基于主动隔热与排风热回收的建筑外窗耦合动态传热模型及实验研究

Exhaust air insulation window is usually a multilayer glazing system and allows the exhaust air from the conditioned space flowing through the air cavity between the glass panes. Due to the convection between the flowing air and the glass pane or venetian blinds, such a window design can recover and utilize the low-grade energy inherent in the exhaust air and makes the interior surface temperature of the window close to the indoor air temperature, which will therefore reduce the building energy consumption and improve the indoor thermal comfort. Heat transfer processed of the exhaust air insulation window simultaneously involve the conduction, convection, long-wave radiation, absorption, reflection, transmission of solar radiation, and enthalpy flow in ventilated channel. An improved unsteady-state heat transfer model integrated with dynamic optical model is developed to analyze the optical and transient heat transfer performance of the window. The optical properties of the entire exhaust air insulation window are obtained by using dynamic optical method, which is based on the energy balance of each component. In addition, the temporal and spatial domains of the unsteady state model are discretized by using finite difference approximation. Numerical solution algorithm of Gauss-Seidel method is adopted to solve the equations and obtain a converged solution for all the nodal temperatures of the exhaust air insulation window. The proposed model is validated by comparing the simulation results and the experimental data. Optimal design theory and design method of the window are carried out. The heat recovery potential and adaptation of the exhaust air insulation window in different climate regions are investigated with theoretical analysis and numerical simulation. The study will provide fundamental theory and analysis tool for the novel window. Basic data will also be supplied for possible engineering application.

排风隔热窗可以充分依赖玻璃夹层空腔中排风气流与玻璃、及内置遮阳百叶表面强制对流换热的特点，利用室内空调排风的低品位能，直接降低外窗室内侧表面与室内空气之间的温差，削弱室外气候对室内环境的影响，对建筑节能及提高室内热舒适性具有重要意义。排风隔热窗中同时存在相互影响的热传递、太阳辐射、及空气流动过程，使得模拟其动态热特性变得十分复杂。提出一种耦合太阳辐射光学传输模型的动态传热模型，采用界面能量平衡原理建立其光学传输模型，采用有限差分法将该外窗的二维非稳态传热模型离散化，采用Gauss-Seidel法对其内部二维方向上各节点的热平衡方程组进行迭代求解，用于研究该外窗在外扰作用下的光学传输与动态传热特性；通过实验对其热特性理论分析方法及模型进行验证。基于上述研究基础，提出排风隔热窗的设计理论与方法，量化分析其在不同气候区的热回收节能潜力及适应性，为该外窗的工程应用提供基础理论、分析手段及基础数据。

排风隔热窗可以充分依赖玻璃夹层空腔中排风气流与玻璃、及内置遮阳百叶表面强制对流换热的特点，利用室内空调排风的低品位能，直接降低外窗室内侧表面与室内空气之间的温差，削弱室外气候对室内环境的影响，对建筑节能及提高室内热舒适性具有重要意义。本项目针对新型排风隔热窗结构，采用理论分析、数值计算和实验验证相结合的方法开展研究，围绕其传热特性、节能潜力、排风热回收性能以及气候适应性等方面进行深入的研究。.本项目针对排风隔热窗建立了一种耦合太阳辐射光学传输模型的动态传热模型，采用界面能量平衡原理建立其光学传输模型，采用区域模型法建立该外窗的二维非稳态传热模型，用于研究该外窗在外扰作用下的光学传输与动态传热特性。搭建排风隔热窗热特性实验平台，将实验测量结果和模拟计算结果进行比较，验证排风隔热窗传热数学模型的可靠性和准确性。定量分析影响排风隔热窗的热工性能的主要因素，包括排风速度、空腔层厚度、百叶倾角、以及百叶材料表面反射率，讨论其最优的参数设计，同时研究不同室内空气参数对其冬季结露的影响。结果表明排风速度对排风隔热窗的热工性能有较大影响，百叶倾角和百叶材料表面反射率对室内太阳辐射得热的控制起着至关重要的作用。计算排风隔热窗在我国不同气候条件下的全年动态逐时负荷，并与内置百叶中空玻璃和Low-e玻璃进行了比较，对排风隔热窗在不同气候区的适用性及节能效果进行探讨，结果表明，排风隔热窗在不同气候条件下的节能效果均十分显著。研究不同气候条件下排风隔热窗和常规热回收装置的综合节能潜力，结果表明，排风隔热窗在夏季工况的热回收节能效果明显优于常规热回收装置，而在冬季工况则出现相反的计算结果，同时，室内新风量对不同气候区最优的排风热回收形式有较大影响。.本项目研究结果表明排风隔热窗具有显著的节能效果，具有潜在的工程应用价值，本项目所建立的方法和得出的结论可为建筑节能领域相关研究提供坚实的理论基础。