The design of heat-integrated water allocation network has become a recent research direction. However

most current models do not treat non-isothermal mixing directly in the water network in order to avoid nonlinearity. Therefore

the number of streams increases dramatically when designing heat exchanger network. In order to manage this problem

a new kind of water network model that considers non-isothermal mixing is developed and combined with the LP transshipment model to perform simultaneous optimization of water and heat integration. Non-isothermal mixing is introduced to improve the water network's energy performance and reduce the complexity of designing heat exchanger network by decreasing stream number. A detailed heat exchanger network to satisfy the targeted water and utility consumption can be designed adequately by the principles of pinch method. The results show that the new model not only targets the optimal water and utility consumption but also obtains a much simpler heat exchanger network. This is from a practical application point of view highly valuable.