JPH109715A - Freezer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the lowering of the life of freezing cycle parts and any cracks in a piping caused by an increase of discharge pressure pulsation by setting a connection position of each discharge piping as an oil separator. SOLUTION: Discharge pipings 3a, 3b from compressors 1a, 1b are each directly connected with an oil separator 9 without being gathered in the middle and are joined at a container of the oil separator 9. The oil separator 9 is a container having a comparatively large capacity, and an introduced high pressure gas refrigerant is reduced in pressure in the container. When there is produced pulsation on discharge pressure, a relation between the discharge pressures Pa, P of the discharge pipings 3a, 3b and the pressure P of the oil separator 9 satisfies an alternate repetition of Pa>Pb>P or Pb>Pa>P. There is a pressure difference due to pulsation between the pressures Pa and Pb, and there is the oil separator 9 between the Pa and Pb and hence the pressure P is lower than the Pa, Pb so that the Pa, Pb are discharged after passage through the oil separator 9 without reversely flowing. Thus, check valves 8a, 8b are not closed owing to a reverse flow, and there is eliminated a temporal increase of discharge pressure of the compressors 1a, 1b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a refrigeration system.

[0002]

2. Description of the Related Art As described in Japanese Patent Application No. 1-287472, the discharge pipes of each compressor are collectively connected between a compressor and an oil separator, and a single discharge pipe is assembled. It was connected to the oil separator inlet.

[0003]

In the above prior art, since the discharge pipes are collectively connected at the pipe section, a temporary reverse flow is generated due to the pressure difference between the discharge pipes due to the discharge pressure pulsation of each compressor. The increase in pressure pulsation and the increase in vibration of the piping have led to problems such as cracking of the piping and shortening of the life of parts.

An object of the present invention is to prevent the backflow of each discharge pipe by connecting each discharge pipe to an oil separator.
The object is to reduce discharge pressure pulsation.

[0005]

In order to achieve the above-mentioned object, the present invention provides a plurality of inlet pipes in an oil separator to enable collective connection in a container.

[0006]

Embodiments of the present invention will be described below.

FIG. 1 is a refrigeration cycle system diagram of a parallel compressor type refrigeration system using the prior art. In FIG. 1, the compressor 1
The discharge pipes 3a and 3b from a and 1b are collective discharge pipes 4.
And the collective discharge pipe 4 is connected to the oil separator 9.
Since the compressors 1a and 1b are positive displacement compressors, pressure fluctuations, so-called pulsations, occur in the discharge pressure. Each discharge pipe 3a, 3
Taking the case where the discharge pressure of b fluctuates at 20 ± 1 kgf / cm ² as an example, the discharge pressures Pa, Pb, P of the discharge pipes 3a, 3b and the collective connection pipe 4 are Pa = 21 kgf / cm ² > P =
20 kgf / cm ² > Pb = 19 kgf / cm ² , or vice versa, and a backflow occurs alternately between the discharge pipes 3a and 3b. Since the check valves 8a and 8b are closed by the backflow, the pressure in the compressors 1a and 1b alternately increases, and the pulsation of the discharge pressure increases.

FIG. 2 is a refrigeration cycle system diagram of a parallel compressor type refrigeration system according to one embodiment of the present invention. In FIG. 2, discharge pipes 3a and 3b from the compressors 1a and 1b are assembled in the middle. Without being connected directly to the oil separators 9, they are gathered in a container of the oil separator 9. The oil separator 9 is a container having a relatively large capacity, and the introduced high-pressure gas refrigerant is depressurized in the container. In the present invention, when pulsation occurs in the discharge pressure as described above, the relationship between the above Pa, Pb, and P is Pa> Pb.
> P or Pb>Pa> P. P
Although a and Pb have a pressure difference due to pulsation, there is an oil separator 9 between Pa and Pb, and since the pressure is lower than Pa and Pb, Pa and Pb pass through the oil separator 9 without flowing backward. And discharged. Accordingly, the check valves 8a and 8b do not close due to the backflow, and the discharge pressure of the compressors 1a and 1b does not temporarily increase. Therefore, the discharge pressure pulsation can be reduced, and the pulsation causes cracks in the piping and freezing The life of the cycle parts is not reduced.

[0009]

According to the present invention, in a parallel-compressor refrigeration system having a plurality of compressors, cracks in piping and reduction in life of refrigeration cycle components caused by an increase in discharge pressure pulsation are eliminated. In addition, since the oil separator container is used for pulsation reduction, other pulsation reduction containers are not required, so that economy and productivity are improved.

[Brief description of the drawings]

FIG. 1 is a cycle system diagram of a parallel-compressor-type refrigeration apparatus using a conventional technique.

FIG. 2 is a system diagram of a cycle of the parallel compressor refrigeration apparatus according to one embodiment of the present invention.

[Explanation of symbols]

1a, 1b: compressor, 2a, 2b, 3a, 3b: discharge pipe, 4, 5: collective discharge pipe, 6: accumulator, 7
a, 7b: suction pipe, 8a, 8b: check valve, 9: oil separator.

Claims (1)

[Claims] 1. A refrigerating apparatus having a parallel compressor in which discharge pipes of a plurality of compressors are connected to a common discharge pipe and respective suction pipes are connected to a common suction pipe. A refrigerating apparatus, wherein a connection position of a discharge pipe is an oil separator.