Volume 9: Sustainable Energy Solutions for Changing the World: Part I

Parameter Optimization and Economic Performance Comparison of SinglePressure Steam Cycle, Steam Flash Cycle and Dual-Pressure Steam Cycle for Waste Heat Recovery Peng Qi, Huaixin Wang

Abstract

This paper focuses on the parameter optimization and economic performance comparison of single-pressure steam cycle (SRC), dual-pressure steam cycle (SDC) and steam flash cycle (SFC) based on the waste heat source with initial temperature of 400-700℃ and mass flow rate of 40kg/s. We take the heat exchanger area per unit power output (APR) as the economic evaluation index and use genetic algorithm (GA) for optimization. The derivation of the formulas shows that as the pinch point temperature difference between the flue gas and working fluid increases, the APRs of SRC, SFC and SDC decrease accordingly. The APRs of SFC and SDC are higher than that of SRC, which is due to the fact that the effect of the increase of total heat exchanger area caused by the SDC and SFC is greater than that of the increase of net power output. With the increase of the initial temperature of flue gas, the optimum APRs of SRC, SFC and SDC decrease accordingly and the degree of decline gradually decreases. When the initial temperature of flue gas reaches 700℃, the optimum APRs of SRC and SFC increase slightly.

Keywords waste heat recovery，economic performance optimization，performance comparison，APR