Investigation of the effects of operating parameters of an internal combustion engine on the performance and fuel consumption of a CCHP system

In the present study, a combined cooling, heating and power (CCHP) system with a gas internal combustion (IC) engine prime mover, called EF7, has been proposed. A numerical model has been presented to evaluate the performance of the system, and for the first time, the effects of operating parameters of the IC engine, such as the combustion start angle, combustion duration, compression ratio and rotational speed, on the performance and fuel consumption of the CCHP system have been studied. Results show that the minimum specific fuel consumption required for power generation is achieved when combustion starts close to top dead centre (TDC) (i.e. 20 degrees before TDC), and combustion duration is up to 5 degrees after TDC. Additionally, for providing heating load, the minimum specific fuel consumption is achieved when combustion occurs further from TDC (i.e. 50 degrees before TDC), and the combustion duration is about 10 degrees. The minimum specific fuel consumption needed for cooling load is obtained when combustion occurs close to TDC (20 degrees before TDC), and combustion duration is about 70 degrees. The findings of this research will help in the design of optimum IC-based CCHP systems capable of providing demand loads with the minimum fuel consumption as well as reducing pollutants. (C) 2020 Elsevier Ltd. All rights reserved.