JPH1062040A - Air conditioner - Google Patents

Abstract

(57) [Problem] To provide an air conditioner that suppresses a decrease in room temperature during a defrosting operation, accelerates the blowing of warm air after restarting a heating operation, and quickly raises the indoor temperature. I do. SOLUTION: The compressor comprises a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, an expansion valve 4, and an indoor heat exchanger 5, which are connected by a refrigerant pipe to form a refrigeration cycle. In the air conditioner, a throttle valve 6 and an auxiliary heat exchanger 7 are provided in series between the indoor heat exchanger 5 and the four-way valve 2,
In the cooling and heating operations, the throttle valve 6 is fully opened and the expansion valve 4 is throttled to a predetermined amount. In the defrosting operation, the expansion valve 4 is fully opened and the throttle valve 6 is throttled to a predetermined amount. It has become.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner capable of preventing a decrease in room temperature during a defrosting operation.

[0002]

2. Description of the Related Art A conventional air conditioner forming a refrigeration cycle includes a compressor 1 and a four-way valve 2 as shown in FIG.
, An outdoor heat exchanger 3, an expansion valve (or capillary tube) 4 ', and an indoor heat exchanger 5', which are annularly connected by refrigerant piping. An outdoor blower 8 controlled by an outdoor control unit (not shown);
It comprises an indoor blower 9 and the like controlled by an indoor control unit (not shown).

[0003] With the above configuration, in Fig. 2, solid arrows indicate the refrigerant flow direction during the cooling operation and the defrosting operation, and broken line arrows indicate the refrigerant flow direction during the heating operation. In the above-described air conditioner, during the heating operation, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 in the outdoor unit passes through the four-way valve 2 and then flows through the indoor heat exchanger 5 ′ while the indoor blower 9
By exchanging heat with room air, heat is released into the room and condensed. The condensed and liquefied liquid refrigerant is decompressed through the expansion valve 4 ′, becomes a low-temperature low-pressure gas-liquid two-phase, is absorbed from the air sent by the outdoor blower 8 while flowing through the outdoor heat exchanger 3, and has a low-temperature low pressure. Is returned to the compressor 1 from the four-way valve 2. During the cooling operation, the operation is the same as that of the heating except that the action of the outdoor and indoor heat exchangers 3, 5 'is reversed by switching the four-way valve 2.

When the outside air temperature is low and the humidity is high, frost is formed on the outdoor heat exchanger 3 during the heating operation, and the heating capacity is reduced. In such a case, the flow of the refrigerant is changed by the four-way valve 2 (cooling cycle), and the defrosting operation starts. At the time of defrosting, the indoor heat exchanger 5 has a very low temperature (-10 degrees or less). For this reason, the cooling air is prevented from blowing into the room as much as possible by reducing the rotation speed of the indoor blower 9 or the like. However, when the defrosting operation is performed, the room temperature decreases, and when the defrosting operation is completed and the heating operation is restarted, the heating capacity does not immediately increase, and it takes time until hot air is blown out, and the room is heated. Time was required.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention suppresses a decrease in room temperature during a defrosting operation, accelerates the blowing of warm air after restarting a heating operation, and quickly raises the indoor temperature. It is an object to provide an air conditioner to be operated.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and comprises a compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger. Become
In an air conditioner formed by connecting these with a refrigerant pipe to form a refrigeration cycle, a throttle valve and an auxiliary heat exchanger are provided in series between the indoor heat exchanger and the four-way valve, and the throttle is used during cooling and heating operations. The valve is fully opened, and the expansion valve is throttled to a predetermined amount. During the defrosting operation, the expansion valve is fully opened, and the throttle valve is throttled to a predetermined amount. Further, the throttle valve is constituted by an electronic expansion valve capable of changing the throttle amount. Further, the air conditioning capacity of the auxiliary heat exchanger is set to be equal to or less than の of the indoor heat exchanger.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An air comprising a compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger, which are connected by a refrigerant pipe to form a refrigeration cycle. In the conditioner, a throttle valve and an auxiliary heat exchanger are provided in series between the indoor side heat exchanger and the four-way valve, and during cooling and heating operations, the throttle valve is fully opened, and the expansion valve is throttled to a predetermined amount. During the defrosting operation, the expansion valve is fully opened, and the throttle valve is throttled to a predetermined amount, thereby suppressing a decrease in the room temperature during the defrosting operation, and blowing the hot air after restarting the heating operation. It will be an air conditioner that quickly raises the indoor temperature.

[0008]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In FIG. 1, 1 is a compressor, 2
Is a four-way valve that switches the flow of the refrigerant discharged from the compressor 1 in accordance with a heating operation, a cooling operation, etc., 3 is an outdoor heat exchanger, 4 is an expansion valve (or a capillary tube), 5 is an indoor heat exchanger, Reference numeral 6 denotes a throttle valve composed of an electronic expansion valve having a structure capable of changing a throttle amount as a throttle mechanism of a refrigerant circuit. Reference numeral 7 denotes an auxiliary heat exchanger whose air-conditioning capacity is equal to or less than half that of the indoor heat exchanger. A refrigeration cycle is formed by being annularly connected by pipes, and during cooling and defrosting operations, the refrigerant circulates as shown by solid arrows, and during heating operation,
The refrigerant circulates as indicated by the arrow in the broken line. An outdoor blower 8 controlled by an outdoor control unit (not shown)
And an indoor blower 9 controlled by an indoor control unit (not shown).

[0009] Of the equipment constituting the air conditioner, the compressor 1, the four-way valve 2, the expansion valve 4 and the throttle valve 6 are not shown, but are not shown, but are used for control mounted in outdoor and indoor control units. The throttle valve 6 is fully opened during the cooling and heating operations, and the expansion valve 4 is throttled to a predetermined amount. During the defrosting operation, the expansion valve 4 is fully opened. The valve 6 is controlled to be throttled to a predetermined amount.

In the above air conditioner, during the heating operation, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 in the outdoor unit passes through the four-way valve 2 and then passes through the auxiliary heat exchanger 7 and the indoor heat exchanger. The heat is exchanged with the indoor air by the indoor blower 9 while flowing through the pipe 5, so that heat is released into the room and condensed. The condensed and liquefied liquid refrigerant is decompressed through an expansion valve (or a capillary tube) 4 to become a low-temperature and low-pressure gas-liquid two-phase. Then, it becomes a low-temperature and low-pressure gas refrigerant and is returned from the four-way valve 2 to the compressor 1. During the cooling operation, the operation is the same as that of the heating except that the operation of the outdoor and indoor heat exchangers 3 and 5 is reversed by switching the four-way valve 2.

Next, at the time of the defrosting operation, the expansion valve 4 is fully opened and a throttle mechanism for reducing the throttle valve 6 to a predetermined amount is used, so that the outdoor heat exchanger 3 and the indoor heat exchanger 5 become condensers. A so-called cooling cycle in which the auxiliary heat exchanger 7 becomes an evaporator,
The outdoor heat exchanger 3 is defrosted. On the other hand, since the air conditioning capacity of the auxiliary heat exchanger 7 on the indoor unit side is as small as 1/2 or less of the indoor heat exchanger 5, the temperature of the auxiliary heat exchanger 7 is small and the room temperature hardly decreases. When the defrosting operation is completed and the heating operation is restarted, the temperature of the auxiliary heat exchanger 7 rises relatively quickly, and the hot air is blown out because the indoor heat exchanger 5 is already a condenser. As soon as possible, the room temperature is quickly raised.

With the above construction, an auxiliary heat exchanger is provided in the indoor unit, and only the auxiliary heat exchanger is used as an evaporator when defrosting or in a cooling cycle, and the indoor heat exchanger and the outdoor heat exchanger are condensed. By operating as an air conditioner, the air conditioner suppresses a decrease in the room temperature during the defrosting operation, and at the same time, the hot air after the restart of the heating operation blows out quickly, and the air conditioner rapidly raises the indoor temperature.

[0013]

As described above, according to the present invention, there is provided an air conditioner which suppresses a decrease in room temperature during defrosting operation, accelerates blowing of warm air after restarting heating operation, and quickly raises the indoor temperature. Become.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of an air conditioner according to the present invention.

FIG. 2 is a diagram showing an air conditioner according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Outdoor heat exchanger 4 Expansion valve 5 Indoor heat exchanger 6 Throttle valve (electronic expansion valve) 7 Auxiliary heat exchanger 8 Outdoor blower 9 Indoor blower

Claims (3)

[Claims] 1. An air conditioner comprising a compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger, which are connected by a refrigerant pipe to form a refrigeration cycle. In, a throttle valve and an auxiliary heat exchanger are provided in series between the indoor side heat exchanger and the four-way valve, and during cooling and heating operations, the throttle valve is fully opened, and the expansion valve is throttled to a predetermined amount,
An air conditioner wherein the expansion valve is fully opened during a defrosting operation, and the throttle valve is throttled to a predetermined amount. 2. The air conditioner according to claim 1, wherein said throttle valve is constituted by an electronic expansion valve capable of changing a throttle amount. 3. The air conditioner according to claim 1, wherein the air conditioning capacity of the auxiliary heat exchanger is less than or equal to half of the indoor heat exchanger.