Parametric study and multi-criteria optimization of total exergetic and cost rates improvement potentials of a new geothermal based quadruple energy system

The current study presents a new designed quadruple energy production system integrated with geothermal energy involving a cascade organic Rankine cycle, liquefied natural gas vaporization process, proton exchange membrane electrolyzer to produce four types of energies, namely electricity power, heating load for vaporizing liquefied natural gas, cooling effect and hydrogen. Besides conventional analyses, advanced thermodynamic and thermoeconomic analyses are conducted to determine the irreversibilities and related cost rates within the components of the desired system to find the amount of total avoidable exergy destruction rate, and total avoidable cost rates. Moreover, the effect of substantial design parameters namely, upper cycle mass flow rate, liquefied natural gas mass flow rate, geothermal mass flow rate, turbine 1 inlet pressure, liquefied natural gas pressure, geothermal pressure and condenser 1 outlet temperature are evaluated on the total avoidable exergy destruction, total avoidable exergy destruction cost and investment cost rates as well as their subdivisions. Sensitivity studies indicate that geothermal mass flow rate has a drastic positive effect on the total avoidable exergy destruction rate and total exergy destruction cost rate within 137.2% and 119.5%, respectively while condenser 1 outlet temperature improves total avoidable investment cost rate by about 0.05 $/h, as compared with other parameters. Finally, Non-dominated Sort Genetic Algorithm-II is applied to achieve the maximum improvement potential for desired system. Optimization results show that total avoidable exergy destruction rate and total avoidable exergy destruction cost rate get 3.27 and 4.9 times, respectively and total avoidable investment cost rate is improved within 17.4% relative to the base point.