To improve the wall insulation in summer, the thermal performance of a new modular evaporative cooling ventilated wall was studied on mechanical ventilation condition. Analyzing the flow and heat transfer conditions in air domain and water domain in the wall, appropriate mathematical model was found. Through CFD analyzing with Fluent, the law, which the main factors influence the heat-insulating performance of the wall, was found and the optimum structural parameters were obtained. It shows that the structure with water layer outside air layer is not suitable for mechanical ventilation and it has only limited energy saving potential. The sandwich wall with air layer outside water layer shows great advantage in heat-insulating performance. The wall with water layer thickness of 1 cm and air layer thickness of 2 cm represents excellent heat-insulating performance and occupies small building space. The evaporative cooling sandwich wall with mechanical ventilation is a promising way to improve the building energy efficiency.%目的 为进一步提高墙体的夏季隔热性能,研究蒸发冷却通风外墙在机械通风状态下的热工性能,确定最佳的墙体结构和通风方式.方法 通过对墙体内空气与水两种流体域的流动传热状况分析,建立了合适的数理模型.借助Fluent软件,研究机械通风状态下该模块墙体的热工性能.结果 水层位于外侧的复合墙体结构不适合机械送风,其节能潜力有限;而水层位于复合墙体内侧的方案,其隔热性能明显优于水层位于复合墙体外侧的方案,水层厚度在lcm左右,空气层厚度在2 cm左右既可取得良好的隔热效果,又能节约建筑空间.结论 利用水的蒸发冷却对外墙内表面进行降温的复合通风外墙结构具有很好的隔热效果,与目前常规的建筑墙体相比,表现出了巨大的性能优势.
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