ABSTRACT

Helicoidal water-air geothermal heat exchanger (HWAGHE) uses the water well as a heat source/sink for air refreshing purposes in space. It has been exploited as a passive technique to minimize the energy uses in buildings. This work goals to estimate the energy and exergy characteristics of HWAGHE for arid zone weather condition of Algeria. The helicoidally geometry enhancing the heat exchange with the soil is chosen to decrease the operating cost and the needed area. The studied HWAGHE was constructed from a flexible PVC pipe with 30 m length and 0.6 m diameter. It was immersed into a drilled borehole with 1 m diameter and 5 m depth. The heat exchange rate with the ground and exergy and energy efficiencies of HWAGHE is evaluated. Experimental findings revealed that the inlet ambient temperature has a considerable impact on the HWAGHE performances mainly when the change in temperature between the ambient and the water well increments. Maximal exergy and energetic efficiencies of the HWAGHE, reaching 89% and 92%, respectively, are obtained at 0.035 kg s⁻¹ mass flow rate.

摘要

螺旋水空气地热换热器 (HWAGHE) 使用水井作为热源/水槽，在太空中进行空气清新。它已被用作一种被动技术，以最大限度地减少建筑物中的能源使用。这项工作旨在估计 HWAGHE 的能量和火用特性，用于阿尔及利亚干旱区的天气条件。选择增强与土壤热交换的螺旋几何形状以降低运营成本和所需面积。所研究的 HWAGHE 由一根长 30 m、直径 0.6 m 的柔性 PVC 管构成。将其浸入直径为 1 m、深度为 5 m 的钻孔中。评估了与地面的热交换率以及 HWAGHE 的火用和能源效率。实验结果表明，入口环境温度对 HWAGHE 性能有相当大的影响，主要是当环境和水井之间的温度变化增加时。在 0.035 kg s 时，HWAGHE 的最大火用和能量效率分别达到 89% 和 92%^-1质量流量。