具有最简结构水回用网络的优化

当前对水回用网络的研究主要集中在如何构造新鲜水量最小的水网络, 却忽视了该水网络的不唯一性.为了降低水回用网络的费用,应考虑水网络的最简结构.今用连接数的概念来描述用水网络的结构复杂性.连接数就是新鲜水道与过程、过程与过程、过程与废水道之间连接个数的总和.今以最小新鲜水量和网络连接数为目标,在网络超结构的基础上,建立了多杂质水回用网络优化的数学模型.用该模型确定的用水网络,具有最小新鲜水用量和最简结构,因而具有很好的经济性.最后通过实例说明了本方法的有效性.

Optimal Water-Using Network with the Simplest Structure

Up to now, the researches on water-using network synthesis have been focused mainly on minimizing the freshwater consumption, ignoring the fact that there are many kinds of networks structures with the same minimum freshwater consumption for a given water system. In order to reduce the total cost of the network, the network with the simplest structure should be chosen from those networks with the same minimum freshwater consumption. In this paper, the conception of connection number is used to express the complex degree of a network. The connection number counts in the total number of connections between processes, between freshwater and processes, and between processes and wastewater discharged, so it is related to the capital cost of the network. Base on the established superstructure of water allocation network, the optimization model for water-using network is established. The model consists of two steps. Firstly, the freshwater consumption is used as the objective function of the optimization, and secondly, the minimum freshwater consumption obtained in the first step is used as a constraint, and the connection number is used as the objective function of the optimization. The model proposed can be used for the water utilization systems with multiple contaminants. The network determined by using the model proposed has the features of minimum freshwater consumption and simplest network structure, and so the network determined would have good economic characteristics. Finally, the advantage and effectiveness of the optimizing method proposed were fully expressed via two practical examples.