Comparative Analysis Of Calculation Models For Aerogel Glazing System And Its Applicability Evaluation In Different Climate Zones

Nano-porous silica aerogel is a super thermal insulation material.In recent years,it has been gradually popularized in the energy saving glazing area due to its specific characteristics including the excellent thermal insulation,high transmittance,high temperature resistance and sound insulation etc.A few scholars have studied the thermal performance of aerogel glazing system.Some of them use the simulation tools like Energy Plus and eQUEST to evaluate the energy perfor mance of aerogel glazing system.The Other scholars carried out their research by analyzing experimental data.The calculation method of simulation tools are based on K-Sc model.K-Sc model is an approximate calculation model which usually makes some assumptions and simplification in the calculation process.Thus the calculation accuracy of the K-Sc model needs to be further investigated.As for the experimental method,it is time consuming,laborious and inflexible.It can't be widely used.The focus of this paper is to establish a calculation model which can be conveniently used and correctly reflect the heat transfer characteristics of aerogel glazing system.With the calculation model,the applicability of aerogel glazing system in various climates of China can be evaluated,and the optimization analysis of the structural and physical parameters of aerogel glazing system can be carried out.At first,the optical model and dynamic heat transfer model of aerogel glazing system have been developed by the interfacial energy balance method and nodes' energy-balance equations respectively.The calculation method of K-Sc model is also introduced in detail.In order to verify the accuracy of the dynamic heat transfer models and the K-Sc model,the calculation results of the two models are compared with the measured data.The results show that for the dynamic heat transfe r model,the calculated results of the transmitted solar heat gain and the temperature of each glass layer are all in good agreement with the measured values.The model is of good enough accuracy.As for the K-Sc model,it turns out to have overestimated the transmitted solar heat gain since its Sc value is giving for the normal incidence.The averaged relative error between the calculated value and measured value is 34.9%.Then,the applicability of aerogel glazing system in different climate zones has been evaluated by employing the dynamic heat transfer model.The applicability evaluation indexes-cumulative hourly heat gain and annual efficient solar energy are applied to compare the energy saving potential of aerogel and other five common glazing systems(including double,triple and 3 kinds of Low-E double glazing systems).The results indicate that except the Hot-Summer Warm-Winter Region,employing aerogel glazing system in other four climate zones in China is energy efficient.The suitable level of employing aerogel glazing system is Harbin> Beijing> Changsha> Kunming.In other words,aerogel glazing system is most suitable for Severe Cold Region,followed by Cold Region.Finally,the effect of extinction coefficient,thermal conductivity,thickness of aerogel pane and orientation on the thermal performance of aerogel glazing system have been analyzed.Some suggestions to the constructional design of the aerogel glazing system applied in Hot-Summer Cold-Winter Region have been proposed.