Keywords: district heating, combined cycle, ambient temperature, boiler load allocation, energy analysis, exergy analysis, performance improvement, CHP, combined heat and power
Energy and exergy analysis of a 16–MW combined cycle district heating system with performance improvements
Results of an energy and exergy analyses performed on a 16–MW University district heating plant located in the Northeast USA are presented in this paper. Unlike past studies, this paper uses actual data to assess CHP plant performance for all the 8760 h in a year (2011). A system of such complexity, considering the large volume of data available and large variations in system load, has not been analysed thermodynamically in the past. Factors affecting efficiency of the district heating plant are analysed, and recommendations for improvement discussed. Seasonal behaviour and part–load characteristics of various individual components in the plant are studied. Energy and exergy calculations are conducted on an hourly basis. Recommendations are made to improve the performance of the system using regression analysis, with potential fuel energy savings of up to 4.06% and annual cost savings of up to $126,840.