Simultaneous Synthesis And Optimization Of Heat Exchanger Network And Steam Power System Using GA/SA

With the development of society and economy, energy issues has become the important topic due to the increasing energy demand all over the world.Today, in the process industry to large-scale, continuous and centralized development, unit operation based on the concept of the traditional industrial design process has been unable to meet the current requirements of energy saving, therefore the system energy turn into the main research directions. A total processing system can be regarded as an integrated system including three main components:Chemical Plant, Heat Exchanger Networks (HEN) and Steam power System. Although, there are considerable progresses in understanding and developing synthesis procedures for each subsystem separately in recent years, enough attention has not been placed on the problem of coordinating the synthesis activity for the three components of the total processing system. This paper had finished the following research works:(1) Based on the analysis of the boiler, steam turbine and gas turbine, a design model of equipment which considered size and operating conditions influence was acquired, and a new design method of steam power system (SPS) which is depended on Parallel genetic/simulated annealing algorithm (GA/SA) was presented. The performance of the methodology was demonstrated with an example and obtained solutions indicating that a minimization cost solution of this problem could get. Set up with multiple HEN ultra structural model of the steam demand.(2) On the basis of the model of non-isothermal mixing of stage-wise superstructure of HEN proposed by Yin Hong-Chao, and a new superstructure of HEN of multiple steam demands was established. Based on improved HEN superstructure model and SPS superstructure model, a simultaneous synthesis and optimization mixed integer nonlinear programming (MINLP) model of the HEN and SPS was set up. Accurate relation of two sub-systems was established relied on Simultaneous synthesis model considering the equation of supply and demand of steam, excluding the calculation of steam prices in the objective function. Compared to the synthesis of a system separately, it could achieve total site integration and avoid considering steam price model.(3) Solving complex MINLP problem was proposed by using GA/SA. The optimization of the total site was performed with GA/SA via the treatment of individual process which instead of complex problems to be solved. The program of the GA/SA was writing based on the C platform, and the product strategy of initial solutions was researched, as well as the operator and the constraint condition. A case study was presented to show the efficiency of the proposed methodology and a better solution would be received.(4) Applied the simultaneous synthesis model and GA/SA to a foundation design process of HEN and SPS based on a fixed separation process of multi-component, the synthesis results could satisfy the requirements of the plant with low cost and high economical benefits, and the proposed methodology could applied to a middle-scale industrial cases.