Current concerns with climate change have resulted in greatly increased interest in power recovery from low grade heat sources. This includes both hot fluid streams which can be expanded directly to produce mechanical power and those which act as a source of heat to closed cycle power generation systems. Power recovery from low grate heat by means of screw expanders with a generalised overview of how best to recover power from such sources, based on thermodynamic considerations, which differs to the approach used in classical thermodynamics textbooks and which includes an...