高含盐废水近零排放技术研究

发布时间：2018-05-19 11:08

  本文选题：高含盐废水 + 近零排放　； 参考：《重庆交通大学》2016年硕士论文

【摘要】：高含盐废水是工业废水中极难处理的废水之一,具有含盐量高、含盐成分复杂、易产生结垢和腐蚀现象、有机物浓度高且难以降解等特点,如何将其处理并达到“近零排放”的低能耗、高处理效率要求,成为国内环保领域的一大难题,因此,探寻一种经济高效的高含盐废水近零排放处理技术是非常必要的。机械蒸汽再压缩(Mechanical Vapor Recompression,MVR)技术是一种高效除盐的近零排放技术,本论文针对高含盐废水的特性,提出一种新型的内置式MVR蒸发处理工艺,在数值模拟计算的基础上,研究MVR内部工作过程,得到强化传热方案,为高含盐废水减量化和零排放奠定一定的基础。论文以脱硫废水为研究对象,采用塑料膜作为板式换热器的换热元件,开发出一种新型的降膜式换热器——板式薄膜换热器,在真空度为80kPa,蒸发温度为60℃,温差为2.3℃,压差为2kPa的条件下,提出适合于处理脱硫废水的MVR处理工艺,分析板式薄膜换热器结构特性和MVR工艺的节能原理,计算工艺系统的物料平衡和热平衡。论文采用Gambit软件建立板式薄膜换热器的二维几何模型,利用Fluent软件实现换热器内部全流道数值模拟。在塑料热交换膜壁厚0.07mm、脱硫废水入口温度40℃、进料量0.6 m~3/h的工艺条件下,得到板式薄膜换热器内部的流场、速度场、温度场和压力场的分布情况,从换热器内部介质的流动与传热过程、热交换膜内部的传热过程等方面讨论MVR内部工作过程,为强化MVR传热提供一定的理论依据。论文采用响应面和Fluent数值模拟相结合的方法,对MVR工艺进行强化传热优化设计。对塑料热交换膜壁厚分别为0.04mm、0.07mm、0.10mm,脱硫废水入口温度分别为20℃、40℃、60℃,进料量分别为0.4 m~3/h、0.6 m~3/h、0.8 m~3/h的多组工艺条件,利用响应面法中的Box-Behnken试验设计方法进行优化方案设计,并利用Fluent软件模拟得到响应值。优化结果:热交换膜壁厚0.04mm、脱硫废水入口温度60℃、进料量0.59m~3/h时MVR传热性能最佳。MVR近零排放技术可使高含盐废水的除盐率达99%以上,回收率达95%,废水排放量仅为5%,实现了高含盐废水的减量化。
[Abstract]:High salt wastewater is one of the most difficult wastewater treatment in industrial wastewater. It has the characteristics of high salt content, complex salt composition, easy to scale and corrosion, high concentration of organic matter and difficult to degrade. How to treat it and achieve the requirement of low energy consumption and high treatment efficiency of "near zero discharge" has become a major problem in the field of environmental protection in China. Therefore, it is very necessary to explore an economical and efficient treatment technology for near-zero discharge of high-salt wastewater. Mechanical Vapor recompression (Vapor) is a near zero discharge technology for high efficiency desalination. In this paper, a new type of built-in MVR evaporation treatment process is proposed, which is based on numerical simulation. The internal working process of MVR was studied, and the enhanced heat transfer scheme was obtained, which laid a foundation for the reduction and zero discharge of high salt wastewater. In this paper, a new type of falling film heat exchanger-plate membrane heat exchanger is developed by using plastic film as heat exchanger element and desulfurization wastewater as research object. The vacuum degree is 80 KPA, the evaporation temperature is 60 鈩，

本文编号：1909869