Based on the insight that the difference between the water network involving regeneration and that involving reuse only is that there is an additional stream, the regenerated stream, in the former one, this paper presents an iterative method for designing water-using networks of single contaminant involving regeneration reuse/recycling. For the networks with a given removal ratio (RR), a reasonable regeneration concentration is obtained first. Add the regenerated stream into the network with reuse only, the network involving regeneration can be formed. Then the design of the networks involving regeneration reuse/ recycling can be performed by using the design procedure proposed for the systems involving reuse only. For the networks with the given regeneration concentration, the final design can be obtained with one iteration. For the networks with a known removal ratio, the final design can be obtained with several iterations. This paper considers the targets of freshwater consumption, regenerated water flow rate, and mass load for regeneration, and all the target items can reflect the total cost of the network. A few literature examples are investigated. The structures of the designs obtained in this work are not complex compared to that reported in the literature, and the calculation of the proposed method is very simple.%具有再生再利用/循环利用的水网络与只有再利用的水网络不同之处在于前者增加了再生水流.如能确定再生水流的浓度和流量并将之加到只考虑再利用的水网络中,即可构成具有再生再利用/循环利用的水网络.在上述思想基础上提出一种迭代法设计具有再生再利用/循环利用的水网络.该方法既可以解决给定移除率(removal ratio,RR)问题,又可以解决固定再生浓度问题.对RR问题,根据水网络及再生过程的特点估算出初始再生水流浓度.再生水流的量待定.将所得再生水流加到只考虑再利用的网络中构成具有再生过程的水网络.设计上述水网络,可以得出新的再生水流的量及浓度.当相邻两次再生浓度之差小于给定值时迭代结束.对RR问题,通常只需几次迭代即可得出最终设计;对于固定再生浓度问题,只需一次迭代即可得出最终设计.设计中考虑了影响水网络设计总费用的新鲜水用量、再生水用量和杂质再生负荷3个主要参数.对文献中几个实例的研究表明,本文方法得到的设计与文献中的设计相当.而设计步骤比文献中的简单.
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