Investigation On The Ignition Technology And Device For The 670t/h Coal Boiler At Low Pressure

Based on the thorough researching coal boiler ignition and atomized nozzle all of the world, the physical model and its 3-D mathematical model of rotary atomized oil nozzle with micro-expanded tangent channel at low pressure are presented. And then the RNG/k- e model is adopted, and the standard k- e parameters are selected for micro-expanded tangent channel and swirling chamber, the calculated objects are separated from one another with net columns of cross uniform, then limited area equations are decided with control volume method, and the SIMPLE method is used, the flow characteristics and optimum structure parameters are gotten, And the same time, the experiments , tests and industrial application had been made, and the significative results are gotten: The angle( θ) of the micro-expanded tangent channel plays an important role for the fluid characteristics, if θ ≤0, the circumfluence at the exit of the nozzle is obviously, and the 9 >0, the solid cone in nozzle are formed easily, but its energy loss is bigger.The better atomized performance and spraying flow intensity are obtained of this nozzle with optimum structure parameters(n=3~4, L≥2.5, θ=2-6°,a/b=1.2 and Rx/rb>2.5) at low pressure. While the initial pressure po=0.8Mpa, Ux,o=0, Uy,0=0, Uz,0=-0.2m/s,the circumfluence isn't exactly formed with θ=6 at the exit of the nozzle, and the energy loss is reduced and the atomized angle can get 80 .The many virtues can be acquired while the nozzle has been used in the ignition technology for the coal boiler: (1)The steady flame and combustion can meet the star-up or the lower burden of the boiler.(2)The coke can't produced on the burner because of the lower heat burden.(3)The lower oil cost and a little maintenance of the equipments are the remarkable feature, etc. And in a word, the security, reliability and economic operation can be obviously improved with the nozzle.The nozzle is widely adequate to the medium atomized instrument about the oil burner and desulphurization & removing dust for coal burning boilers.