Energy and Economic Optimization of Regenerative Organic Rankine Cycle with in Energy Recovery System of a Steel Plant
Subject Areas : OptimizationDavood Atashbozorg 1 , Afshin Mohseni Arasteh 2 , Gholamreza Salehi 3 * , Masoud Torabi Azad 4
1 - Department of Energy system Engineering, NT.C., Islamic Azad University, Tehran, Iran
2 - Department of Physical oceanography. NT.C., Islamic Azad University, Tehran Iran
3 - Department of Mechanical Engineering, CT.B., Islamic Azad University, Tehran, Iran
4 - Department of Physical oceanography. NT.C., Islamic Azad University, Tehran Iran
Keywords: Energy recovery, Organic Rankine Cycle, Regenerative, Steel Plant, Optimization, NSGAII,
Abstract :
This paper is to provide the design, analysis, and optimization of regenerative ORC for the waste heat recovery in a steel-works facility. A feedwater heater is installed in the system to further increase thermal efficiency. The system is examined by energy, exergy, and thermos-economic approaches. To achieve the highest performances, the selection of various parameters is carried out by using NSGA-II optimizing both exergy efficiency and total annual cost at the same time. The software MATLAB interface with REFPROP library is used for modeling and design variables include turbine inlet pressure, superheat temperature difference, condenser pressure, and the isentropic efficiencies of the rotating components. Thus, it has been shown that a proper tuning of some of these parameters may bring a satisfactory compromise between thermodynamic and economic performance. The optimum design gave a maximum exergy efficiency of 64.88%, an energy efficiency of 38.23%, a net power output of 1756.2 kW, and an estimated annual cost of $14.88 million. These results suggest that optimization of ORC systems could be a viable and practical solution for better energy utilization in heavy industries.