Exergy analysis and exergetic sustainability index of package boiler

Energy utilisation in the fertiliser industry can be improved by conserving energy. One way to achieve this is by modifying the operating conditions of the package boiler. Research shows that 94.3% of the total exergy destruction of the package boiler is obtained from the evaporator component with a value of 2.7 x 10(8) kJ/hour. The modification of evaporator operating conditions involves lowering the inlet temperature of boiler feed water (BFW) by Delta T (196 degrees C-116 degrees C). This decrease in BFW temperature increases the latent heat required and reduces the convection heat carried by the flue gas to produce superheated steam. The optimum temperature of BFW is 161 degrees C which results in a reduction in exergy destruction of 6.2 x 10(6) kJ/hour and produces a difference in loss costs based on actual data (196 degrees C) of Rp 1,370,354,743/hour. The exergetic sustainability index (ESI) obtained was 0.918.