OCR Text |
Show conventional (non-FBC) boiler because most studies have shown the AFB systems to be somewhat less costly than conventional boilers. A complex and detailed analysis of the impact of boiler costs on the utilization of coal in industry was performed to see if the savings potential from packaging would be large enough to have a noteable effect. This analysis estimated the usage of oil, gas, and coal in industrial boilers based on economic incentives. Ten regions of the country were considered. Existing boiler size distribution within each region, capacity factors, and regional fuel costs were used to determine the economical fuel choice for each size, capacity factor, and region. With this approach, the effect that the cost savings of the packaged PFB would have on the fuel mix was estimated. Current usage of fuel in industrial boilers is shown in Fig. 7. In contrast, the fuel mix with the 30% savings in capital cost of the shop-fabricated FBC system is also shown, indicating a substantial potential shift from oil and gas to coal. It should be noted that it is assumed that this savings is only for boilers in the 50,000 to 200,000 lb/h steam capacity size range. The economic ground rules used in this analysis are shown in Table 5. The results indicate that development of a packageable system would double the coal use in industrial boilers and cut the oil use in half. CONCLUSIONS The significant findings that can be drawn are: 1. Being able to shop fabricate industrial boiler equipment provides substantial cost reductions over field-erected systems. 2. Both AFB and PFB are more compact than conventional boilers. 3. The auxiliary equipment required with coal-fired units prohibits a package as compact as with oil or gas. 4. The PFB boiler module is probably capable of being totally shop fabricated and shipped by rail for sizes as large as 150,000 lb/h of steam. 5. The freeboard height of the AFB may prohibit rail shipment of even just the boiler module and causes doubt as to the feasibility of a truly packaged AFB. 21-19 |