基于模拟退火算法的低温余热发电系统参数优化

为提高低温余热发电系统的综合性能,以单位发电量所需换热面积为目标函数,采用模拟退火算法对ORC系统的参数进行优化。研究结果表明:当热源温度和流量分别为120℃与62 kg/s,蒸发器内最小传热温差为10℃时,蒸发器内的最佳压力和流速分别为0.615 MPa与1.23 m/s;冷凝器内的最佳压力和流速分别为0.102 MPa与1.37 m/s;与传统算法相比,优化结果使单位发电量所需换热面积减少23%。随着热源温度的升高,最优目标函数值先降低后升高,在热源温度为200℃时达到最低值;综合考虑目标函数值及系统输出净功,蒸发器内合适的最小传热温差为15℃。

Parametric optimization of low-temperature waste heat power generation system by simulated annealing algorithm

An optimized mathematical model was established to improve the performance of low-temperature waste heat power generation system.The ratio of the total heat exchanger area to net power output was used as the objective function and it was optimized using the simulated annealing algorithm.The heat resource is the flue gas when the mass flow is 62 kg/s and temperature is 120 ℃.When the minimum temperature difference between evaporator and flue gas is 10℃,the results show that the optimal pressure and velocity in evaporator are 0.615 MPa and 1.23 m/s,respectively.And the optimal pressure and velocity in condenser are 0.102 MPa and 1.37 m/s,respectively.The ratio of the total heat exchanger area to net power output decreases by 23% compared with conventional method.The optimal value of objective function reaches the minimum when the heat source temperature is 200 ℃.In order to get lower value of objective function and higher net power output,the proper temperature difference of evaporator is 15 ℃.