JPH035680A - Air conditioner - Google Patents

Abstract

PURPOSE:To perform a heating operation while performing a defrosting operation by a method wherein in case of performing a defrosting operation, a part of refrigerant discharged out of a compressor passes through the first refrigerant passage, thereafter the refrigerant passes in the second refrigerant passage through a metering device and the remaining refrigerant passes in the second refrigerant passage through an indoor heat exchanger and an expansion valve. CONSTITUTION:In case of performing a defrosting operation, a part of refrigerant vapor of high temperature and high pressure discharged out of a compressor 1 passes from a four- way valve 4 via a three-way valve 8 and further passes through the first refrigerant passage 6, thereafter the refrigerant passes through a metering device 10, its pressure is reduced, the refrigerant temperature is low and the refrigerant pressure is low. The refrigerant enters the second refrigerant passage 7. At this time, an outdoor heat exchanger 3 is heated by refrigerant of high temperature and high pressure passing through the passage 6 and then frosts adhered to the heat exchanger is melted. Remaining refrigerant vapor of high temperature and high pressure discharged out of the compressor 1 passes through a four-way valve 4, radiates heat into an interior air through an indoor heat exchanger 2 and the refrigerant is condensed and liquified, thereafter a pressure of the refrigerant is reduced by an expansion valve 5 to get its low temperature and low pressure and then the refrigerant may flow into the second refrigerant passage 7. During this period, a heating operation is carried out. The refrigerant of low temperature and low pressure flowed into the passage 7 is evaporated in the passage 7, then the refrigerant returns back again into the compressor 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an air conditioner equipped with a defrosting function.

(Prior art) Defrosting in conventional air conditioners involves changing the flow path of the refrigerant flowing through the refrigerant circuit to flow high-temperature refrigerant into the outdoor heat exchanger, thereby heating the outdoor heat exchanger. The frost that had formed on the outside of the outdoor heat exchanger was melted.

That is, in the refrigerant circuit as shown in FIG. 4, during normal heating operation, the high-temperature, high-pressure refrigerant 1 air compressed by the compressor 21 passes through the four-way valve 22 to the indoor heat exchanger, as shown by the dotted arrow. After being condensed and liquefied at 23 and depressurized at an expansion valve 24, it evaporates at an outdoor heat exchanger 25 to become low-temperature vapor, and returns to the compressor 21 via the four-way valve 22 again. On the other hand, during defrosting operation, as shown by the solid arrow, a discharge bypass two-way valve 26 is provided in the refrigerant flow path connecting the inlet of the indoor heat exchanger 23 and the inlet of the outdoor heat exchanger 25. By opening the door, the high-temperature, high-pressure refrigerant vapor compressed by the compressor 21 directly flows into the outdoor heat exchanger 25, thereby heating the outdoor heat exchanger 25 and reaching the outside of the outdoor heat exchanger 25. Frost thaws.

(Problem to be Solved by the Invention) However, in this defrosting method, the high-temperature, high-pressure refrigerant vapor discharged from the compressor is passed through the outdoor heat exchanger to melt the frost. There was an inconvenience that heating operation could not be performed. In addition, when normal heating operation is restarted after defrosting operation, it may take time for heating to start up in order to warm up the indoor heat exchanger and the piping connected to it.
There was an inconvenience that driving efficiency deteriorated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an air conditioner that can perform heating operation while performing defrosting operation.

(Means for Solving the Problems) The air conditioner of the present invention includes a refrigerant circuit having a compressor, an indoor heat exchanger, an outdoor heat exchanger, a four-way valve, and an expansion valve. A refrigerant flow path and a second refrigerant flow path are provided, an inlet of the first refrigerant flow path is connected to the expansion valve via a three-way valve, and an outlet of the first refrigerant flow path is connected to the expansion valve through a two-way valve. connected to the outdoor heat exchanger connection port of the valve, while the inlet of the second refrigerant flow path is connected to the expansion valve, and the outlet of the second refrigerant flow path is connected to the outdoor heat exchanger connection port of the four-way valve. and the outlet of the first refrigerant flow path is connected to the inlet of the second refrigerant flow path via a throttle device, and
The inlet of the refrigerant flow path is connected to the discharge port of the compressor or the indoor heat exchanger connection port of the four-way valve via the three-way valve, and during defrosting operation, a part of the refrigerant discharged from the compressor is After passing through the first refrigerant flow path, the refrigerant flows through the expansion device into the second refrigerant flow path, and the refrigerant other than the refrigerant flowing through the flow path passes through the indoor heat exchanger, the expansion valve, and then into the second refrigerant flow path.
The refrigerant is made to flow through the refrigerant flow path.

(Function) In FIG. 1, while the two-way valve 9 is closed, the discharge connection port 8a and the outdoor heat exchanger connection port 8b of the three-way valve 8 are opened, the expansion valve connection port 8c is closed, and the discharge connection port 8a4 is heated by the outdoor heat exchanger. Defrosting operation is performed with the exchanger connection port 8b in communication.

A part of the high-temperature, high-pressure refrigerant vapor discharged from the compressor 1 in this state passes through the four-way valve 4, the three-way valve 8, and the first refrigerant flow path 6.
After passing through, the refrigerant is depressurized through the expansion device 1O, becomes low temperature and low pressure, and flows into the second refrigerant flow path 7. At this time, the outdoor heat exchanger 3 is heated by the high-temperature, high-pressure refrigerant vapor passing through the first refrigerant flow path 6, and the frost formed on the outdoor heat exchanger 3 is melted.

On the other hand, the remainder of the high-temperature, high-pressure refrigerant vapor discharged from the compressor 1 passes through the four-way valve 4 and is condensed and liquefied in the indoor heat exchanger 2, and then is depressurized by the expansion valve 5 to become low-temperature and low-pressure, and is transferred to the second refrigerant flow path. 7. At this time, the indoor heat exchanger 2 is heated by the high-temperature, high-pressure refrigerant vapor passing through the indoor heat exchanger 2, and heating operation is performed.

The low-temperature, low-pressure refrigerant that has flowed into the second refrigerant flow path 7 is
After being evaporated in the second refrigerant flow path 7, the refrigerant returns to the compressor 1 via the four-way valve 4 and repeats the circulation cycle.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

[First example] FIG. 1 shows an outline of the overall configuration of an air conditioner.

In the figure, this device includes a compressor 1, an indoor heat exchanger 2,
The refrigerant circuit includes an outdoor heat exchanger 3, a four-way valve 4, and an expansion valve 5. The outdoor heat exchanger 3 is provided with a first refrigerant flow path 6 and a second refrigerant flow path 7.

That is, the inlet 6a of the first refrigerant flow path 6 is connected to the expansion valve 5 and the indoor heat exchanger connection port 4b of the four-way valve 4 via the three-way valve 8, and the expansion valve 5 is connected by switching the three-way valve 8.
Alternatively, it communicates with the indoor heat exchanger connection port 4b of the four-way valve 4. Further, the outlet 6b of the first refrigerant flow path 6 is
It is connected to the outdoor heat exchanger connection port 4a of the four-way valve 4 via the two-way valve 9, and is also connected to the inlet lower a of the second refrigerant flow path 7 via the expansion device 10.

On the other hand, the lower inlet a of the second refrigerant flow path 7 is connected to the outlet 6b of the first refrigerant flow path 6 via the expansion device 10 as described above, and is also connected to the expansion valve 5. Further, the outlet lower b of the second refrigerant flow path 7 is connected to the outdoor heat exchanger connection port 4a of the four-way valve 4.

The three-way valve 8 is switched by an electric solenoid (not shown), and during normal heating operation, the discharge connection port 8a is closed and the expansion valve connection port 8c and the outdoor heat exchanger connection port 8b are open. Therefore, during defrosting operation, the discharge connection port 8a and the outdoor heat exchanger connection port 8b are opened, and the expansion valve connection port 8c is closed. The two-way valve 9 is also opened and closed by an electric solenoid (not shown), and is open during normal heating operation and closed during defrosting operation. As the three-way valve 9, a pyroft two-way valve that can automatically close the valve due to the pressure of the refrigerant when the refrigerant upstream of the two-way valve 9 becomes high pressure can also be used. In this case, the pilot two-way valve opens during normal heating operation because the refrigerant on the upstream side of the pilot two-way valve is depressurized by the expansion valve 5 and is at low pressure, and during defrosting operation, high-pressure refrigerant vapor is opened. Since the refrigerant flows into the first refrigerant flow path 6 via the three-way valve 8, it is closed.

Next, the operation of the air conditioner will be explained.

The flow of refrigerant during normal heating operation is shown by dotted arrows, and the flow of refrigerant during defrosting operation is shown by solid arrows.

During normal heating operation, high-temperature, high-pressure refrigerant vapor discharged from the compressor 1 flows into the indoor heat exchanger 2 through the four-way valve 4.
It releases heat into the indoor air and condenses into liquid. At this time, heating operation is performed by the high-temperature, high-pressure refrigerant vapor passing through the indoor heat exchanger 2 radiating heat to the indoor air. The condensed and liquefied high-temperature, high-pressure refrigerant flows into the expansion valve 5, is depressurized, expands, becomes low-temperature and low-pressure, and flows into the first refrigerant flow path 6 and the second refrigerant flow path 7 of the outdoor heat exchanger 3. As a result, it absorbs heat from the outdoor air and evaporates, becoming low-temperature, low-pressure steam. Then, the refrigerant flowing out from the first refrigerant flow path 6 and the second refrigerant flow path 7 of the outdoor heat exchanger 3 passes through the four-way valve 4, returns to the compressor 1, is compressed, and repeats the circulation cycle.

On the other hand, during defrosting operation, a part of the high-temperature, high-pressure refrigerant vapor discharged from the compressor 1 passes through the four-way valve 4, the three-way valve 8, the first refrigerant flow path 6, and then passes through the expansion device 10 to reduce the pressure. The refrigerant becomes low temperature and low pressure, and flows into the second refrigerant flow path 7. On this occasion,
The outdoor heat exchanger 3 is heated by the high-temperature, high-pressure refrigerant vapor passing through the first refrigerant flow path 6, and the frost formed on the outdoor heat exchanger 3 is melted. Further, the remainder of the high temperature and high pressure refrigerant vapor discharged from the compressor 1 passes through the four-way valve 4 to the indoor heat exchanger 2.
After the refrigerant radiates heat to the indoor air to condense and liquefy, the refrigerant is depressurized by the expansion valve 5 to become low temperature and low pressure, and flows into the second refrigerant flow path 7. At this time, heating operation is performed by the high-temperature, high-pressure refrigerant vapor passing through the indoor heat exchanger 2 radiating heat to the indoor air.

The low-temperature, low-pressure refrigerant that has flowed into the second refrigerant flow path 7 is
After evaporating in the second refrigerant flow path 7, the refrigerant passes through the four-way valve 4, returns to the compressor 1, is compressed, and repeats the circulation cycle.

[Second Example] This example is shown in FIG. In this embodiment, a pilot three-way valve is used as the three-way valve 8, and a discharge connection port 8a of the viroft three-way valve and an indoor heat exchanger connection port 4 of the four-way valve 4 are used.
A bypass two-way valve 11 operated by an electric solenoid is provided between the refrigerant and the refrigerant, and the flow of the refrigerant can be changed by operating the bypass two-way valve 11.

This pilot three-way valve 8 normally communicates with the outdoor heat exchanger connection port 8b and the expansion valve connection port 8c, and only when refrigerant pressure is applied to the discharge connection port 8a, the outdoor heat exchanger and the outdoor heat exchanger are connected. It is configured so that it communicates with the device connection port 8b.

According to this air conditioner, by keeping the bypass two-way valve 11 closed during normal heating operation, the discharge connection port 8
Since the pressure of the refrigerant is no longer applied to a, the outdoor heat exchanger connection port 8b and the expansion valve connection port 8c communicate with each other, and heating operation can be performed. In addition, during defrosting operation, by opening the bypass two-way valve 1■, refrigerant pressure is applied to the discharge connection port 8a, so that the outdoor heat exchanger connection port 8b and the discharge connection port 8
A is in communication with the air conditioner, and defrosting operation can be performed. The other configurations, refrigerant flow, etc. are similar to those in the first embodiment.

Next, a specific example of the outdoor heat exchanger 3 used in the present invention will be described.

(First Specific Example) The outdoor heat exchanger 3 of this specific example is shown in FIG. The outdoor heat exchanger 3 has a first refrigerant flow path 6 disposed upstream of the flow F of outdoor air, and a second refrigerant flow path 7 disposed downstream of the flow F of outdoor air. That is, the first refrigerant flow path 6 and the second refrigerant flow path 7 are arranged in parallel, and heat transfer fins 12 capable of conducting heat are thermally coupled between the tube bundles of these refrigerant flow paths 6.7. . As the material of the outdoor heat exchanger 3, a metal with good thermal conductivity such as copper or aluminum is used.

According to this outdoor heat exchanger 3, high-temperature refrigerant vapor flows into the first refrigerant flow path 6 and low-temperature refrigerant flows into the second refrigerant flow path 7 during defrosting operation. Therefore, in the first refrigerant flow path 6, the heat of the refrigerant vapor is sequentially conducted from the first refrigerant flow path 6 through the heat transfer fins 12, and becomes high temperature. On the other hand, heat is absorbed in the second refrigerant flow path 7, resulting in a low temperature. Then, the frost formed near the first refrigerant flow path 6 is sequentially melted by the heat of the refrigerant vapor that is sequentially thermally conducted along the first refrigerant flow path 6. On the other hand, the frost formed near the second refrigerant flow path 7,
Since the second refrigerant flow path 7 has a low temperature, it will be sequentially melted by the flow F of outdoor air that has been warmed near the first refrigerant flow path 6 and turned into hot air.

(Effects of the Invention) As described above, according to the present invention, heating can be continued even during defrosting operation, so when switching to normal heating operation after defrosting operation, the indoor heat exchanger Sufficient heating capacity can be obtained without warming up piping etc. connected to the indoor heat exchanger, and operational efficiency can be improved.

[Brief explanation of the drawing]

1 to 3 show drawings according to the present invention;
The figure is a system configuration diagram schematically showing the overall configuration of an air conditioner according to the first embodiment, FIG. 2 is a system configuration diagram schematically showing the overall configuration of the air conditioner according to the second embodiment, and FIG. FIG. 4 is a perspective view schematically showing the overall configuration of an outdoor heat exchanger according to the first specific example, and FIG. 4 is a system configuration diagram schematically showing the overall configuration of a conventional air conditioner. 5... Expansion valve 6... First refrigerant flow path 6a... Inlet 6b... Lower outlet... Second refrigerant flow path 7a... Inlet 8... Three-way valve 9... Two Way valve 10...throttle device 7b...outlet 1...compressor 1a...discharge port 2...indoor heat exchanger 3...outdoor heat exchanger 4...four-way valve 4a...・Outdoor heat exchanger connection port 4b...Indoor heat exchanger connection port

Claims (1)

[Scope of Claims] 1) In a refrigerant circuit having a compressor, an indoor heat exchanger, an outdoor heat exchanger, a four-way valve, and an expansion valve, a first refrigerant flow path and a second refrigerant flow path are provided in the outdoor heat exchanger. is provided, the inlet of the first refrigerant flow path is connected to the expansion valve via a three-way valve, and the outlet of the first refrigerant flow path is connected to the outdoor heat exchanger connection port of the four-way valve via a two-way valve. On the other hand, the inlet of the second refrigerant flow path is connected to the expansion valve, the outlet of the second refrigerant flow path is connected to the outdoor heat exchanger connection port of the four-way valve, and the second refrigerant flow The outlet of the first refrigerant flow path is connected to the inlet of the refrigerant flow path via a throttle device, and the inlet of the first refrigerant flow path is connected to the discharge port of the compressor or the indoor heat of the four-way valve via the three-way valve. Connected to the exchanger connection port, during defrosting operation, a part of the refrigerant discharged from the compressor passes through the first refrigerant flow path, passes through the expansion device, and flows into the second refrigerant flow path. An air conditioner, characterized in that refrigerant other than the refrigerant flowing through the flow path flows through the indoor heat exchanger and the expansion valve, and then through the second refrigerant flow path.