Journal of Propulsion and Energy ISSN:2734-1887(Print) 2765-0049(Online)

Thermodynamic performances of a combined heat and power (CHP) cogeneration system using organic Rankine cycle (ORC) are investigated based on energy, exergy, and entransy principles. The present system comprises of an ORC driven by a low-grade heat source and a process heater in a parallel circuit configuration. The entransy balance equations including entransy work, entransy dissipation, and entransy loss are established, which are consistent with those of energy and exergy. Several forms of efficiencies and composition ratios such as exergy destructions, entransy dissipations, and losses are introduced as well. Influences of key system parameters such as source temperature, turbine inlet pressure, and selection of different working fluids on the system performances are analyzed. Present results show that energy, exergy, and entransy performances are greatly influenced by the system parameters and working fluid. In addition, entransy analysis shows different results from energy or exergy analyses, and in some situations, it shows existence of optimal points, which do not occur in energy or exergy analyses.