TY  - EJOU
AU  - Li, Hongtao 
AU  - Liang, Liqiang 
AU  - Li, Jiageng 
AU  - Ji, Yunguang 
AU  - Dong, Fuqiang 

TI  - Optimization of Temperature Field Uniformity Induced by Heating-Element Configuration and Its Effect on Melting Rate of Phase Change Materials
T2  - Energy Engineering

PY  - 
VL  - 
IS  - 
SN  - 1546-0118

AB  - The configuration of multiple heat sources within a latent heat thermal energy storage (LHTES) unit directly influences the uniformity of the temperature field and profoundly affects the melting process of the phase change material (PCM). To investigate the impacts of heating-element configurations on temperature field homogenization and melting rate of paraffin in an LHTES unit, this study introduces a dimensionless scaling factor <i>η</i> (defined as the ratio of the center-to-center distance between adjacent heating-element to the characteristic dimension of the container) and establishes a theoretical model for the optimal spacing of heating-element based on the Stefan condition. A combined approach of three-dimensional transient numerical simulation and experimental validation is employed to study the impact of heating-element configuration on melting efficiency in a 2 × 3 rectangular cylindrical-heating-element array. An experimental system with a measurement setup consisting of a 30-point thermocouple array and an infrared thermal imager was constructed to test and compare the temperature fields under different heating-element-distance Δ<i>s</i>, respectively (Δ<i>s</i> = 30, 60, and 90 mm). The results show that, under equal power input, the unit achieves the shortest melting time at Δ<i>s</i> = 60 mm, which is 3.4% and 5.4% shorter than that at Δ<i>s</i> = 30 and 90 mm, respectively. A parallelogram array with a 45° misaligned angle further reduces the melting time by 5.2% compared to the rectangular array, Furthermore, an optimal scaling factor <i>η</i><sub>opt</sub> = 0.34 is obtained, which reduces the melting time by 8.7% compared to the case of <i>η</i> = 0.30. This study employs an integrated experimental and numerical approach to investigate how multiple heat-source configurations influence the melting process of phase-change materials (PCMs). The experimental results agree well with the simulation results, with a maximum relative deviation of 6.4%. This confirms the accuracy and engineering applicability of the numerical method, although some experimental uncertainties—particularly fluctuations in local temperature distributions—were observed. This study provides a quantitative basis for improving melting uniformity, and offers theoretical guidance to optimize structural compactness and heating-element configuration in LHTES units, which demonstrates promising practical applicability.
KW  - Latent heat thermal energy storage; heating-element configuration; temperature field uniformity; melting rate; optimal spacing

DO  - 10.32604/ee.2026.076827