TURBO COMPRESSOR AND TURBO CHILLER USING SAME

摘要

The purpose of the present invention is to provide: a turbo compressor which is provided with an open impeller and has the minimal gap between the shroud and the impeller such that efficiency is improved and the safe operating region is enlarged; and a turbo chiller using the same. The turbo compressor (1) is provided with an open impeller (3 and 4) with a shroud (16 and 17) provided on the side of a casing (6), and the rotary shaft (5) is supported by a radial magnetic bearing (7 and 8) and a magnetic thrust bearing (9 and 10). The turbo compressor (1) is provided with a control unit (22) that comprises: a load calculating means (23) that calculates the axial thrust load generated by the pressure distribution of the compressor (1); and an axial support position control means (24) that controls a gap (S) between the impeller (3 and 4) and the shroud (16 and 17) to be a target gap (S1) by varying, on the basis of the axial thrust load, the axial support position of the rotary shaft (5) due to the magnetic thrust bearing (9 and 10).