太阳能—相变水箱蓄热系统的运行特性研究
发布时间：2018-12-09 19:09
【摘要】：相变材料具有储能密度大、储能能力强、相变过程中温度恒定等特点,它在相变过程中能够吸收(释放)大量热量,非常适用于能量储存的材料。把相变材料制成相变单元放置太阳能蓄热水箱中,可提高水箱储能密度、增加太阳能蓄热水箱的蓄热量,提供更多的生活用水；同时将相变材料制成相变单元,使相变材料能够灵活应用于余热回收、新能源利用和电力调节等领域。以实验与模拟作为主要的研究手段,从相变单元的设计,太阳能-相变蓄热水箱的设计到圆柱体相变单元的蓄放热特性以及太阳能-相变蓄热水箱的运行特性等方面进行了相关研究： 首先在选择了适合应用于太阳能蓄热的相变材料后,设计了圆柱体相变蓄热单元,并通过数值模拟的方式对圆柱体相变蓄热单元在60℃、70℃、80℃三种温度工况下的相变规律进行了模拟研究。圆柱体相变单元在三种温度工况下的熔化规律都为自上而下,由外而内；凝固过程圆柱体相变单元呈现出由相变单元的壁面向中间逐渐凝固的规律。 然后通过实验对比研究了不同强化传热方式下圆柱体相变蓄热单元的蓄放热特性,同时对圆柱体相变蓄热单元内相变材料的温度分布进行了研究,并得出膨胀石墨对提高相变材料的传热性能比方形金属网格与圆形金属网格更为明显的结论。 最后以西昌地区的太阳能资源为例,计算出满足西昌地区一个三口之家的生活热水需要太阳能集热器面积为2.4m2、集热水箱的容积为180L,并在此基础上根据课题组前期的研究成果设计了太阳能-相变水箱及其蓄热系统。计算出了太阳能-相变水箱中相变材料的填充率,结果表明蓄热水箱中填放41个圆柱体相变蓄热单元在冬季的西昌地区就可以比普通太阳能蓄热水箱多储存45.7L的生活热水。在此基础上将太阳能-相变水箱与太阳能集热系统进行耦合成完整的蓄热系统,通过通过模拟计算对太阳能-相变水箱内部的运行特性进行了研究,对水箱内部温度场分布与相变材料蓄放热特性进行了相关分析。在加装相变蓄热单元后,蓄热水箱的蓄热时间为285min,连续放热过程的时间为42min；在用水间隔为5mmin的情况下,水箱出水温度在40℃以上的时间为89min；用水间隔为10min的情况下,水箱出水温度在40℃以上的时间为85min。
[Abstract]:Phase change material has the characteristics of high energy storage density, strong energy storage ability and constant temperature during phase transformation. It can absorb (release) a large amount of heat during the phase transition process, so it is very suitable for energy storage materials. When the phase change material is made into a phase change unit and placed in the solar energy storage tank, the energy storage density of the water tank can be increased, the heat storage of the solar energy storage water tank can be increased, and more domestic water can be provided. At the same time, the phase change material is made into phase change unit, which can be used flexibly in the fields of waste heat recovery, new energy utilization and electric power regulation. Using experiment and simulation as the main research means, from the design of phase change unit, The design of solar-phase change storage tank is related to the heat storage and exothermic characteristics of the cylindrical phase change unit and the operation characteristics of the solar-phase change storage tank. After the phase change material, The cylindrical phase change heat storage unit is designed, and the phase transition law of cylindrical phase change heat storage unit at 60 鈩，
本文编号：2369890
[Abstract]:Phase change material has the characteristics of high energy storage density, strong energy storage ability and constant temperature during phase transformation. It can absorb (release) a large amount of heat during the phase transition process, so it is very suitable for energy storage materials. When the phase change material is made into a phase change unit and placed in the solar energy storage tank, the energy storage density of the water tank can be increased, the heat storage of the solar energy storage water tank can be increased, and more domestic water can be provided. At the same time, the phase change material is made into phase change unit, which can be used flexibly in the fields of waste heat recovery, new energy utilization and electric power regulation. Using experiment and simulation as the main research means, from the design of phase change unit, The design of solar-phase change storage tank is related to the heat storage and exothermic characteristics of the cylindrical phase change unit and the operation characteristics of the solar-phase change storage tank. After the phase change material, The cylindrical phase change heat storage unit is designed, and the phase transition law of cylindrical phase change heat storage unit at 60 鈩，
本文编号：2369890
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