Main content area

Multi-objective optimization for design of a steam system with drivers option in process industries

Wu, Le, Liu, Yongzhong, Liang, Xiaoqiang, Kang, Lixia
Journal of cleaner production 2016 v.136 pp. 89-98
case studies, compressors, electric motors, electricity, energy, environmental impact, industry, life cycle assessment, models, pumps, steam, turbines
In process industries, a steam system is usually constructed to satisfy the demands of steam and electricity in a plant, in which steam turbines and electric motors are commonly used to drive rotating equipment, such as pumps and compressors. In this paper, a multi-objective optimization model for the design of a steam system with drivers option for rotating equipment is proposed to simultaneously minimize the economic and environmental objectives. It features that the energy performances of steam turbines and electric motors are embedded in the model, and the environmental impacts caused by both the material of equipment and the utilities consumption in the system are evaluated by life cycle assessment method. A steam system of the hydrotreating units in a refinery is taken as a case study to demonstrate the application of the proposed method. The Pareto front of the economic and environmental objectives is obtained, and three scenarios on the Pareto front are analyzed and discussed. Results show that appropriate drivers option can effectively reduce both the economic and environmental impacts of the steam system. In addition, the preference of steam turbines and electric motors in the system is intensively dependent on the two objectives. Consequently, the drivers option for the power demand in a plant should be determined before the entire steam system is designed and optimized.