In order to measure the heat flux arriving to the inner surface of the boiler furnace from the flame, method for measuring heat flux and the heat flux-meter were studied.
Thin disk sensor was used for heat flux measurement sensor. Thin disk sensor consists of a thin metallic foil disk bonded at its periphery, over a cavity, to a metallic body. Thermocouples measure the temperature difference between the center and the edge of the thin foil disk. The temperature difference is directly proportional to the rate of heat transfer to the foil disk. Thermocouples change the temperature difference into milivolt signal.
Chromel was used for the foil and Alumel for the body. For long time use and high heating rates the body was cooled by water. To calibrate the heat flux-meter, the calibration furnace was made. As the result of calibration, the milivolt signal of the heat flux-meter was directly proportional to the heat flux arriving on the surface of the thin foil disk. The signal was most affected by the condition of the surface of the foil disk.
In order to investigate wether the heat flux can be measured from the flame in the boiler furnace or not, the heat flux was measured by heat flux-meter. As the result, a reasonable signal was obtained.
