98/03985 Particle size and velocity measurements in the radiant section of an industrial-scale, coal-fired boiler: the effect of coal type

Abstract

To improve understanding of the complex phenomena involved in pulverized coal combustion in utility boilers and to develop information suitable for model validation of comprehensive combustion codes, a series of measurements was taken on a 160 MW corner-fired, pulverized-coal fired boiler operated by New York State Electric and Gas. The measurements discussed here include those of particle size, velocity, concentration, and data rate for the full-load, baseline operating condition firing the boiler on different coals. The types of coals used during this test were three bituminous coals, one with a relatively high fixed carbon and low volatiles, labeled coal type B, one with a lower fixed carbon and higher volatiles content, labeled coal type A, and a coal similar to the type A coal in composition, labeled coal type C. Data were collected at four ports in a vertical line along the north wall of the boiler and at one additional port at the nose level of the boiler on the east wall. Significant variations in particle size and velocity were observed due to the change in coal type at the nose of the boiler, while measurements lower in the radiant section showed smaller differences. Vertical trends in the meanmore » particle sizes in the upper part of the radiant section show larger variations when using the type B coal than are seen when the boiler was fired on the type A coal. Profiles of volume mean diameter and velocity taken at the nose of the boiler for all three coals used also show significant differences due to coal type. The maximum values in the rate Probability Density Functions (PDF`s) for the type A coal shows an increase toward higher data rates with increasing vertical location in the boiler, while the maximum value in the PDF`s shows a decrease toward lower rates for the type B coal.« less