JPS6089658A - Method of testing leakage of refrigeration circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention comprises a refrigeration cycle using a rotary compressor, and a non-return check is installed in the refrigeration cycle to prevent backflow from the suction side of the rotary compressor. The present invention relates to a leak test method for a refrigeration circuit provided with a valve.

(b) Prior Art The prior art will be explained with reference to FIGS. 1 and 2. 1st
The figure shows a refrigeration circuit using a four-tally compressor, where (1) is a rotary compressor, (2) is a condenser, and (3) is a rotary compressor.
is a dehydrator, (4) is a capillary tube as a pressure reducer, and (5) is provided on the outflow side (4a) of the capillary tube (4), and the outflow side (4a) and the suction side (1a) of the compressor (1). A differential pressure valve operated by a pressure difference of
When the compressor (1) is stopped, the flow path is closed to prevent high temperature refrigerant from flowing into the evaporator (6). (7) is the accumulator as a refrigerant liquid reservoir, and (8) is the suction side (of the compressor (1)).
These check valves prevent backflow from 1a), and are connected to each other by piping to form a predetermined refrigeration cycle. Note that due to the structure of the rotary compressor (1), the check valve (8) has a high pressure on the suction side (1a) when the rotary compressor (1) is stopped. This is provided to prevent people from entering.

As shown in FIG. 2, the refrigeration circuit with such a configuration consists of an outer box (10) of a refrigerator (9), a freezer compartment (lla) that is cooled to freezing temperature, and a refrigerator compartment (llb) that is cooled to below the freezing point.
), and the majority of the refrigeration circuit is housed between the inner box α1) and the inner box α1). That is, the condenser (2), the capillary tube (
4), differential pressure valve (5), accumulator (force and check valve (
8) is buried in a heat insulating material αa that is filled between the inner box 01) and the outer box (9) using an on-site foaming method, and the evaporator (6) is installed in the freezer compartment (lla) and the refrigerator compartment (llb). placed between
The compressor (1), dehydrator (3), and charge pipe side for injecting and discharging nitrogen gas for leak testing and injecting refrigerant are arranged at the rear of the lower end of the refrigerator (1).

The leak test for the refrigeration circuit in such a configuration is as follows:
In the middle of the refrigeration circuit piping, and the back plate (10a) of the outer box QO
) is carried out before filling the insulation material α2 before installing the aft. For example, a leak test is performed by injecting and pressurizing nitrogen gas into the refrigeration circuit between the charge pipe α3) and the condenser (2), excluding the compression aft). In case of compression, nitrogen gas is injected and pressurized into the refrigeration circuit between the charge pipe side and the capillary tube (4), excluding (1), the condenser (2) and the de-idulator (3). Performing leak test. However, in either case, nitrogen gas cannot be injected into the refrigeration circuit from the check valve (8) side, so nitrogen gas must be injected and pressurized from the capillary tube (4) side. Therefore, the capillary chest (4) acts as a resistance to nitrogen gas injection, resulting in the disadvantage that injection takes an extremely long time, and the pressurization of the refrigeration circuit by nitrogen gas tends to be insufficient, making it impossible to perform a reliable leak test. As mentioned above, even if a leak is found after the refrigeration circuit is buried inside the insulation material (10
), the inner box Q]) also had to be replaced, resulting in a major drawback.

(c) Purpose of the Invention In view of the above, the present invention provides a leak test method for a refrigeration circuit that can inject leak test gas into the refrigeration circuit in a short period of time and can sufficiently pressurize the circuit. It is.

B) Structure of the Invention The present invention constitutes a predetermined refrigeration cycle by a rotary compressor, a condenser, a capillary tube, an evaporator, an accumulator, and a check valve that prevents backflow from the suction side of the compressor. A bypass pipe is installed to short-circuit the check valve, and a leak test is performed by injecting and pressurizing a leak test gas into the refrigeration cycle circuit in the middle of the refrigeration cycle piping, and after the leak test, the bypass pipe is closed. This configuration is characterized by a closed process.

(e) Embodiment FIGS. 1 and 2 show an embodiment of the present invention, and the explanations of the reference numerals already explained as the conventional example will be omitted.

α4) is a bypass pipe with one end connected to the achievator (7) and the other end connected to the connector (L5) so as to short-circuit the check valve (8). It has a thick inner diameter. Then, the refrigeration circuit equipped with the bypass pipe (14) is installed from the rear of the outer box (QO) before the back plate (10a) is attached. That is, the evaporator (6) is inserted between the freezing compartment (lla) and the refrigerating compartment (llb), and the condenser (2), capillary tube (4), differential pressure valve (5), and achievator (7) are installed. ) and check valve (8) are piped and located at the rear of the inner box (11), and the condensate pipe is piped to the charge pipe 0, the dehydrator (3), and the outflow side (1b) of the compressor (1). pipe (2) on the suction side of the device (2)
a) is placed underground at the rear of the lower end of the inner box (11). Then, a nitrogen gas pipe (not shown) for leak testing is connected between the charge pipe (I3) and the cabillary chest (4) or between the charge pipe (13) and the pipe (2a), and nitrogen gas is injected and pressurized. Perform a leak test using a detector, etc. After completing this leak test, the bypass pipe Oa is pinched and crushed to close it. After this closing process, a back plate (10a) is attached to the back of the outer box α0), and a foam-in-place insulation material (12) is injected and foamed between the outer box 00) and the inner box 00) to form the outer box (10). The refrigeration circuit interposed between the inner box (111) and the
) etc. are fixed to the rear of the lower end of the inner box α1) and piped to perform evacuation and seal off refrigerant injection. That is, when injecting and pressurizing nitrogen gas for leak testing into the refrigeration circuit, it is possible to quickly inject the nitrogen gas into the evaporator (6) etc. through the bypass pipe (14) and apply sufficient pressure. I can do it. After the leak test is completed, the bypass pipe (14
) on the suction side (1a) when the compressor (1) is stopped without impairing the function of the check valve (8).
) can prevent the backflow of high-temperature refrigerant from the

(f) Effects of the Invention As described above, the present invention provides a rotary compressor, a condenser,
A predetermined refrigeration cycle is configured by a capillary tube, an evaporator, an accumulator, and a check valve that prevents backflow from the suction side of the compressor, and a bypass pipe is provided to short-circuit the check valve. A leak test gas is injected and pressurized into the refrigeration cycle circuit midway through the refrigeration cycle piping to perform a leak test, and the bypass pipe is closed after the leak test. Gas injection is extremely short, reducing work time, and sufficient gas pressure can be applied to the refrigeration circuit, making it possible to reliably detect leaks and prevent leaks from occurring after filling the insulation material. There is no. Therefore, this is extremely convenient for refrigerators and the like in which the refrigeration circuit is embedded within a heat insulating material.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, FIG. 1 is a refrigeration circuit diagram of a refrigerator to which the present invention is applied, and FIG. 2 is a rear perspective view of the refrigerator to which the present invention is applied. (1)...Rotary compressor, (2)...Condenser, (4)...Capillary cheep, (6)...Evaporator, (7)...Accumulator, (8) ...Check valve, Q4) ...Bypass pipe.

Claims (1)

[Claims] 1. A rotary compressor, a condenser, a capillary tube, an evaporator, an accumulator, and a check valve that prevents backflow from the suction side of the compressor constitute a prescribed refrigeration cycle. A short-circuiting bypass pipe is provided, a leak test gas is injected and pressurized into the refrigeration cycle circuit midway through the refrigeration cycle piping, a leak test is performed, and the bypass pipe is closed after the leak test. Leak test method for refrigeration circuit. .