External Board Composite Wall Thermal Performance Study

According to related research,China’s total energy consumption accounts for about 26.7% of the total social energy consumption,and under the condition of considering the whole life cycle of buildings,total energy consumption accounts for 30% to 40% of total energy consumption society. Therefore, building energy conservation has become an important part of energy conservation in China. For a long time, change the wall thermal performance to meet the demand of the indoor thermal comfort is an important content of building energy efficiency technology.This topic is in this background, a certain distance from the building wall outside surface decorate cement fiberboard, form external board composite wall. Through outside hangs board and outer wall surface temperature difference caused by the thermal pressure ventilation, take part in the outer wall of heat, can greatly reduce or even eliminate the building cooling load, In the southern humid area of strong solar radiation and relatively long summer, the structure has a strong suitability.In this paper, to solve above problems, through the research of hanging board composite wall thermal performance test methods, and weather conditions in the summer, determination of the hourly variation of parameters, such as the wall inside and outside surface temperature, heat flux, the room inside and outside air temperature, ventilated cavity after cladding entrance wind speed and temperature, outdoor meteorological parameters and air conditioning power consumption. Then use fluent software simulated the thermal pressure ventilation process of hanging board composite wall, the simulation results were compared with the measured results, determined the effectiveness of the simulation method. Finally by using fluent software to optimize hanging board composite wall structure parameters. In this paper, the main results are:Summer weather conditions in Guangzhou, external hanging board composite wall was tested, obtained the changing rule of the external board composite wall internal and external surfaces temperature, heat flux, the room inside and outside air temperature, ventilated cavity after cladding entrance wind speed and temperature, outdoor meteorological parameters(air temperature and humidity, wind direction, wind speed, solar radiation intensity) and the air conditioning power consumption over time.Similar cases in outdoor weather conditions, comparate ventilation, airtight, ordinary three wall under the air conditioning condition and airtight conditions of thermal performance; and compare the ventilation wall cavity in the presence of aluminum foil in the working condition of air conditioning and sealing conditions of thermal performance; Finally contrast in a ventilated wall cavity moulding board, extruded board, rock wool board three insulation plate in the working condition of air conditioning and sealing conditions of thermal performance; the plugin is obtained calcium silicate board composite wall delay and attenuation of the outdoor temperature wave effect, and use test data,using internal surface heat flow meter method to calculate the equivalent thermal resistance of the hang board composite wall out, provided the certain basis of the external board composite wall application in hot and humid areas.By using fluent software simulated the external hanging board composite wall thermal pressure ventilation, the simulation results were compared with the measured results, determined the effectiveness of the simulation method. Finally by using fluent software to optimize hanging board composite wall structure parameters(the thickness of external hanging board, thickness of cavity, the cavity height, and channel into the outlet area).