【作者】 徐冬；

【导师】 刘伟；

【作者基本信息】 华中科技大学 ， 工程热物理， 2007， 硕士

【摘要】 多孔太阳墙系统是一种新型的太阳能采暖技术,它能够做到高效采暖、有效通风。多孔太阳墙系统由集热系统和气体输送系统两部分组成,本文讨论的集热系统包括多孔墙体和热气流流道两部分,气流输送系统采用地板下送风方式。本文首先介绍了多孔太阳墙系统的原理、特点及国内外应用实例,接下来对多孔太阳墙集热系统及地板送风系统分别进行数值模拟及分析研究,多孔墙体采用局部非热力学平衡的双方程多孔介质模型,流道及房间考虑自然对流影响。对集热系统内传热与流动情况进行了数值模拟,分析了进口速度分布对集热性能的影响,多孔渗透率和流道宽度对进口速度分布的影响,进出口压差、固相有效导热系数、气体与固体骨架间体积对流换热系数对多孔墙体内温度分布的影响,最后分析了多孔墙渗透率、流道宽度、进出口压差、固相有效导热系数、气体与固体骨架间体积对流换热系数对出口空气平均温度、质量流量及吸热率的影响,并从场协同原理角度分析多孔太阳墙集热系统的传热强化。结果表明,适当的渗透率和进出口压差取值,在一定范围内增大流道宽度,提高固相有效导热系数和气固间体积对流换热系数,都有利于提高集热性能。对地板送风系统内传热与流动进行了数值模拟,得到室内温度分布及流场分布,分析了地板送风口尺寸、进气参数及架空地板设计对送风口风量分布的影响。结果表明:地板上采用非均等尺寸即离入口近的送风口采用大尺寸,离入口远的采用小尺寸,增高地板下空间,架空地板采用斜坡式都有利于使送风口风量分布均匀。本文通过对集热系统和地板送风系统的数值模拟及分析研究,对多孔太阳墙系统内传热与流动过程有较直观的认识,并为系统参数的选取提供了参考。更多还原

【Abstract】 Solar-wall is a novel solar heating technology which has proven to be effective both in heating and ventilation. It consists of a heat collector system which includes a porous wall and a passage between the porous wall and the existing wall and an air distribution system which adopts under floor air distribution in this thesis.The principle, characteristic and examples of solar-wall are introduced at first. Then, the heat collector system and under floor air distribution system are numerically studied. The non-equilibrium porous media model has been used to describe the porous wall and buoyancy-driven flows in the passage and apartment are taken into account.The flow fields and heat transfer characteristics in the heat collector system are numerically simulated. The effect of inlet velocity distribution on the performance of collector system and the effect of permeability and width of passage on inlet velocity distribution are analyzed. Then the effect of pressure difference between inlet and outlet, efficient conductivity of matrix and heat coefficient between flow and matrix on the temperature distribution in the porous wall is analyzed. At last, the effect of these parameters on the mean air temperature of outlet, mass flow rate, heat absorption of air is analyzed. Also, the heat transfer enhancement of heat collector system is studied according to field synergy principle. The outcome indicates appropriate permeability and widths, improving efficient conductivity and heat coefficient may improve the performance of heat collector system.The flow fields and heat transfer characteristics in the under floor air distribution system are numerically simulated. The temperature and velocity distribution are available by finite volume method. The effect of sizes of floor diffuser, inlet air parameter and design of under floor on the air flow distribution is analyzed. The outcome indicates increasing the height of raised floor, adopting slope floor design and non-uniform floor diffuser may improve the equality of air flow in every floor diffuser. Through the simulation and analysis of the heat collector system and under floor air distribution system, the flow fields and heat transfer characteristics of solar-wall are more intuitionistic and reference is provided to the parameter selection.更多还原