Abstract: A compression refrigerating machine for enabling an alternative refrigerant to be used by removing water content or chlorine which may be mixed into a lubricating oil. The compression refrigerating machine includes a vaporizer, a condenser, a compressor for compressing a refrigerant gas from the vaporizer, a drive source for driving the compressor, a lubricating oil line in which a lubricating oil is circulated and a refrigerant line in which a refrigerant is circulated. The lubricating oil line provides with a device for removing water content or for removing chlorine.

Abstract: A centrifugal compressor has a diffuser with stator blades arranged therein for converting the kinetic energy of a fluid discharged from an impeller into a pressure energy. The stator blades have leading edges inclined in the downstream direction while extending away from a side plate toward a core plate. Auxiliary blades having a chord length shorter than that of each of the stator blades have leading edges inclined in the downstream direction while extending away from the side plate toward the core plate and are arranged at positions radially inward of the stator plates in such a manner that one of the surfaces of each of the auxiliary blades faces a stator blade. The compressor is capable of operating without suffering from surging and rotating stall even in a low flow rate region.