About the Problem of Utilization the Low-Potential Heat and Recent Perspective Developments

Problem of utilization of the low-potential heat and its perspectives are considered and one example from the author works is presented in detail. Description of the project and the results obtained are presented by a development of the Liquid Metal Magnetohydrodynamic (LMMHD) Gravitational Mini Power Plant (GMPP) for utilization of the low-potential heat from any available low-exergy sources, which are the huge sources of the wasted energy around the globe. Project is based on the experience by the LMMHD energy transformation with gravitational vapour/gas-lift driving principle. An example of the GMPP was developed and designed for small local consumers (100kW-1MW) for the application in the geothermal low-temperature sources 150-250C, big ferries (unused hot waters from engine), hot waters and gases from metallurgical and chemical factories, and many other similar customers. The drawings for the construction have been made and the optimal parameters computed for some potential liquid metal working media and two variants of the unit modules assembling have been elaborated (parallel assembling for getting the desired voltage or consecutive assembling for obtaining the desired current in the electrical network). The optimal height of the liquid metal circulating loop was obtained in the range 10-15 m, and the voltage in a unit 1-2 Volt.