Techno-economic analysis of combined heat and power generation systems with regard to solar energy for lubricant oil refinery utilization

The heat and power demands are supplied by site utility systems. One way of increasing efficiency and reducing energy consumption in process is optimizing site utility. This paper aims to investigate transient modeling and optimization of site utility systems with regard to solar energy. This model calculates steam supply, steam flow rate for site demand, and power generated by the gas engine and steam turbines with the objective function of maximizing total revenue. By the use of this model, in a site utility of refinery, the amounts of gas engine fuel consumption, power generated, cogeneration efficiency, and total revenue will increase and boiler fuel consumption will decrease. Using heat recovery equipment to recover exhaust gas energy of engine, conformity of steam supply and demand and reduction in the amount of steam letdown are the reasons that cause to reduce boiler fuel consumption and increase cogeneration efficacy. Finally, the great advantage in combination of conventional system with the use of solar energy as parabolic trough concentrator is evaluated by a transient model.