A key review on performance improvement aspects of geothermal district heating systems and applications

This paper deals with a comprehensive analysis and discussion of geothermal district heating systems and applications. In this regard, case studies are presented to study the thermodynamic aspects in terms of energy and exergy and performance improvement opportunities of three geothermal district heating systems, namely (i) Balcova geothermal district heating system (BGDHS), (ii) Salihli geothermal district heating system (SGDHS), and (iii) Gonen geothermal district heating system (GGDHS) installed in Turkey. Energy and exergy modeling of geothermal district heating systems for system analysis and performance evaluation are given, while their performances are evaluated using energy and exergy analysis method. Energy and exergy specifications are presented in tables. In the analysis, the actual system operational data are utilized. In comparison of the local three district heating systems with each other, it is found that the SGDHS has highest energy efficiency, while the GGDHS has highest exergy efficiency.