Design Of Solar Chimney For Enhanced Natural Ventilation And Indoor Thermal Environment Simulation In Green Building

Solar chimney enhanced ventilation has multiple advantages,for example,healthy ventilation,energy conservation,and avoiding privacy infringement,noise and dust issues caused by opening window for ventilation.It's a natural ventilation technology that utilizes non-pollution solar energy to sustain the driven force by thermal pressure ventilation.From the 1st chapter to the 3rd chapter,the characteristics of solar chimney are analyzed from the aspects of mechanism,performance related parameters,as well as system types by using the methods of literature study and case study.The cases of solar chimney in green buildings are analyzed and summarized from the aspects of geometry modeling,material and form composition.The design methods of enhanced ventilation for solar chimney in green building are then investigated from the perspective of climate analysis,form design of solar chimney,mode of combination with building,as well as integration with energy-saving technology.In chapter 4 a multi-storey office building has been studied as an example,then it takes the multi-storey office building unit space as the prototype and analyzes the influence of solar chimney ventilation design methods on indoor thermal environment of multi-storey office buildings by Computational Fluid Dynamics.The design methods are simulated from the five aspects of solar chimney inlet position relations,solar chimney external wall absorption coefficient,form composition of solar chimneys and buildings,solar chimney height changes,as well as solar chimney depth changes.The conclusions are as follows: 1)when the air inlet of solar chimney is located above the floor,ventilation is more efficient than the cases in which the air inlets of solar chimney are located in the middle or at the bottom of the floors;2)Increasing the absorption coefficient of the surface of the chimney can improve the ventilation effect,but it has little effect on the ventilation rate,indoor temperature and indoor wind speed;3)In the combined relation of the separation,interpenetration and inclusion of the solar chimney and the building,the physical relation of interpenetration and inclusion has better ventilation performance than the separation,but the difference of indoor temperature and wind speed is not significant;4)In the range of study,it can be see that the ventilation effect of solar chimney increases with the increase of the height of solar chimney,and the indoor temperature of the top floor of multi-storey office building is more susceptible to the influence of the height of solar chimney;5)Within the range of investigation,the ventilation effect of solar chimney increases with the increase of the depth of solar chimney,and the indoor temperature and wind speed also have obvious changes.The transient simulation method is used to simulate the effect of enhanced ventilation of solar chimney on indoor thermal environment in multi-storey office buildings.From 8:00 to 13:00,the ventilation rate,indoor temperature and velocity of indoor air inlet of solar chimney gradually increased,while decreased gradually from 13:00 to 18:00,reaching the maximum at 13:00.The time that the maximum ventilation rate of solar chimney reached is delayed by 1 hour compared with the maximum solar radiation intensity in the South direction.In chapter 5,the method is applied and simulated through the design competition based on the design method and numerical simulation results of solar chimney ventilation.According to the application form of vertical solar chimney and composite stairwell solar chimney,Computational Fluid Dynamics was used in the case.The results show that the enhanced ventilation design of solar chimney can improve the indoor thermal environment and enhance the indoor ventilation efficiency under the condition of thermal pressure ventilation.Different design methods have different effects on the indoor thermal environment,it is necessary to combine other technologies to improve the indoor thermal environment.The research results provide a reference for the design of solar chimney in green buildings.