ADVANCED ORGANIC RANKINE CYCLES IN BINARY GEOTHERMAL POWER PLANTS CYCLES DE RANKINE À VAPEUR ORGANIQUE DANS LES CENTRALS GEOTHERMIQUES BINAIRES

In the last two decades the binary power plant, utilizing the Organic Rankine Cycle (ORC), has become a preferred means of exploiting low to moderate enthalpy geothermal resources. It has been widely used to utilize the brine in existing single flash plants and in many other applications as an efficient and reliable way of employing a geothermal resource, in the form of brine only or brine and low pressure steam coming from a separator. Over the years the basic ORC has been improved and modified to better adapt the cycle to various conditions of the heat source. More then 800 MW of such plants are in operation, about 90% of them manufactured by Ormat. In this paper we describe some advanced versions of the Organic Rankine Cycle and their application for an efficient utilization of geothermal fluids having specific thermal and chemical properties. Resume