Studies On The Natural Convection Heat Transfer Of The Phosphogypsum Cavity Mold Beamless Floor

The phosphogypsum cavity mold beamless floor is a new type of concrete hollow floor cover,which uses a cavity mold box made of industrial waste phosphogypsum as a filling body.There is little research on the natural convection heat transfer in the hollow floor,and the research on the thermal insulation performance of the gypsum plaster cavity without beam roof is not perfect.Based on the study of natural convection heat transfer of phosphogypsum cavity mold beamless floor has practical significance for the analysis and improvement of the thermal performance of phosphogypsum cavity mold beamless floor.Compared with the middle floor,the top roof is the focus of building heat transfer analysis.This article will focus on the study of the top floor.Through the study of the heat transfer mechanism in the cavity,it is found that there is no natural convective heat transfer under the heat insulation condition in summer,and there is natural convection heat transfer under the winter heat preservation condition.With Fluent software,the parameters of natural convection heat transfer on the floor are calculated.The natural convection heat transfer in the floor is strong,and the intensity of natural convection heat transfer increases with the height of the section of the floor.Based on the study of natural convection heat transfer,the thermal resistance of the conventional thickness of the phosphogypsum cavity mold beamless floor is calculated.Compared with the solid concrete floor with the same section height,the phosphogypsum cavity mold beamless floor has good thermal insulation performance.The phosphogypsum cavity mold beamless floor can't meet the building energy-saving requirements in the actual use process,and the thermal insulation construction measures are still needed.Using Fluent to analyze the two-dimensional model of the floor with a cavity thickness of 180 mm,it is found that the reason why the thermal insulation performance of the floor is not ideal is that there is a thermal bridge and natural convection heat transfer in the floor during the heat transfer process.In order to solve the thermal bridge and natural convection heat transfer problems affecting the thermal insulation performance of the phosphogypsum cavity mold beamless floor,several improved methods are proposed.Through calculation,it is verified that the improved method can effectively solve the heat bridge and natural convection heat transfer problems,and greatly improve the thermal insulation performance of the phosphogypsum cavity mold beamless floor.