Investigating a ۴E analysis to study the effect of diesel-engine operating condition on the performance of waste heat recovery cycles

Various solutions have been used to improve the performance of HD diesel egines to tackle the problems caused by fossil fuels. In this paper, a MTU ۴۰۰۰ R۴۳L heavy-duty diesel engine was studied using experimental study and thermodynamic modeling to investigate the effect of engine speed on waste heat. After determining the waste heat potential, technical limitations such as back pressure and dew point were also taken into account to determine the heat that can be recovered. Three cycles of ORC, SRC, and CSO were introduced to recover the waste heat of the intercooler, water heat exchanger, and exhaust gas. All three cycles were studied from ۴E (Energy, Exergy, Economic and Environmental) point of view. The results showed that increasing the speed up to ۱۶۰۰ rpm leads to a rise in engine waste heat, and after passing this speed, the waste heat decreases, and a non-linear behavior is observed. From the energy point of view, in the best condition, the efficiency of the CSO cycle is ۴۳.۴% more than the ORC cycle and ۵۳.۳% more than the SRC cycle. However, the difference between the three introduced cycles is insignificant from the exergy point of view. Fuel energy saving ratio results showed that the CSO cycle is more economical than ORC and SRC cycles for all modes. The CSO has highest performance in ACO۲ER and the rate of ACO۲ER of CSO is the highest, also using a CSO waste heat recovery can reduce the annual tax about ۲۵۳۵۱ $ per year.

Keywords:

HD Diesel Engine , Experimental Study , Waste Heat Recovery , FESR