风速风向对建筑物南墙冬季太阳辐射净得热量的影响

发布时间：2018-06-26 23:40

本文选题：太阳能 + 南墙　；参考：《东华大学》2017年硕士论文

【摘要】：在建筑供暖能耗中,仅通过外墙造成的能耗约占50%。不仅围护结构保温是建筑节能的重要组成部分,建筑外围护结构冬季吸收太阳辐射的净得热量也是影响建筑节能的关键因素。不同保温形式通过影响建筑外围护结构的外表面温度,影响墙体吸收太阳辐射实际得热量和建筑节能效果。辐射到建筑外围护结构的太阳能,一部分通过对流换热散发到大气中,剩余部分传入墙体内部,这部分热量才是墙体实际吸收的太阳能。墙体表面对流换热过程受到风速、风向、室内外温度、室外太阳辐射等因素的影响,其中风速和风向决定了室外对流换热系数。为此,本文采用CFD数值模拟,研究了以上海为代表的长江下游地区,风速、风向对不同保温形式建筑南墙实际吸收的太阳辐射热量的影响。通过分析墙体内温度场及墙体吸收太阳辐射能随时间的变化规律,计算了不同工况在连续日照情况下,墙体的太阳辐射净得热量随连续日照天数的变化。本文还进一步比较了风速和风向两者影响南墙冬季太阳辐射净得热量的程度,并讨论了长江下游地区5个典型城市的太阳辐射净得热量。结果表明,随着日照天数的增加,内保温南墙外表面温度日变化先周期上升后达到周期稳定,而外保温南墙外表面温度日变化基本不随日照天数变化。另外,风速越大,南墙太阳辐射净得热量越小。南墙为迎风面时,墙体表面对流散热量远大于南墙为背风面时的情况,进而太阳辐射实际得热量比南墙为背风面时的情况小。风向、风速都会影响到南墙冬季太阳辐射净得热量,其中前者的影响远大于后者。这使得风向风频相近的地区南墙净得热量相近,但风速接近的地区净得热量却不一定相近。通过对长江下游地区5个典型城市的南墙太阳辐射净得热量的研究计算,结果表明,尽管太阳辐射强度和太阳高度角均近似相等,但风速风向的作用使得各城市的冬季南墙的太阳辐射净得热量差别较大,其中冬季主导风向为北风的地区,建筑物对太阳能的实际吸收率最高。
[Abstract]:In the energy consumption of building heating, the energy consumption only caused by the external wall is about 50%., not only the heat preservation of the enclosure structure is an important part of the building energy saving, but the net heat absorption of the solar radiation in the outer enclosure structure is also the key factor affecting the energy saving of the building. The wall absorbing solar radiation actually gets heat and building energy efficiency. The solar energy radiates to the outer enclosure structure of the building. Some of the heat is emitted into the atmosphere through convection heat transfer, the rest is introduced into the wall interior. This part of the heat is the solar energy absorbed by the wall. The convection heat transfer process of the wall surface is subjected to wind speed, wind direction, indoor and outdoor temperature. In this paper, the influence of wind speed and wind direction on the solar radiation heat absorbed by the south wall of different thermal insulation buildings in the lower reaches of the Yangtze River is studied by CFD numerical simulation. The temperature field in the wall is analyzed by the analysis of the temperature field in the wall of Shanghai. And the wall absorbs the solar radiation energy with the change of time, and calculates the change of the net solar radiation heat of the wall with the continuous sunshine days under the condition of continuous sunshine in different working conditions. This paper further compares the influence of wind speed and wind direction on the net heat of the solar radiation in the south wall in winter, and discusses 5 areas in the lower reaches of the Yangtze River. The solar radiation of the typical city is net heat. The result shows that with the increase of sunshine days, the diurnal temperature changes of the outer surface of the inner wall of the inner insulating wall first rise to the periodic stability, but the daily change of the outer surface temperature of the outer wall of the outer wall does not change with the sunshine days. In addition, the greater the wind speed, the smaller the net heat of the south wall is the net heat of the sun. In the wind surface, the convection heat dissipation of the wall surface is much greater than that of the south wall to the leeward surface, and the solar radiation actually gets less heat than the south wall to the leeward surface. Wind direction and wind speed will affect the net heat of the solar radiation in the south wall in winter, and the former is far greater than the latter. This makes the south wall of the area with the wind direction close to the area net. The net heat of the area near the wind is not similar. Through the study of the net heat of the solar radiation from the south wall of the 5 typical cities in the lower reaches of the Yangtze River, the results show that the solar radiation intensity and the sun height angle are almost equal, but the effect of wind speed and wind direction makes the south wall of the cities in the winter the solar radiation. There is a great difference in net heat gain. In winter, where wind direction is north wind, the actual absorption rate of solar energy is the highest.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU111.4

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