室内外气温对冬季墙体太阳辐射净得热量的影响

发布时间：2018-05-13 12:18

本文选题：冬季 + 室内温度　；参考：《东华大学》2017年硕士论文

【摘要】：长江中下游地区经济发展迅速,由于该地区冬季湿冷,室内热环境较差,越来越多的居住建筑开始考虑冬季供暖,而这势必会增加全年总能耗。考虑到围护结构对太阳能的实际吸收效果是影响供暖能耗的主要因素之一,故准确估计南墙对太阳能实际吸收率,对探索减少建筑供暖能耗的方法具有重要意义。北方地区建筑外墙普遍使用外保温方案,但夏热冬冷地区冬季室内外温差远小于北方地区,故内保温和外保温方式均很普遍。在相同的太阳辐射强度作用下,墙体外侧材料的热容量不同,会引起外墙外表面温度不同,进而造成外墙外表面对流散热量不同,从而影响到墙体对太阳能的实际吸收效果。已有的研究表明,墙体外侧材料特性(保温层或承重层)会影响到墙体对太阳能的吸收效果,但在这些研究中,多以室外气候条件为稳定的周期性变化或某一个典型日的气象参数为背景,而实际中建筑物经历多天的连续日照,外墙表面温度有可能逐渐升高,外墙对太阳辐射的吸收量却会逐渐减小。由此可见,连续晴朗天数对建筑物实际吸收的太阳能有一定的影响,且这种影响在供暖能耗对太阳辐射实际吸收率较敏感的夏热冬冷地区是不可忽略的。本文利用实际气象数据,并采用数值模拟的方法,对建筑物南墙传热过程了连续数天的动态模拟计算,分析了南墙太阳辐射净得热量与室内外气温、保温层位置和连续晴朗天数之间的关系。研究结果表明,当室内温度一定时,室外最低温度每升高4°C,内、外保温南墙外表面温度都升高近4°C,且南墙每日净得热量升高220 k J/m~2左右。相同室外温度下,室内温度每升高5°C,内、外保温南墙外表面温度有小幅升高,但内、外保温南墙每日净得热量均降低约280 k J/m~2。当室内外气温条件相同时,连续晴朗天数较短时(如3天以内),内保温南墙对太阳能的实际吸收量比外保温时高30%到80%,墙体采用内保温更有利于外墙对太阳能的吸收利用。当连续晴朗天数较长时(如10天以上),内、外保温南墙的太阳辐射实际吸收率近似相等。此外,本文采用数学拟合方法,得到了一个南墙太阳能每日实际吸收率与室内外平均温差和连续日照天数的半经验方程,可以作为快速计算不同保温层位置的南墙在不同室内外温差时的太阳辐射实际得热量的有效工具。
[Abstract]:The economy of the middle and lower reaches of the Yangtze River develops rapidly. Due to the cold and humid winter and the poor indoor thermal environment, more and more residential buildings begin to consider heating in winter, which is bound to increase the total energy consumption of the whole year. Considering that the actual absorption effect of solar energy is one of the main factors affecting heating energy consumption, it is of great significance to estimate the actual solar energy absorption rate of the south wall accurately and to explore ways to reduce the energy consumption of building heating. The external insulation scheme is widely used in the exterior wall of buildings in the north area, but the difference of indoor and outdoor temperature in winter is much smaller than that in the northern area, so both internal and external insulation methods are very common. Under the action of the same solar radiation intensity, the heat capacity of the outer wall materials will be different, which will cause the external wall surface temperature to be different, and then cause the external wall surface convection heat dissipation different, thus affect the wall to the actual absorption effect of solar energy. Existing studies have shown that the properties of materials outside the wall (insulation or load-bearing layer) affect the absorption of solar energy by the wall, but in these studies, Most of them take outdoor climatic conditions as stable periodic changes or meteorological parameters of a typical day as the background. In practice, the external wall surface temperature may increase gradually when buildings experience continuous sunshine for many days. However, the amount of solar radiation absorbed by the exterior wall will gradually decrease. It can be seen that continuous sunny days have a certain influence on the actual solar energy absorbed by buildings, and this effect can not be ignored in the hot summer and cold winter areas where the heating energy consumption is sensitive to the actual absorption rate of solar radiation. Based on the actual meteorological data and the numerical simulation method, the heat transfer process of the south wall of the building has been calculated dynamically for several days, and the net solar radiation of the south wall and the indoor and outdoor air temperature have been analyzed. The relationship between the position of the insulation layer and the continuous sunny days. The results show that when the indoor temperature is constant, for every 4 掳C increase in the minimum outdoor temperature, the outer surface temperature of the inner and outer thermal insulation wall increases nearly 4 掳C, and the net heat of the south wall increases about 220k J/m~2 per day. Under the same outdoor temperature, for each 5 掳C increase in indoor temperature, the outer surface temperature of the inner and outer thermal insulation wall increases slightly, but the net heat of the inner and outer thermal insulation south wall decreases by about 280k / m ~ (-1) per day. When the indoor and outdoor temperature conditions are the same, the continuous sunny days are shorter (such as less than 3 days), the actual absorption of solar energy in the inner wall is 30% to 80% higher than that in the external heat preservation, and the use of internal heat preservation on the wall is more favorable to the absorption and utilization of solar energy on the external wall. When the continuous sunny days are longer (such as more than 10 days), the actual solar radiation absorptivity of the inner and outer thermal insulation walls is approximately equal. In addition, by using mathematical fitting method, a semi-empirical equation of the actual absorption rate of solar energy in the south wall, the average indoor and outdoor temperature difference and the days of continuous sunshine is obtained. It can be used as an effective tool to calculate the actual heat of the solar radiation of the south wall with different positions of the insulation layer under different indoor and outdoor temperature differences.
【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

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