提出一种带有中间热集成的精馏塔序列(IHISDC)的流程,针对三组元混合物分离的简单塔直接序列,对该流程进行了分析。与传统热集成精馏序列(HISDC)相比,提出的IHISDC通过中间换热器将高压塔的精馏段与低压塔的提馏段进行局部热集成,使能量集成精馏塔之间的压力差更小,进而使能耗费用下降。同时发现,IHISDC中的高压塔再沸器热负荷和低压塔冷凝器热负荷增加,由于换热器数量的增加,IHISDC的投资费用较大。为了进一步降低IHISDC的年度总费用,需要对其设计参数进行优化。
A configuration of an intermediate heat-integrated sequence of distillation columns(IHISDC)is proposed in this paper.The IHISDC configuration is analyzed by applying it in a direct sequence of distillation columns for ternary mixture separation.In this configuration,heat is transferred from the rectifying section of the high pressure column to the stripping section of the low pressure column through intermediate heat exchangers.Comparing to the conventional heat integrated sequence of distillation columns,the proposed IHISDC system presents smaller pressure difference between the two heat-integrated columns in the sequence,and consequently saves the energy cost for the reboiler of the high pressure column or for the condenser of the low pressure column.It is also found that the heat duties of the reboiler of the high pressure column and the condenser of the low pressure column are higher,and that the investment cost increases with the increase of the number of heat exchangers.The IHISDC needs to be optimized in order to lower its total annual cost(TAC).