Optimal Design Of Heat Integrated Water Networks Considering Pressure Drop Effects

Energy crisis and shortage of water resources have caused widespread concern all over the world. And vigorously promote energy saving and emission reduction has become a consensus of governments in the world. Energy saving and emission reduction is to save energy and reduce energy consumption and reduce emissions. Process industry is not only energy-intense but also is the main pollutant emission. So it is very important to design the reasonable water network and heat exchanger network for process industry. The optimal design study of water network and heat exchanger network are relatively mature now, but the study of water network optimal design considering heat exchanger is less. What is more, considering pressure drop effects are more less when heat exchanging. Ignore the pressure drop impact will lead to great difference between the design and engineering practical situation, even can not implementation.This paper studies optimal design of integrated water networks considering pressure drop effects, by using particle swarm optimization, which is an effective tool.First, this paper researches on the theory and method of the heat exchanger comprehensive and optimization problem about home and abroad. According to the existing limitations of solving algorithm, an improved particle swarm optimization is presented, which was verified through the test function. And for the following model of heat exchange network and heat integrated water networks, which both considering pressure drop effects, the new algorithm is an effective tool.Second, for the synthesis and optimization of heat exchanger network considering pressure drop effects, based on stage-wise superstructure, an mixed integer nonlinear programming model with least annual cost as objective function is established. Which optimizing heat transfer area, unit number, utility consumption and pressure drop consumption simultaneously. The model is split heat exchanger network while containing the case of the stream no splitting. The proposed model will be solved by particle swarm optimization and can do better in global optimal solution. Optimizing heat transfer area, unit number, utility consumption and pressure drop consumption simultaneously. All that in order to make the optimization design of heat exchanger network more accord with engineering practice. And at last through four examples to verify the feasibility of the method. Last, basing on the idea and method of the proposed model of heat exchanger network synthesis and optimize, this paper attempts to optimize and design the heat integrated water network, which considering the pressure drop. The stepwise method is used to optimize the water utilization and heat exchanger networks simultaneously. While expecting the specific design of the heat integrated water network more close to the actual project, and also can provide some theoretical guidance for energy-saving and emission reduction in process industry.