Thermodynamic Analysis (Energy and Exergy) of a Proposed Thermoelectric Based System for Heat Recovery from Molten Slag in the Steel Industry

Nowadays, the use of thermoelectric as one of the methods of recovering waste heat energy has received much attention. In this research, while presenting a new thermal energy recovery system in the molten slag of steel Industry, thermodynamic analysis of the proposed system from the perspective of energy and exergy is also presented. Then the effect of various parameters including Seebeck coefficient on the performance of the proposed system is investigated. The results of modeling in both power cycle and thermoelectric cycles have been validated by previous research. The results of thermodynamic analysis show that the largest contribution to the exergy destruction of the proposed system is related to the heat recovery system. According to the results, the production capacity of the heat recovery system from the total production capacity is about 49% and the efficiency of the first law of thermodynamics for the proposed system is 24.7% and the efficiency of the second law of thermodynamics is 32.88%. Economic analysis indicates that with thermoelectric generator cost of 1 $/W the payback rate of investment is less than 2 years.