【作者】 吴兴；

【导师】 高立新；

【作者基本信息】 哈尔滨工业大学 ， 供热、供燃气、通风及空调工程， 2011， 硕士

【摘要】 在太阳能建筑的发展过程中,亟需解决太阳能与建筑一体化的问题。多孔渗透型太阳墙供热系统是解决以上问题的有效途径之一。本论文利用CFD技术,从多孔集热板的局部换热和太阳墙的整体流动两个方面进行数值研究,并对局部的流动换热进行了场协同分析。通过多孔集热板进行数值模拟和场协同分析发现:空气流过多孔集热板时不仅存在粘性阻力损失,还存在着惯性损失;在外表面区域内空气的温度场和速度场的协同程度最高,是空气和集热板之间的主要换热区域;渗流速度是影响集热性能的主要因素,孔距和孔径对热性能的影响较小;对于特定的集热板,换热效率只和雷诺数、孔隙率以及集热板的相对厚度有关,并给出了准则关联式;和传统的集热板相比,空气流过多孔渗透型集热板时的场协同性要好。本论文还建立了适用于多孔渗透型太阳墙的多孔介质模型,并以太阳墙表面风压的形式引入风速的影响。通过模型的数值计算发现,在太阳墙表面的顶部和底部区域速度小于平均抽吸速度,但对于高度较小的太阳墙,不会发生回流现象;随着抽吸速度的增大,风速的影响越来越小,表面温度和速度分布越均匀;空腔厚度越小,表面的温度和速度分布越不均匀。更多还原

【Abstract】 In the process of development of solar architecture, the way how to integrate the solar air heating devices into the building is a problem. The porous transpired plate solar wall is an effective way to those problems. By the CFD technology, this paper studied numerically this solar air heating device in two perspectives: the local convection of plate and the flow of the whole solar wall. And make field synergy analysis for local representative area of the porous collector plate.Through the numerical simulation and field synergy analysis, we found that not only viscous drag loss, but also the inertia losses existed in the air flow over the plate. Because the fields of temperature and velocity are more synergical in the area of the outer surface of the plate, more energy exchange would take place in here. The transpired velocity is the main factor affecting performance of the collector, and pore pitch and diameter has less effect compared with velocity. For specific collator, the efficiency of heat exchange is only ralated to Reynolds, porosity, and the relative thickness, not influenced by solar radiation and outdoor air temperature. Compared to conventional soalr collector plate, the field synergy of the air flowing over the porous transpired collector plate is better.The paper also established a porous media model which is suit for porous transpired solar wall, and introduced effection of wind in the form of wind pressure. Through numerical calculation, we found that the local transpired velocity is less than the average pumping speed in the top and bottom of the surface of the plate, but for the low condition, there is not the flowback phenomenon happens. With the pumping speed increased, the influence of the wind becomes smaller, and the distribution of the surface temperature and transpired velocity are more uniform. But the thinner of the cavity, the surface temperature and transpired velocity are more uneven.更多还原