The Design and Performance Optimization of Thermal System Components

A general analytical approach which directly determines the optimum thermodynamic and economic behavior of thermal systems and which is described in detail in von Spakovsky and Evans (1987) and von Spakovsky (1986) is briefly discussed here in the context of establishing a “stable economic environment” around each cycle component. Such environments allow for isolated, individual component optimizations which need not to be performed at the time the system is optimized, but which nonetheless correspond to some overall system optimum. In these environments, very “detailed” thermoeconomic component models can be optimized without the added complications resulting from a consideration of all the other system variables. The development and optimization of these “detailed” models is illustrated using the example of a feedwater heater. Utilizing the Second Law and typical Second Law costing techniques, the method presented here provides for the creation of mathematical models which balance operating costs and capital expenditures. Such models can be solved numerically for the optimum design point or the optimum operating point of a thermal system and each of its components.