Simulations Of Natural Gas Premixed Combustion In Ported Ceramic Plaque Radiator

With highly developed inner solid surface and excellent property of heat transferring and accumulation, porous media can play an important role in combustion. Premixed combustion in inert porous media has so far been proven to be an advanced combustion technology in which premixed fuel and air burn within a porous bed. The technology has many obvious advantages over conventional premixed combustion, in which the premixed fuel and air burn as a free flame that is stabilized at the burner, with reduced emissions of combustion-related pollutants, wider domain of flammability, much higher thermal efficiency and radiant heat outputs, energy saving, uniform heat distribution and so on. The ported ceramic plaque is a sort of porous media, and also is the core discreteness of the gas-fired infrared ported ceramic burner. Through theory analysis and numerical estimation, this paper investigated the ported ceramic plaque comprehensively and mostly conducted these aspects of the work as follows:1. The three-dimensional steady model was established. The premixed combustion was simulated in the ported ceramic plaque ( a single bore) through using the software of FLUENT, the temperature field, the consistence field distribution and the position of flame in stabilization combustion were gained. Also it concluded that natural gas-air premixed combustion has three different phases (natural gas-air mixture premixed heated phase, and combustion phase and pollution gas heating phase) in the bore. Besides, it discussed the process of catching fire and investigated the backfire character.2. The natural gas premixed combustion was simulated under different projects and the impact of combustion character was analyzed by heat load, surplus air coefficient, porosity of the ported ceramic plaque and conduct coefficient of the ported ceramic plaque.3. The mechanism of NOx formation was discussed while the nature gas was combusted with air under a fully premixed condition in ported ceramic plaque. The model of NOx formation was established. The NOx emission was predicted numerically based on the predicted flame temperature profile and the reason why NOx emission is low in this kind of burning process was analyzed in details. At...