An energy and exergy analysis of a microturbine CHP system

The micro-turbine is known as a producer of high-grade energy (work) and also low energy (heat). The following low grade heat energy have been modeled under ISO ambient conditions (international standard organization), i.e. 15 ℃ and 1 bar, to utilize the waste heat energy of a 200 kW micro-turbine combined with a single effect absorption chiller, an organic ranking cycle using R245fa (ORC-R245 fa) as a working fluid, a multi-effect distillation desalination (MED) and a thermal vapor compression MED Desalination unit (TVC-MED). The thermal comparison was carried out based on an energy and exergy analysis in terms of electric efficiency, exergetic efficiency, carbon footprint, and energy utilization factor (EUF). The software package IPSEpro has been used to model and simulate the proposed power plants. As a result, utilizing the exhaust waste heat energy in single-effect absorption chillier has contributed to stabilize ambient temperature fluctuation, and gain the best exergetic efficiency of 39%, while the EUF has reached 72% and the carbon footprint was reduced by 75% in MED and TVC-MED Desalination respectively. The results also reveal that TVC-MED is more efficient than traditional MED as its gain output ratio (GOR) is improved by 5.5%. In addition, ORC-245fa generates an additional 20% of the micro-turbine electricity generation