Haile Araya Nigusse et al Int. Journal of Engineering Research and Applications www.ijera.com ISSN : 2248-9622, Vol. 4, Issue 8( Version 3), August 2014, pp.141-147 www.ijera.com 141 | Page Performance Analysis of a Shell Tube Condenser for a Model Organic Rankine Cycle for Use in Geothermal Power Plant Haile Araya Nigusse 1 , Hiram M. Ndiritu 1 , Robert Kiplimo 1 1 Department of Mechanical Engineering, Jomo Kenyatta University of Agriculture and Technology, Kenya ABSTRACT The global energy demand increases with the economic growth and population rise. Most electrical power is currently generated by conventional methods from fossil fuels. Despite the high energy demand, the conventional energy resources such as fossil fuels have been declining. In addition to this harmful combustion byproducts are resulting global warming. However, the increase of environmental concerns and energy crisis can be minimized by sustainable utilization of the low to medium temperature heat resources. The Organic Rankine Cycle power plant is a very effective option for utilization of low grade heat sources for power generation. Heat exchangers are the main components of the Organic Rankine Cycle power plant which receives heat energy from the heat source to evaporate and condense the low boiling temperature organic working fluid which in turn drives the turbine to generate power. This paper presents a simplified approach to the design, fabrication and performance assessment of a shell tube heat exchanger designed for condenser in a model Organic Rankine Cycle geothermal power plant. The design involved sizing of heat exchanger (condenser) using the LMTD method based on an expected heat transfer rate. The heat exchanger of the model power plant was tested in which hot water simulated geothermal brine. The results of the experiment indicated that the heat exchanger is thermally suitable for the condenser of the model power plant. Keywords - Shell tube heat Exchanger, Heat transfer Co-efficient, LMTD. I. Introduction Energy consumption increases with growth in economies and population. The increase in energy demand will occur mainly in developing countries, where economic growth rates are high and people are shifting from biomass energy sources like wood and agricultural waste to electricity. However, the increase of environmental concerns and energy crisis has resulted in need for a sustainable approach to the utilization of the earth's energy resources. Worldwide, geothermal power plants have a capacity of about 12 GW power generations as of 2013 and in practice supply only about 0.3% of global power demand [1]. However, the conventional geothermal power plants utilize the high temperature and pressure geo-fluid and operate at low efficiency due to the heat loss in the exhausted steam and brine. The Organic Rankine Cycle power plant is a very attractive option for utilization of low-grade geothermal heat sources for power generation. Heat exchangers are the main components of the Organic Rankine Cycle geothermal power plant to receives heat energy from the hot water (brine) and vaporize and condense the low boiling temperature organic working fluid which drives the turbine to generate power. This paper presents design, fabrication and performance assessment test of the shell and tube heat exchanger designed for the condenser of a model Organic Rankine Cycle power plant. Performance tests of the heat exchanger were conducted by relating the inlet and outlet temperatures and the overall heat transfer coefficient to the rate of heat transfer between the working fluid (n-pentane) and the cooling water. Heat exchanger is an apparatus or equipment built for efficient heat transfer between two or more fluid streams at different temperatures. The shell tube heat exchanger is widely used in many binary cycle power plants. This widespread application can be justified by the availability of codes and standards for design and fabrication; it can be manufactured from a wide variety of materials and ability to be produced in the widest variety of sizes and styles. Moreover, It can be designed for a wide range of limits on the operating temperature and pressure [2, 3]. A typical counter flow shell and tube heat exchanger is shown in figure 1 RESEARCH ARTICLE OPEN ACCESS