ENERGY AND EXERGY ANALYSES OF A DISTRICT HEATING SYSTEM IN A COLD CLIMATE

In the industrialized world, due to the depletion of fossil fuels over time, the insufficient use of renewable energy sources, and the high cost of obtaining these resources, the optimum use of the energy used in the world has become very important. Therefore, not only the energy analysis of the systems is sufficient, but also the exergy analysis is required for a district heating system. In this study, energy and exergy analyses of two steam boilers that can produce 8 tons and 12 tons of steam per hour, 49 heat exchangers located under different buildings and 8473-m pipeline carrying steam between these heat exchangers and the boiler were made. As a result of the analyses, although the total energy efficiency in the boilers, which is the most important part of the system, was found to be 88% on average, the exergy efficiency was found to be 32%. The exergy efficiency of the whole system was found to be 29%. From the results obtained in the study, it become obvious that the energy analysis of the systems only would not be sufficient, but it was also very important to perform the exergy analysis.