A method of cooling a two-stage centrifugal compressor and the two-stage centrifugal compressor to perform the method

Abstract

The method of cooling a two-stage centrifugal compressor containing two radial impellers (110, 120) mounted on a common shaft (13), in the central part of which there is a rotor (140) of the electric motor (14) surrounded by a stator (141), which is mounted in the housing (8) of the compressor. Between the impeller (110) of the first stage (11) of the compressor and the electric motor (14), the shaft (140) is mounted in the first radial gas-dynamic bearing (16), and between the impeller (120) of the second stage (12) of the compressor and the electric motor (14), the shaft (13) is mounted in the second radial gas-dynamic bearing (17) and in the double-sided axial gas-dynamic bearing (18), whereas the output (112) of the first compressor stage (11) is connected with the input (121) of the second compressor stage (12). Around the outside of the stator (141) the liquid state coolant is run which is heated as a result of the passage around the stator (141) and the resulting gaseous coolant is used to cool the rotor (140), the second radial gas-dynamic bearing (17) and the double-sided axial gas-dynamic bearing (18), whereas the bearings (17, 18) are at the same time cooled by the coolant brought from the second spiral chamber (1201), whereas the gaseous coolant from the first spiral chamber (1101) is brought to cool the first radial gas-dynamic bearing (16). The two-stage centrifugal compressor to perform the method is further described.