单杂质水网络节水优化应用研究

发布时间：2018-04-19 12:42

本文选题：水网络 + 夹点法　；参考：《西安石油大学》2015年硕士论文

【摘要】：水资源短缺是人类目前面临的重大问题,节水减排已成为企业追求生产效率和保护环境等方面的重点,以节约新鲜水、减少废水为目的水网络优化技术受到了越来越多的关注。为应对全球可利用水资源短缺日益严重的现状,在提倡可持续发展的形势下,世界各国对水资源的合理利用及废水的处理方式提出了更高的要求。本文在对比水网络优化常用方法的基础上,分析其各自存在的优缺点及适用范围,确定使用夹点法来研究本文所要优化的只考虑单杂质的用水网络。介绍了夹点法的主要分析步骤:利用浓度—负荷曲线或问题表法确定夹点位置并得到最小新鲜水流率、根据需要选用最大传质推动力法或最小匹配数法对所研究水网络中的各级水流进行合理分配、明确每级用水管线的分配水量并做出水网络分配图。分析某石化厂用水单元现状,收集有效数据并进行对比分析,筛选出具有优化价值的用水单元,最终选取含有六个用水单元的水网络作为研究对象,以悬浮物为其关键杂质,利用夹点法进行水网络优化改造:首先采用问题表法求出最小新鲜水流率,再运用最小匹配数法确定各级流量分配关系,得到水网络优化后的水流分配图。改造之前新鲜水用量为210t/h,改造之后新鲜水用量降为90t/h,节水率为57.14%,优化之后的水网络最大程度提高了水的利用率,实现了水流梯级利用。运用浓度—负荷曲线计算夹点来确定最小新鲜水流率的过程中,需要通过移动供水线来取得与浓度—负荷曲线的交点,如果所取交点不准确将对最小新鲜水流率的确定产生偏差,而运用问题表法计算将能够得到准确数据,然而当所研究水网络中用水单元较多时,运用问题表法计算最小新鲜水流量的过程将变得十分繁琐,计算过程中出现错误的几率也大大提高,本文采用Visual Basic编程设计出可实现问题表法计算过程的计算软件,该软件包括窗体模块和程序命令编辑模块两部分。窗体模块实现对需求数据的输入和最终结果的输出,程序命令编辑模块实现计算过程的计算机化。该软件适用于有确定用水单元的水网络计算过程,人机交互界面清晰,数据输入与输出过程简洁,程序命令简单易懂。为了应对所研究水网络中用水单元可能出现增减的情况,采用Matlab与Excel相结合的方法计算最小新鲜水流率。运用Matlab软件编辑实现问题表法计算要求的M文件,在M文件中增加调用用来输入已知数据Excel文件的命令,并将问题表法计算过程中每一步骤的计算结果在另外一个Excel中显示。Matlab和Excel的组合在求解水网络最小新鲜水流率的过程中不受制于所研究用水单元个数的限制,并且在显示输出数据的Excel中包含了问题表法计算过程中每一步的计算结果,便于验证。
[Abstract]:The shortage of water resources is a major problem facing mankind at present. Water saving and emission reduction has become the focus of enterprises in the pursuit of production efficiency and environmental protection. Water network optimization technology for the purpose of saving fresh water and reducing wastewater has been paid more and more attention.In order to cope with the increasingly serious shortage of available water resources in the world, under the situation of advocating sustainable development, countries all over the world have put forward higher requirements for the rational utilization of water resources and the treatment of wastewater.On the basis of comparing the common methods of water network optimization, this paper analyzes their respective advantages and disadvantages and their applicable scope, and determines to use the pinch method to study the water use network which only considers single impurity to be optimized in this paper.The main analytical steps of the pinch method are introduced in this paper: using the concentration-load curve or the problem table method to determine the location of the pinch point and to obtain the minimum fresh water flow rate.According to the need, the maximum mass transfer driving force method or the minimum matching number method are selected to rationally distribute the water flow in the studied water network, and the water distribution quantity of each stage water pipeline is determined and the distribution diagram of the water network is made.The present situation of water unit in a petrochemical plant is analyzed, the effective data is collected and compared, and the water unit with optimized value is screened out. Finally, the water network with six water units is selected as the research object, and the suspended substance is regarded as the key impurity.The method of pinch point is used to optimize the water network. Firstly, the minimum fresh water flow rate is obtained by using the problem table method, and then the distribution relationship between different levels of flow is determined by the method of minimum matching number, and the flow distribution diagram after the optimization of the water network is obtained.The dosage of fresh water was 210 t / h before revamping, the dosage of fresh water decreased to 90 t / h, and the water saving rate was 57.14. The optimized water network improved the water utilization rate to the greatest extent and realized the cascade utilization of water flow.In the process of determining the minimum fresh water flow rate by using the concentration load curve to calculate the pinch point, it is necessary to obtain the intersection point with the concentration load curve by moving the water supply line.If the intersection points are not accurate, the minimum fresh water flow rate will be deviated, and the accurate data can be obtained by using the problem table method. However, when there are more water units in the water network studied,The process of calculating the minimum fresh water flow by using the problem table method will become very complicated, and the probability of errors in the calculation process will be greatly increased. In this paper, a calculation software is designed by using Visual Basic to realize the calculation process of the problem table method.The software includes form module and program command editing module.The form module realizes the input of the requirement data and the output of the final result, and the program command editing module realizes the computerization of the calculation process.The software is suitable for the calculation process of water network with definite water unit. The interface of human-computer interaction is clear, the process of data input and output is simple, and the program command is simple and easy to understand.In order to deal with the possible increase or decrease of water unit in the studied water network, the minimum fresh water flow rate is calculated by combining Matlab and Excel.Using Matlab software to edit the M file required by the problem table method, adding the command to input the known data Excel file into the M file.The results of each step of the problem table method in another Excel show that the combination of. Matlab and Excel is not limited by the number of water units studied in the process of solving the minimum fresh water flow rate of the water network.And the Excel which displays the output data contains the calculation results of each step in the calculation process of the problem table method, which is easy to verify.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ085;TQ021.8

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