JPH0593549A - Refrigerator - Google Patents

Abstract

PURPOSE:To provide a stable one-side operation by providing a check valve for preventing reverse flow of refrigerant gas on the way of a discharge gas temperature control injection tube in a refrigerator having a twin type scroll compressor. CONSTITUTION:The refrigerator comprises a refrigerating cycle having a twin type scroll compressor 11, a condenser 2, a liquid reservoir 3, an expansion valve 4 and an evaporator 5, a liquid injection tube for connecting the reservoir 3 to intermediate pressure parts 1ca, 1cb of the compressor, and check valves 7a, 7b for preventing reverse flows of refrigerant gas at the time of liquid injection during a one-side operation. Check valves are respectively provided in discharge gas temperature control liquid injection tubes of the scroll compressor to prevent reverse flow of the refrigerant gas during the one-side operation, thereby performing a stable operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration system equipped with a twin compressor for introducing a liquid refrigerant into an intermediate pressure portion (hereinafter referred to as "liquid injection") for controlling discharge gas temperature, and is particularly stable. The present invention relates to a refrigeration system that realizes a single lung operation.

[0002]

2. Description of the Related Art A conventional device has a mechanism for controlling the amount of liquid injection, as described in JP-A-1-269866, but it does not have a check valve.

[0003]

The above-mentioned prior art has no problem in a refrigerating apparatus having only one pair of scroll wrap and electric motor (hereinafter referred to as "single machine") in one chamber. For twin-type scroll compressors with liquid injection in each lap as shown in the range, and when operating these two motors independently (hereinafter referred to as "single lung operation"), for liquid injection while stopped There was a problem that the refrigerant flows backward in the liquid refrigerant introduction pipe of.

An object of the present invention is to provide a refrigerating apparatus which enables stable liquid injection even when the twin scroll compressor is operated in one lung.

[0005]

The above object is to provide a check valve in each liquid refrigerant introduction pipe for liquid injection,
This is achieved by preventing the backflow of the refrigerant even when the twin scroll compressor is operated in one lung.

[0006]

When a single-lung operation is performed in a refrigeration system equipped with a twin scroll compressor by controlling the capacity of the compressor, the intermediate pressure part in the lap during operation becomes the intermediate pressure between the suction pressure and the discharge pressure. Although it is possible to receive the introduction of the liquid refrigerant, almost all of the intermediate pressure portion in the lap when stopped is at the same discharge pressure. This causes a pressure difference between the discharge pressure and the outlet of the condenser that takes out the high-pressure liquid refrigerant, and this pressure difference becomes a reverse pressure in the liquid refrigerant introduction pipe for liquid injection, and the refrigerant in the lap stopped The gas flows back and is introduced into the intermediate pressure section through the liquid refrigerant introduction pipe for liquid injection during operation, but this check valve prevents backflow even if this backpressure occurs and stabilizes. It becomes possible to perform one lung operation.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, a twin-type scroll compressor 1, a condenser 2, a liquid receiver 3, an expansion valve 4, and an evaporator 5 constitute a basic refrigeration cycle, and a high-pressure liquid refrigerant discharged from the liquid receiver 3 for cooling discharge gas is discharged. An intermediate pressure through hole inlet portion 1c opened in each of the scroll wraps 1aa and 1ba through a solenoid valve 6
The check valves 7a and 7b and the flow rate adjusting capillaries 8a and 8b form a liquid injection circuit in the middle of the respective pipes while flowing into a and 1cb.

In the above cycle, during the operation of both lungs, since the intermediate pressure through hole inlet portions 1ac and 1bc are at the intermediate pressure, the liquid refrigerant flows toward the compressor 1 to cool the discharged gas. During single lung operation, for example, when the No. 1 side electric motor 1ba operates and the No. 2 side electric motor 1bb stops, the pressure at the No. 2 side through-hole inlet portion 1bc becomes almost the same as the discharge pressure, and the reverse. Reverse pressure is applied to the stop valve 7b. If the check valve 7b is not provided here, the high-pressure gas passes through the through hole 1bc and the capillary 8b and enters the liquid injection line on the No. 1 machine side, and the function for cooling the discharge gas raises the discharge gas. It will be.

For this reason, the check valve 7b operates and only a predetermined liquid refrigerant can be supplied even during the single lung operation. Further, as the one lung operation, when the No. 1 side is stopped and the No. 2 side is in operation, the No. 1 side check valve 7a similarly prevents backflow.

As a result, stable single lung operation becomes possible.

[0011]

According to the present invention, there is an effect that the twin scroll compressor can be stably operated in one lung.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle system diagram showing an embodiment of the present invention.

[Explanation of symbols]

1 ... Twin scroll compressor, 1aa, 1ab ... Scroll wrap, 1ba, 1bb ... Compressor electric motor, 1c
a, 1cb ... Intermediate pressure through hole inlet, 2 ... Condenser, 3 ... Liquid receiver, 4 ... Expansion valve, 5 ... Evaporator, 6 ... Electromagnetic valve, 7a, 7
b ... Non-return valve, 8a, 8b ... Capillary tube.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyoshi Hiraoka 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Shimizu Plant, Hitachi, Ltd. (72) Osamu Hagiri 390 Muramatsu, Shimizu-shi, Hitachi Hitachi Shimizu Engineering Co., Ltd. Within

Claims (1)

[Claims] 1. A twin scroll compressor having two pairs of scroll wraps and electric motors for driving the scroll wraps is mounted in one chamber, and is connected to a condenser, a pressure reducer and an evaporator to form a refrigerant circuit. Then, in the refrigeration apparatus that introduces the high-pressure liquid refrigerant at the outlet of the condenser into the through holes opened in the compression chamber where the scroll wrap has an intermediate pressure between the suction pressure and the discharge pressure, the liquid refrigerant introduction into each through hole A refrigeration system having a check valve in a pipe.