Energy and Exergy analysis of a novel geothermal-driven trigeneration system based on harnessing binary mixtures.

The two-level cooling output is the main framework of the bi-evaporator technology by which the refrigeration cycles’ capability enhances. Hence, the current study is motivated to assess the feasibility of thermal energy utilization of geothermal energy for an innovative trigeneration system encompassing a bi-evaporator-based refrigerator, a heating terminal, an electricity generation setup. In this paper, a tri-generation system of cooling, heating, and power generation is proposed, which can simultaneously produce all three outputs. The Rankine cycle is combined with an improved ejector refrigeration cycle, where the outlet flow from the second evaporator creates suction in the ejector and activates the ejector refrigeration cycle. In addition, binary working fluids are used instead of pure working fluids to enhance the system's performance. The proposed system is thermodynamically analyzed based on the first and second laws of thermodynamics for various mixtures. The highest power, refrigeration capacity, and heating output are found to be 33 kW, 214 kW, and 306 kW, respectively, for the R236fa/Pentane mixture. Additionally, the highest energy and exergy efficiencies are 54.7% and 27.48%, respectively, for the R142b/Pentane mixture.