Patent ID: 6237351
Filing Date: 2001-05-29
Classification: B60H,F25B

Abstract:
A refrigerant cycle system for an air conditioner for a compartment, said refrigerant cycle system comprising:a case for forming an air passage which has an air inlet at one end thereof for sucking air and an air outlet at the other end thereof for blowing air into the compartment;a blower for blowing air into said air passage;a compressor disposed in a refrigerant cycle, said compressor having a suction port for sucking low-pressure refrigerant in said refrigerant cycle, a gas injection port for injecting middle-pressure gas refrigerant in said refrigerant cycle thereto, and a discharge port for discharging compressed high-pressure refrigerant;a condenser disposed in said air passage, in which high-pressure refrigerant discharged from said discharge port of said compressor flows to heat air in said air passage;a first pressure reducing unit for decompressing a part of high-pressure refrigerant discharged from said condenser to have a middle pressure during a heating mode for heating the compartment;a refrigerant-refrigerant heat exchanger for performing heat exchange between the other part of high-pressure refrigerant discharged from said condenser and middle-pressure refrigerant having passed through said first pressure reducing unit so that high-pressure refrigerant directly from said condenser is cooled and middle-pressure refrigerant from said first pressure reducing unit is evaporated;a second pressure reducing unit for decompressing high-pressure refrigerant cooled in said refrigerant-refrigerant heat exchanger to a low pressure during said heating mode;an exterior heat exchanger, disposed outside said air passage, for performing heat exchange between low-pressure refrigerant after passing through said second pressure reducing unit and outside air during said heating mode;an accumulator for separating low-pressure refrigerant from said exterior heat exchanger during said heating mode into gas refrigerant and liquid refrigerant, and for introducing gas refrigerant and oil into said suction port of said compressor;an evaporator disposed in said air passage on an upstream air side of said condensor, in which low-pressure gas-liquid refrigerant in said refrigerant cycle flows to cool air in said air passage; anda third pressure reducing unit, disposed at a refrigerant inlet side of said evaporator, for decompressing refrigerant to be introduced into said evaporator to a low pressure during a cooling mode for cooling the compartment; whereinsaid refrigerant cycle is formed in such a manner that middle-pressure gas refrigerant evaporated in said refrigerant-refrigerant heat exchanger is introduced into said gas injection port of said compressor during said heating mode;during said cooling mode, said refrigerant cycle is formed in such a manner that high-pressure gas refrigerant discharged from said compressor is heat-exchanged with outside air in said exterior heat exchanger, and low-pressure refrigerant having passed through said evaporator is introduced into said accumulator; andsaid refrigerant cycle includes a first refrigerant bypass passage through which refrigerant discharged from said condenser directly introduced into said exterior heat exchanger while bypassing said refrigerant-refrigerant heat exchanger and said second pressure reducing unit.