JP2011145011A - Air conditioning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioning device that prevents remaining of frost and achieves high-performance heating capacity at low cost. <P>SOLUTION: The air conditioning device is provided with a refrigerating cycle connecting at least a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger by a refrigerant circuit. The outdoor heat exchanger is formed by refrigerant flow passages of a plurality of systems. The outdoor heat exchanger is functioned as an evaporator and any inlet of the refrigerant flow passages of a plurality of systems in use is located on the uppermost stage of the outdoor heat exchanger or the second stage from the uppermost stage of a refrigerant flowing pipe. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an outdoor heat exchanger used in an air conditioner.

  Conventionally, this type of outdoor heat exchanger has a low-pressure-loss refrigerant path when used as an evaporator so that it has high performance when used in either an evaporator or a condenser. When it is used, it is a refrigerant path in which subcooling is easily taken on the outlet side (see Patent Document 1).

  FIG. 5 is a diagram illustrating a refrigerant path of an outdoor heat exchanger of a conventional air conditioner. In FIG. 5, the refrigerant path of the outdoor heat exchanger includes a refrigerant outlet side during heating operation (inlet side during cooling operation) 6a1, 6b1, 6d1, 6e1 on the leeward side, and a refrigerant inlet side during heating operation on the windward side ( Outlet side during cooling operation) 6c1, 6f1, and the refrigerant path on the refrigerant outlet side (inlet side during cooling) 6a1, 6b1, 6d1, 6e1 during heating operation is made up of four systems consisting of 6a, 6b, 6d, 6e. The refrigerant path on the refrigerant inlet side during heating operation (outlet side during cooling operation) 6c1 and 6f1 is composed of two systems consisting of 6c and 6f, and the number of refrigerant paths is larger from the inlet side to the outlet side during heating. It has a configuration provided.

  In addition, there is a refrigerant path of an outdoor heat exchanger of a conventional air conditioner as shown in FIG. In FIG. 6, as the refrigerant path of the outdoor heat exchanger, the refrigerant flows in from the lowermost step portion 71 of the windward outdoor heat exchanger during heating, and after flowing between a plurality of refrigerants in one system, the outdoor heat exchanger The refrigerant is divided into four refrigerant paths at the refrigerant path inlets 7a1, 7b1, 7c1, and 7d1 and flows out from the leeward refrigerant path outlets 7a2, 7b2, 7c2, and 7d2. .

Japanese Patent Laid-Open No. 2001-174101

  However, in the refrigerant path shown in FIG. 5, for the air conditioner that switches the four-way valve and performs the defrosting operation in the cooling cycle, the temperature of the refrigerant circulating in the outdoor heat exchanger during the defrosting operation is also high. Although defrosting operation is possible without problems, the amount of heat to the indoor side is also required for air conditioners that perform defrosting operation while performing heating operation without switching the four-way valve during heating operation Therefore, the temperature of the refrigerant circulating in the outdoor heat exchanger during the defrosting operation is difficult to rise, especially between the upper part of the outdoor heat exchanger and the casing of the outdoor unit, and between the lower part of the outdoor heat exchanger and the base of the outdoor unit. It had the subject that the frost adhering in between was easy to melt away.

  Further, in the refrigerant path shown in FIG. 6, by applying the first half part of the refrigerant path to a part where frost is not easily melted (at both ends in the longitudinal direction of the outdoor heat exchanger), relatively high-temperature refrigerant is applied to this part. Although the problem of unmelted frost is eliminated, the routing of the refrigerant flow pipe connecting the heat transfer pipe is complicated and the cost is increased, and the pressure loss is increased by extending the refrigerant path. There were problems such as deterioration in heating performance and cost increase due to increased refrigerant amount.

Therefore, an object of the present invention is to solve the conventional problems described above, and to provide an air conditioner that can eliminate the remaining melting of frost and can realize high-performance heating capacity at low cost.

  To achieve the above object, in an air conditioner including a refrigeration cycle in which at least a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger are connected by a refrigerant circuit, the outdoor heat exchanger has a plurality of refrigerant flow paths. The inlet of any of the plurality of refrigerant flow paths when the outdoor heat exchanger is used as an evaporator is positioned in the uppermost stage of the outdoor heat exchanger or the second stage refrigerant circulation pipe of the outdoor heat exchanger. Features.

  According to the present invention, refrigerant having a relatively high temperature is caused to flow through the upper stage of the outdoor heat exchanger where frost is not easily melted during the defrosting operation, so that the frost is not melted and the refrigerant circulation pipe is routed. It can be simplified and realized at low cost.

The schematic diagram of the refrigerating cycle of the air conditioner in Embodiment 1 of this invention. The figure which shows the refrigerant | coolant path | route of the outdoor heat exchanger in Embodiment 1 of this invention. The figure which shows the temperature of the refrigerant | coolant distribution pipe | tube of the outdoor heat exchanger at the time of the defrost operation in Embodiment 1 of this invention. The figure which shows the refrigerant | coolant path | route of the outdoor heat exchanger in the modification of this invention The figure which shows the refrigerant | coolant path | route of the conventional outdoor heat exchanger The figure which shows the other refrigerant path of the conventional outdoor heat exchanger

  The present invention is an air conditioner including a refrigeration cycle in which at least a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger are connected by a refrigerant circuit, and the outdoor heat exchanger includes a plurality of refrigerant flow paths, An inlet of any one of a plurality of refrigerant flow paths when the outdoor heat exchanger is used as an evaporator is positioned at the uppermost stage of the outdoor heat exchanger or the second stage refrigerant circulation pipe of the outdoor heat exchanger. Accordingly, it is possible to flow a refrigerant having a relatively high temperature through the upper part of the outdoor heat exchanger in which frost is not easily melted during the defrosting operation, and it is possible to eliminate the remaining frost.

  More specifically, when the outdoor heat exchanger is used as an evaporator, the refrigerant flow path to the outdoor heat exchanger flows into the lowermost refrigerant circulation pipe of the outdoor heat exchanger in one system, and at least two or more It is preferable to divide the refrigerant flow pipes of the outdoor heat exchanger into a plurality of refrigerant flow paths. This ensures that the refrigerant with the highest temperature flows through the lowermost part of the outdoor heat exchanger, and the frost between the outdoor heat exchanger and the outdoor unit base where frost is likely to remain undissolved during the defrosting operation. It will be possible to melt reliably, and the outlet side when the outdoor heat exchanger is used as a condenser will be a one-line refrigerant path, so that subcooling can be easily taken and cooling performance can be improved. it can.

  More specifically, the outdoor heat exchanger is configured in two rows on the windward side and the leeward side with respect to the airflow generated by the outdoor fan, and one system of the inlets of the plurality of refrigerant flow paths and the outdoor heat exchanger. It is preferable that the inlet of the refrigerant flow path is positioned in the upwind heat exchanger, and the outlets of the plurality of refrigerant flow paths are positioned in the upwind heat exchanger. This ensures that the refrigerant with the highest temperature flows through the lowermost part of the outdoor heat exchanger, and the frost between the outdoor heat exchanger and the outdoor unit base where frost is likely to remain undissolved during the defrosting operation. It will be possible to melt reliably, and the outlet side when the outdoor heat exchanger is used as a condenser will be a one-line refrigerant path, so that subcooling can be easily taken and cooling performance can be improved. it can.

In addition, the air conditioner preferably uses an outdoor heat exchanger as an evaporator having a refrigerant flow path in which the inlets of a plurality of refrigerant flow paths are located at the uppermost stage of the outdoor heat exchanger or the second stage from the uppermost stage. The temperature sensor which determines the completion | finish of a defrost operation is comprised in the exit side in the case of having performed. Thereby, it becomes possible to melt | dissolve the frost of the upper part of the outdoor heat exchanger which tends to generate | occur | produce frost unmelting at the time of a defrost operation more reliably.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a schematic diagram of a refrigeration cycle of an air conditioner according to Embodiment 1 of the present invention. In FIG. 1, the air conditioner includes an outdoor unit 14 and an indoor unit 13. The outdoor unit 14 includes a compressor 1 that compresses refrigerant, a four-way valve 2 that switches between cooling operation and heating operation, an electronic expansion valve 4 that is a throttle mechanism, an outdoor heat exchanger 5, a first bypass circuit 11, a first A two-way valve 6, a refrigerant heater 7, a second bypass circuit 12, a second two-way valve 8, and an outdoor fan 10 are arranged. The indoor unit 13 includes an indoor heat exchanger 3 and an indoor fan 9.

  In the defrosting operation of the air conditioner, as indicated by the arrow, the first two-way valve 6 is opened, whereby the refrigerant heated by the refrigerant heater 7 flows through the first bypass circuit 11 and is compressed. The high temperature refrigerant discharged from the compressor 1 is caused to flow through the second bypass circuit 12 by opening the second two-way valve 8 and to flow into the outdoor heat exchanger 5 at the same time as flowing into the machine 1. Thus, the defrosting operation is performed while the heating operation is performed.

  The outdoor heat exchanger 5 in the air conditioner configured as described above will be described in detail. FIG. 2 is a diagram illustrating a refrigerant path of the outdoor heat exchanger 5, and FIG. 3 is a diagram illustrating a temperature change of each refrigerant flow pipe of the outdoor heat exchanger 5 during the defrosting operation.

  In FIG. 2, the outdoor heat exchanger 5 is configured in multiple stages in the vertical direction in two rows of the windward side and the leeward side with respect to the airflow generated by the outdoor blower 10, and is used in the defrosting operation and the outdoor heat exchanger 5. Is used as an evaporator, the refrigerant flows into the outdoor heat exchanger 5 from the lowermost refrigerant circulation pipe 51 on the windward side, passes through one refrigerant path, and passes from the refrigerant circulation pipe 52 to four refrigerant paths. Divided. That is, as shown in FIG. 3, the hottest refrigerant flows into the lowermost refrigerant circulation pipe 51 of the outdoor heat exchanger 5, and the outdoor heat exchanger 5 and the outdoor where frost is not easily melted during the defrosting operation. It becomes possible to melt the frost between the machine base 21 reliably. In addition, when the outdoor heat exchanger 5 is used as a condenser, the outlet side becomes one refrigerant path and is located on the windward side, so that a subcool can be easily taken and the cooling performance can be improved.

  The separated refrigerant flows into the windward refrigerant flow pipes 53a, 53b, 53c, and 53d, and the refrigerant flows out of the outdoor heat exchanger 5 from the leeward refrigerant flow pipes 54a, 54b, 54c, and 54d. To do. In this way, when the outdoor heat exchanger 5 is used as an evaporator, the pressure loss can be reduced, the heating performance can be improved, and the outdoor heat exchanger 5 can be When used with a condenser, the refrigerant circulates from the leeward refrigerant circulation pipes 54a, 54b, 54c, 54d to the leeward refrigerant circulation pipes 53a, 53b, 53c, 53d. The heat exchange efficiency can be improved and the cooling performance can be improved. Furthermore, since one of the four refrigerant paths is caused to flow from the refrigerant circulation pipe 53a at the second stage from the uppermost stage of the outdoor heat exchanger 5, the temperature is relatively high as shown in FIG. It becomes possible to circulate the refrigerant through the uppermost part of the outdoor heat exchanger 5 and melt the frost between the outdoor heat exchanger 5 and the outdoor unit casing 22 where frost is not easily melted during the defrosting operation. Is possible.

Further, as shown in FIG. 2, the outdoor unit 14 further includes a temperature sensor 15 for detecting the temperature of the refrigerant flow pipe on the outlet side of the refrigerant flow pipe 54a, and the temperature sensor 15 is melted with frost. The defrosting operation of the air conditioner is finished, and the defrosting operation is finished in a state where the frost at the uppermost part of the outdoor heat exchanger 5 is surely melted. It becomes possible to do.

  In the above embodiment, as shown in FIG. 2, one of the four refrigerant paths is caused to flow from the uppermost stage of the outdoor heat exchanger 5 into the second stage refrigerant circulation pipe 53a. . However, the present invention is not limited to this, and as shown in FIG. 4, one of the four refrigerant paths may flow into the uppermost refrigerant circulation pipe 53 a of the outdoor heat exchanger 5.

  Since the air conditioner according to the present invention can improve cooling and heating performance, it can also be applied to an air conditioner that performs a defrosting operation by switching a four-way valve.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Indoor heat exchanger 4 Electronic expansion valve 5 Outdoor heat exchanger 6 First two-way valve 7 Refrigerant heater 8 Second two-way valve 9 Indoor fan 10 Outdoor fan 11 First bypass circuit 12 Second bypass circuit 13 Indoor unit 14 Outdoor unit 15 Temperature sensor 51 Refrigerant flow pipe 52 Refrigerant flow pipe 53a, 53b, 53c, 53d Refrigerant flow pipe 54a, 54b, 54c, 54d Refrigerant flow pipe

Claims (4)

In an air conditioner including a refrigeration cycle in which at least a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger are connected by a refrigerant circuit,
The outdoor heat exchanger is composed of a plurality of refrigerant flow paths, and the inlet of one of the refrigerant flow paths of the multiple systems when the outdoor heat exchanger is used as an evaporator is the uppermost stage of the outdoor heat exchanger. Or it is located in the refrigerant | coolant distribution pipe of the 2nd stage | paragraph from the uppermost stage, The air conditioner characterized by the above-mentioned. When the outdoor heat exchanger is used as an evaporator, the refrigerant flow path to the outdoor heat exchanger is one system and flows into the lowermost refrigerant flow pipe of the outdoor heat exchanger, and at least two or more of the outdoor The air conditioner according to claim 1, wherein the air conditioner is divided into a plurality of refrigerant flow paths after flowing through the refrigerant flow pipe of the heat exchanger. The outdoor heat exchanger is configured in two rows on the windward side and the leeward side with respect to the air flow generated by the outdoor fan, and the inlet of the plurality of refrigerant channels and the one channel refrigerant channel of the outdoor heat exchanger 3. The air conditioner according to claim 1, wherein an inlet of the airflow is positioned in the heat exchanger on the windward side, and outlets of the plurality of refrigerant flow paths are positioned in the heat exchanger on the windward side. Machine. On the outlet side when the outdoor heat exchanger is used as an evaporator of the refrigerant flow path located at the uppermost stage of the outdoor heat exchanger or the second stage from the uppermost stage of the plurality of refrigerant flow paths, The air conditioner according to any one of claims 1 to 3, further comprising a temperature sensor for determining the end of the defrosting operation.