Thermodynamic Efficiency Analysis of a Combined Power and Cooling (ORC-VCRC) System Using Cyclopentane (C5H10) as a Substitute for Conventional Hydrocarbons

The present study investigation aims to contribute to the field of energy engineering by exploring the performances of cyclopentane gas as promising working fluid in combined power and cooling (ORC–VCRC) system. The present research emphasizes the comparative computation of various thermodynamic performance characteristics of (ORC–VCRC) system activated by low temperature heat sources using cyclopentane gas as a substitute to the conventional hydrocarbons (butane, isobutene, propane and propylene) widely used in (ORC–VCRC) system. A computer code was developed using MATLAB software for the numerical simulation. The performance characteristics computed are the performance indicators (overall coefficient of performance (COPoval) and working fluid mass flow rate of per kW cooling capacity (MkW), expansion ratio in expander (EPR) and compression ratio in compressor (CMR). Furthermore, the effects of different operating parameters (e.g., boiler, condenser, and evaporator temperatures, isentropic efficiency of expander (ηexp), and isentropic efficiency of compressor (ηcomp)) on performance indicators are also examined for each working fluid. Results showed that under the same operating parameters, the use of cyclopentane gas as a working fluid in (ORC–VCRC) system exhibited a higher COPoval and lower MkW compared with conventional hydrocarbons. When boiler temperature reaches 90 °C, the COPoval of cyclopentane increase by 14 %, 19.8 %, 43.8 % and 59 % compared to those of butane, isobutene, propane and propylene, respectively. However, the MkW of cyclopentane reduced by 19.1 %, 29.2 %, 44.3 % and 53.7 % compared to same fluids, respectively. On another hand, the study revealed that the COPoval rises as the temperature of the boiler, evaporator, exp and comp rises. Conversely, when the condenser temperature rises, the COPoval value falls for all fluids. Overall, the study confirms that cyclopentane gas could be a promising working fluid in terms of performance indicators for (ORC–VCRC) system.