Although systems are available for the generation of power from low-temperature heat sources in the industrial sector - i.e., organic-Rankine-cycle systems (ORC) - they are only available for medium and large-scale applications. Smaller systems have not been economically feasible because: (1) there is a lack of turbines that have adequate efficiency in the required size range, and (2) the costs associated with low initial production quantities are too high. This project will demonstrate the conversion of low-temperature waste heat into power using a scroll turbine in a Micro-Steam Cycle (MSC) that uses water as the working fluid. The use of water instead of an organic working fluid would substantially reduce the cost of the system compared to ORC scroll turbines. Phase I will determine technical feasibility by designing and building a prototype system, and conducting tests to demonstrate that the scroll turbine can be operated at relatively high temperature (about 210ºC). This will require the design of a new oil lubrication system capable of managing two immiscible fluids, such as oil and water, in a bi-phase expansion process.
Commercial Applications and Other Benefits as described by the awardee: Numerous potential commercial applications include industrial waste-heat recovery systems; exhaust-gas heat recovery within landfill power generation units; combined heat and power systems, such as micro-cogeneration with boilers, for use in buildings and commercial facilities; and renewable energy applications, such as biomass and thermal-solar systems. The elimination of organic fluids also would provide environmental benefits because the organic fluids are often toxic and flammable, and associated with ozone depletion and global warming
