复杂平流多效精馏系统能量集成模型及过程模拟

为了更合理利用能量,将平流多效精馏系统中各效塔底产品、第1效至第n-1效塔顶产品及首效再沸器中加热生蒸汽的冷凝液用于预热原料液,建立由多效精馏及多级预热2个子系统构成的复杂平流多效精馏系统的能量集成模型。用于模拟具有切点系统的高度非理想溶液的平流多效精馏过程,用迭代法结合矩阵法求解。结果表明:用系统余热预热原料液可节省加热生蒸汽消耗量25%～35%,是1种非常有效的节能措施;各效精馏塔回流比及再沸器的有效传热温差、首效塔底再沸器中加热生蒸汽压力(或温度)、末效塔顶压力(或温度)、原料液的预热温度等参数,对平流多效精馏系统的操作费用及设备费用影响很大。

The energy integration model and process simulation of the complex paralled-feed multi-effect distillation system

In order to utilize energy more fu]ly and reasonably,the condensate of the heating steam in the rebeiler of the first effect,and the product ofthe top of vari-effect distillation tower except the last one,and the product of the bottom of vari-effect distillation tower were used to preheat feed flow.The energy integration model of the complex paralled-feed distillation system was established,whichwas composed of two subsystem--multi-effect distillation system and multilevel preheating system.The model can be suitable forhighly nonideal systems as"Tangent System"and it can be solved by iterative method and matrix method.The simulation resultsshowed that using residual heat to preheat feed flow was the effective measure to save the heating vapor by 25%～35%.and the operat-ing reflux ratio of vari-effect distillation column,the heat-transfer temperature difference of vari-effect rebeiler,the vapor pressure(ortemperature)of the heating vapor of the first effect,the vaporpressure(or temperature)at the top of the last effect and the temperatureof feed flow have great effects on the operating cost and equipment depreciation cost of the paralled-feed multi-effect distillation system.