Expansion machine for a low power-output steam Rankine-cycle engine

摘要: Abstract The performance of the expansion device in a Rankine-cycle engine is one major parameters dictating engine's overall energy-conversion efficiency. In this paper, screening process undertaken to choose most suitable machine for steam engine, operating principally as ‘mini’ combined heat-and-power unit, described. low power-output range (i.e. 5–20 kW) envisaged rotary, positive-displacement machines offer many advantages compared with turbines and reciprocatingpiston expanders. So rotary-vane, helical-screw Wankel-type devices were short listed. However further assessments, based upon operational problems cost effectiveness, led finally choice expander proposed application. Nevertheless, be commercially successful, existing designs need modified optimised.