Exergy and thermoeconomic analysis of the combined MED desalination system and the Allam power generation system

Because of population growth, demands for water and energy for domestic, industrial, and agricultural usages are increasing. Considerable research has been conducted in recent years to evaluate the thermodynamics and optimization of desalination systems. One important concept is the capacity to integrate power generation systems with desalination plants. The purpose of this study is to analyze the exergy and thermoeconomics of the combined desalination system (MED) and Allam power generation system. The key advantage of this proposed system is to use the heat generated in the Allam power generation system to operate the desalination system. Similarly, due to the performance of the Allam generation system, the amount of carbon dioxide produced is virtually zero. By determining the processes and solving the governing equations, the properties of the fluids passing through the combined cycle of Allam and MED are determined and thermodynamic, exergetic and thermoeconomic analysis is performed along with the thermoeconomic optimization of the system. In this research, genetic algorithm has been used for optimization and the result has been described in multi-objective optimization. Subsequently, parametric analysis and the effect of design variables on the system cost function have been accomplished. The results show that in a specific vector of decision variables, the objective functions including, the exergetic efficiency and the cost of the product produced by the system are optimized simultaneously. In conventional desalination plants, a boiler is used to supply the steam entering the desalination system. After conducting the model simulation of the desalination system, the Allam generation system is modeled as well. Thus, by combining these two systems, the heat generated by the Allam generation system can be used to evaporate water in the desalination system. In the ideal case, the price of fresh water of using the steam produced by the boiler is $1.131 per cubic meter, and by means of the steam produced by the power generation system would be $1.087 per cubic meter. Hence, the results indicate that combining the desalination system with the Allam generation system provides a 4% reduction. Reducing carbon dioxide emissions is also a significant benefit of this system.