Aerodynamic performance test of helium gas compressor model for GTHTR300

Takada, Shoji; Takizuka, Takakazu; Kunitomi, Kazuhiko ; Yan, X.

Design and evaluation method to reduce blade tip clearance to around 1 mm, which is around 30% lower than that of the same power industrial air compressor, was newly developed for the helium gas compressor of the GTHTR300 to enhance design efficiency. The method was verified in the aerodynamic performance test using a 1/3 scale, 4-stage helium gas compressor model. The blade tip clearance was numerically evaluated so that it should be around 0.4 mm in operation, and also measured during operation by using optical displacement sensor in the test. Aerodynamic performance tests were successfully carried out using the test model, which was connected with a helium gas loop. The inlet pressure was varied from 0.196 to 0.883 MPa. The measured efficiency was around 84 % at the design pressure ratio and the rated rotational speed of 10800 rpm, which prospected that the helium gas compressor of the GTHTR300 can be operated with efficiency over 90 % by extrapolation. The present study is entrusted from the Ministry of Education, Culture, Sports, Science and Technology of Japan.