严寒地区住宅厨房油烟颗粒物扩散机理和沉积特性的数值模拟分析

Numerical Simulate on Diffusion Mechanism and Deposition Characteristics of Cooking Particles from the Residential Kitchen in the Severe Cold Area

目的研究住宅厨房中细颗粒物的扩散规律,提出合理改善厨房环境的措施。方法运用计算流体动力学的方法,模拟9种典型的通风工况。结合重整化群(RNG)湍流模型和滑移通量模型模拟厨房空间气流场,预测颗粒物分布。量化影响颗粒物扩散的各项机制,同时计算朝向壁面的沉积通量。结果远离热源处的温度梯度太小,使得热泳力对颗粒物的传输过程没有显著影响。由湍流影响的滑移通量平均阶数约是由重力和动量变化率影响的350倍。开门会导致更多颗粒物沉积在地板上,沉积通量在1.5×10^(-5)~2×10^(-5)。结论湍流在颗粒物的扩散中起主导作用,增强吸油烟机容纳热羽流能力,能降低厨房空间颗粒物浓度。

In order to fully grasp the distribution of fine particles in the residential kitchen,nine typical ventilation conditions were simulated by computational fluid dynamics methods.Combining the Renormalization Group(RNG)turbulence model and the drift flux model were used to simulate the airflow field in the kitchen space and to predict the distribution of particles.Various mechanisms that affect the diffusion of particles were quantified and deposition flux toward the wall was calculated.The results show that when the oil fume particles diffuse in the kitchen,the temperature gradient far away from the heat source is too small,so that the thermophoretic force has no significant effect on the transfer process of the particles.Average order for drift flux affected by turbulence is about 350 times that affected by gravity and the change rate of momentum.Opening the door will cause more particles to deposit on the floor,and the deposition flux is between 1.5×10^(-5)and 2×10^(-5).The research results show that the turbulence plays a leading role in the diffusion of particles,and the concentration of particles in the kitchen space can be reduced by increasing the capacity of the range hood to contain the thermal plume.