Design of multi-stage turbine comprehensive performance test rig and joint commissioning verification of 1.5-stage turbine

The flow and heat transfer phenomena within the air-cooled turbine of heavy-duty gas turbines are highly complex and coupled. Accurately predicting these phenomena is critical to the successful development of turbine components. To meet the test validation requirements for turbine components, this paper developed a multi-stage turbine comprehensive performance test facility with high mass flow rate, high speed, and high power output. This facility was designed for aerodynamic and cooling performance verification of key turbine components. Based on the specifications of the typical heavy-duty gas turbine and similarity scaling theory, a calculation method for testing requirements was proposed. The test facility operates with inlet total pressures ranging from 0.2 to 0.8 MPa, inlet total temperatures from 573 to 773 K, a maximum mass flow rate of 110 kg/s, a maximum output power of 30 MW, and a maximum speed of 5000 r/min. The facility comprises subsystems including an air supply system, inlet system, exhaust system, cooling air inlet system, and transmission system. Detailed analyses and optimizations were conducted for flow field uniformity, pneumatic hammer effects, exhaust temperature control, cooling air regulation capacity, and rotor dynamic characteristics of the drive train. Design criteria were established, such as limiting the maximum post-shock pressure to ≤1.3 times the design pressure, ensuring post-expansion wave pressures above 0 kPa, and maintaining a temperature variation rate below 20% for air piping design and equipment selection. Commissioning of the test rig was accomplished via test validation with a 1.5-stage turbine test article. The measured energy balance efficiency was 86% and the shaft power efficiency was 76% at the design point, Under different conditions the measured energy balance efficiency exceeded the shaft power efficiency by 4%—13%, which provides a basis for the accurate power loss quantification in turbine design. Analysis of testing power losses, including bearing friction losses, windage losses, and leakage losses, was conducted through testing verification. The commissioning results demonstrated that the test facility exhibits stable structural integrity and smooth operation, meeting the design requirements and possessing the capability to conduct comprehensive performance testing of multi-stage turbines.