the third coil 40 is also preferably provided in the indoor unit, and the third coil 40 is connected to the first coil 20 and the second coil 30 through a flow path through which a refrigerant flows, The refrigerant is condensed or evaporated according to the flow direction of the refrigerant changed by the cooling operation or the heating operation.

At this time, the third coil 40 exchanges heat with each other with the refrigerant flowing through the coil and the supply air passing through the outside of the coil, so that the heat of condensation or evaporation of the refrigerant is conducted to the supply air, thereby condensing or evaporating the refrigerant. , The supply air is heated and cooled by the heat of condensation and evaporation of the refrigerant, thereby heating or cooling the room.

The compression unit 10, the first coil 20, the second coil 30, and the third coil 40 are connected to each other by the first refrigerant passage 100 to the seventh refrigerant passage 700, The first refrigerant flow path 100 connects the discharge side of the compression part 10 and the first coil 20 so that the refrigerant flows along the first refrigerant flow path 100 from the discharge side of the compression part 10. It flows to the first coil 20.

At this time, an oil separator 110 is provided on the discharge side of the compression unit 10 of the first refrigerant flow path 100, and the oil separator 110 flows in the refrigerant discharged from the compression unit 10, Separated and recovered, and the oil recovered from the oil separator 110 flows back into the compression unit 10 along the oil flow channel connected to the third refrigerant flow channel 300 connected to the inlet side of the compression unit 10 As a result, it is provided as a lubricant for the first and second compressors 11 and 12.

Here, a check valve is provided on the outlet side of the oil separator 110 of the first refrigerant flow path 100 to prevent reverse flow of the refrigerant compressed with high temperature and high pressure discharged from the compression unit 10.

And the second refrigerant passage 200 connects the first coil 20 and the third coil 40, so that the refrigerant flows from the first coil 20 along the second refrigerant passage 200. It flows to the third coil 40.

Here, a first expansion valve 51 is provided at one side of the third coil 40 of the second refrigerant flow path 200, and the first expansion valve 51 flows into the third coil 40. The former refrigerant is expanded (reduced) to a state capable of absorbing sufficient heat, so that the expanded (reduced) refrigerant is introduced into the third coil 40.

In addition, a solenoid valve for selectively opening and closing the second refrigerant passage 200 is provided near a point where the first expansion valve 51 is provided among the second refrigerant passages 200, and the second refrigerant passage 200 ), while branching from the inlet end of the solenoid valve and joining the outlet end of the solenoid valve, the second return refrigerant passage 201 is provided with the refrigerant flow path 201 based on the solenoid valve. The flow direction is reversely flowed, and a check valve is provided to flow only the refrigerant flowing out of the third coil 40 and flowing back to the first coil 20.

In addition, a check valve is provided in the vicinity of the first coil 20 of the second refrigerant passage 200 to prevent reverse flow of the refrigerant flowing from the first coil 20 to the third coil 40, Among the second refrigerant passages 200, a third return refrigerant passage 202 branched from the inlet end side of the check valve and joined to the outlet end side of the check valve is provided. The second expansion valve 52 is provided, and when the refrigerant flows from the first coil 20 to the third coil 40, it flows along the second refrigerant flow path 200 in which a check valve is formed. , When flowing from the third coil 40 to the first coil 20, it flows along the third return refrigerant flow path 202 provided with the second expansion valve 52.

And the third refrigerant flow path 300 connects the other side of the third coil 40 and the four-way flow path switching valve 60, so that the refrigerant flows along the third refrigerant flow path 300 to the third coil 40 It flows to the four-way flow path switching valve (60).

The four-way flow path switching valve 60 is configured to switch the flow condensation of the refrigerant, and includes first to fourth ports, and the first port is selectively connected to a second port or a fourth port, and the third The port is selectively connected to the second port or the fourth port in response to the operation of the first port.

At this time, the first refrigerant flow path 100 on the discharge side of the compressor 10 is connected to the first port of the four-way flow path switching valve 60, and the first coil ( 20) The first refrigerant flow path 100 on one side is connected, and the third refrigerant flow path 300 is connected to the second port of the four-way flow channel switching valve 60, and A fourth refrigerant flow path 400 is connected to the 3 port.

Therefore, when the first port and the fourth port are connected by selective switching of the four-way flow path switching valve 60, the second port is connected to the third port, so that the first refrigerant flow path on the discharge side of the compressor 10 (100), the first refrigerant flow path 100 at one side of the first coil 20 is connected, and the flow path of the refrigerant to which the third refrigerant flow path 300 and the fourth refrigerant flow path 400 are connected. And, when the first port and the second port are connected by selective switching of the four-way flow path switching valve 60, the third port is connected to the fourth port, so that the first refrigerant on the discharge side of the compressor 10 The flow path of the refrigerant to which the flow path 100 and the third refrigerant flow path 300 are connected, and the fourth refrigerant flow path 400 and the first refrigerant flow path 100 at one side of the first coil 20 are connected. To achieve.

In addition, the fourth refrigerant flow path 400 connects the four-way flow path switching valve 60 and the inlet side of the compression unit 10 to connect the inlet side of the compression unit 10 so that the refrigerant is converted into the fourth refrigerant. It flows from the four-way flow path switching valve 60 along the flow path 400 to the inlet side of the compression unit 10.

Here, a liquid separator 310 is provided at the inlet end of the compression part 10 of the fourth refrigerant flow path 400, and the liquid separator 310 is the compression part 10 through the fourth refrigerant flow path 400. Among the refrigerants flowing into the gas phase, only the gaseous refrigerant is introduced into the compression unit 10.

In addition, the fifth refrigerant passage 500 is branched from the first refrigerant passage 100, and among the first refrigerant passages 100, a fourth port of the four-way passage switching valve 60 and the first coil ( While branching between 20), the refrigerant is connected to the second coil 30 so that the refrigerant flows from the four-way channel switching valve 60 to the second coil 30 along the fifth refrigerant channel 500. .

At this time, a check valve is provided in the fifth refrigerant flow path 500 to prevent reverse flow of the refrigerant flowing from the four-way flow path switching valve 60 to the second coil 30.

In addition, a three-way control valve 70 is provided at a branch point of the first refrigerant passage 100 at which the fifth refrigerant passage 500 is branched, and the three-way control valve 70 includes the first refrigerant passage 100 and the 5 Controls the opening of the refrigerant flow path 500 in stages.

Therefore, since the opening and closing of the fifth refrigerant passage 500 is controlled in accordance with the amount of reheating of the supply air required, the three-way control valve 70 enables precise temperature control. It is preferable that the opening and closing of the first refrigerant passage 100 connected to the refrigerant passage 500 is controlled stepwise with the fifth refrigerant passage 500 by the three-way control valve 70.

In addition, at a point in the first refrigerant passage 100 where the three-way control valve 70 is provided, a first return refrigerant passage in parallel with the first refrigerant passage 100 so as not to pass through the three-way control valve 70 101 is formed, and the refrigerant flowing out from one side of the first coil 20 flows through the first return refrigerant flow path 101 without passing through the three-way control valve 70.

At this time, a check valve and a solenoid valve are provided together on the first return refrigerant flow path 101, so that the refrigerant flowing out of the first coil 20 flows along the first return refrigerant flow path 101.

And the sixth refrigerant passage 600 connects the second coil 30 and the second refrigerant passage 200, so that the refrigerant flows from the second coil 30 to the second refrigerant passage 200. .

At this time, a check valve is provided in the sixth refrigerant passage 600 so that the refrigerant flowing out of the second coil 30 does not flow back and flows into the second refrigerant passage 200.

In addition, the air conditioning system using a heat pump according to an embodiment of the present invention is provided with a seventh refrigerant passage 700, the seventh refrigerant passage 700 is the compression unit ( While branching from the outlet side of 10), it is connected to the first coil 20 side of the second refrigerant flow path 200, so that the refrigerant discharged from the compression unit 10 does not pass through the first coil 20, It is bypassed to flow along the second refrigerant flow path 200 immediately.

Therefore, in the air conditioning system using a heat pump according to an embodiment of the present invention, the refrigerant discharged from the compression unit 10 through the four-way flow path switching valve 60 together with the three-way control valve 70 is the first Among the coil 20 and the third coil 40, the flow flows to the first coil 20 or the third coil 40, and the flow direction of the refrigerant is determined according to the operation mode of the system. .

As an example, an air conditioning system using a heat pump according to an embodiment of the present invention will be described with reference to a cooling operation mode and a heating operation mode, which are typical operation modes.

First, referring to FIG. 2, in the cooling operation mode of the present invention, the first port and the fourth port of the four-way flow path switching valve 60 are connected, the second port is connected to the third port, and the four-way flow path is switched. A connection path between the first port and the fourth port of the valve 60, the first refrigerant passage 100 on the discharge side of the compressor 10 and the first refrigerant passage 100 on one side of the first coil 20 are connected. And, the third refrigerant flow path 300 and the fourth refrigerant flow path 400 are connected by a connection between the second port and the third port of the four-way flow path switching valve 60.

At this time, the high-temperature, high-pressure refrigerant compressed by the compression unit 10 is discharged from the compression unit 10 and flows into one side of the first coil 20 along the first refrigerant flow path 100, and the first The high-temperature, high-pressure refrigerant introduced into the first coil 20 is condensed by heat exchange with the outside air in the first coil 20 and then flows out to the other side of the first coil 20, and the second refrigerant flow path ( It flows along 200 to one side of the third coil 40.

Here, the refrigerant flowing along the second refrigerant flow path 200 flows into the first expansion valve 51 before flowing into one side of the third coil 40, and flows into the first expansion valve 50. The refrigerant is expanded (reduced) to a low temperature and low pressure, and then flows into one side of the third coil 40 through the second refrigerant flow path 200, and the refrigerant introduced into the third coil 40 is evaporated. The supply air is cooled by evaporation heat, and the cooled supply air is provided to the room for cooling.

And the refrigerant flowing out to the other side of the third coil 40 flows along the third refrigerant flow path 300 to the second port of the four-way flow path switching valve 60, and A connection path between the second port and the third port forms a refrigerant circulation path flowing to the inlet side of the compression unit 10 along the fourth refrigerant flow path 400.

Here, the three-way control valve 70 selectively controls the opening of the fifth refrigerant passage 500 in stages according to the cooling load and the temperature of the supply air, and the refrigerant compressed by the compression unit 10 is the first It flows into the first coil 20 along the refrigerant flow path 100, and the three-way control valve 70 changes the fifth refrigerant flow path compared to the opening of the first refrigerant flow path 100 according to the cooling load and the temperature of the supply air. By controlling the opening of 500 in stages, the refrigerant flows into the second coil 30 together with the first coil 20, and the supply air is reheated by the refrigerant condensation action of the second coil 30.

At this time, the first refrigerant flow path 100 is controlled by the three-way control valve 70 to control the fourth refrigerant flow path 400 and the open path, thereby enabling precise temperature control step by step.

3, in the heating operation mode of the present invention, the first port and the second port of the four-way flow path switching valve 60 are connected, the third port is connected to the fourth port, and the four-way flow path is switched. A connection path between the first port and the second port of the valve 60, the first refrigerant flow path 100 on the discharge side of the compressor 10, and the third refrigerant flow path 300 are connected, and the four-way flow path switching valve ( The fourth refrigerant passage 400 and the first refrigerant passage 100 at one side of the first coil 20 are connected through a connection path between the third and fourth ports of 60).

The discharge side of the compression unit 10 is connected to the other side of the third coil 40 through the four-way flow path switching valve 60, and the inlet side of the compression unit 10 is connected to one side of the first coil 20 and Connected.

At this time, the high-temperature, high-pressure refrigerant compressed by the compression unit 10 is discharged from the compression unit 10 and flows along the first refrigerant flow path 100, while a third refrigerant through the four-way flow path switching valve 60 The high-temperature, high-pressure refrigerant flowing through the flow path 300 to the other side of the third coil 40 and flowing into the third coil 40 is condensed in the third coil 40 due to heat exchange with the supply air. Thereafter, it flows out to one side of the third coil 40 and flows into the other side of the first coil 20 along the second refrigerant flow path 200.

Here, the refrigerant compressed by the compression unit 10 flows out to the third coil 40 and provides heat to the supply air with condensation heat generated while condensing in the third coil 40, so that the heated supply air is indoors. It is provided as a heating system.

In addition, the refrigerant flowing out to one side of the third coil 40 is introduced into the first expansion valve 51, and the refrigerant introduced into the first expansion valve 51 is expanded (depressurized) to a low temperature and a low pressure, After joining the second refrigerant passage 200 along the second return refrigerant passage 201, the second refrigerant passage 200 flows into the other side of the first coil 20.

At this time, the refrigerant flowing along the second refrigerant flow path 200 passes through the third return refrigerant flow path 202 provided with the second expansion valve 52 before flowing into the first coil 20. The refrigerant flowing into the second expansion valve 52 by the second expansion valve 52 is once again expanded (reduced) to a low temperature and low pressure, and then the second refrigerant flow passage The refrigerant introduced into the first coil 20 through 200 and introduced into the first coil 20 absorbs heat from outside air by evaporation heat generated while evaporating.

In addition, the refrigerant flowing out of the first coil 20 flows to the fourth port of the four-way flow path switching valve 60, and the third port and the fourth port of the four-way flow path switching valve 60 are connected to each other. A refrigerant circulation path flowing to the inlet side of the compression unit 10 along the fourth refrigerant flow path 400 is formed.

Here, when defrosting is required in the first coil 20 where the evaporation of the refrigerant occurs, the seventh refrigerant flow path 700 is selectively opened, so that a part of the high-temperature and high-pressure refrigerant discharged from the compression unit 10 is transferred to the seventh. It flows into the first coil 20 through the refrigerant passage 700 through the second refrigerant passage 200 and defrosts the first coil 20 with heat of the refrigerant.

The present invention has been described with reference to the embodiments shown in the drawings, but these are merely exemplary, and those of ordinary skill in the art will appreciate that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

10: compression unit
20: first coil
30: second coil
40: third coil
50: first expansion valve
51: second expansion valve
53: third expansion valve
60: four-way flow path switching valve
70: three-way control valve
100: first refrigerant flow path
200: second refrigerant flow path
300: 3rd refrigerant flow path
400: 4th refrigerant flow path
500: 5th refrigerant flow path
600: 6th refrigerant flow path

Claims (5)

A first compressor that constantly compresses and discharges the low-temperature and low-pressure gaseous refrigerant into a high-temperature and high-pressure gaseous refrigerant, and a second compressor that selectively compresses and discharges the low-temperature and low-pressure gaseous refrigerant into a high-temperature and high-pressure gaseous refrigerant according to the amount of cooling and heating load. Compression unit including;
A first coil connected to the compression unit through a flow path through which the refrigerant flows, and condensing or evaporating the refrigerant flowing according to the flow direction of the refrigerant changed by a cooling operation or a heating operation;
A second coil connected to the first coil through a flow path through which the refrigerant flows, and reheating the supply air with condensation heat of the refrigerant selectively introduced according to the cooling load and the humidity of the supply air;
A third coil connected to the first coil and the second coil through a flow path through which the refrigerant flows, and condensing or evaporating the refrigerant flowing according to the flow direction of the refrigerant changed by a cooling operation or a heating operation;
An expansion valve provided on one side of the third coil to expand the condensed refrigerant to reduce pressure to a low temperature and low pressure, and then provide the condensed refrigerant to the third coil;
A first refrigerant passage connecting the discharge side of the compression unit and one side of the first coil;
A second refrigerant passage connecting the other side of the first coil and one side of the third coil;
A third refrigerant passage connected to the other side of the third coil and the inlet side of the compression unit;
A fourth refrigerant passage branching from the first refrigerant passage and connecting one side of the second coil;
A fifth refrigerant passage connecting the other side of the second coil and a second refrigerant passage;
A first refrigerant flow path on the discharge side of the compressor is connected to a first port, a first refrigerant flow path on one side of the first coil is connected to a fourth port, and the third refrigerant flow path is connected to a second port, and a third port A fourth refrigerant flow path is connected to the four-way flow path switching valve for selectively changing the flow direction of the refrigerant according to the cooling and heating operations; And
It is connected to the first refrigerant flow path through which the refrigerant flows through the first coil and the fifth refrigerant flow path through which the refrigerant flows through the second coil, so that the refrigerant flows into the second coil in stages according to the amount of reheating required for supply air An air conditioning system using a heat pump comprising a three-way control valve.
delete The method according to claim 1,
It is provided on the discharge side of the compression part of the first refrigerant flow path,
An air conditioning system using a heat pump including an oil separator for resupplying the refrigerant discharged from the compression unit to the compression unit after filtering and recovering the compressor oil from the refrigerant.
The method according to claim 1,
While branching from the outlet side of the compression unit among the first refrigerant flow channels, it is connected to the other side of the first coil among the second refrigerant flow channels, and the high-temperature and high-pressure refrigerant discharged from the compression unit during a heating operation is transferred to the other side of the first coil. An air conditioning system using a heat pump including a seventh refrigerant flow passage through which the first coil is defrosted with heat of refrigerant.
The method according to claim 1,
An air conditioning system using a heat pump including a liquid separator provided at an inlet end of the compression unit of the third refrigerant flow path and allowing only gaseous refrigerant to flow into the compression unit.

Images