Research On Angle Factors Between Multi-radiation Panel And Enclosure Structures Or Human Body

Buildings are the most important circumstances in the daily work and life.It has been proved that the environment in buildings closely related to the health.As a new developing technology of air-condition system,the radiant air-conditioning system has it's advantages and have a good effect in improving the indoor environment.Many parameters,including angle factor,would influence the radiation heat transfer between radiation system and other surfaces.So it's meaningful to do some researches on it.The first chapter introduced the history,advantages and disadvantages of the radiant air-conditioning system.And give way to the conception of angle factor.After introduced research status of angle factor,this paper found shortcomings of researches.And then introduced researches have done in this paper.The second chapter introduced the theories and basic laws of radiation heat transfer and the angle factor.Derived equations in calculating angle factors and overviewed different methods of angle factor calculation.In chapter three,curve integral formula is used to derive the expression of angle factor from both infinitesimal area and rectangle area to a vertical surface.Then obtained the functional relationship between the size of surface or the radiant panel and angle factor.Angle factor is related to the width to height ratio of the surface and height of panel to the surface ratio and the distance.Compared the difference of angle factor between rectangular surface and infinitesimal area positioned on the symmetry axis of the surface with the same height,and then found that the difference is smaller than 3%in the worst condition.So the infinitesimal area positioned on the symmetry axis could be an alternative to rectangle area in angle factor calculation.So we could get the relationship between the location the radiant panel placed and the angle factor,furthermore it's a simpler method to calculate the angle factor between rectangle areas.In this paper,we built a 3D human model for numerical simulation based on the standard of human size in China and relative researches.Angle factors between human body and sidewall cooling panels have been simulated by Fluent then.We found that it's reasonable to simplified human body to cuboids according to the simulation results.So a simplified cylinder model,identified by the results of chapter 4,to calculate the shade effects between two human body in chapter 5.Use Fluent to check the agreements between angle factor results of human body and cylinder model.When the distance from human to model is more than 2m,the relative error is less than 2%.While the distance is less than 2m,the paper has modified the results to lower than 5%.