Comprehensive preliminary experimental performance investigation of a micro-CHP system by using an equipped test room

By using an equipped test room, the performance of a gas engine based micro-CHP (m-CHP) system with the nominal capacity of 49 kW (14 and 35 kW electricity and heat, respectively) is investigated experimentally. Both common operation strategies of m-CHP units, i.e. following electrical and thermal loads are studied. Experiments are done for electrical loads of 7, 8.75, 10.5, 12.25 and 14 kW as well as water outlet temperature of 55, 60, 65, 70 and 75 °C. Subsequently, based on the reported data comprehensive sensitivity analyses to find performance map and beneficial points to retrofit performance of the system are done. The impact of variation of heat and electricity demands on different parameters like caloric input value of fuel, generated heat and electricity, the temperature of exhaust gases and overall efficiency of the system are discussed during the sensitivity analyses. The results show that the possible minimum water outlet temperature is the best magnitude for it. Moreover, using the m-CHP unit in moderate to full electrical loads does not change the values of parameters like overall efficiency. Therefore, the full electrical loading operation is suggested. In this condition, the extra electricity can be either sold or given to the hot water provision system, which does not only have efficiency but also technical and economic benefits.