Exergy, economic, and exergoenvironmental analyses of new combined heat and power process based on mechanism analysis of working fluid screening

Abstract

A screening strategy was established for obtaining an optimal working fluid (R1234yf) based on quantum chemical analysis. The weak hydrogen bond interactions of R1234yf enhanced the performance of the organic Rankine cycle. The proposed process produced 49.28 MW of electricity and 0.5 MPa of steam. The optimal process was evaluated by multifactor analysis of exergy, economic, and exergoenvironmental performance. Exergy analysis demonstrated the exergy loss to be 37.92% and the power system to be greater than that of the heating system. The exergy losses of the turbine, the evaporator and condenser for the organic Rankine cycle reach maximum values of 19.17%, 4.48%, and 4.72%, respectively. Economic analysis indicated that the operating cost and total annual cost of the proposed process were $ 2.37 × 106 and $14.01 × 106, respectively. Among the equipment, the cost of the condenser was the highest due to the large heat transfer area. Exergoenvironmental analysis proved that the exergy destruction effect on the environment was the lowest when maintaining the outlet temperature at 38 °C.