A new approach to design energy efficient water allocation networks

An energy efficient water allocation network is designed more easily by solving the sequential mathematical model than the simultaneous mathematical model. But in existing sequential models, the interactions between the design of a water allocation network and design of a heat exchanger network have not been fully taken into account. To consider the energy performance during synthesizing water allocation networks, in this paper, firstly, the reason why different water allocation networks have different energy performance is analyzed. It is found that reducing the number of temperature local fluctuations along the sub-streams in water allocation networks is beneficial for energy performance of the system. There are two methods to reduce the number of temperature local fluctuations, one is to reduce the unnecessary flows of water in the networks, the other is to reduce the number of sub-stream temperature peaks or vales. By considering the two methods, a new mathematical model only concerning water allocation networks is presented and the resultant networks feature good energy performance.