论文标题
潜热热能存储设备中充电率的基于物理的缩放率
A Physics-based Scaling of the Charging Rate in Latent Heat Thermal Energy Storage Devices
论文作者
论文摘要
热能储存（TES）越来越多地被认为是有效组合热量和功率（CHP），浓缩太阳能（CSP），加热通风和空调（HVAC）的重要组成部分，并且由于它减少了峰值需求，同时帮助管理能量的间歇性可用性（例如，从太阳能或风能）来减少峰值需求。潜热热能存储（LHTES）是一个可行的选择，因为其储能密度很高。 LHTES热交换器的参数分析已集中于在相变流体中以层流流的数据获取数据，然后将功能形式（例如功率定律或多项式）拟合到这些数据。另外，在本文中，我们提出了一个参数框架，可以通过识别所有相关的流体参数和相应的无量纲数来分析LHTES设备。我们使用有限体积方法在相变材料（PCM）和传热流体（HTF）中使用有限体积方法对LHTES设备进行了64个模拟。我们观察到，借助HTF中有足够的能量，HTF雷诺数和prandtl数量对传热速率的影响可以忽略不计。在这种情况下，我们提出了基于傅立叶数字（$ fo $），grashof号码（$ gr_p $）和prandtl数字（$ pr_p $）的LHTES设备的能量存储（或熔体分数）的时间尺度，并观察A $ GR_P^1 $和$ PR_P^1 $和$ PR_P^{（1/3）$ 3 {（1/3）。我们还确定了随时间的熔体分数变化中的两个不同区域，即线性和渐近区域。我们还预测了两个区域之间过渡时熔体部分的临界值。从这些分析中，我们就LHTE设备的设计程序得出了一些结论。
Thermal energy storage (TES) is increasingly recognized as an essential component of efficient Combined Heat and Power (CHP), Concentrated Solar Power (CSP), Heating Ventilation and Air Conditioning (HVAC), and refrigeration as it reduces peak demand while helping to manage intermittent availability of energy (e.g., from solar or wind). Latent Heat Thermal Energy Storage (LHTES) is a viable option because of its high energy storage density. Parametric analysis of LHTES heat exchangers have been focused on obtaining data with laminar flow in the phase changing fluid and then fitting a functional form, such as a power law or polynomial, to those data. Alternatively, in this paper we present a parametric framework to analyze LHTES devices by identifying all relevant fluid parameters and corresponding dimensionless numbers. We present 64 simulations of an LHTES device using the finite volume method at four values of the Grashof, Prandtl and Reynolds numbers in the phase change material (PCM) and heat transfer fluid (HTF). We observe that with sufficient energy available in the HTF, the effects of the HTF Reynolds number and Prandtl number on the heat transfer rate are negligible. Under these conditions, we propose a time scale for the variation of energy stored (or melt fraction) of the LHTES device based on the Fourier number($Fo$), Grashof number($Gr_p$) and Prandtl number($Pr_p$) and observe a $Gr_p^1$ and $Pr_p^{(1/3)}$ dependency. We also identify two distinct regions in the variation of the melt fraction with time, namely, the linear and the asymptotic region. We also predict the critical value of the melt fraction at the transition between the two regions. From these analyses, we draw some conclusions regarding the design procedure for LHTES devices.
