Energy System Integration Technology And Industrial Case Study In The Coal Chemical Processes

The new coal chemical industry in our country is booming,with the development of chemicals and energy products represented by olefins,methanol,natural gas,etc.However,the consumption of coal and other fossil fuels will bring a series of environmental problems,among which the contradiction between economic development and environmental protection is prominent.In addition,the coal chemical industry also faces low resource efficiency,low system integration and other issues.Therefore,it is necessary to integrate the energy of coal chemical processes.Based on the previous research,this study extends the research to the field of heat exchanger network synthesis and steam power system integration.There are two innovations in this paper.Firstly,an adaptive genetic algorithm based on the local optimal strategy of maximum energy recovery is proposed,and an industrial example is studied.The objective is to improve the energy integration of the plant and to find a heat exchanger network structure with the lowest annual total cost.Secondly,the integrated model of steam power system is established for the existing coal-fired gas plants,and the optimization model of MINLP is developed under single and multi-operating conditions.Its goal is to select the appropriate operating parameters so that the power generation in the plant can be reasonably controlled,and the operating cost is the lowest.In the aspect of heat exchanger network,through the verification of two typical cases in literature,the novel heat exchanger network method can reduce the cost of utilities and get the lowest annual total cost.Two typical industrial cases,the methanation unit and the methanol plant,are further studied by using this method.The results show that the annual total cost of the optimized methanation unit and methanol plant are reduced by 16.7% and 50% respectively.In terms of steam power system,the integrated model is used to simulate and verify the five actual working conditions of the existing coal-to-gas plant,and the simulation results show that the relative error is within the acceptable range(?5%).In addition,the results of MINLP operation optimization of the steam power system under single and multi-operating conditions show that the operation parameters of the steam power system can be reasonably adjusted to meet the production demand of the chemical industry area,and the total operation cost of the optimized steam power system can be reduced by 6.29 million yuan compared with that before the optimization,and the economic benefits obtained are remarkable.At present,the coal-based energy and chemical industry has become the resource structure and basic characteristics of our country for a long period of time.It is necessary to coordinate the relationship among heat exchanger network,steam power system and reaction separation process so as to optimize the system synchronously and synthetically,further reduce energy consumption,enhance enterprise profits and enhance enterprise competitiveness.