How to Decide the Design Ambient Temperature for a Geothermal Organic Rankine Cycle Power Plant

Abstract

It is a common practice to specify the design ambient temperature for a geothermal Organic Rankine Cycle power plant with air cooled condensers. The specified value is normally the historical average ambient temperature for the region where the plant is located. Power production of an Organic Rankine Cycle plant is greatly influenced by the extreme summer and winter ambient temperatures. In this paper the author evaluates a geothermal power plant performance by simulation and utilizing historical statistical measures for ambient temperature. Average, mode and median ambient temperature values are chosen in turn as the design temperature. The annual cumulative electrical power productions of the plant are compared to determine the most optimal statistical measure for the ambient temperature. This study is based on an actual resource data from an operating geothermal Organic Rankin Cycle power plant in Turkey. This simulation study considers three statistical measures of Average, Mode and Median for ambient temperature. The Mode shows more promising outcomes than the other two measures.