Abstract: The effects of gas inlet velocity and the nozzle and throat diameter ratio on the combustion performance of a new type combustor for baking furnace were studied by a 2dimensional rotation axis numerical models. The results indicated that the highest temperature in the combustion chamber increased with the increase of the gas inlet velocity. When the gas inlet velocity was fixed， with the increase of the nozzle and throat diameter ratio of the combustor， the flame shape changed from the pyriform to the dovetailed shape and the highest temperature decreased at first and then increased gradually. The flame length increased with the increase of the gas inlet velocity and decreased with the increase of the nozzle and throat diameter ratio of the combustion chamber.

Key words: combustors, temperature distribution, combustion performances, flame length, baking furnace