Development of a non-premix radiant burner. Final report

摘要

The objective of the first project period is to: make a study into materials suitable for the non-premix radiant burners (NPRB); choose the materials for the construction; make proposals for the design of the NPRB; test the different proposals with a CFD-model. In pursuit of finding a suitable material it is necessary first to estimate the maximum temperature that will occur in the burner. It has been estimated that the maximum adiabatic flame temperature will be about 2400-2500 K. The maximum temperature in the burner will of course never reach this level. A more realistic temperature was estimated to 2100-2300 K. The final choice was made after having contacted some of the leading producers. It was possible to find one producer that could produce burners of one of the suggested materials, zirconia. Several construction ideas for the NPRB have been discussed and some of them tested with a CFD-model. The proposed burner concept has been modified in order to obtain a homogenous temperature distribution, enhance air and gas mixing and reduce the maximum material temperature. The conditions for the CFD- calculations have been as follows: burner height x width: 300 mm x 300 mm; fuel input: 50 kW (specific load: 550 kW/m(sup 2)); combustion air temperature: 800 deg. C; furnace temperature: 900 deg. C; excess air: 5%. Discussions and calculations have shown that the most promising way to distribute the gas in the burner is by using perforated ceramic tubes. The CFD-calculations have been based on ten tubes with an outer diameter of 10 mm, each perforated with 40 1 mm holes. (EG)