Experimental and numerical investigation of the melting process and heat transfer characteristics of multiple phase change materials

Abstract

The melting and heat transfer characteristics of multiple phase change materials (PCMs) are investigated both experimentally and numerically. Multiple PCMs, which consist of three PCMs with different melting points, are filled into a rectangle-shaped cavity to serve as heat storage unit. One side of the cavity is set as heating wall. The melting rate of multiple PCMs was recorded experimentally and compared with that of single PCM for different heating temperatures. A two-dimensional mathematical model to describe the phase change heat transfer was developed and verified experimentally. The properties of multiple PCMs, including the effect of the melting point difference (combined type), thermal conductivity, and latent heat, on the heat transfer performance of the PCM were analyzed numerically. The results show that, the melting time decreases before it increases, with an increasing melting point difference for the multiple PCMs. In addition, the melting point decreases with increasing distance from the heating wall. Most of these types of multiple PCMs melt faster than the single PCM, and the multiple PCMs, with the melting point arranged as 322 K/313 K/304 K, has the shortest melting time in this study. The melting rate of the multiple PCMs, 322 K/313 K/304 K, accelerates faster than for the single PCM as the thermal conductivity, latent heat, and heating wall temperature increase. Finally, generalized results are obtained using a dimensionless analysis for both single and multiple PCMs.

Performance study on multiple phase change materials heat storage system during melting process based on entransy theory

“…Narasimhan 13 confirmed that multiple PCMs can provide better performance and faster heat storage and release rate than single PCM. Li et al 14 studied the melting and heat characteristics of multiple PCMs experimentally and numerically. Jamil et al 15 combined nano‐materials with various PCMs to improve the thermal performance of photovoltaic panels.…”

“…As shown in the above literature, multiple PCMs can effectively improve the performance of heat accumulator. However, previous studies, including the author's recent research, 34,35 have focused on the effects of thermophysical parameters such as melting temperature difference, thermal conductivity, and latent heat of PCMs on their properties. 36 In fact, the proportion of PCM will also significantly affect its performance, which is rarely reported.…”

Numerical investigation of cross plate fin heat sink integrated with phase change material for cooling application of portable electronic devices

“…They reported that the use of honeycomb insert shows higher effectiveness with reference to cost and lightweight. Melting heat transfer analysis of multiple PCMs inside a rectangular cavity was performed by Li et al 41 through experimental and numerical investigation. It is reported that the use of multiple PCMs makes the heat transfer more uniform and decreases the melting time.…”

Role of thermal energy storage for enhancing thermal performance of evacuated tube with compound parabolic concentrator collector

“…In addition to the above works, several numerical and analytical studies have been performed to explore the technological benefits of utilizing multiple PCMs in the TES system in terms of storage capacity, charging and discharging rates, overall efficiency, number of stages, utilization ratio and capacity ratio. [13][14][15][16] An increasing attention has been focused on the development of non-tracking solar collectors particularly, the evacuated tube with compound parabolic concentrator that operates over a wide range of acceptance angles with less collector area requirement. The compound parabolic concentrator (CPC) can be designed with an acceptable concentration ratio to collect both direct beam sunlight and a part of diffuse light and concentrate both on the absorber tubes.…”

“…According to the optimization studies by Khor et al, 12 the charging times of different PCMs should be made close to one another to attain higher cyclic efficiency with less quantity of PCM. In addition to the above works, several numerical and analytical studies have been performed to explore the technological benefits of utilizing multiple PCMs in the TES system in terms of storage capacity, charging and discharging rates, overall efficiency, number of stages, utilization ratio and capacity ratio 13‐16 …”