Numerical investigation of passive stabilization of the surface temperature using PCM and metal foam

Mirosław Seredyński,S Grądziel,T Sobota,S Łopata,W Zima

doi:10.1051/matecconf/201824005027

Mirosław Seredyński, S Grądziel + Show 3 more

Open Access

https://doi.org/10.1051/matecconf/201824005027

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Abstract

Stabilization of the temperature of PVs is of great importance, due to strong relation between operating temperature and its efficiency. Due to low thermal conductivity of PCM, intensification of heat transfer to the operating material is needed. The four fully passive PV’s temperature stabilization systems, based on the phase change material (PCM) are numerically investigated in this paper. Apart from the natural convection promotion, intensification of heat transfer is done with aluminium fins and aluminium foam. The simplified computational model based on the equilibrium formulation of energy transport equation, taking into account viscous and inertial fluid flow resistances in the porous material, is formulated and solved with the general purpose software - ANSYS Fluent. Proposed model is succesfully verified by comparing the results with available in literature numerical solutions.Simulations outcomes are presented, the temperature and liquid fraction distributions in proposed geometry configurations, temperature variations determined in selected points and averaged on the heated surface temperature plots. Presented results help to assign the best configuration.

Highlights

The temperature stabilization of electronic devices and photovoltaics is very important due to restricted operational requirements and considerable impact of temperature on their efficiency
The numerical model of heat transfer in the composite based on the nonequilibrium energy balance formulation neglected effect of natural convection in the molten phase change materials (PCM)
The composite material used as the heat sink, the graphite foam infused with PCM, had much higher thermal conductivity, equal to 16.6 W/(mK), than the conductivity of pure PCM, equal to 0.25 W/(mK)

Summary

Introduction

The temperature stabilization of electronic devices and photovoltaics is very important due to restricted operational requirements and considerable impact of temperature on their efficiency. The common materials considered for PV temperature stabilization are organic pcm’s, which are chemically stable, non expensive, safe and does not cause corrosion in metals Their main drawback is a low thermal conductivity, close to 0.2 W/(mK), so some effort is needed to intensify the heat transfer between the hot surface and the heat storage material [2]. Analysis of the role of internal finning of the PCM container exposed to high thermal radiation flux on the temperature limiting was investigated by the same authors (Huang et al.) [5] and [6]. The composite made of graphite matrix impregnated with PCM was used by Atkin and Farid [9] for temperature stabilization of PV cells This solution was compared to other stabilization methods, based on passive cooling with fins. The mechanisms of heat transfer to PCM are discussed, based on the average temperature history of the hot surface

Problem statement

Computational model

F kPCM kF

Verification

Results and discussion

Conclusions