Influence of superheat and expansion ratio on performance of organic Rankine cycle-based combined heat and power (CHP) system

Studies have shown that the group A working fluid systems are superior in performance to other fluid systems. According to the parametric analyses, the increase in superheat has a positive effect regardless of the configuration in the system using the group B working fluids. Other working fluid systems can also be expected to enhance the performance by increasing the degree of superheat in system configurations where an internal heat exchanger (IHE) and a post-heater (PH) are employed together. Increasing the volumetric expansion ratio and the isentropic efficiency of the expander improves the performance of all working fluid systems. Especially, it has been concluded that the addition of the post-heater is essential if the CHP performance is to be improved by increasing the volumetric expansion ratio and the isentropic efficiency of the expander.