透明围护结构位置分布对高大空间热风供暖效果的影响

发布时间：2018-06-05 03:27

本文选题：高大空间 + 透明围护结构总面积　；参考：《东华大学》2017年硕士论文

【摘要】：能源消耗现在已经是中国的一个重要问题,其中建筑能耗已约占总能耗的23%,特别是作为建筑能耗的主要组成部分的供暖供冷能耗。在冬季需要热风供暖的高大建筑空间中,由于浮力的作用,热空气会上浮,驱使室内热量在空间上部积累,从而导致下部人员空间的气温相对较低,故热风供暖时的能耗问题一直是暖通空调领域关注的重点。近年来,透明围护结构(玻璃窗)的面积比逐渐增大,进一步加剧了高大空间热风供暖时室内空间上部热空气积累与下部人员空间热量需求之间的矛盾。当建筑侧墙上玻璃面积比例较大时,由于内表面温度相对较低,使其附近空气降温下沉并在下部堆积,从而导致高大空间室内上下温差过大的现象。本文首先通过实验数据验证了数值模拟方法的可信度和准确性,然后将数值模拟方法应用于本文需要研究的高大空间。利用数值模拟方法探究了透明围护结构面积和位置对高大空间热风供暖效果的影响。研究结果表明,天窗表面附近冷空气的下沉气流对上浮热气流造成了干扰作用,减小了室内热力分层现象。当送风速度和风口面积一定时,温度梯度随着平天窗面积的增大而减小。随着平天窗玻璃面积增大,高大空间上部温度明显下降,但人员空间温度下降幅度并不大。当侧墙上有较大玻璃面积时,由于侧窗表面附近冷空气沿着冷表面下沉到地面附近,同时进一步阻止了送风热气流进入人员空间,造成室内温度分层现象明显,侧墙上的玻璃面积的增大则会显著增大室内垂直温度分布并大幅降低人员空间温度。因此,在窗户位置由屋顶向侧墙迁移过程中,即使玻璃总面积不变,人员空间温度也会明显下降并且室内垂直温度梯度增大。天窗面积和侧窗面积的增加均会增大能耗,但天窗面积增加造成的能耗增量不明显,并且降低了室内垂直温度梯度,而侧窗面积增加则会大幅度增强室内热力分层现象,并明显提高了供暖能耗。为改善透明围护结构面积较大的高大空间的供暖效果,提高送风速度能够降低室内垂直温度梯度,具有较好的改善效果。而提高送风温度的改善效果甚微,甚至反而增大了室内垂直温度梯度,能量利用系数下降。
[Abstract]:Energy consumption is now an important problem in China, of which building energy consumption has accounted for about 23% of the total energy consumption, especially as the main component of building energy consumption. In the tall building space that needs hot air heating in winter, the thermal air will float up because of the effect of buoyancy, which drives the indoor heat to accumulate in the upper space. As a result, the temperature of the lower staff space is relatively low, so the energy consumption of hot air heating has always been the focus in the field of HVAC. In recent years, the area ratio of the transparent enclosure structure (glass window) has gradually increased, which further aggravates the accumulation of hot air in the upper space and the space heat of the lower staff in the upper space of the high space hot air heating. When the glass area is large in the wall of the building, the temperature of the surrounding air is cooled down and accumulated in the lower part due to the relatively low temperature of the inner surface of the wall, which leads to the excessive temperature difference between the upper and lower rooms in the large space. The numerical simulation method is applied to the large space which is needed to be studied in this paper. The effect of the area and position of the transparent enclosure on the heating effect of the tall space is explored by numerical simulation. The results show that the downdraft of cold air near the surface of the skylight has a interference effect on the floating heat flow and reduces the indoor thermal power. The temperature gradient decreases with the increase of the flat window area when the air velocity and the area of the tuyere are fixed. As the glass area of the flat skylight increases, the temperature of the upper space is obviously decreased, but the decrease of the temperature of the personnel space is not significant. When there is a large glass surface on the side wall, the cold air near the side window surface is along the cold air. When the surface is down to the ground, it can further prevent the air flow into the staff space, and the indoor temperature stratification is obvious. The increase of the glass area on the side wall will significantly increase the vertical temperature distribution in the room and greatly reduce the space temperature of the personnel. Therefore, the position of the window door is from the roof to the side wall, even if it is moved. When the total area of the glass is constant, the temperature of the personnel space will decrease obviously and the vertical temperature gradient in the room increases. The increase of the skylight area and the side window area will increase the energy consumption, but the increase of energy consumption caused by the increase in the area of the skylight is not obvious, and the vertical temperature gradient in the room is reduced, while the increase of the side window area will greatly enhance the indoor thermal stratification. In order to improve the heating effect of large space with large area of transparent enclosure, improving the air supply speed can reduce the vertical temperature gradient in the room, and it has a good improvement effect. The improvement effect of the air supply temperature is very little, even the vertical temperature gradient in the room and the energy utilization coefficient are increased. Drop.
【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】：TU832

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