Investigating the effects of load demands on selection of optimum CCHP-ORC plant

Abstract

Optimum design of combined cooling, heating and power (CCHP) generation system with Organic Rankine Cycle (ORC) is presented to find the optimum prime mover and its benefit for various cooling, heating and electrical load demands using Real Parameter Genetic Algorithm (RPGA). Annual benefit is selected as objective function which shows the benefit of CCHP-ORC system compared with conventional system. To find the optimum prime mover (among the gas engine, diesel engine and gas turbine) and its benefit in different load demands, two non-dimensional design parameters named electric cooling ratio and nominal power ratio are defined. The optimum results are presented in form of 3D figures which show the values of benefit for each prime mover at different load demands. The optimum results show that the highest values of annual benefit are obtained for the highest values of heating load demand. It is also observed that, for lower electrical and higher heating load demands, the gas turbine is more profitable while for higher electrical and heating load demands, diesel engine is more profitable than the other studied prime mover. In addition some range of load demands in which the use of CCHP-ORC plant is not profitable (in comparison with traditional system) are also investigated and presented. Finally, sensitivity analysis is performed and results are presented when electricity and fuel price change.