北非地区大空间相变屋面联合夜间通风节能策略

Large Space PCM Roof Combined with Night Ventilation Energy-saving Strategy in North Africa

博物馆作为大空间公共建筑,因其空间体积大、人流量大、室内环境要求高的特征导致空调能耗过高,节能减排潜力巨大。在北非地区,夏季气候干热、太阳辐射高、气温日较差大的特点,为相变屋面联合夜间通风的节能技术提供应用条件。将相变屋面联合夜间通风技术应用于大空间博物馆建筑,建立考虑温度分层的建筑能耗仿真模型,研究了不同相变因素和通风参数对空调能耗的影响。结果表明,在热带沙漠气候下,当相变层厚度小于15 mm时,宜采用高相变温度的PCM(RT35HC);当相变层厚度超过15 mm时,宜采用低相变温度的PCM(RT27),可以保证相变材料的完整相变循环,随着厚度的增加,其节能率也逐渐增加;通风时间段取1:00-8:00,换气次数取9次/h时节能效果最佳。在地中海气候下,当相变层厚度为5 mm时,宜采用高相变温度的PCM(RT31);当相变层厚度超过5 mm时,宜采用低相变温度的PCM(RT27),但设计厚度超过20 mm之后节能率增加不再显著;通风时间段取1:00-8:00,换气次数取6次/h时节能效果最佳。研究成果为北非地区两种典型气候下大空间建筑应用相变屋面联合夜间通风技术提供节能设计策略。

As a large space public building,the museum has a huge potential for energy conservation and emission reduction due to its large space volume,large flow of people,and high requirements for indoor environment.In the North African region,the characteristics of dry and hot summer climate,high solar radiation,and large daily temperature range provide application conditions for energy-saving technologies such as PCM roofing combined with night ventilation.The PCM roofing combined with night ventilation technology is utilized to large space museum buildings,establishing a building energy consumption simulation model considering temperature stratification,the effects of different phase change factors and ventilation parameters on air conditioning energy consumption are expounded.The results show that in the tropical desert climate,when the thickness of the PCM layer is less than 15 mm,PCM with high phase change temperature(RT35HC)should be used;When the thickness of the PCM layer is designed to exceed 15 mm,it is advisable to use PCM(RT27)with a low phase change temperature to ensure the complete phase change cycle of the phase change material.As the thickness increases,its energy-saving rate also gradually increases.The best energy-saving effect is obtained when the ventilation period is 1:00-8:00 and the Air changes per hour is 9 times/h.In the Mediterranean climate,when the thickness of the PCM layer is 5 mm,PCM(RT31)with high phase change temperature should be used;When the thickness of the phase change layer is designed to exceed 5 mm,it is advisable to use PCM(RT27)with a low phase change temperature.However,while the design thickness exceeds 20 mm,the increase in energy efficiency is no longer significant;The best energy-saving effect is obtained when the ventilation period is 1:00-8:00 and the Air changes per hour is 6 times/h.The results of this study provide energy-saving design strategies for the application of phase change roofing combined with nighttime ventilation technology in large space buildings under two typical climates in North Africa.