不同气候区自驱热障墙体热性能模拟研究

Simulation Study on Thermal Performance of Self-driving Thermal Barrier Walls in Different Climate Regions

内嵌管式热障墙体可兼顾建筑节能和室内热舒适要求,但低品位能源传输过程中的泵驱循环换热方式导致该类墙体存在一定的低效换热和高驱动能耗问题。设计了1种利用相变热驱循环替代传统泵驱循环的新型自然驱动热障墙体(Self-Driving Thermal Barrier Wall,SDTBW),为明晰SDTBW在不同气候区运行条件下的热响应特征及其性能差异,建立并验证了SDTBW动态传热模型,分析了其在不同注冷/热温度下的动态传热特性,对比了SDTBW应用于不同气候区时的热响应特征、累计冷/热负荷及其下降率。结果表明:在所研究的3个气候区条件下应用SDTBW均可有效提升墙体综合热性能,验证了SDTBW的技术可行性;其外表面传热特性主要受不同气候区室外热环境影响,内表面传热特性主要受冷/热源温度影响;当注冷/热温度与室内设定温度相同时,不同气候区应用的SDTBW冷/热负荷降幅达85.2%/87.0%;但随注冷/热温度的下降/上升,天津地区SDTBW需求节能率逐渐高达广州地区约5倍(夏季),高达哈尔滨地区约1.2倍(冬季)。

The embedded pipe thermal barrier wall can consider both the requirements of building energy efficiency and indoor thermal comfort,but the pump-driven cycle of heat transfer in the low-grade energy transmission process leads to certain inefficiencies in heat transfer and high drive energy consumption in this type of wall.A new type of naturally driven thermal barrier wall(self-driving thermal barrier wall,SDTBW)using a phase change thermal drive cycle,replacing the traditional pump drive cycle,was designed.To clarify the thermal response characteristics of SDTBW under different operating conditions and the performance differences in different climate zones,a dynamic heat transfer model of SDTBW was established and validated,and its dynamic heat transfer characteristics were analyzed at different injection cooling/heating temperatures.This paper further compared the thermal response characteristics,cumulative cooling/heating load,and the reduction rate of SDTBW applied in different climate zones.The results indicate that the application of SDTBW can effectively improve the comprehensive thermal performance of the walls under the conditions of the three climate zones studied,verifying the technical feasibility of SDTBW.The heat transfer characteristics of its outer surface are mainly affected by the outdoor thermal environment in different climate zones,while the heat transfer characteristics of its inner surface are mainly affected by the temperature of the cooling/heating source.When the injection cooling/heating temperature is the same as the indoor setting temperature,the cooling/heating load of SDTBW applied in different climate zones falls by 85.2%/87.0%.But with the drop/rise of injection cooling/heating temperature,the energy saving rate of SDTBW in Tianjin gradually reaches about 5 times that in Guangzhou(summer)and 1.2 times that in Harbin(winter).