摘要 |
The purpose of the present invention is to provide: a turbo compressor which is provided with an open impeller and has a 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, 4) with a shroud (16, 17) provided on the side of a casing (6), and the rotary shaft (5) is supported by a radial magnetic bearing (7, 8) and a magnetic thrust bearing (9, 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, 4) and the shroud (16, 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, 10). |