Auger-type refrigerating plant

Abstract

The spiral freezer of the invention includes a refrigerant cycle flow path comprising a screw compressor, a condenser, a heat-saving device, a main expansion valve and an evaporator, a heat-saving flow path in order to make refrigerant shunting from said cycle flow path move through supporting expansion valve 1 and then move through over-cooling flow path of the heat-saving device exchanging heat with refrigerant of the cycle flow path to inflow opening of double-pipe used for cooling the motor driving by the screw compressor, and a gas-cooling flow path from outflow opening of cooling jacket to the middle pressure department of the screw compressor. Thermal cones located on the gas-cooling flow path can detect temperature and accord to which to regulate the opening of the assisted expansion valve, so that the refrigerant becomes gas-liquid mixed state in the heat-saving flow path and the refrigerant becomes gas state in the gas-cooling flow path. Using said structures can simplify the structure and enhance the cooling capacity.

Description

technical field [0001] The invention relates to a spiral refrigeration device using a spiral compressor and an economizer. Background technique [0002] Previously, screw refrigeration plants using screw compressors and economizers have been known. [0003] In Japanese Patent Application Laid-Open No. 7-180917, a semi-hermetic spiral refrigeration device is disclosed. The refrigerant cooled by the economizer is introduced between the suction port and the discharge port in the spiral compressor, and The intermediate pressure section not connected to the suction port and the discharge port in the screw compressor, on the other hand, will start from the economizer, pass through the first expansion valve, and reach the refrigerant circulation flow path of the evaporator at the The refrigerant branched before the first expansion valve passes through another second expansion valve, is introduced into a motor that drives the screw compressor, passes through the motor, and is intro...

AI Technical Summary

Problems solved by technology

[0006] In the case of the above-mentioned Japanese Patent Application Laid-Open Report, JP 7-180917, JP 2000-179486, JP 2000-220893 and JP 2001-227830, especially in Japan In Japanese Patent Application Publication No. 2000-179486 and Japanese Patent Application Laid-Open No. 2000-220893, as clearly described as the shaft seal mechanism 1.8 or the shaft seal mechanism 1.9, between the penetrating motor and the screw compressor A shaft seal must be provided around the drive shaft of the next door to prevent leakage of refrigerant gas from the space inside the motor to the suction port of the screw compressor (the above motor is introduced with refrigerant flowing out of the economizer), so there is problems that complicate the structure

If the sealing effect of this part is insufficient, once the leakage of the above-mentioned refrigerant gas occurs, the performance of the screw compressor will be greatly reduced.

[0007] Moreover, in the case of the spiral refrigeration devices described in the above five patent documents, when a refrigerant in a liquid state is introduced into the motor, a large stirring loss will occur in the motor. Due to such a problem, it is necessary to Introduces the expanded gaseous refrigerant in the superheated state into the motor

As a result, the problem of so-called reduced freezing capacity

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