Encontro de Energia no Meio Rural Agrener
SOSA-ARNAO, Juan Harold, MODESTO, Marcelo and NEBRA, Silvia A. Two proposals to determine the efficiency of bagasse boiler. In Proceedings of the 6. Encontro de Energia no Meio Rural, 2006, Campinas (SP, Brazil) [online]. 2006 [cited 08 December 2013]. Available from: <http://www.proceedings.scielo.br/scielo.php?script=sci_arttext&pid=MSC0000000022006000200046&lng=en&nrm=iso> .
This work analyzes and compares two proposals for determination of the bagasse boiler efficiency, one of it based on bagasse higher heating value (HHV), the other one based on bagasse lower heating value (LHV). The methodology of calculation, for both proposals, uses the heat loss method. The results, obtained through the two proposal's, presented important differences; the boiler efficiency determined through the proposal of code ASME PTC 4.1, based on HHV, highlights the effect of bagasse moisture content upon boiler efficiency. This effect, in the Beatón and Lora proposal, is hidden, because the energy required to evaporate the bagasse moisture content and the water vapour from hydrogen contained in the fuel are discounted in the LHV calculation. Three types of boilers, with different capacity and leaving steam properties were analysed. Considering the boiler constituted by a sequential arrangement of a steam generator, an air heater and an economizer, a simulation was made determining the influence of the variation of the air heater exit gases temperature upon theirs performances. The performance analysis was based on the second law of thermodynamics.
Keywords : bagasse; efficiency; exergy.