| With the acceleration of urbanization,the social problems brought about by urban flooding and heat island effect are emerging day by day,and people are urgently seeking a way to use the harmonious development of nature to alleviate these problems.As a part of the green building,green roofing is an effective technical measure by building green roof on the roof,which has become a hot topic for many scholars today.This green roof consists of vegetation,matrix and drainage layers.This study puts forward a matrix of recycled biocarbon as a green roof,analyzes the roof runoff law and temperature heat current change characteristics of 4 different roofs through experimental observation and theory,scientifically evaluates the control ability of the green house face runoff and its thermal performance,and obtains the following main conclusions.(1)Green roof has a significant regulating effect on rainwater runoff,the regulatory ability is closely related to the matrix thickness,matrix composition and rainfall parameters,and biocarbon soil as the matrix roof has better rainwater control ability.In the early stages of rainfall,green roofs can slow the runoff flow time and peak flow,and after the rainfall,it can also extend the production time,which reduces the roof runoff rate and relieves the pressure of urban surface runoff.Through the correlation analysis of green roofing retention rate,it is found that the effect of rain water retention on green roof has a significant correspondence with rainfall,duration,intensity and previous dry weather cycle severance.(2)The green roof has better insulation and cooling effect.Compared with the average temperature reduction of ordinary heat shield roofs and different green roofs at the same time,3 to 5℃,The difference between the maximum temperature of the two house panels is 6 to 15 degrees C,reducing the peak of the heat flow by 8 to 20 W/m 2 on average.Increasing the substrate thickness can reduce the bottom temperature of the roof structure layer,the substrate thickness plays a key role in the attenuation of the temperature fluctuation sourty of outdoor environment,and the increase of the substrate thickness can effectively improve the attenuation of the temperature facing the plant house.Comparing the change slower and attenuating temperature between green roofs,biochar has better cooling performance as a matrix of green roof insulation. |
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