局部铺设热水盘管墙体辐射系统模拟及铺设面积对热舒适的影响

Simulation of thermal-radiating wall with hot water coils partly paved and the influence of installed area size on thermal comfort

针对墙体辐射供暖系统进行了模拟计算,提出局部铺设热水盘管的构想.利用Fluent进行模拟计算,分析了非稳态下的墙体热流密度、平均温度和温度场分布,并对不同铺设面积的居室热舒适性进行了分析.计算结果表明,在进出水温差为5℃、热水流量是0.3 m3·h-1且管间距为250mm的前提下,局部铺设墙体热水盘管的铺设面积占全部铺设的2/3时,室内便能达到人体热舒适要求,此时平均期望满意度(PMV)为-0.28,期望不满意度(PPD)为7%;局部铺设的铺设面积占全部铺设的5/6时,室内热环境最舒适,PMV为+0.14,PPD为5%;当全部铺设时热舒适度反而下降了,此时PMV为+0.5,PPD为10%.局部铺设相对于整面铺设可节约材料,并在保证人体热舒适的前提下有效节能.

The wall radiating heating system was studied,and a conception of hot water coils partly paved in the wall is presented.A heat transfer model was established to simulate the thermal performance of the wall by Fluent.The average heat flux,temperature and temperature distribution of the thermal-radiating wall under unsteady conditions were analyzed.The influence of installed area size on indoor thermal comfort was also analyzed.The results show that when the temperature difference between inlet and outlet water is 5 ℃,rate of flow is 0.3m3·h-1,tube spacing is 250 mm,and the area of partly paved coils is 2/3of the fully paved area,PMV(predicted mean vote)is-0.28,PPD(predicted percentage of dissatisfied)is 7%,the values are in the range of thermal comfort;when the proportion reaches to 5/6,PMV is+0.14 and PPD is 5%,the indoor thermal environment is the most comfortable;while when the wall is fully paved,PMV is+0.5and PPD is 10%,indoor thermal comfort is reduced.The wall with hot water coil partly paved can economize on materials in comparison with a fully paved wall,and it can save energy effectively while delivering themal comfort.