Numerical Simulation Of Natural Ventilation And Climate Effect Research On Residencial Building

Building energy consumption accounts for a large proportion (about 40%) in energy consumption in today's society. Building energy saving is attracting more and more attention of people. Natural ventilation is an effective way in building energy saving. It not only can cool down and dehumidify the air but also can bring in fresh and healthy air. For the situation that air conditioning is largely used and energy is consumed excessively in nowadays, this paper studies the possibility and effectivity of energy saving by using natural ventilation in residential buildings.The object of this research is a residential district in Tianjin. The outdoor wind environment of the residence in summer and winter is simulated by using CFD method, and the interior ventilation of two types of apartment in one of the buildings is also simulated. The influence of various factors (such as outdoor climate, window setting and room layout) on interior airflow distribution is analyzed as well. The standardκ-εmodel of steady turbulent flow in software FLUENT is used to simulate the interior and outdoor airflow field. Three-dimensional velocity field, temperature and pressure field, and so on are obtained. The interior thermal comfort index PMV-PPD in various simulation conditions with Fanger's Thermal Comfort Equation are calculated out, and effects of the natural ventilation in summer is evaluated further.The outdoor air velocity field and pressure field in summer and winter are firstly simulated. The effect of various climates on the building ventilation and outdoor wind field on people is analyzed. The results showed that ventilation in the windward side of the buildings is notable, while wind pressure in the leeward side of the buildings is not obvious. The strong wind region in the outdoor area can be found in the area neighboring buildings. The interior airflow distribution in A-type and B-type apartments with all the windows open and partially closed is simulated respectively in summer. It can be found that the natural ventilation inside the apartment is obviously affected by the location of the inlet and outlet of the wind and the layout of the room.The zone which can meet 80% and 90% of the comfort requirement is put forward by the computing thermal comfort index according to two international standards of thermal comfort evaluation (standards of ISO7730 and ASHRAE), and the changes of percentage of dissatisfaction under various conditions is analyzed. The interior thermal comfort condition was not only related to temperature and wind velocity, but also infected by the window setting and room layout.The analysis of natural ventilation in buildings by numerical simulation, not only can evaluate their ventilation conditions, but also can provide a certain reference value for building planning and design.