Performance of a Hero's Turbine Using Two-Phase Mixture as a Working Fluid : Experimental Results in an Air-Water Two-Phase Flow System

Abstract

The development of an expander with high efficiency using a low-quality vapor-liquid mixture as the working fluid is very important from the view point of effective utilization of water dominated geothermal resources and waste heat sources from factories. The fundamental performance characteristics of a Hero's turbine, which is a radial outflow reaction turbine, have been investigated experimentally using an air-water two-phase mixture as the working fluid. Small scale models of the Hero's turbine, which incorporate a 200 mm dia. disk with three nozzles, were tested in the range of Gt=0.6 to 1.2 kg/s and Gg=0 to 12.4×10-3 kg/s. The effects of air flow rate, water flow rate, and quality on the efficiency and each loss have been discussed. Furthermore, the two-phase flow configuration in the passage of turbine was observed.