Evaluation Of Energy-saving Effect Of Thermal Insulation Coatings In Cold Areas

With the increasingly prominent environmental problems and the shortage of energy resources such as coal,oil and natural gas,energy problem has become an important factor restricting social and economic development.Forty percent of global energy consumption comes from the construction sector,while HVAC equipment consumes a lot of energy during the use of buildings.Therefore,building exterior wall insulation material as an important part of building envelope structure insulation and heat preservation has developed most rapidly,and various types of building insulation materials,especially building thermal insulation coatings and other new materials on the market are emerging in endlessly.In order to better evaluate the energy-saving effect of our thermal insulation coatings and promote the application of thermal insulation coatings in engineering,we urgently need an accurate and effective evaluation method of energy-saving effect of building thermal insulation coatings.The purpose of this paper is to find an effective evaluation method of energy-saving effect of reflective thermal insulation coatings and radiation thermal insulation coatings by analyzing their energy-saving mechanism,simulating their energy consumption and measuring their energy-saving effect,and to study the energy-saving effect of their application in cold areas..Firstly,by introducing the situation of solar radiation on buildings,the working mechanism of radiation thermal insulation coating is analyzed.Based on heat balance theory and difference method,a heat transfer model of envelope structure is established.The heat transfer of envelope structure is divided into outer surface heat transfer of envelope structure,inner surface heat transfer of envelope structure and inner surface heat transfer of envelope structure.Using one-dimensional heat transfer model and Stephen Boltzmann’s law,radiation,convection and heat conduction are combined,and the heat transfer model of envelope structure under steady state is simplified.Secondly,using the heat transfer model of the envelope under steady state,the heat transfer effects of reflective thermal insulation coatings and radiative thermal insulation coatings on the envelope structure are calculated and analyzed.Through calculation,the heat transfer of enclosure structure can be reduced by 84.9%in summer and 20.6%in high emissivity coatings.In winter,the heat loss of enclosure structure can be increased to some extent by reflective heat insulation coatings,while the heat transfer loss of enclosure structure in winter can be reduced by 1.28 W/m~2 by high emissivity inner wall coatings.Thirdly,this paper uses DeST-h energy consumption simulation software to build a building model in cold areas,and simulates the indoor temperature and energy consumption of air conditioning in natural conditions after the application of reflective thermal insulation coatings and radiative thermal insulation coatings.Through simulation and analysis,the energy saving rate of reflective thermal insulation coating in summer is 34.29%,while that of radiative thermal insulation coating is 14.6%.Finally,several typical thermal insulation coatings are selected to monitor and evaluate their energy-saving effect throughout the year.This paper tests the thermal insulation and thermal insulation properties of several thermal insulation coatings,establishes a set of energy-saving evaluation system of thermal insulation coatings,monitors and evaluates the impact of two thermal insulation coatings on indoor temperature and energy consumption of air conditioning throughout the year.In cold areas,the energy consumption of high solar reflectance in summer decreases by 4.74kWh,while in winter,the energy consumption of air conditioning can be saved by23.65 kWh with high emissivity interior wall coating.