JPH06341740A - Operating method for heat pump type air conditioner - Google Patents

Abstract

PURPOSE:To prevent an abnormal rise of the temperature of a compressor due to a decrease in the quantity of liquid refrigerant supplied onto the suction side of the compressor and also to surely melt a large quantity of frost and ice sticking to the lower part of an outdoor heat exchanger and on a drain pan, at the time of a heating operation. CONSTITUTION:A cooler 18a is constructed by using a circuit in the lower part of an outdoor heat exchanger 18, the bypass circuits 24 and 25 leading a part of a gas refrigerant discharged from a compressor 1 onto the suction side of the compressor 1 through the cooler 18a, a solenoid on-off valve 20 and a restrictor 21 are provided. The solenoid on-off valve 20 is made open at the time of an abnormal rise of the temperature of the compressor 1 and a defrosting operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of operating a heat pump type air conditioner.

[0002]

2. Description of the Related Art FIG. 2 shows a refrigerant circuit of a conventional heat pump type air conditioner. During cooling operation, the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the four-way valve 2 and flows through each circuit of the multi-circuit type outdoor heat exchanger 18 as shown by the solid line arrow to the outside air. By radiating heat, it condenses and liquefies into high-pressure liquid refrigerant. The liquid refrigerant merges in the distributor 16 via the distribution pipes 17a, 17b, 17c, and is then throttled by the cooling throttle 15A to become a low-pressure liquid gas two-phase refrigerant.

This liquid gas two-phase refrigerant passes through a pipe joint portion 13, an inside / outside connecting pipe 12, a pipe joint portion 11, a check valve 10, and a distributor 8
Is distributed in the process of passing through each circuit of the multi-circuit type indoor heat exchanger 6 through the distribution pipes 7a and 7b, and the indoor air is cooled to evaporate and become a low-pressure gas refrigerant.

This gas refrigerant is sucked into the compressor 1 through the pipe joint 5, the inside / outside connecting pipe 4, the pipe joint 3, the four-way valve 2, the accumulator 22, and the suction pipe 23.

During the heating operation, the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the four-way valve 2, the pipe joint part 3, the inside / outside connecting pipe 4, and the pipe joint part 5 as shown by the broken line arrow in the room. The heat enters the heat exchanger 6, where it is condensed and liquefied to become a high-pressure liquid refrigerant. This liquid refrigerant enters the heating throttle 9 through the distribution pipes 7a and 7b and the distributor 8, and is throttled here to become a low-pressure liquid gas two-phase refrigerant.

This liquid gas two-phase refrigerant enters the outdoor heat exchanger 18 through the pipe joint 11, the inside / outside connecting pipe 12, the pipe joint 13, the check valve 14, the distributor 16, the distribution pipes 17a, 17b and 17c. Here, it is evaporated and vaporized into a low-pressure gas refrigerant. Then, this gas refrigerant returns to the compressor 1 via the four-way valve 2, the accumulator 22, and the suction pipe 23.

When the temperature of the compressor 1 rises abnormally, the open / close valve 20 is opened. Then, during the cooling operation, the high-pressure liquid refrigerant flowing out from the outdoor heat exchanger 18 passes through the on-off valve 20, is decompressed by the throttle mechanism 21, is sucked into the compressor 1 from the suction pipe 23, and cools it.

During the heating operation, the low-pressure liquid gas two-phase refrigerant flowing out from the check valve 14 is sucked into the compressor 1 through the on-off valve 20, the throttle mechanism 21 and the suction pipe 23 to cool it.

When the outdoor heat exchanger 18 is frosted during the heating operation, the four-way valve 2 is switched to perform the defrost operation in which the refrigerant flows in the direction of the solid line arrow as in the cooling operation.

[0010]

In the above conventional air conditioner, when the on-off valve 20 is opened during the heating operation,
Low-pressure liquid gas two-phase refrigerant flowing out from the check valve 14
Although it is sucked into the compressor 1 through 0, the throttle mechanism 21, and the suction pipe 23, the pressure difference between the pressure of the liquid-gas two-phase refrigerant flowing out from the check valve 14 and the suction pipe 23 is small, so the compressor 1 There was a problem that the amount of liquid refrigerant required for cooling No. 1 could not be supplied to the compressor 1.

In addition, as shown in FIG. 3, the drain flowing down from the outdoor heat exchanger 18 during the heating operation is the outdoor heat exchanger.
Since a large amount of frost 34 adheres to the lower part of 18 and the drain pan 33, there is a problem that the frost 34 cannot be reliably removed during the defrost operation.

The present invention has been invented to solve the above-mentioned problems, and the gist of the invention is to provide a compressor, a four-way valve, an outdoor heat exchanger, a throttle and an indoor heat exchanger. A refrigerant circuit is formed by the reactor and a cooler is configured by using the circuit below the outdoor heat exchanger,
In a heat pump type air conditioner formed by forming a bypass circuit for guiding a part of discharge gas of the compressor to the suction side of the compressor through the cooler, an electromagnetic opening / closing valve, and a throttle, when the temperature of the compressor rises. The electromagnetic on-off valve in the bypass circuit is opened, the refrigerant liquefied in the cooler is bypassed to the suction side of the compressor to cool the compressor, and the de-frost operation opens the electromagnetic on-off valve in the bypass circuit. In the method for operating a heat pump type air conditioner, the discharge refrigerant gas introduced into the cooler melts the frost in the lower part of the outdoor heat exchanger.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENT One embodiment of the present invention is shown in FIG. The cooler 18a is configured by utilizing the circuit below the outdoor heat exchanger 18.

The gas refrigerant discharged from the compressor 1 is cooled by a cooler.
A refrigerant circuit 24 to be introduced into 18a and a refrigerant circuit 25 to introduce the high-pressure liquid refrigerant condensed and liquefied by the cooler 18a into the suction pipe 23 of the compressor 1 are provided, and these refrigerant circuits 24 and 25 form a bypass circuit. Has been formed.

An electromagnetic on-off valve 20 and a throttle 21 are provided in the refrigerant circuit 25. The electromagnetic on-off valve 20 is not shown when the temperature of the gas discharged from the compressor 1 rises above a predetermined value and during defrost operation. It is opened according to the command from the control device, and the others are closed. Other configurations are similar to those of the conventional one shown in FIGS. 2 and 3, and corresponding members are designated by the same reference numerals.

However, when the temperature of the gas discharged from the compressor 1 rises above a predetermined value, the solenoid opening / closing valve 20
When is opened, part of the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 enters the cooler 18a through the refrigerant circuit 24 regardless of whether it is in the cooling operation or the heating operation, and radiates heat to the outdoor air. By doing so, it is condensed and liquefied to become a high-pressure liquid refrigerant. The liquid refrigerant passes through the refrigerant circuit 25 and the electromagnetic on-off valve 20 interposed therein and is reduced in pressure by being throttled by the throttle 21 and then supplied to the compressor 1 through the suction pipe 23 to cool it.

However, even during the heating operation, the cooler 18
Since the high-pressure liquid refrigerant condensed and liquefied in a is supplied to the compressor 1, a sufficient amount of the liquid refrigerant can be supplied to the compressor 1, and thus the compressor 1 can be cooled effectively.

Further, during the defrost operation, the four-way switching valve 2 is switched and the electromagnetic opening / closing valve 20 is opened at the same time.
The high-temperature, high-pressure gas refrigerant discharged from the compressor 1 is a cooler.
Enter 18a. Therefore, a large amount of frost 34 adhering to the lower portion of the outdoor heat exchanger 18 and the drain pan 33 can be reliably melted.

[001 8]

According to the present invention, when the temperature of the compressor rises, the electromagnetic on-off valve in the bypass circuit is opened, and the refrigerant liquefied by the cooler is bypassed to the suction side of the compressor to cool the compressor. The temperature rise of the compressor can be reliably prevented even during heating operation. Also, during defrost operation, the electromagnetic on-off valve in the bypass circuit is opened, and the frost in the lower part of the outdoor heat exchanger is melted by the discharged refrigerant gas introduced into the cooler. Can surely melt frost.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram of an air conditioner in which the method of the present invention is implemented.

FIG. 2 is a refrigerant circuit diagram of a conventional air conditioner.

FIG. 3 is a partial perspective view of an outdoor heat exchanger of a conventional air conditioner.

[Explanation of symbols]

 1 Compressor 2 Four-way valve 18 Outdoor heat exchanger 9, 15 Throttle 6 Indoor heat exchanger 18a Cooler 20 Electromagnetic on-off valve 21 Throttle 24, 25 Bypass circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI technical display location F25B 13/00 321 9335-3L (72) Inventor Hideaki Kasahara Asahi-cho, Nishibiwajima-cho, Nishikasugai-gun, Aichi prefecture Sanchome No. 1 Mitsubishi Heavy Industries, Ltd. Air Conditioning Factory

Claims (1)

[Claims] 1. A compressor, a four-way valve, an outdoor heat exchanger, a throttle and an indoor heat exchanger to form a refrigerant circuit, and a cooler is constructed by utilizing a circuit below the outdoor heat exchanger, A heat pump type air conditioner in which a bypass circuit for guiding a part of gas discharged from a machine to the suction side of the compressor through the cooler, the electromagnetic on-off valve, and the throttle is formed, and the bypass is used when the temperature of the compressor rises. The electromagnetic on-off valve in the circuit is opened, the refrigerant liquefied in the cooler is bypassed to the suction side of the compressor to cool the compressor,
A method for operating a heat pump type air conditioner, characterized in that during defrost operation, an electromagnetic on-off valve in the bypass circuit is opened, and frost in the lower portion of the outdoor heat exchanger is melted by the discharged refrigerant gas introduced into the cooler.