Research on Full Premixed Combustion and Emission Characteristics of Non-Electric Gas Boiler

Abstract

NOx has become one of the main culprits causing the global greenhouse effect, and excessive emissions of NOx can also cause some common diseases in humans. The denitrification of power plant boilers has been 100% popularized, and their denitrification efficiency has reached national and local environmental requirements (such as Selective Catalytic Reduction, SCR). However, small gas boilers, due to their use of relatively clean fuels, have relatively low NOx emissions. But, local environmental protection departments have weak supervision of small clean fuel boilers, and these equipment generally lack specialized denitrification equipment, resulting in NOx emissions still not meeting standards. In addition, there are many small gas boilers, resulting in high total emissions. The fully premixed burner of a small gas boiler has the effect of suppressing NOx production during combustion. This study designed a surface porous burner with different combustion intensities at different positions. The experimental results and numerical calculations show that for horizontal combustion, the burner has different intake rates at different axial positions, enabling uniform combustion throughout the entire furnace, with NOx emissions below 30 mg/Nm3. The numerical simulation results show that the NOx emissions are 26.6 mg/m3. The calculated results are in good agreement with the actual situation. The generation of NOx is mainly thermal, with a maximum error of 15.4% between the calculated and experimental values. The difference between the calculated value of O and the experimental one is 5.1%. It can be seen that numerical simulation has considerable accuracy.

Keywords

• natural gas
• fully premixed
• simulation
• NO<i>_x</i>