Overheat preventing method for prescribed displacement type compressor and apparatus for the same

摘要

An overheating prevention method for a fixed displacement type compressor having an overheating prevention device for introducing a part of high pressure liquefied coolant, liquefied in a compressor of a refrigeration cycle, into a compression chamber maintained under a compression stroke of the compressor through a connecting pipe, and for controlling a flow rate of the liquefied coolant flowing through the communication pipe to thereby cool the compressor. The connecting pipe is communicated with the compressor so that an average pressure within the compressor is reduced relative to a condensed pressure under a minimum operational pressure ratio condition at which the introduction of the liquefied coolant is required for cooling the compressor, within an operational pressure range in which the condensed pressure and evaporation pressure are respectively variable. The high pressure liquefied coolant may be introduced into the compression chamber, kept under the compression stroke, from a plurality of positions.