Numerical Simulation And Energy-saving Analysis Of Building Thermal Environment

Building thermal environment is an importance foundation for the evaluation of building energy consumption, and it is indispensable guiding significance for the engineering practice.The wall surface temperature measurement on all direction which lasts a whole month was conducted at a residential builing during the early summer in the urban of GuangZhou City of China. A theoretical model, considering the effects of solar radiation, environmental radiation, the convective heat transfer, natural ventilation heat transfer and the radiation heat transfer between the inner surfaces of the envelope structure, is built for the heat exchange between the envelope and the indoor and outdoor environment. The temperature changes of the envelope inner surface and the indoor air in the early summer of Guangzhou City is calculated. Also numerical simulation of the temperature field change for real reinforced concrete model which is made up of slab, beams, column and brick walls is conducted. At last, base on the Building thermal environment, the dynamic change trend of the building hourly load is calculated.The results show that the change roles are basically identical between the calculated value and the measured value. The indoor air temperature changes with the outdoor air temperature and the difference between them is largening in the morning, and till 14:00 PM, it begins to reduce. The outer surface temperature changes of the building vary with the sun elevation angle and the sun azimuth. The sharpest change of the temperature occurs on the roof and next comes the west-side wall. The inner surface temperature of the envelopes present a relatively small variation in the morning, then rose obviously in the afternoon, and finally become flat till 16:00PM.The theory of the temperature field is also suitable for the computation of the fire temperature field.The result shows that:1, the temperature distributions of the surfaces exposed to fire in all directions is not uniform and the integral structure temperature field calculation of building under fire is a problem that should be considered in three dimensional method.2, the wave-like temperature distribution is showed in the exposed surface because of the steel bars.3, the fire resistance analysis of the slab and column which are viewed as a Whole should be considered simultaneously.Using the results of the Building thermal environment to analyze the dynamic building load, and the result shows that:In the model, the heat release of the building envelop account for 82% of the total building heat release, so the reformation of building envelop is very important to building energy saving. The result show that only conducting the thermal reformation to the door, windows and the walls can decrease by 1.76×10~6KJ of the envelop heat load, decrease by 23.08% compared with the former envelop heat load.