Investigation of the energetic and exergetic performance of the Gonen geothermal district heating system

Abstract

This article describes a performance evaluation of the Gonen geothermal district heating system (GGDHS) in Balikesir, Turkey on the basis of energy and exergy analyses. The case study covers the actual system data taken from the GGDHS in Balikesir, Turkey. General energy and exergy analyses of the geothermal district heating systems are introduced. Then, these analyses applied to the GGDHS using actual thermodynamic data for its performance evaluation in terms of energy and exergy efficiencies are presented. In addition, a parametric study on the effect of varying reference state properties on the energy and exergy efficiencies of the system that has been conducted to find the optimum performance and operating conditions is explained. In this article, the authors undertake a parametric study to investigate how varying reference temperature from 0°C to 20°C will affect the energy and exergy efficiencies of the GGDHS and develop two significant correlations (with a correlation coefficient of 0.99), which can be used for predicting the efficiencies. Two parametric expressions for energy and exergy efficiencies were developed as a function of the reference temperature. Both energy and exergy flow diagrams illustrate and compare the results under different conditions. For the actual system that is presented, the system energy and exergy efficiencies vary between 0.41 and 0.60 and 0.60 and 0.70, respectively.