Experiment Study On The Insulation Properties And Energy Consumption Characteristics Of The Green Roof In A Full-size Building Model

Green roof has the effectiveness of alleviating the urban heat island effect, reducing building energy consumption, increasing the green area of the city, is to improve the building thermal environment and solve the problem of building energy efficiency is one of effective methods. Green roof using plants keep out of the sun radiation, plant photosynthesis, transpiration and evaporation cooling effect of planting soil layer to effectively reduce through the roof to indoor quantity of heat, realizes the roof insulation cooling, so as to improve the indoor thermal environment, buildings goals to reduce energy consumption of air conditioning.In this paper, through the establishment of the full-size construction mode of contrast experiment test platform, test study of the insulation performance and the energy consumption characteristics of the green roof, the ceramsite evaporation roof, the cohesive soil evaporation roof and the exposed roof, is purpose to obtain the full-size construction mode of green roof insulation performance and energy consumption characteristic parameters and the evaluation index, to provide experimental basis for its application and promotion.Test building is located in panyu a businesses on the roof and select five rooms for comparison test room, five test room construction area of29.64m2, the room’s tectonic pattern, palisade structure and window are same, two of the test room roof is set to the green roof, plant as a grass, a test room roof laid ceramsite, another test room roof laid cohesive soil, and selecting a bare roof as a comparison test room at the same time. In2013August, September and October for84days of testing. Selection during sunny day period of the test data of heat insulation performance and energy consumption characteristics analysis, through analysis of the different structure roofing insulation performance parameters, the energy consumption characteristics of the index, and the thermal insulation performance, energy consumption characteristics and analyzes the correlation between the climate parameters, calculate the different heat insulation roofs of the thermal performance of heat transfer and the relevant parameters.The results show that green roof show good heat insulation and cooling effect, in the condition of natural ventilation, green roof one, green roof two, ceramsite roof and cohesive soil roof than bare roof inner surface, down6.0℃, the highest temperature of6.0℃,5.5℃and5.0℃; green room one, green room two, ceramsite of vegetation of indoor air temperature and the cohesive soil room to room than a bare room, indoor air, down1.1℃, the average temperature of1.1℃,0.9℃and0.7℃; green roof one, green roof two, ceramsite roof, roof of cohesive soil and exposed roof inner surface temperature amplitude are:0.6℃,0.6℃,0.7,0.8and2.7℃, the peak valley difference are:1.1℃,1.2℃,1.3℃,1.4℃and5.3℃; Indoor air temperature amplitude are:1.8℃,1.7℃,1.7℃,1.8℃and1.9℃, the peak valley difference are:3.4℃,3.3℃,3.2℃,3.4℃and3.7℃. Under the air conditioning running state, green roof one, green roof two, ceramsite roof and interior of cohesive soil roof than bare roof, down5.1℃, the highest temperature of5.1℃,4.4℃and3.8℃; green room one, green room two, ceramsite of vegetation average indoor air temperature and the cohesive soil room to room than a bare room, indoor air, down0.8℃, the average temperature of0.8℃,0.8℃and0.3℃; green roof one, green roof two, ceramsite roof, roof of cohesive soil and exposed roof inner surface temperature amplitude are:0.4℃,0.5℃,0.5℃,0.8℃and2.5℃, the peak valley difference are:0.8℃,0.9℃,1.0℃,1.6℃and4.7℃; Indoor air temperature amplitude are:0.7℃,0.9℃,0.8℃,0.9℃and1.0℃, the peak valley difference are:1.8℃,2.0℃,1.8℃,1.9℃and2.3℃. Indoor air conditioning set temperature of26℃, compared with the bare room, green room one, green room two, ceramsite of vegetation room and room of cohesive soil total power consumption reduced6.73kWh, respectively,7.60kWh,6.75kWh,4.04kWh; green roof one power saving amount per unit area is0.2129kWh/(d·m2), unit volume power saving amount is0.0546kWh/(d·m3); green roof two electricity quantity per unit area is0.2571kWh/(d·m2), unit volume power saving amount is0.0659kWh/(d·m3); Ceramsite roof energy saving quantity per unit area is0.2179kWh/(d·m2), unit volume power saving amount is0.0559 kWh/(d·m3); Clay roofing energy saving quantity per unit area is0.1305kWh/(d·m2), unit volume power saving amount is0.0335kWh/(d·m3).Roof insulation performance and energy consumption is mainly affected by the outdoor climate parameters. Green roof insulation performance and energy consumption and the outdoor climate parameters correlation relationship is order from large to small is:outdoor air temperature, solar radiation intensity, outdoor air relative humidity, wind speed. Vegetation roofing structural hourly temperature and the outdoor air temperature and solar radiation intensity correlation decreases step by step.Sunny day period of green roof has good heat insulation effect, compared with the bare roof, green roof one, green roof two, ceramsite roof huts and viscosity average calculation of the heat transfer of heat flow were decreased by2.8W/m2,2.8W/m2,2.2W/m2,1.4W/m2; Green roof one, green roof two, ceramsite roof and roof during the day time of cohesive soil heat transfer heat loss were71.4%,92.8%,64.9%and74.2%respectively; Green roof one, green roof two, ceramsite roof, roof of cohesive soil and the heat transfer coefficient calculation value of exposed roof are:0.58-0.74W/(m2·K),0.43-0.63W/(m2·K),0.62W/(m2·K),0.75W/(m2·K),0.89W/(m2·K).