Performance test results of 80 K centrifugal compressor for helium refrigerator

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:45486

Asakura, H; Kato, D; Saji, N; Ohya, H; Kubota, M; Kaneko, Y; Nagai, S ^[1]; Toyama, R ^[2]

---

1. Ishikawajima-Harima Heavy Industries Co., Ltd., Tokyo (Japan)
2. Super-GM, Osaka (Japan)

The authors have developed a completely oil-free compressor used for the highly reliable helium refrigeration system for a superconducting generator and carried out performance tests under actual condition. The compressor is designed to achieve a pressure ratio of 8 with only 4 stages by cooling the compressor inlet at 80 K with liquid nitrogen, thus acquiring high reliability of long-term maintenance-free operation together with the use of magnetic bearings for oil-free operation. The compressor at each stage is independently driven by a 25 kW built-in motor at the speed of 100,000 rpm, with the power supplied by a variable frequency inverter. The performance test was carried out at each stage, by incorporating the compressor in the closed loop test equipment using helium gas. It was recognized from the test results that the specified pressure ratio of each stage was achieved at the speed below the rated one of 100,000 rpm. It was found that each stage of the compressor has a flat characteristics of adiabatic efficiency over the wide flow range. The mechanical rotation characteristics at low temperatures was also confirmed to be sufficiently stable.

• OSTI ID: 45486
• Report Number(s): CONF-930703--
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
COMPRESSORS
CRYOGENICS
PERFORMANCE TESTING
REFRIGERATORS
SUPERCONDUCTING GENERATORS