有机朗肯循环发电系统的多目标参数优化

建立以热回收率及单位输出功率所需换热面积为目标的多目标优化模型,利用模拟退火算法对循环采用R123、R236ea、R245fa、R227ea、R600等五种工质时的参数进行优化计算。结果表明:采用多目标优化模型可以协调各评价指标间的关系,更好地满足工程实际的需求;热源温度为140℃、循环采用R123时,最佳蒸发压力为0.69 MPa、冷凝压力为0.11 MPa,最佳蒸发压力随着冷凝压力的升高而增大;当管内流速超过0.5 m·s^-1时,流速对系统性能的影响较小。蒸发器内的最小传热温差为15℃。随着热源温度升高,循环的最佳蒸发压力增大。在分析的几种工质中,热源温度在100~220℃时,循环采用R123时性能最佳。

Multi-objective parametric optimization of power generation system based on organic Rankine cycle

A multi-objective optimal model was developed, in which the screening criteria include heat recovery efficiency and heat exchanger area per unit power output.The model was optimized using the simulated annealing algorithm for R123, R236ea, R245fa, R227ea and R600.The results show that the multi-objective optimization model can coordinate the relationship of different criteria and is better for system economy than that of a single screen criterion.At heat source temperature of 140℃, the optimal evaporation and condensation pressures using R123 are 0.69 MPa and 0.11 MPa, respectively.The optimal evaporation pressure increases with the condensing pressure.The velocity in tubes should be more than 0.5 m·s^-1 and the optimal pinch point in evaporator is about 15℃.As the waste heat temperature increases, the optimal evaporation pressure increases.In the waste heat temperature range from 100℃ to 220℃, R123 is the best working fluid among the five working fluids.