Application of Combined Pinch and Exergy Analysis for Energy and Emissions Optimization of Steam Power Plants

The ability of Pinch Technology is related to design and analysis of processes; however, it can’t be used individually for heat and power system. In the other words, exergy analysis can apply for evaluation of heat and power systems. It can determine unavoidable parts of energy systems and specify the maximum potential of optimization.

The main limitation of exergy analysis is the lake of general and clear method for design of system. The combined pinch and exergy analysis that using the advantages of both methods satisfy the limitations. In this paper, the RAMIN Ahvaz thermal power plant as a case study is defined. Furthermore, using CPEA the potential of optimization has been determined and evaluated.

Three proposed modification scenarios have been used for optimization of Power Plant as follows: 1. approaching pinch temperatures 2. Increasing steam in boiler and 3.Decreasing pressure of condenser.

With employing both methods the efficiency of power plant has been increased by 1.7%. In addition, the fuel consumption is about 1569 m3/h and flue gases have been reduced by 1.7% (20t/h). So, the emissions have been reduced by 1.7%. The Thermoflow (Steam Pro) software has been applied for simulation of case study. In addition, Aspen Pinch Software has been employed for CPEA.