Study On Thermal Insulation Of Porous Phosphogypsum Wall

Guizhou Province is rich in phosphate mining resources.Phosphogypsum and other wastes will be produced in the manufacture of phosphoric acid and other related chemical products.This paper takes the reuse of phosphogypsum wastes as the research background.According to the characteristics of phosphogypsum materials,such as low thermal conductivity,high plasticity and low price,the thermal insulation performance of porous phosphogypsum sheets is studied.At present,the research on porous phosphogypsum plate is not perfect,this paper focuses on the research in this field.The heat transfer coefficient and thermal resistance were tested according to the preparation of porous phosphogypsum plate and the principle of heat flow meter.Finally,several factors affecting the model of porous phosphogypsum plate were simulated according to the software.The main work and research of this paper are as follows:(1)Based on the heat transfer theory,this paper discusses how the three heat transfer modes of heat conduction,heat convection and heat radiation act on the porous phosphogypsum plate,and explores the heat transfer performance of the porous phosphogypsum plate.In order to facilitate this study to simplify the establishment conditions of heat preservation and heat insulation,the two adopt a unified evaluation standard,namely,the heat transfer coefficient and thermal resistance value for quantitative analysis.(2)The porous phosphogypsum plate was compared with the porous brick, and the effects of plate void ratio,plate void arrangement number,plate void arrangement mode and plate void type on the thermal insulation performance of porous phosphogypsum plate were discussed.(3)The phosphogypsum board was made and the thermal conductivity of phosphogypsum material was tested.The effects of temperature and relative humidity on the thermal conductivity of phosphogypsum board were analyzed.The parallel porous phosphogypsum plate and staggered porous phosphogypsum plate were made by mold,and placed in the same maintenance environment as phosphogypsum plate.The heat transfer coefficient and thermal resistance of the two plates were measured by hot box method.The heat transfer coefficient thermal resistance of the staggered plate and the parallel plate were analyzed, and pave the way for the numerical simulation below.(4)The operation basis and method of ANSYS FLUENT software are intro-duced,and the feasibility of its application in numerical simulation is also introduced.By establishing the same numerical model as the actual test,the corre sponding simulation data are obtained.By comparing the simulated data with the experimental data,it is found that there is little difference between the simulated data and the actual experimental data,and the same growth law is observed,which reflects the reliability of numerical simulation.(5)Finally,according to the above mentioned several influencing factors of porous phosphogypsum plate were numerical simulation optimization.The heat transfer performance of the model is improved by increasing the void ratio of the plate.By increasing the difference between the long axis length and the short axis length of elliptical hole in the plate,the heat transfer performance of the model is also improved accordingly.The heat transfer performance of the model is also improved by adding holes in the plate.Through the numerical simulation of the plate models with four kinds of holes,the results show that the rectangular hole model has the best heat transfer performance.