基于风幕技术的厨房油烟治理及净化试验研究

Experimental innovation for kitchen oilgrease fume purification and control based on the wind curtain technology

为了治理厨房油烟污染,通过分析厨房油烟产生的机理及特点,设计一种基于风幕技术形成的控烟流场,可防止厨房油烟外溢的新型风幕吸油烟机。提出风幕吸油烟机的"闭合流场"理论,依据空气动力学、流体力学和势流叠加原理,建立了闭合流场的数学模型。经厨房试验表明,风幕射流出口速度初期衰减较快,后期衰减变缓,流场各点理论风速与实测风速基本吻合,数学模型合理可靠;当射流初速度为2m/s时,风幕吸油烟机的控烟吸程为1.5~1.7m,排烟控制区域中风速均在0.38m/s以上,能够有效抑制厨房油烟向外逸散;油烟机开启前后呼吸带处PM2.5的平均质量浓度由80.6mg/m^3降到了5.3mg/m^3,并结合实际厨房状况及大气环保要求,提出了综合油烟净化处理系统方案。

The given paper is aimed to introduce a design scheme for controlling the cooking fume and oil-grease pollution in the individual home on the basis of analyzing the mechanism and characteristic features of the kitchen pollution in hoping to control and prevent from the spillover of kitchen cooking fume through the gas exhausting chemney.As is well known,the rotation of the synthetic moving wheel of the air curtain smoke suction machine can induce the external pressure and internal suction air current,while the velocity of the air curtain jet tends to decrease gradually and then enters the suction inlet.What is more,since the superposition of the external pressure flow field and the internal suction flow field tend to formulate a"closed smoke flow field",it is necessary to establish a mathematical model of closed flow field on the basis of the aerodynamic principle,hydrodynamics and the potential flow-current superposition.The results of the kitchen test show that the velocity of the outlet velocity of the wind curtain jet tends to be faster in the early stage and its later turns to attenuate to get slower.The theoretical wind velocity of the flow field should be basically consistent with the measured wind speed with the mathematical model turning to be reasonable and reliable.For example,when the initial velocity of the jet is 2 m/s,the smoke control pressure of the smoke exhauster should be equal to 1.5-1.7 m,with the speed of the stroke in the control area of the exhaust smoke being over 0.38 m/s,which can effectively restrain the release of the kitchen fume.It is in such a way that the average concentration of PM2.5 in the releasing zone pre-&-pro the hood opening can be reduced from 80.6 mg/m3 to 5.3 mg/m3.Thus,combined with the actual kitchen situation and the atmospheric environmental protection demands,we have managed to bring about a scheme of comprehensive cooking fume purification scheme,which can be expressed in the following way:If the oil grease fume can be treated by Na OH aqueous solution of one percent mass fraction,the average mass concentration of PM2.5 at the outlet of the exhaust fan can be reduced to 1.7 mg/m3,thus,the cooking fume purification can be made much more effective and efficient than it is now.