Organic Rankine Cycle Based Geothermal Energy for Power Generation in Egypt

Abstract

Low temperature geothermal resources are located in many areas and represent a high potential energy resource. One of the most common tech-nologies, efficient and to exploit this type of resource is the binary cycle tech-nology. Organic Rankine Cycle (ORC) is one of the main types of binary cycles. Electricity generation from low enthalpy geothermal energy using ORC is a talented technology. This paper addresses the design of binary cycle power plant utilizing one of the low temperature geothermal resource of temperature 92˚C using four alternative working fluids: Butane, Isobutane, Pentane and 1,1,1,3,3-Pentafluoropropan (R245fa). Bir Nabi is the well under considera-tion which located in the Eastern desert, Egypt. Three operation parameters: geothermal temperature, reinjection temperature and geothermal flow rate are taken into consideration to analyze the performance of the power plant for different fluids. A performance analysis is conducted on ORC binary power plant using MATLAB programming to study the variation of output power and efficiency with the operation parameters. Also, the effect of these para-meters on the area of ORC binary cycle power plant components; preheater, evaporator and condenser is presented. The geothermal resources tempera-tures are in the range of 90˚C to130˚C, the mass flow rate of the geothermal fluid ranges between 10 kg/s and 50 kg/s and reinjection temperature ranges from 30˚C to 70˚C. The results indicate that, the highest output power and plant efficiency are obtained with Pentane.