Design and features of the ECC-55 experimental rig for gas-dynamic tests of model centrifugal compressor stages

The theory and practice of centrifugal process compressors (CPC) design and calculations are based on generalization of experimental data. In the previous century, model CPC stages were actively tested everywhere. During the last decade, interest in model experiments rose again. Test rigs are constructed and actively operated by CPC manufacturers and universities in the USA, Japan, China, Germany, Italy, Czech Republic and Poland. There are both open-loop and closed-loop test rigs; rotors of the models are supported by oil, roller or magnetic bearings and driven by electric motors through gear trains or belt drives and have a drive power in the range of 45– 1600 kW. The analysis shows that an open-loop test rig at an impeller speed of about 200 m/s is suitable for designing of model stages for a wide range of CPCs, developing engineering mathematical models, and verification of optimization solutions and CFD calculations. Such new test rig has been built at the Center for Science and Technology (CST) of SPbPU. A high-frequency electric motor directly drives the rotor at up to 10500 rpm. The impellers of model stages with their diameter of 350 mm can have a design flow rate at up to 0.15. A digital measuring system provides measurement of the gas-dynamic characteristics of a stage within a few minutes. Commissioning tests have confirmed operability of this test rig and its systems.