【作者】 谢冬雷；

【导师】 刘晓华；

【作者基本信息】 大连理工大学 ， 热能工程， 2007， 硕士

【摘要】 带热压缩的低温多效蒸发海水淡化系统由于可以利用低品位的电厂抽汽热量，可以较大的提高了造水比，有效降低了制水成本。本文对带热压缩的低温多效蒸发海水淡化系统进行了研究。针对海水淡化系统横管降膜蒸发器，分别总结了管内冷凝侧与管外蒸发侧的换热系数关联式，比较了管内径、入口蒸汽流速、蒸汽冷凝温度、出口蒸汽干度对管内蒸汽冷凝侧换热系数的影响；研究了传热温差以及喷淋密度对管外蒸发侧换热系数的影响。结合不同的污垢系数，进行了总传热系数的影响因素分析。同时对横管降膜蒸发器冷凝侧管内流动阻力计算进行了总结与分析。针对6种不同流程，在质量守恒和热量守恒方程的基础上，建立了包括蒸发器、冷凝器、预热器、闪蒸罐和喷射器在内的带热压缩的低温多效蒸发海水淡化系统的数学模型。采用基于高斯-约旦消元法的等面积迭代方法对带热压缩的低温多效蒸发海水淡化系统的数学模型进行了求解；利用Visual Basic语言编制了带热压缩的低温多效蒸发海水淡化系统的计算求解程序，该程序针对6种不同的流程既可以进行设计计算也可以进行校核计算，具有良好的通用性和可再植入性且界面友好。利用求解结果，针对进口海水温度、第一效加热蒸汽温度、系统浓缩比、电厂抽汽参数、外界热源预热量以及预热位置、热压缩布置形式等参数对系统性能的影响进行了分析与比较，同时分别针对串联和并联流程、有热压缩和无热压缩的低温多效海水淡化系统方案进行分析。比较了带热压缩的6种低温多效海水淡化的流程，综合考虑，并联4+2流程的综合性能较好，其结果可以指导工程设计与实际运行。更多还原

【Abstract】 As MED-TVC(low-temperature multi-effect distillation with thermal vapor compression)has some technical advantages through the possibility of utilizing low temperature waste heat sources, increasing gained output ratio and reducing water cost, it was studied In the dissertation .The heat transfer coefficients inside and outside the horizontal tube were summarized. Not only the effects of tube diameter, inlet vapor velocity, steam condensing temperature and outlet vapor quality on the inside heat transfer coefficient, but also the effect of overall heat transfer temperature difference and flow density on the outside heat transfer coefficient were studied and compared. On these basis, the overall heat transfer coefficient was calculated in terms of different fouling resistance.Based on the mass and energy equations, the physical model and mathematic model of 6 different kinds of MED-TVC was established. Equal-area design method the mathematic model was solved through Equal-area design method combined Gauss-Jordan elimination. By using Visual Basic programming language, the MED-TVC calculation software was worked out which had better generality, friendly interface and re-embeddability. Both design calculation and check calculation can be done by the software.The effect of the feed seawater temperature, the heating steam temperature of NO.1 evaporator, the concentration ration, the steam extraction, the quantity and location of preheat flow, the form of TVC on performance of a distiller is discussed. Not only serial flow and parallel flow, but also system with and without TVC was compared. Synthetically, 4+2 parallel flow showed the best performance among the 6 flows.The conclusions provide a significant guidance in the specific extent of engineering.更多还原