Effect Of Gas Flow By Range Hoods In Random Opening In The Residential Kitchen Public Exhaust Flue In High-rise Building

In the big cities of our country，high building have gradually become a generalform of urban houses, and the kitchen as "heart" of the residence, its cleanness is moreand more attention by people.At present vertical concentration exhaust system is amainly form in high-rise residential kitchen flue, Main problems of the exhaust way isthat the check valve is used for a long time, its surface will be soiled by the dirt, thickoily, which does’t normally make check valve open, thus Range hoods can’t dischargeFG, there is a flow backward phenomenon.sometimes the flame string to the sticky tothick oily, which can give rise to fire. In the flue, The minimum and maximum exhaustvolume are very different, which brings distress to the user choosing Range hoods,These question may often lead to harmful gas fill in kitchen，which is not well topeople.This paper first studied32layer on the house kitchen flue flow field, when rangehoods are in evenly distributed opening and3kinds of different temperature, whencoefficient of coincidence use are in12.5%,31.2%,50%,62.5%,81.2%,100%sixkinds of conditions, the floor are increasing，the pressure of flue is lower, at the bottomof the floor appears the highest pressure, which make the bottom users flue smoke notunobstructed, Along with the increase of coefficient of coincidence use and pressure isrising that is, the more coefficient of coincidence use, the higher pressure at the bottomof flue, the greater the bottom users will be more serious problems to flow backward; Inmain flue，the floor are higher, air volume is larger，the more coefficient of coincidenceuse, the larger air volume at the top of flue,In the range hoods opening section, airvolume increased significantly, and at exhaust outlet air volume reaches maximum out. when range hoods are in unevenly opening and3kinds of different temperature,pressure and air flow rate are changing with the change of the floor height;whencoefficient of coincidence use are in62.5%and68.75%two kinds of conditions,temperature difference is at the same time, the floor are increasing，each floor pressureis different, and the maximum pressure is not appear at the bottom, but there is ainflection point, on the left of the inflection point, the higher the pressure,on the right inthe inflection point, the lower the pressure, and in the near of the inflection point, thepressure is bigger, Here’s the user will be more serious problems to flow backward;Each floor air volume are not identical,but at exhaust outlet air volume are identical. Indifference of temperature,not at the same time, the of pressure each floor will increasewith the increase of temperature difference,especially the indoor temperature is lowerthe temperature outside, the pressure of each floor will be significantly reduced; In thesame conditions the volume of each floor is the same.