Thermoeconomic optimization for the design of heat recovery in bagasse boilers

The main concepts of some thermoeconomic methods were applied in bagasse boilers installed in sugar mills to optimize the design of heat recovery components (air heaters, economizers and bagasse dryers) under five arrangements, by trading off the component costs with the running costs in order to minimize the steam costs, considering the enhancing costs of energy and resources. The method was developed under a global strategy and could be applied to any kind of bagasse boiler; its main steps are energy and exergy analysis, thermoeconomic accounting and optimization. It was applied to a RETO CV-45-28 boiler and the steam cost may decreased about 48 746 US$/grinding season, also may obtained a bagasse surplus equivalent to 925 t of conventional fuel. It shows that in current bagasse boilers there is a profitable reduction of exergy losses from exhausting gases beyond the traditional operation levels of heat recovery.