rotary screw, screw, compressor, test stand, test
ABSTRACT A new high-performance test stand tests both constant speed and variable speed semi-hermetic rotary screw R134A water chiller compressors ranging from approximately 250 to 600kW rated refrigeration capacity. The stand produces rapid post-production functional tests with excellent accuracy, higher measurement accuracy laboratory-quality tests, and also manually-directed tests of any duration. All tests include startup, warmup and steady state data recording at three operating conditions (typically full load displacement, intermediate load and unload). Some compressor models additionally perform an oil shuttle control valve test. The test sequence is automatic, requiring operator intervention only to mount and connect the Unit Under Test (UUT), scan barcodes and start the test. Following test completion, the operator disconnects and removes the UUT. A workstation computer prints and saves a comprehensive test report automatically. Two test stations increase throughput by allowing a UUT that has completed testing to be reclaimed and unloaded, and a new UUT to be loaded and evacuated on one station while a third UUT is running a test on the other station. A Programmable Automation Controller (PAC) monitors and controls the refrigerant circuit and the UUT variable frequency drive as well as auxiliary equipment such as lube oil, vacuum and reclaim systems. Other integrated controls include a touchscreen operator interface and three personal computers (PCs).