JP2001201217A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner in which heating can be performed, and moreover even during defrost operating and defrosting time can be shortened. SOLUTION: The air conditioner comprises a heat pump type refrigeration cycle for circulating refrigerant discharged from the discharge opening 2 of a compressor 1 via a four-way valve 5, an outdoor heat exchanger 8, an electronic expansion valve 7, an indoor heat exchanger 6, and the four-way valve 5 to the suction opening 3 of the compressor 1. The path of the outdoor heat exchanger 8 is divided into first and second paths 9, 10, and both paths are connected in series through an auxiliary electronic expansion valve 11. The other end of the first path 9 is connected with the electronic expansion valve 7, and the other end of the second path 10 is connected with the four-way valve 5. The discharge opening 2 of a compressor 1 is connected with the first and second paths 9, 10 through a hot gas bypass pipe 12 provided with an on/off valve 13 and the throttle opening of the electronic expansion valve 7 and the auxiliary electronic expansion valve 11 is controlled, depending on the operation mode along with opening/closing of the on/off valve 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner, and more particularly, to a structure of a refrigerant circuit for effectively performing a defrosting operation.

[0002]

2. Description of the Related Art As shown in FIG. 6, a conventional air conditioner has a compressor 1 for compressing a refrigerant vapor, and a compressor 5 for cooling or heating operation which discharges the refrigerant discharged from the compressor 1. A four-way valve that switches together, 8 is an outdoor heat exchanger provided with a blower fan (not shown) that is installed outside and exchanges heat with the outside air, 7 is an electronic expansion valve through which the refrigerant passes and expands,
Reference numeral 6 denotes a configuration of an indoor heat exchanger that is installed indoors and exchanges heat of refrigerant with indoor air. There are mainly two types of defrosting operation methods in this configuration: a reverse method and a hot gas bypass method. In the reverse method, the flow direction of the refrigerant is the same as that in the cooling operation, and the high-temperature and high-pressure refrigerant vapor discharged from the compressor 1 first flows into the outdoor heat exchanger 8,
The heat defrosts the outdoor heat exchanger 8 with the heat. In this case, the blower fan (not shown) is stopped so as not to send cool air into the room. In the hot gas bypass method,
The flow direction of the refrigerant is the same as in the heating operation, but a high-temperature and high-pressure refrigerant liquid flows into the outdoor heat exchanger 8 so that the electronic expansion valve 7 is not throttled, and the heat defrosts the outdoor heat exchanger 8. I do.

[0003]

However, in the above configuration, the high-temperature and high-pressure refrigerant for defrosting is supplied from one end of the outdoor heat exchanger regardless of whether the defrosting operation method is the reverse method or the hot gas bypass method. Due to the method of inflow, there is a problem that the outflow side is less likely to be defrosted than the inflow side, and it takes a long time to defrost. In addition, the reverse method has a problem that heating cannot be performed during the defrosting operation. In view of the above problems, an object of the present invention is to provide an air conditioner that can perform heating even during a defrosting operation and can shorten a defrosting time.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a refrigerant discharged from a discharge port of a compressor by using a four-way valve, an outdoor heat exchanger, an electronic expansion valve, an indoor heat exchanger, In an air conditioner including a heat pump refrigeration cycle circulating to a suction port of the compressor via a four-way valve, a path of the outdoor heat exchanger is divided into a first path and a second path, and both paths are assisted. The other end of the first path is connected to the electronic expansion valve via an electronic expansion valve,
The other end of the path is connected to the four-way valve, and the discharge port side of the compressor and the first path and the second path are connected by a hot gas bypass pipe having an on-off valve, The throttle opening of the electronic expansion valve and the auxiliary electronic expansion valve and the opening and closing of the on-off valve are controlled in accordance with the operation mode.

During the defrosting operation, the four-way valve is connected so that the discharge port side of the compressor is connected to the indoor heat exchanger, and the suction port side of the compressor is connected to the outdoor heat exchanger. First, the electronic expansion valve is fully opened, the auxiliary electronic expansion valve is throttled, the on-off valve is closed, and then, when the first pass defrost is completed, the electronic expansion valve is throttled. The auxiliary electronic expansion valve is fully opened and the on-off valve is opened.

During normal cooling operation and heating operation, the electronic expansion valve is throttled, the auxiliary electronic expansion valve is fully opened, and the on-off valve is closed.

Further, the hot gas bypass pipe is connected between the discharge port side of the compressor and the auxiliary electronic expansion valve and the second path.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the embodiments of the present invention shown in FIGS. 1
Is a compressor provided with a discharge port 2, a suction port 3, and an accumulator 4 for compressing refrigerant vapor; 5, a four-way valve for switching the flow of refrigerant discharged from the discharge port 2 of the compressor 1 in accordance with an operation mode; Is an indoor heat exchanger that is installed indoors and exchanges refrigerant with indoor air, 7 is an electronic expansion valve that can adjust the opening degree of a throttle through which the refrigerant passes and expands, and 8 is an outdoor expansion valve that is installed outside and This is an outdoor heat exchanger in which the heat exchange of the refrigerant is performed and the path is divided into a first path 9 and a second path 10.

The first path 9 and the second path 10 are connected in series via an auxiliary electronic expansion valve 11 which can adjust the opening degree of a throttle through which the refrigerant passes and expands. One end is connected to the electronic expansion valve 7, and the other end of the second path 10 is connected to the four-way valve 5.

Reference numeral 12 denotes a hot gas bypass pipe having an electromagnetic on-off valve 13 for connecting the discharge port 2 side of the compressor 1 with the auxiliary electronic expansion valve 11 and the second path 10. Is an outdoor unit control unit that controls the four-way valve 5, the electronic expansion valve 7, the auxiliary electronic expansion valve 11, and the on-off valve 13 according to an operation mode.

Next, the operation and effect of the above configuration will be described. First, the heating operation indicated by item No. 1 in FIGS. 1 and 2 will be described. The outdoor unit control unit 14 connects the four-way valve 5 to the discharge port 2 of the compressor 1 and the indoor heat exchanger 6, and connects the suction port 3 of the compressor 1 and the outdoor heat exchanger 8 to each other. The electronic expansion valve 7 is throttled, the auxiliary electronic expansion valve 11 is fully opened,
Control is performed to close the on-off valve 13. The high-temperature and high-pressure refrigerant vapor discharged from the discharge port 2 of the compressor 1 passes through the four-way valve 5, radiates heat to the indoor air in the indoor heat exchanger 6, condenses by heating, and is condensed by heating. The high-temperature and high-pressure refrigerant liquid is expanded by the electronic expansion valve 7 to become a low-temperature and low-pressure refrigerant liquid, and the low-temperature and low-pressure refrigerant liquid is supplied from the first path 9 to the second path 9 of the outdoor heat exchanger 8. The refrigerant flows into 10 and evaporates by absorbing heat from the outside air to become low-temperature low-pressure refrigerant vapor. The low-temperature low-pressure refrigerant vapor returns to the suction port 3 of the compressor 1 through the four-way valve 5.

Next, the defrosting operation shown in FIG. 3 and FIG. 4 and the item No. 2 and No. 3 in FIG. 2 will be described. First, as shown in item No. 2 in FIGS. 3 and 2, as a first step, the outdoor unit controller 14 connects the four-way valve 5 to the discharge port 2 of the compressor 1 and the indoor heat exchanger 6. Is switched to connect the suction port 3 of the compressor 1 to the outdoor heat exchanger 8, the electronic expansion valve 7 is fully opened, the auxiliary electronic expansion valve 11 is throttled, and the on-off valve 13 is opened. Is controlled to be closed. In this state, the high-temperature and high-pressure refrigerant vapor discharged from the discharge port 2 of the compressor 1 passes through the four-way valve 5,
The indoor heat exchanger 6 radiates heat to the indoor air, and condenses by heating to form a high-temperature and high-pressure refrigerant liquid. The high-temperature and high-pressure refrigerant liquid is not throttled by the electronic expansion valve 7 and is cooled. The liquid flows into the first path 9 of the outdoor heat exchanger 8 as it is, and the heat defrosts around the first path 9,
The high-temperature and high-pressure refrigerant liquid is expanded by the auxiliary electronic expansion valve 11 to become a low-temperature and low-pressure refrigerant liquid, and the low-temperature and low-pressure refrigerant liquid flows into the second path 10 of the outdoor heat exchanger 8 and enters the outside air. Then, the refrigerant evaporates and becomes low-temperature low-pressure refrigerant vapor by absorbing heat from the refrigerant, and the low-temperature low-pressure refrigerant vapor returns to the suction port 3 of the compressor 1 through the four-way valve 5.

Next, as shown by item 3 in FIGS. 4 and 2, as a second step, the four-way valve 5 is connected to the discharge port 2 of the compressor 1 and the With the heat exchanger 6 being connected, and the air conditioner being switched to connect the suction port 3 of the compressor 1 and the outdoor heat exchanger 8,
The electronic expansion valve 7 is throttled, the auxiliary electronic expansion valve 11 is fully opened, and the on-off valve 13 is controlled to be opened. In this state, the high-temperature and high-pressure refrigerant vapor discharged from the discharge port 2 of the compressor 1 passes through the four-way valve 5, radiates heat to the indoor air in the indoor heat exchanger 6, and is condensed by heating. The high-temperature and high-pressure refrigerant liquid becomes the low-temperature and low-pressure refrigerant liquid by being expanded by the electronic expansion valve 7, and the low-temperature and low-pressure refrigerant liquid becomes the first path 9 of the outdoor heat exchanger 8. And evaporates by absorbing heat from outside air to become low-temperature and low-pressure refrigerant vapor. On the other hand, a part of the high-temperature and high-pressure refrigerant vapor discharged from the discharge port 2 of the compressor 1 passes through the hot gas bypass pipe 12 from the auxiliary electronic expansion valve 11 and the second path 10 to the second path. The heat flows into the path 10 and the heat defrosts around the second path 10. As a result of the defrosting, the temperature of the high-temperature and high-pressure refrigerant vapor is lowered, mixed with the low-temperature and low-pressure refrigerant vapor from the first path 9 and returned to the suction port 3 of the compressor 1 through the four-way valve 5.

By connecting the hot gas bypass pipe 12 between the discharge port 2 of the compressor 1 and the auxiliary electronic expansion valve 11 and the second path 10, the hot gas bypass pipe 12 is connected to the hot gas bypass pipe 12. Although the inflowing high-temperature and high-pressure refrigerant vapor does not have to pass through the auxiliary electronic expansion valve 11 having a slight flow path resistance even though it is fully opened, the defrost around the second path 10 is more effectively performed. be able to.

Next, the cooling operation indicated by item 4 in FIGS. 5 and 2 will be described. The outdoor unit controller 14 connects the four-way valve 5 to the discharge port 2 of the compressor 1 and the outdoor heat exchanger 8, and connects the suction port 3 of the compressor 1 and the indoor heat exchanger 6 to each other. The electronic expansion valve 7 is throttled, the auxiliary electronic expansion valve 11 is fully opened, and the on-off valve 13 is controlled to be closed. The high-temperature and high-pressure refrigerant vapor discharged from the discharge port 2 of the compressor 1 passes through the four-way valve 5 and flows from the first path 9 to the second path 10 of the outdoor heat exchanger 8 to radiate heat to the outside air. As a result, the refrigerant liquid condenses into a high-temperature and high-pressure refrigerant liquid, and the high-temperature and high-pressure refrigerant liquid expands at the electronic expansion valve 7 to become a low-temperature and low-pressure refrigerant liquid. , And cools and evaporates by absorbing heat from room air to become low-temperature low-pressure refrigerant vapor. The low-temperature low-pressure refrigerant vapor returns to the suction port 3 of the compressor 1 through the four-way valve 5.

[0016]

As described above, according to the present invention,
The air conditioner can perform heating during the defrosting operation and can shorten the defrosting time.

[Brief description of the drawings]

FIG. 1 is a diagram showing a refrigerant circuit diagram and a control block diagram of an embodiment of an air conditioner according to the present invention, showing a heating operation state.

FIG. 2 is an explanatory diagram showing the contents of control of an embodiment of the air conditioner according to the present invention.

FIG. 3 is a diagram showing a refrigerant circuit diagram and a control block diagram of an embodiment of the air conditioner according to the present invention in a mixed state, showing a defrosting operation state in a first pass.

FIG. 4 is a diagram showing a refrigerant circuit diagram and a control block diagram of an embodiment of the air conditioner according to the present invention in a mixed state, showing a defrosting operation state in a second pass.

FIG. 5 is a diagram showing a refrigerant circuit diagram and a control block diagram of one embodiment of the air conditioner according to the present invention, showing a cooling operation state.

FIG. 6 is a refrigerant circuit diagram of a conventional air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Discharge port 3 Suction port 5 Four-way valve 6 Indoor heat exchanger 7 Electronic expansion valve 8 Outdoor heat exchanger 9 1st pass 10 2nd pass 11 Auxiliary electronic expansion valve 12 Hot gas bypass pipe 13 On-off valve

Claims (4)

[Claims] 1. A refrigerant discharged from a discharge port of a compressor,
An air conditioner including a four-way valve, an outdoor heat exchanger, an electronic expansion valve, an indoor heat exchanger, and a heat pump refrigeration cycle that circulates to the suction port of the compressor via the four-way valve. Dividing the path into a first path and a second path, connecting both paths in series via an auxiliary electronic expansion valve, connecting the other end of the first path to the electronic expansion valve,
The other end of the path is connected to the four-way valve, and the discharge port side of the compressor and the first path and the second path are connected by a hot gas bypass pipe having an on-off valve, An air conditioner characterized by controlling a throttle opening degree of the electronic expansion valve and the auxiliary electronic expansion valve and opening and closing of the on-off valve in accordance with an operation mode. 2. The four-way valve so that a discharge port side of the compressor is connected to the indoor heat exchanger and a suction port side of the compressor is connected to the outdoor heat exchanger during a defrosting operation. First, the electronic expansion valve is fully opened, the auxiliary electronic expansion valve is throttled, and the on-off valve is closed. Next, when the first pass defrosting is completed, the electronic expansion valve is throttled. 2. The air conditioner according to claim 1, wherein the auxiliary electronic expansion valve is fully opened, and the on-off valve is opened. 3. The air according to claim 1, wherein during normal cooling operation and heating operation, the electronic expansion valve is throttled, the auxiliary electronic expansion valve is fully opened, and the on-off valve is closed. Harmony machine. 4. The hot gas bypass pipe according to claim 1, wherein the hot gas bypass pipe is connected between a discharge port side of the compressor and the space between the auxiliary electronic expansion valve and the second path. Air conditioner.