CO2 emission reduction by geothermal-driven CCHP tailored with turbine bleeding and regeneration CHP; economic/multi-aspect comparative analysis with GA-based optimization

Abstract

The current research compares a geothermal-driven combined cooling, heating, and power generation cycle (B–CCHP) and a modified version using turbine bleeding and regeneration process named the TBR-CCHP cycle. These cycles incorporate organic Rankine systems, an ejector cooling system, and a heat pump system. The procedure of this study entails (i) introduction of an innovative CCHP setup, (ii) structural modification of the devised cycle, (iii) evaluation based on thermodynamic laws, (iv) optimization through GA, (v) sensitivity (vi) evaluation of the design parameters, Profitability assessment. The results indicate that the TBR-CCHP system achieves the most significant energy and exergy efficiencies with values of 87.83 % and 70.29 %, respectively. The system demonstrates heating load, cooling load, net electricity production, and total exergy destruction values of 80.38 kW, 24.26 kW, 34.44 kW, and 22.32 kW, respectively. Through optimization using genetic algorithm, improvements in energetic efficiency, exergetic efficiency, and overall energy destruction of 7.93 %, 25.53 %, and 34.83 % are seen in the B–CCHP system, and 7.37 %, 19.87 %, and 33.43 % in the TBR-CCHP system. The study reveals that in the TBR-CCHP system, the compressor is identified as the primary source of irreversibility, with reduced irreversibility during optimization. A comprehensive examination of critical parameters of the cycles indicates the significance of optimizing the generator pressure. Also, the payback period in the modified system is reduced to 6.72 years compared to the base cycle, which has a value of 8.43 years.

Keywords

• Geothermal energy
• Modified heat integration mode
• CCHP process
• Genetic algorithm
• Economic examination