管壳式相变储热器性能快速预测研究

为了构建一种具有普适性的完全熔化时间预测公式，引入一种无量纲储热时间的概念，定义为实际储热时间与基准储热时间的比值。基准储热时间通过静态近似法获得，可以基本反映完全熔化时间与其影响参数的非线性关系，有效降低了无量纲储热时间拟合关联式的非线性度，并扩大了其适用范围。针对套管式固液相变储热器，通过数值模拟方法分析了Stefan数、无量纲长度以及外内径比率三个参数对无量纲储热时间的影响规律，并拟合了关联式。结果显示，所构建的经验关联式具有较好的应用范围和预测准确度；在考虑的参数范围内，快速预测结果的误差可以控制在10%以内。所提出的无量纲储热时间及其关联式构建方法可推广应用于其他固液相变储热器。

Performance prediction of shell-and-tube latent heat thermal energy storage unit

In order to construct a universal prediction method for complete melting time, a concept of dimensionless heat storage time is introduced, which is defined as the ratio of actual melting time to referenced melting time. The referenced melting time obtained by static approximation method can basically reflect the non-linear relationship between the melting time and its influencing parameters, which effectively reduces the non-linearity of dimensionless melting time fitting correlation and enlarges its application scope. The influence of Stefan number, dimensionless length and ratio of outer diameter to inner diameter on dimensionless melting time of shell-and-tube latent heat thermal energy storage unit was analyzed by numerical simulation method, and the correlation equation was fitted. The results show that the empirical correlation has a wide application range and high prediction accuracy. Within the parameters considered in this paper, the error of fast prediction results is no more than 10%. The dimensionless heat storage time and its correlation method proposed in this paper can be popularized to other forms of solid-liquid phase change thermal energy storage devices.