太阳能相变炕影响因素分析及热工性能模拟

Analysis of Influencing Factors and Thermal Performance Simulation of Solar Phase Change Kang

本文设计了一种太阳能热水供热与相变蓄热组合的热炕供热系统,为提高蓄热炕的热响应,配置了高导热复合相变材料,利用数值模拟对炕体单元进行三维非稳态瞬态传热模拟。通过控制变量法,对太阳能相变蓄热炕的相变材料导热系数、相变温度、相变潜热等炕体热工特性影响因素进行模拟分析,得出:相变材料导热系数、供水温度、相变潜热对相变炕的热响应时间影响显著,且相变潜热决定放热时长,相变温度、相变温度范围对相变炕的垫面温度有明显影响。最后,以十二水磷酸氢二钠复合相变材料作为炕体的蓄热材料,对炕体进行蓄放热模拟设计,发现垫面温度昼间可达到17.1℃,夜间可达到30.3℃,可以很好地满足居民的热舒适要求。

In this paper,a hot kang heating system combining solar hot water heating with phase change heat storage is designed.In order to improve the thermal response of the heat storage kang,a high thermal conductivity composite phase change material is configured,and the three-dimensional unsteady transient heat transfer simulation of the kang unit is carried out by numerical simulation.Through the control variable method,the factors influencing the thermal characteristics of the solar energy phase-change heat storage kang,such as thermal conductivity,phase-change temperature and phase-change latent heat,are simulated and analyzed.The results show that thermal conductivity,water supply temperature and phase-change latent heat of the solar energy phase-change heat storage kang have significant effects on the thermal response time of the phase-change kang,and the phase-change latent heat determines the heat release time,and the phase-change temperature and phase-change temperature range have significant effects on the surface temperature of the phase-change kang.Finally,taking disodium hydrogen phosphate dodecahydrate composite phase change material as the heat storage material of the kang body,a 24-hour heat storage and release simulation design of the kang body is carried out,and it is found that the temperature of the mat surface can reach 17.1℃in the daytime and 30.3℃at night,which can well meet the thermal comfort requirements of residents.