Researches On The Optimizing Approaches In Water-network System Of Refinery

There is a considerable gap on refining industry, water recycling and water reduction between China’s oil refining industry and the overall level and international advanced level. the crude oil refining industry with an average water consumption1.08t/t[24], than the advanced international level of0.5t/t is1times. Therefore, there is great potential for saving water in oil refining industry. This paper mainly studied the refinery water network optimization and did some analysis for wastewater conservation, so that to create a method which can improve wastewater reusing reduce fresh water consumption and wastewater emissions in the oil refining industry.First of all, the paper reviewed the background and meaning of the subject, summarized the research status of the water network optimization of refineries at home and abroad, and then under the refinery in general, analysis the refinery’s water-water treatment-the state of drainage systems; And then, introduced the multi-objective optimization problem definition and the concept of pareto solution, and give a detailed description of the NSGAII algorithm, which was mainly used in this computation.Secondly, this paper established the model which considered lumped process units water network optimization, to produce the maximum profit, minimum cost of water, wastewater emission. According to refinery production process, consider the materials, production and marketing of fresh water consumption optimal balance, to establish the corresponding constraint expression; Based on the considering the lumped plant network optimization model of water, the material balance of all production equipment and program switch were considered as the new constraints, then established the model of a multi-plant network optimization of water network.Finally, a refinery as an example, established the model which considered lumped process units water network optimization and the model of a multi-plant network optimization of water network. And use NSGAII algorithm to solve the two models, the obtained pareto solution solves guaranteed production successfully and as much as possible to reduce fresh water consumption and sewage emissions, which verifies that the proposed operation of water network optimization method.