JPH01208678A - Heat pump type air conditioner - Google Patents

Abstract

PURPOSE:To prevent a reduction of a heating capability and also prevent a reduction of a sucking pressure of a compressor by a method wherein a circuit in case of performing a defrosting operation is formed as a heating bypass circuit provided with a heating solenoid valve not passing through an outdoor heat exchanger as well as in expansion valve. CONSTITUTION:During a defrosting operation, a heating solenoid valve 22 of a heating bypass circuit 23 is opened and coolant may act simultaneously to a heating circuit in which the coolant is flowed from a compressor 1 to a four- way valve 12, an indoor heat exchanger 13, a heating solenoid 22 and a compressor 11, in sequence and to a second circuit for a defrosting circuit in which the coolant is flowed from the compressor 11 to a defrosting solenoid valve 18 kept open when defrosted to a merging flow part 17, an outdoor heat exchanger 15, the fourway valve 12 and the compressor 11 in sequence. That is, the heating solenoid valve 22 and the defrosting solenoid 18 are opened only when the defrosting operation is carried out, they are closed under another operating mode and the resistances of the defrosting bypass circuit 19 and the heating bypass circuit 23 are made substantially equal to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a refrigerant circuit for a heat pump type air conditioner.

BACKGROUND OF THE INVENTION Conventionally, the refrigeration cycle of a heat pump type air conditioner has a configuration as shown in FIG. That is, the compressor 1 is connected to a four-way valve 2 by a refrigerant pipe, and the four-way valve 2, an indoor heat exchanger 3, an expansion valve 4, and an outdoor heat exchanger 5 are sequentially connected to form a refrigeration cycle. There is. Further, a bypass circuit 9 is provided between the discharge pipe 6 of the compressor 1 and a confluence son provided between the expansion valve 4 and the outdoor heat exchanger 6 via a solenoid valve 8. With this configuration, during defrosting during heating operation, the refrigerant flows sequentially from the compressor 1 to the four-way valve 2, the indoor heat exchanger 3, the expansion valve 4, the outdoor heat exchanger 6, the west valve 2, and the compressor 1. The air flows from the compressor 1 into the main circuit for heating, bypasses the solenoid valve 8 that opens during defrosting, flows into the confluence 7 between the expansion valve 4 and the outdoor heat exchanger 6, and flows into the main circuit. Even if they merge, a hot gas bypass defrosting circuit that defrosts the box that has formed frost on the outdoor heat exchanger 5 is constituted by a circuit that operates at the same time.

Problems to be Solved by the Invention In such a conventional configuration, during the defrosting operation during heating, the indoor heat exchanger 3. The flow path resistance of the main circuit from the expansion valve 4 to the confluence section 7 is extremely large compared to the flow path resistance of the bypass circuit from the compressor 1 to the confluence section 7 via the stain magnetic valve 8. The refrigerant circulation amount is significantly smaller than the refrigerant circulation amount flowing through the bypass circuit 9,
There were problems in that the heating capacity decreased, refrigerant accumulated in the indoor heat exchanger 3, and the suction pressure of the compressor 1 decreased too uniformly.

The present invention solves these problems by preventing a significant decrease in heating capacity and compressor suction pressure during defrosting operation, improving heating capacity and alleviating the decrease in compressor suction pressure. The purpose is to draw.

A means to solve problems In order to solve this problem, the present invention provides a compressor.

A refrigeration cycle in which a four-way valve, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger are sequentially connected; and a defrosting bypass circuit including a defrosting solenoid valve between the compressor and the outdoor heat exchanger. , a heating bypass circuit bypassing the indoor heat exchanger and the outdoor heat exchanger and having a heating solenoid valve connected to the suction pipe side.

With this configuration, during defrosting operation, refrigerant flows sequentially from the compressor to the compressor through a heating bypass circuit equipped with a four-way valve, an indoor heat exchanger, and a heating solenoid valve, and defrosts from the --way compressor. The refrigerant flows sequentially from the defrosting bypass circuit equipped with a solenoid valve to the outdoor heat exchanger, four-way valve, and compressor. The amount of refrigerant circulated that causes frost is divided, and the amount of refrigerant circulated becomes approximately equal.

EXAMPLE Hereinafter, an example according to the present invention will be explained with reference to FIG. Compressor 11 is connected to four-way valve 12 via refrigerant piping. The four-way valve 12, the indoor heat exchanger 13, the expansion valve 14, and the outdoor heat exchanger 15 are sequentially connected by refrigerant piping to constitute a heat pump type refrigeration cycle. In addition, the compression stage 11
From the discharge pipe 16, a defrosting solenoid valve 18 which is opened during defrosting is connected to the confluence part 17 between the expansion valve 14 and the outdoor heat exchanger 15.
A defrosting bypass circuit 19 is provided via a defrosting bypass circuit 19, and a branch part 20 is connected between the indoor heat exchanger 13 and the expansion valve 14, and a confluence part 25 of the suction pipe 21 of the compressor 11 is connected from this branch part 2o.
A heating bypass circuit 23 is configured via a heating electromagnetic valve 22 that is connected to and opens during defrosting.

During cooling operation, the refrigerant flows sequentially from the compressor 11 to the four-way valve 12, the outdoor heat exchanger 15, the expansion valve 14, the indoor heat exchanger 13, the four-way valve 12, and the compressor 11, and during the heating operation, the refrigerant flows from the compressor 11 to the four-way valve 12, the indoor heat exchanger 13, the four-way valve 12, and the compressor 11. Valve 12, indoor heat exchanger 13, and expansion valve 1
4, the outdoor heat exchanger 15, the four-way valve 12, and the compressor 11, the refrigerant circulates for cooling and heating similar to a conventional refrigeration cycle.

In the above configuration, during defrosting operation, the heating solenoid valve 22 of the heating bypass circuit 23 is opened, and the refrigerant is supplied from the compressor 11 to the four-way valve 12. Indoor heat exchanger 13° Heating solenoid valve 22.
In the heating circuit that sequentially flows to the compression stage 11, and in the other circuit, the refrigerant flows from the compressor 11 to the confluence section 17 from the defrosting solenoid valve 18, which is opened during defrosting, to the outdoor heat exchanger 15.
Two circuits, ie, a defrosting circuit that sequentially flows through the four-way valve 12 and the compressor 11, operate simultaneously. That is, the heating solenoid valve 22 and the defrosting solenoid valve 18 are opened only during defrosting operation, and are closed in other operation modes, so that the resistances of the defrosting bypass circuit 19 and the heating bypass circuit 23 are approximately equal. This is what we are doing. However, the heating solenoid valve 22 may be opened and used for overload control during heating operation. Also, expansion valve 1
4 may be either a temperature-type expansion valve or an electronic expansion valve, but in the case of an electronic expansion valve, it may be fully closed during defrosting operation.

Effects of the Invention As is clear from the description of the above embodiments, according to the present invention, the circuit during defrosting operation is a heating bypass circuit equipped with a heating solenoid valve that does not pass through an expansion valve and an outdoor heat exchanger. Therefore, it is possible to make the flow path resistance of the defrosting bypass circuit and the flow path resistance of the heating bypass circuit almost equal, preventing a decrease in heating capacity, and also reducing the refrigerant flow in the indoor heat exchanger. Since the accumulation of water can be eliminated, it is possible to obtain the effect that a drop in the suction pressure of the compressor can also be prevented.

[Brief explanation of the drawing]

FIG. 1 is a refrigeration cycle diagram of a heat pump type air conditioner according to an embodiment of the present invention, and FIG. 2 is a refrigeration cycle diagram of a conventional heat pump type air conditioner. 11...Compressor, 12...Four-way valve, 1
3... Indoor heat exchanger, 14... Expansion valve, 15... Outdoor heat exchanger, 18... Solenoid valve for defrosting, 19... ...defrosting bypass circuit, 2
1... Suction pipe, 22... Solenoid valve for heating, 23... Bypass circuit for heating. Name of agent: Patent attorney Toshio Nakao and one other person

Claims (1)

[Claims] A defrosting cycle comprising a refrigeration cycle in which a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger are connected in sequence, and a defrosting solenoid valve between the compressor and the outdoor heat exchanger. A heat pump air conditioner comprising a bypass circuit and a heating bypass circuit that bypasses the indoor heat exchanger and the outdoor heat exchanger and includes a heating solenoid valve connected to the suction pipe side.