多效蒸发注射用水系统的热力过程优化  

Thermodynamic processes optimization of multiple effect evaporation system of water for injection

作　　者：肖轶文 吴淑英[1] 彭德其[1] 吴志民[2] Yiwen XIAO;Shuying WU;Deqi PENG;Zhimin WU(School of Mechanical Engineering,Xiangtan University,Xiangtan,Hunan 411105,China;School of Chemical Engineering,Xiangtan University,Xiangtan,Hunan 411105,China)

机构地区：[1]湘潭大学机械工程学院,湖南湘潭411105 [2]湘潭大学化工学院,湖南湘潭411105

出　　处：《过程工程学报》2022年第7期917-926,共10页The Chinese Journal of Process Engineering

基　　金：国家自然科学基金资助项目(编号:51206071);湖南省自然科学基金资助项目(编号:2019JJ40284)。

摘　　要：针对生产注射用水多效蒸发过程中能耗大及产水不稳定的问题,进行了多效蒸发热力过程系统优化。依据质量守恒和能量守恒方程,建立了蒸发器、预热器和冷凝器数学模型,考虑蒸汽流动阻力损失,基于Matlab/Simulink多体工具箱,以等面积法为原则进行迭代求解。通过模拟计算分析效数、预热方式对系统热力性能的影响。结果表明,效数增加使得系统比传热面积、造水比增加以及比?耗减小,且后两者的变化幅度会逐渐降低。效数低于5时,使用产水预热的方案更优;效数高于5时,混合预热方案更优。混合预热方案下,系统效数较大时,蒸汽在管道内流动引起的温降和压降快速上升,最终导致造水比下降以及比?耗值趋于恒定。Aiming for the problems of large energy loss and unstable water production in multiple effect evaporation water for injection system, different preheating methods were designed to improve the water production process,and the Matlab/Simulink multi-body toolbox was used to simulate the system and optimize the thermodynamic process.According to the equations of mass and energy conservation, the mathematical models of evaporator, preheater and condenser were established with the loss of steam flow resistance. Based on the Matlab/Simulink multi-body toolbox, the iterative solution was carried out by the equal area method. The experimental data were compared with the results which were simulated by the Matlab/Simulink multi-body toolbox. The maximum error was 6.71%. Considering the waste of secondary steam energy in multiple effect evaporation system, different preheating methods were used to recover the residual heat. The influence of the number of effects and the preheating mode on the thermal performance of the system was analyzed. The results indicated that with the growth of the number of effects the specific exergy consumption decreased, specific heat transfer area and gained output ratio of the system increased, and the latter two have decreased rate of change. When the number of effects was less than 5, using the condensate preheating scheme was more excellent. When it was more than 5, using the mixture preheating scheme was superior. While the number of effects was greater in scheme mixture preheating,temperature drop and pressure drop which caused by the flow of steam rapidly rised, gained output ratio weakened and specific exergy consumption tended to be constant. This work proposed a new preheating method for the multiple effect evaporation system, which improved the utilization rate of energy in this system by recovering the residual heat of the last-effect secondary steam. The new preheating method can provide a reference for the design and transformation of the multiple effect evaporation system.

关 键 词：多效蒸发 造水比 比?耗 比传热面积 

分 类 号：TQ460.5[化学工程—制药化工]