Traditionally, blending coals of differing ranks complicates the combustion system design for boilers and requires over-sizing and compromising of optimal performance as individual equipment is required to operate in a non-ideal mode. In such a scenario, effectively, the equipment must try to meet the differing needs of both coals at the same time which means that it won’t be operating as efficiently as would otherwise be the case. | Sumitomo Corporation for EVNGENCO1 Duyen Hai 3 Extension, 1 x 660 MWnet Power Project COMBUSTION AND PULVERIZED COAL FIRING SYSTEM July 7, 2014 In-Furnace Blending Technique Traditionally, blending coals of differing ranks complicates the combustion system design for boilers and requires over-sizing and compromising of optimal performance as individual equipment is required to operate in a non-ideal mode. In such a scenario, effectively, the equipment must try to meet the differing needs of both coals at the same time which means that it won’t be operating as efficiently as would otherwise be the case. B&W has extensive experience with a wide range of coals sourced world-wide and recognizes that for a design that will utilize differing ranks of fuels, such as those proposed here, a better design solution is required. For this project, B&W is proposing to utilize an In-Furnace Blending Technique and has designed the equipment to complement this strategy while still providing maximum fuel flexibility for 100% operation on either Coal A or Coal B. In practice, B&W has developed a strategy for blending Coal A and Coal B in the furnace rather than in the coal handling system. The In-Furnace Blending Technique simplifies the coal handling system and reduces associated costs by eliminating the need for coal blending equipment in the coal yard. It also allows the pulverizers to operate more efficiently and reduces the total number required, because the more difficult to grind coal is isolated in particular mills. Each coal is fed, without need for blending, to the selected raw coal storage silos. All silos can be filled with Coal A, all with Coal B, or any combination of silos with either Coal A or Coal B. This provides fuel flexibility while minimizing equipment requirements. All feeders, pulverizers, and control hardware remain identical among the six supplied pulverizers. This provides for 100% MCR operation firing Coal A and 100% MCR .
