Ventilation System And Strategy Research Of Residential Building Based On Source Identification Theory In Cold And Severe Cold Area

To reduce building energy consumption,most residential buildings have varying degrees of closure.As a result,the ventilation of indoor rooms is becoming less and less,Indoor pollutants are also unable to be effectively eliminated in time.TIndoor ventilation is currently the most effective way to control the indoor air quality,ventilation design should meet the indoor personnel daily life need the fresh air volume,ensure indoor comfort.And when a sudden pollution bursts a ventilation method can quickly and efficiently purify indoor pollution,to ensure the health of operator.As a result,the pollution source identification theory combined with ventilation technology for indoor air quality is of great significance.In typical cold and severe cold region city Shenyang,pollutant concentration in winter residence status field measurements were carried out.The measurement content mainly includes indoor CO2 concentration,formaldehyde concentration,temperature,concentration of PM2 5 and PM10.Test results show that the average indoor formaldehyde concentration is 0.23 mg/m3,the average CO2 concentration is 1500 ppm,which is far beyond national indoor pollutant concentrations standard.The residential natural ventilation experiment was also carried out.Experiment indoor pollutant concentration decline rapidly,results show that the average indoor formaldehyde concentration is 0.05mg/m3,the average CO2 concentration is 700 ppm,but because of serious winter outdoor haze phenomena,indoor concentrations of PM2.5 and PM10 concentration increased.Indoor temperature drops at the same time,caused low indoor thermal comfort environment.That means the ventilation method can remove indoor pollutants,but can’t control the natural ventilation of the removal of indoor pollutants.At the same time,it also can bring new pollutants,and a dramatic loss of indoor temperature and an additional indoor heating load.So we should consider use a controllable mechanical ventilation to control indoor air quality.In this paper,the design of ventilation system and traditional ventilation system is the difference from the pollution source identification technology application in the ventilation system,which can find sources through identification method,and the process is rapid.And then the targeted ventilation can make indoor pollutants removed quickly and efficiently.Firstly,the process starts with assuming possible pollution source location,and then according to different pollutants concentration range calculating air output.For example,when the concentration of pollutants exceeds the range in 0%～30%,air volume air supply is 130～156 m3/h,according to the calculation;when the concentration of pollutants exceeds the range of 30%～50%,air volume air supply is 156～180 m3/h;when the concentration of pollutants exceeds the range of more than 50%;air volume air supply is 180～240m3/h.Then the process continues with designing different ventilation form corresponding to different pollutants position and the combination of different supply air and ventilation form which can get system supply strategy,and through the CFD simulation analysis under different air distribution strategy and ventilated effect,and the optimal strategy was determined.When the concentration of pollutants is in the guest room,the vents from the sitting room and the guest room work,and the sitting room air supply is responsible for air pollutant concentration under the standard,while the guest room air supply is responsible for new air supply.When the concentration of pollutants is in the bedroom,the vents from the sitting room work;when the concentration of pollutants is in the bedroom,the vents from the sitting room and bedroom work.The sitting room air supply is responsible for air pollutant concentration under the standard,while the bedroom air supply is responsible for new air supply.In this paper,the theory of pollution source identification is combined with the ventilation system.Different ventilation strategies are designed for different locations of pollution sources to improve the current status of residential buildings in cold and severe cold areas.And it is of great significance to improve the air quality of indoor environment in residential buildings.