Conference article

The design and analyis of a flexible combined heat and power (CHP) system where the exhaust of two gas turbines is utilized as the heat source for a steam Rankine cycle is proposed in this paper. The case of study is the Johan Castberg off-shore facility, located in the Barents Sea, Norway. The steady-state design of the CHP system is developed with a specialized software based on the peak demand conditions of the platform, which account for 58 MW of electric and shaft power, and 52 MW of heat. A multi-objective optimization approach is followed in order to attain optimal designs where high efficiency is achieved while keeping reasonable weight to power ratios. Once the power cycle design is selected, the detailed dynamic modeling of the different components integrating the cycle is presented and implemented in Modelica language. Steady-state design and off-design validation of the thermal power plant model is carried out, and preliminary results are presented to show the ability of the dynamic model to provide reasonable information of the steam bottoming cycle transient operation.

dynamic process simulation, steam Rankine cycle, waste heat recovery, multi-objective optimization, offshore flexible operation, Modelica, genetic algorithm.