COMPRESSOR

PURPOSE:To prevent liquid compression and make it near the isothermal compression so as to improve its efficiency, in compressing refrigerant gas under turning of a swirler, by providing the title device with an injection nozzle, its change-over valve and a swirler for injecting liquid refrigerant in a minite fog state at an optional timing. CONSTITUTION:In a rotary compressor for compressing refrigerant gas, a compression space 20, which is contracted between a roller 12 and a vane 19 by the turning motion of the roller 12, is formed in a cylinder 11. A liquid refrigerant injection device 17 is positioned in the vicinity of the refrigerant gas exit 101 so as to face to the compression chamber at approximately any position in a compression stroke. The liquid refrigerant injection device 17 is provided with a nozzle 23, a valve body, swirler, an electro-magnet and an armature. When pulse-formed voltage is applied to the electro-magnet, the armature is inhaled to open the valve, so that minite fog like liquid refrigerant decentered and swirled by the swirler is injected through the small hole of the nozzle 23. Accordingly, this liquid refrigerant is easily gasified so as to prevent liquid compression, and also is made near the isothermal compression so as to prevent the valve from being damaged and obtain the maximum energy efficiency.