Preliminary Design of an Axial-Flow Turbine for Small-Scale Supercritical Organic Rankine Cycle

A small-scale organic Rankine cycle (ORC) with kW-class power output has a wide application prospect in industrial low-grade energy utilization. Increasing the expansion pressure ratio of ORC is an effective approach to improve efficiency. However, there lack suitable expander for that can operate high efficiency under condition large and small mass flow rate. Aiming at design high-efficiency axial-flow turbine system, this paper investigates performance proposes method improvement. First, preliminary conducted optimize geometric parameters aerodynamic parameters. Then, effects tip clearance trailing edge thickness on are analyzed off-design conditions. The results show two-stage or three-stage evidently better than single-stage one. close while speed lower. Meanwhile, loss leakage be significantly reduced via reducing clearance, thus improved significantly. estimated arrives 0.82, which 33% higher conventional turbine. Considering limitation speed, feasible choice ORC.