Pilot-scale Investigation of Heat Flux and Radiation from an Oxy-coal Flame

Paper from the AFRC 2015 conference titled Pilot-scale Investigation of Heat Flux and Radiation from an Oxy-coal Flame

The University of Utah is performing ongoing experiments in their 1.5 MW pulverized coal fired furnace (L1500) to better understand the behavior of oxy-coal flames and to provide operating data sets for model validation. In this particular study, the furnace was fired on a Utah Bituminous (Sufco) coal with oxygen and flue gas recycle. A number of experiments were performed throughout a week period, all with identical operating conditions. The multiple sets of data will be used to quantify the repeatability of conditions and the uncertainty in measured values. For these tests the furnace was fitted with 8 water cooled tube bundles in the first four sections of the reactor. The temperature of the water in and out and the temperature of tube surface were measured, along with the cooling water flow rate. A set of three radiometers were installed in the near flame region. These devices were configured to differentiate between radiation from the hot refractory walls and from the coal flame. From these data the heat flux could be determined by multiple methods at four axial locations relative to the flame. Close scrutiny of the heat flux and radiometer data indicate that these techniques are sensitive enough to resolve changes in burner operating conditions. However the magnitude of the heat transfer is not constant throughout a test period due to accumulation of ash on heat transfer and background surfaces.