Abstract
The control of surge for centrifugal compressors was performed by using a nozzle injection system. A part of the flow at the scroll outlet of compressor was re-circulated to an injection nozzle installed on the inner wall of the suction pipe of compressor through the bypass pipe and injected to the impeller inlet. Two types of compressors were tested at the rotational speeds of 50,000rpm and 60,000rpm with the parameter of the circumferential position of the injection nozzle. The experimental results suggested that the optimum circumferential position, which effectively deduced the flow rate for the onset of surge, did not depend on the compressor system.
