Investigation of seasonal variations in the energy and exergy performance of the Gonen geothermal district heating system

In this paper, time-dependent changes in the energy and exergy performance of the Gonen geothermal district heating system (GDHS) due to seasonal differences in the energy requirement of the system are investigated. In this extend, over a one-year period the system is monitored by using fixed and portable measuring devices and all the data needed for the calculations are collected. Energy and exergy analysis of the system and its main components is carried out for winter, summer and transition seasons separately, considering the seasonal changes in the heating load of the system. The highest energy and exergy efficiencies of the overall Gonen GDHS are determined to be 45.78% and 50.45% in the transition seasons, respectively, while the lowest energy and exergy efficiencies are found to be 31.72% and 39.34% in the winter season, respectively. Besides, the annual average energy and exergy efficiencies are determined to be 41.07% and 45.86%, respectively. (C) 2011 Elsevier Ltd. All rights reserved.