【作者】 叶群峰；

【导师】 杨玲霞；

【作者基本信息】 郑州大学 ， 水利水电工程， 2002， 硕士

【摘要】 水处理工程设计包括工艺设计和水力设计两部分，国内外都对工艺设计进行了广泛的研究。本文查阅了大量的水处理工程资料，发现有关这方面水力计算的资料极为缺乏。 本文首先论述了课题提出的背景和意义，指出影响升流式厌氧污泥床(UASB)处理效果的因素，其中布水器的均匀布水和三相分离器的分离效果直接影响处理效果。论文是从水力学方面考虑，旨在通过改进布水性能和分析整个流场来揭示反应器内的水流特征，为优化设计提供一定的依据，并且总结了UASB发展现状和新型结构。 本文主要分为两大部分，第一部分为UASB布水器的水力计算，主要根据有限元法建立线性代数方程组，利用赛德尔迭代法进行了计算。为了布水均匀，设每个孔口的出流量相同，计算得到孔口的水头，根据孔口出流公式，从而得到孔口直径和各管段的直径。基本原理是参照环状管网的计算方法，在主要考虑局部阻力的情况下，采用有限元法计算了当已知处理废水量时，布水器各管段和孔口的直径，以达到布水均匀的目的。厌氧反应器UASB在实际运行中，其底部的布水器经常出现堵塞，从而造成了配水情况达不到设计要求。为了提高处理效果，针对工程中布水器的结构特点，本文指出了尺寸结构上存在的不足。根据市政工程中环状管网的水力计算原理，并考虑布水器所必须涉及的局部阻力，利用有限单元法进行水力计算。文中的计算方法为水处理工程提供了布水器的设计依据和更为合理的结构尺寸。 第二部分为针对该型布水器的UASB内部流场的数值计算。第二部分是在的一部分的基础之上进行的。本文系统地介绍了数值计算中的各种方法，主要有有限体积法、自适应网格、有限分析法、有限元法等。并且介绍了有限差分法的历史及在环境工程中的应用。阐述了初始条件确定的原则，分不定常和定常两种情况，指出各种线性方程组的求解方法。列举了各种边界条件的处理原则和方法，着重论述了固体壁面上的涡量边界条件。网格的划分也是计算流体力学的一个重点，分析了各种方法的优缺点，提出UASB网格划分的方法，采用正方形网格能较好的满足计算精度。最后根据本文的特殊情况，首先选定柱坐标系为计算坐标系，这样虽然使得基本方程变得复杂，但却将问题由三维减少到二维，大大地减轻了处理问题 郑州大学硕士学位论文 的负担。然后采用流函数、涡量为基本变量，通过推导流函数方程和涡量 传输方程，最后选择采用传统的有限差分法对方程进行离散，离散后的方 程组应用欠松驰迭代法进行求解。 固体壁面的涡量处理是这一方法的一大难点，通过壁面点对邻近结点 的泰勒展开，推导出壁面涡量计算公式。 基本数学模型是 8“y6“V IDyn ＝＝十J＝二＝＝＋r山 ＆‘和‘厂 和 16W8Q lbW6Q＿16w＿（“DlbQ QD‘OI 二 ：：： ：：：一二 ＝n ＝＝ Q一 ；＝ ＝n O＝yi ＝＝＋二 ＝：：一 －－－＋＝＝l r＆ar r和 ＆r‘＆l旷r和r’＆’J 将上面两式应用中心差分格式离散得到 门。；＿。。；hi。＿；。＼，＿。＿；l ／，二TD／L＋W：；。十／，；＋V：；一＿…厂；一叭；卜叩“Q厂0 4’‘’‘”‘’‘’”‘”‘”’‘””‘”’2”””‘’“”’‘’‘””’l Ih“hi。。＼hill＿。；－，一 q’。一卜（1十一了）一＿…f，＋；一／；；）1 仆I叫Q厂：；＋Q二。＋q’，； I”4r“”sr“””“”‘’‘’“”1114’ ＿＿；＼hi＿。；＿。、＼11 ［l。。V＿。；＿．＼ ＋Q：；卜二二p：。一q，川一＿卜什‘，＿；一W二．；JQ：，一q ＊ 8厂’‘”‘”“’－’”‘“if 6）’“’”‘’“”’ l；1））’riP一［tHll 壁面上的涡量计算公式分别是 h“八 ＿…；＋l．；一W；．J …。；．； Q 二－ ＊万向） （＿hi 厂IZ＋二I 飞／、Q； Q；二一辽，牟；一W／于 （ 万向 h“厂”’”””’‘”“”2 求解步骤分三步进行：第一步用上一迭代得到的涡量和流函数计算这 一次的更多还原

【Abstract】 Technological and hydraulic designs are the two aspects in the water treatment engineering. Technological design researches are performed far and wide both in domestic and abroad. The information on hydraulic computation is very scarce after it had been consulted.Background and significant of the thesis are narrated first. Some factors that influence the efficiency of Upflow Anaerobic Sludge Blanket (UASB) are pointed. Unification of the water distributor and the effect of separation of three-phase separator are more important. Considering the hydraulics, the thesis aims to improve the water distributor and uncover the flow character in UASB through analyzing the whole flow zone. It also can provide foundation for reasonable design. Development situation and new forms of UASB are summarized.There are two main parts in the paper. The one is the hydraulic computation of water distributor in UASB. Linear algebra equations are founded by finite element method and Seidel iteration method is used for computation. In order to reach the unification, the fluxes of each hole are assumed to be same so as to calculate the water head of each orifice. Then the diameter of each pipe segment is computed by orifice outflow formula According to the computational method of network, diameters of pipes are determined with finite element method when the fluxes of wastewater is known, as concerning the local resistance, in order to achieve uniformity in the first part. The water distributor on the bottom of UASB is often jammed, when operating in practice. So that uniformity of water distribution is destroyed. In order to improve the efficiency of water treatment, the lack of this construction is put forward in the paper in the light of the characters of the water distributor in engineering. Local resistance should be concerned at the same time, according to the principle of hydraulic computation of the gridiron in the municipal engineering. Hydraulic computation is performed by finite element method. Design references and more reasonable structure dimensions about water distributors are provided for water treatment engineering.The second part is the numerical computation of flow zone in UASB related to this type of water distributor. This part is on the basis of the first one. Some kinds of numerical computation methods are recommended systematically including finite volume method, finite analysis method, finite element method and self-fit mesh method. The history of finite differential method and application in environmental engineer are represented. The initial conditions that include both steady flow and unsteady flow are expounded. The ways of linear equation groups are referred. Boundary treatment fundamentals and measures are illustrated. Especially, vortex boundary condition on solid wall is emphasized. Plotting mesh is also a keystone in computational fluid dynamics. Method of mesh plotting of UASB is presented after analyzing some ways. Foursquare mesh can meet with precision. Cylindrical coordinates are selected according to the unique character. The basic equations become more complicated, but the problem can be simplified by reducing dimensions from three to two. So it can lighten the load. Then, stream function and vortex are adopted as the basic variables. Thus, stream function and vortex equations can be achieved. At last, the equations that disperse with finite differential method can be solved by super relaxation iteration.Vortex on the solid walls is the most difficulties. The nods on walls Taylor outspread, formula that is used to calculate vortex on wall can be deduced.The basic math model is as followsThe two formulas are dispersed by center differential format.The formulas of vortex on wall are follows(r direction)(z direction)Solution process can be divided into three steps. The first step is to calculate stream function with vortex and stream function that is gained from last time iteration. The second step is to compute vortex from last time iteration and stream function fr更多还原