Turbo refrigerator

Abstract

A turbo refrigerator includes a centrifugal compressor configured to compress a refrigerant by rotation of an impeller having a plurality of blades, a condenser configured to cool the compressed refrigerant, a first expansion valve and a second expansion valve connected in series and configured to decompress the refrigerant from the condenser to form two phases of a gas and a liquid, an evaporator configured to evaporate the refrigerant from the second expansion valve, an economizer disposed between the first expansion valve and the second expansion valve and configured to separate the refrigerant into two phases of a gas and a liquid, and an introduction path configured to allow the gas phase separated from the refrigerant in the economizer to flow between a front edge and a rear edge of a blade in a main flow channel between the neighboring blades of the impeller.

1 . A turbo refrigerator comprising:
 a centrifugal compressor configured to compress a refrigerant by rotation of an impeller having a plurality of blades;   a condenser configured to cool the compressed refrigerant;   a plurality of decompressors configured to decompress the refrigerant from the condenser to form two phases of a gas and a liquid and connected to each other in series in a number greater than the number of stages of the centrifugal compressor;   an evaporator configured to evaporate the refrigerant passing through the plurality of decompressors;   gas-liquid separators disposed between the decompressors and configured to separate the refrigerant into the two phases of the gas and the liquid; and   an introduction path configured to cause the gas phase separated from the refrigerant to flow between a front edge and a rear edge between the neighboring blades in at least one of the gas-liquid separators.   
     
     
         2 . The turbo refrigerator according to  claim 1 , wherein the introduction path allows the gas phase to flow closer to the front edge side than an intermediate section between the front edge and the rear edge of the blade. 
     
     
         3 . The turbo refrigerator according to  claim 1 , wherein the introduction path allows the gas phase to flow in a flowing direction of the refrigerant on a meridional plane of the impeller. 
     
     
         4 . The turbo refrigerator according to  claim 1 , wherein the introduction path comprises a guide vane formed parallel to the blade on an inner circumferential surface of the introduction path. 
     
     
         5 . The turbo refrigerator according to  claim 1 , wherein an end section of the blade side of the introduction path has a diameter that gradually increases downstream.