Performance of Latent Thermal Storage with Spherical Capsules Enclosed Phase Change Material

球形胶囊封闭相变材料潜热储存性能

基本信息

批准号：
04650537
负责人：
SAGARA Kazunobu
金额：
$ 1.41万
依托单位：
MIE UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

项目摘要

Energy performance of phase change thermal storage in an air-based solar heating system was stueied. expeerimental study was conducted for investigation of heat transfer process in a spherical capsule enclosed phase change material(PCM), in which temperature response was measured for melting and freezing processes under various air flow rate. Then, three theoretical models, quasi-steady model, uniform temperature model and linear temperature distribution model, for heat transfer process in a spherical capsule enclosed PCM were developed to select an appropriate model for estimation of a long-term energy performance of a phase change thermal storage system. Convective heat transfer coefficient vetween capsule surface and ambient air and pressure drop across the PCM tank were obtained from experiments under various flow rate. Assuming a simple air-based solar heating system with heat pump, system simulation was carried out in order to study the long-term energy performance for five days under Japanese winter weather condition. And the performance of a phase change thermal storage was compared with other sensible thermal storage mateials as gravel and brick. The effect of PCM tank capacity on the long-term performance was studied as well as the effect of melting temperature, shape of PCM tank, collector area and air flow rate for the best use of PCM's merits. It was found tha the overall COP of thermal storage tank using PCM has a peak at smaller capacity than the other sensible thermal storage materials, and the peak is sharper. This means that PCM storage tank has a superior performance for tank capacity, but excessive tank capacity results in lower performance than the other materials.

在基于空气的太阳能加热系统中，相变热存储的能量性能。进行了实验性研究，以研究球形胶囊封闭相变材料（PCM）中的传热过程，其中测量了在各种空气流速下用于熔化和冷冻过程的温度响应。然后，开发了三个理论模型，即准稳态模型，均匀温度模型和线性温度分布模型，用于球形胶囊封闭的PCM中的传热过程，以选择适当的模型，以估算相变热存储系统的长期能量性能。在各种流速下，从实验中获得了对流传热系数在胶囊表面与环境空气和压力下降之间。假设有一个简单的空气加热系统带有热泵，则进行系统模拟，以研究日本冬季天气条件下的五天的长期能量性能。相位变化的热存储的性能与其他明智的热储存式伴侣（如砾石和砖块）进行了比较。研究了PCM储罐容量对长期性能的影响以及熔化温度，PCM储罐形状，收集器区域和空气流量的影响，以最佳利用PCM的优点。发现使用PCM的热储罐的总体COP的峰值比其他明智的热储物材料小，并且峰值更清晰。这意味着PCM储罐的储罐容量具有出色的性能，但是过多的储罐容量会导致性能低于其他材料。