Variable Rate Natural Gas/Coal Co-Firing

摘要

In this age of abundant, and supposedly, inexpensive natural gas many utilities are opting for conversion of some environmentally marginal coal units to natural gas. However, both long-term and short-term history has shown that the economic pendulum can swing back toward coal as gas prices fluctuate. Once converted away from coal, it is unlikely that a natural gas plant will ever be re-permitted to burn coal. One potentially viable alternative is to marry coal burners with higher, and variable, volume natural gas igniters. Utilizing varying volumes of natural gas in varying furnace locations based on gas pricing and unit load can provide a level of economic, environmental and unit dispatch flexibility that may extend the life of many small to medium sized coal-fired generating units. This paper explores the performance benefits obtained by a southern US generating station utilizing Dual Orifice Co-Firing Igniters in a full-scale demonstration.