本文係以數值模擬與實驗的方式探討填充相變化材料微膠囊顆粒之矩形容器其熱能儲存之特性。 矩形容器左右垂直壁面分別為等溫加熱/冷卻壁面，其餘邊壁為絕熱壁。微膠囊內含相變化材料為18烷。 容器冷熱壁間溫度差分別維持在12、16、18與20oC，其相關無因次參數及範圍如下:高寬比，AR = 1；達西數,Da = 1.42×10E-9；普蘭度數，Prf =0.707；萊利數, Raf =1.67×10E7~2.78×10E7；史蒂芬數,Stem=0.125~0.23；及次冷參數,Sbc=-0.375~0.25。 此外，針對所探討的實驗模型建構對應之數學模式，並進行與實驗相對應條件之數值模擬，分析容器內相變化材料微膠囊熔解過程，進而探討其熱能儲存量和速率。

The present study aims to examine, via a complementary approach of experimental measurement and numerical simulation, thermal energy storage characteristics in a rectangular enclosure of air packed with microencapsulated phase change material (MPCM). The enclosure is differentially heated by the two vertical isothermal surfaces, while the other surfaces are considered thermally insulated. The core phase change material within the MPCM is n-Octadecane. Thermal energy storage experiments have been undertaken for various temperatures differences between hot and cold surfaces across the enclosure of 12C, 16C, 18C, 20C, with the pertinent dimensionless parameters in the following ranges: the aspect ratio, AR = 1; the Darcy number, Da = 1.42×10E-9; the Prandtl number, Prf = 0.707; the Rayleigh number, Raf =1.67×10E7~2.78×10E7; the Stefan number, Stem = 0.125 ~ 0.230; and the subcooling factor, Sbc = 0.375 ~ 0.250. Numerical simulations have been performed based on a mathematical modeling mimicking the experimental configuration considered to further elucidate the heat transfer characteristics and the thermal energy storage efficiency of the enclosure.

Ahmed, M., Meade, O., Medina, M.A., “Reducing Heat Transfer across the Insulated Walls of Refrigerated Truck Trailers by the Application of Phase Change Materials,” Energy Conversion and Management, Vol.51,pp.383-392,2010.

Beckermann, C., Viskanta, R., Ramadhyani, S., “A Numerical Study of Non-Darcian Natural Convection in a Vertical Enclosure Filled with a Porous Medium,” Numerical Heat Transfer, Vol.10, pp.557-570, 1986.

Evers, A.C., Medina, M.A., Fang, Y., “ Evaluation of the Thermal Performance of Frame Walls Enhanced with Paraffin and Hydrated Salt Phase Materials using a Dynamic Wall Simulator,” Building and Environment, Vol.45, pp.1762-1768, 2010.

Heim, D., “ Isothermal Storage of Solar Energy in Building Construction,” Renewable Energy, Vol.35, pp.788-796, 2009.

Ho, C.J., “A Continuum Model for Transport Phenomena in Convective Flow of Solid-Liquid Phase Change Material Suspensions,” Applied Mathematical Modeling, Vol.29, 805-817, 2005.

Huang, Y.L., “Experimental Investigation of Fluid Flow and Internal Convection Heat Transfer in Mini/Micro Porous Median,” Heat and Mass Transfer International Conference, December, 18-21, 2009.

Hubble, O., Diller, E., “A Hybrid Method for Measuring Heat Flux,” Journal of Heat Transfer, Vol. 132, 031602-1,2010.

Ismail, K.A.R, Moraes, R.I.R., “ A Numerical and Experimental Investigation of Different Containers and PCM Options for Cold Storage Modular Unit for Domestic Applications,” International Journal of Heat and Mass Transfer, Vol.51, pp.4195-4202, 2009.

Kladias, N., Prasad, V., “Experimental Verification of Darcy-Brinkman-Forchheimer Flow Model for Natural Convection in Porous Media,” Journal of Thermophysics and Heat Transfer, Vol.5, NO.4, pp.50-576,1990.

Lauriat, G., Prasad, V., “Non-Darcian Effects on Natural Convection in a Vertical Porous Enclosure,” International Communications in Heat and Mass Transfer, Vol.32, pp.2135-2148,1989.

Liu,H., Awbi, H.B., “Performance of Phase Change Material Boards under Natural Convection,” Building and Environment, Vol.44, pp.1788-1793,2009.

Marvel, R.L., Lai, F.C., “Natural Convection From a Porous Cavity With Sublayers of Nonuniform Thickness: A Lumped System Analysis,” Journal of Heat Transfer, Vol.132, 032602-1,2010.

Nakayama, A., Ando, K., Yang, C., “A Study on Interstitial Heat Transfer in Consolidated and Unconsolidated Porous Media,” Heat and Mass Transfer, Vol. 45, pp.1365-1372,2009.

Pourshaghaghy, A., Hakkaki-Fard, A., Mahdavi-Nejad, A., “Direct Simulation of Natural Convection in Square Porous Enclosure,” Energy Conversion and Management, Vol. 48, pp.1579-1589,2007.

Saeid, N.H., Pop, I., “Non-Darcy Natural Convection in a Square Cavity Filled with a Porous Medium,” Fluid Dynamics Research, Vol.36, pp.35-43,2004.

Saito, M.B., Lemos, M.J.S.D., “Laminar Heat Transfer in Porous Channel Simulated with a Two-Energy Equation Model,” International Communications in Heat and Mass Transfer, Vol.36, pp.1002-1007,2009.

Varol, Y., Oztop, H.F., Mobedi, M., Pop, I., “Visualization of Heat Flow Using Bejan’s Heatline due to Natural Convection of Water near in Thick Walled Porous Cavity,” International Journal of Heat and Mass Transfer, Vol.53, pp.1691-1698,2010.

Wang, J., Xie, H., Xin, Z., “Thermal Properties of Paraffin Based Composites Containing Multi-Walled Carbon Nanotubes,” Thermochimica Acta, Vol.488, pp.39-42, 2009.

Wu, S., Fang, G., Liu, X., “Dynamic Charging Performance of a Solar Latent Heat Storage Unit for Efficient Energy Utilization,” Chemical Engineering Technology, Vol.33, pp.455-460,2010.

陳嘉正,“方形容器內充填相變化材料微膠囊之熱能儲存特性研究” ,國立成功大學機械工程研究所碩士論文,2009.

劉文恭,“方形容器內氧化鋁－水奈米流體之自然對流熱傳現象之實驗研究” ,國立成功大學機械工程研究所碩士論文,2007.