TW200607912A - Energy recovery system - Google Patents

Abstract

An energy recovery system, for extracting energy from a source of waste heat (e.g., hot waste fluid from small industrial installations, automotive combustion engines, etc.) the system being a closed Rankine cycle system with a circulating working fluid. The system comprises: a first heat exchanger for receiving source fluid, incorporating the waste heat, at a first temperature and outputting said waste fluid at a second temperature, and for receiving said working fluid at a third temperature and outputting the working fluid at a fourth temperature, said fourth temperature being higher than said third temperature and higher than the boiling point of the working fluid; a turbine unit, arranged to receive the working fluid output from the first heat exchanger at a first pressure and to output the working fluid at a second pressure, said second pressure being lower than the first pressure, the turbine unit thereby imparting rotational energy to a turbine shaft mounted within the turbine unit; an electromechanical conversion unit (including an alternator), coupled to the turbine shaft, for converting said rotational energy into electrical energy, a cooling system, coupled to the turbine unit and to the first heat exchanger, for receiving the working fluid from the turbine unit at a fifth temperature, cooling the fluid, and supplying the fluid to the first heat exchanger at said third temperature. A technique for controlling the output power of the alternator is also disclosed. Special turbine, bearing, torque coupling, power control and working fluid purification techniques are also disclosed.