Targeting the cogeneration potential for Total Site utility systems

It is important to target the cogeneration potential of utility systems in the process of designing or retrofitting Total Site utility systems. Simulation software has been widely used in process design and analysis. However, it is rarely employed in estimating of the cogeneration potential of a utility system. A new method is presented in this paper for targeting the cogeneration potential of Total Site utility systems with a commercial software. The simulator is used to calculate the temperatures of steam mains, steam flowrates and shaft power rates. Shaft power generation by steam turbines in expansion zones are computed with the built-in simulation module. Compared to the existing approaches, the new method needs neither establishing iterative calculation, nor programming procedure, and it requires fewer parameters. For the illustrated case studies, the results obtained by this method are comparable to those obtained in the literature. It is shown that the calculation procedure proposed in this paper is simple, and the results obtained are accurate. In addition, the calculation of the steam turbine capital cost and environmental footprints are considered in the targeting procedure to provide decision makers with a more complete picture of the designed sites. This should allow them to efficiently screen and compare the major design options on the basis of both economic and environmental performance.