Optimization Study On High Efficiency Capture Technology Of Kitchen Range Hood

Cooking oil fume is the main source of indoor air pollution in the family kitchen,and is also one of the important pollution sources of the particulate pollutants in the urban atmosphere.Without timely elimination of water vapor,oil pollution,burning appendages and waste heat generated during cooking,it will pollute kitchen environment and threaten the health of operators.Most of the family use kitchen range hood to remove cooking oil fumes.Capture efficiency of range hood significantly influence indoor personnel's health and comfort.With the increasing demand for indoor air quality,more attention has been paid to rise capture efficiency of range hood of household kitchen.Based on a comprehensive summary of related research of domestic and abroad on the structure optimization of kitchen range hood,we explored the characteristics of rectifying plate which is widely used in the top suction hood of household kitchen and put forward three kinds of optimization design,it is the slit type rectifying plate,movable rectifying plate,and the center hole rectifying plate.CFD numerical simulation is applied to study the effect of three kinds of rectifier plates for cooking oil fume collection effect.The computing method of capture efficiency based on particulate residence time is put forward,which was used to evaluate the efficiency of three kinds of optimization schemes.The following conclusions were drawn:The traditional square rectifying plate can effectively control the oil fume flow.The first capture efficiency increases with the increase of the exhaust air flow rate,reaching a peak of 81.5%at 16m~3/min.The capture efficiency of the slit type rectifying plate also increased with the increase of the exhaust air flow rate.The peak value reached 82.5%at 17m~3/min,and the capture efficiency was higher than 80%in the 11~20m~3/min exhaust air flow rate range.The first capture efficiency of movable rectifying plate first increased and then decreased with the increase of exhaust air flow rate.The peak value reached 80%at 12m~3/min and the capture efficiency was better in the range of 9~12m~3/min exhaust air flow rate.Capture efficiency of center hole rectifying plate fluctuates obviously with the increase of the exhaust air volume.The peak value is 85%at 15m~3/min,and the capture efficiency is obviously decreased with the increase of flow rate after peak.The effect is better in the range of12~18m~3/min exhaust air flow rate.In summary,the central hole rectifying plate which has high trapping efficiency,wide scope of application and make low energy consumption is the best design.Capture efficiency of slot type rectifying plate also higher than traditional square rectifying,this type rectifying plate has strong anti-interference ability,especially suitable for high exhaust air flow rate.Movable rectifying plate suitable for small volume exhaust air flow rate.