Research On The Influence Of Emissivity Of Inner Surface Of Envelope On Indoor Thermal Environment

In recent years,with the continuous improvement of science and technology,the research of radiation characteristics of object surface has developed rapidly in the fields of national defense science and technology,aerospace industry,urban planning,land surveying and mapping,etc.,and has greatly promoted the progress of detection,guidance,stealth,imaging simulation and other technologies.As an important part of architecture,building envelope structure is the medium of isolating indoor and outdoor environment,and an important carrier of creating comfortable indoor environment and building thermal insulation.In the process of heat transfer of enclosure structure,the radiation heat transfer of inner surface accounts for more than 60% of the total heat transfer of inner surface.In the process of heat exchange between indoor human body and environment,when the human body reaches the thermal comfort state,the radiation heat dissipation accounts for 45%?50%.Radiation heat transfer on the inner surface of enclosure is an important factor affecting indoor thermal comfort,and is also the most important way in the process of heat exchange between human body and environment.As one of the most important parameters of radiation heat transfer,the radiation rate of the inner surface of building envelope plays a decisive role.However,due to the complexity of boundary conditions,common materials and technical constraints,there is no systematic and experimental study on radiation heat transfer of multi-surface systems.The main manifestations are as follows:(1)There is no systematic experimental study.(2)Radiation heat transfer model of multi-surface system without transparent and non-transparent envelopes.(3)There is no rule of influence of internal surface emissivity on indoor thermal environment.(4)The influence of different surface emissivity on human thermal comfort without natural ventilation.Anti-aging and anti-UV performance is deficient and short;In view of the above problems,this paper mainly makes the following research work:(1)Research on radiation heat transfer of multi-surface system in enclosure structure based on internal surface emissivity.The influence trend of internal surface emissivity on indoor thermal environment in enclosed refrigeration space is obtained through experimental research and theoretical research.(2)The influence of internal surface emissivity on human thermal comfort was found out through experimental study.At the same time,a new PMV model is established based on different surface emissivity.(3)To study the effect of surface emissivity of enclosure structure on indoor thermal comfort under natural ventilation,the expected value of low emissivity natural ventilation building is 0.78.(4)The effects of window-wall ratio,internal surface emissivity and reflectivity on indoor thermal environment are studied.In this paper,the influence mechanism of radiation rate on indoor thermal environment is studied,and the multi-surface radiation heat transfer model under different radiation rate is obtained.The real radiation heat transfer is effectively described,and the optimum radiation rate of the inner surface of the enclosure structure is quantified.It provides high-performance green building materials for the development of building energy saving.The paper and its conclusions are theoretical.Value and application value.