Modelling and optimization of utility systems

New methods have been developed for the modelling of steam turbines and gas turbines. In particular, the new models give a better description of part-load performance than previously published models. These models have been incorporated, along with those for the other elements of steam systems, into an overall model for utility cogeneration systems. The degrees of freedom of steam systems allow significant opportunity for cost reduction through optimization. This results from the complexity of the interactions within such systems, the continually changing demands on the system and the complexity of cost tariffs for power and fuel. This paper presents improved methods for both the simulation and optimization of utility systems based on the improved models. Using the method presented, significant cost savings can be made by optimizing the system operation at no capital cost. Case studies show a significant potential for cost savings.