Heat transfer performance of thermal energy storage components containing composite phase change materials

Abstract

This study concerns about the heat transfer behaviour of composite phase change materials (CPCMs) based thermal energy storage components. Two types of components, a single tube and a concentric tube component, are designed and investigated. The CPCMs consist of a molten salt based phase change material, a thermal conductivity enhancement material (TCEM) and a ceramic skeleton material. A mathematical model was established to model the heat transfer behaviour. The modelling results were first compared with experiments and reasonably good agreement with the experimental data was obtained, demonstrating the reliability of the model. Extensive modelling studies were then carried out under different conditions. The influence of thermoproperties, surface roughness and size of the CPCMs as well as heat transfer fluid (HTF) velocity were examined. The results show that the thermal contact resistance between the CPCMs should be considered. Increasing the mass fraction of TCEMs and thickness of CPCMs as well as the HTF velocity intensifies the heat transfer behaviour of component. The concentric tube based component offers a better heat transfer performance compared with the single tube based component, with the total heat storage and release time ∼10 and 15% shorter, respectively, for a given set of conditions.

Performance of a liquid cooling‐based battery thermal management system with a composite phase change material

“…The phase‐transition of the PCM was solved with the enthalpy‐porosity approach, and the melting and solidifying processes was simulated with the melting and solidification model. The natural convection and thermal radiation that occurred within the CPCM are neglected due to confinement of the PCM in the interparticle voids of the EG/PCM composite . The non‐equilibrium thermal model was employed for describing heat transfer phenomenon in the metal foam‐based CPCM, with the energy equations solved separately for porous media and PCM .…”

A novel high temperature electrical storage heater using an inorganic salt based composite phase change material

“…As mentioned in Section 2, the CPCM is composed of three ingredients of a PCM, a TCEM and a CSM. A number of theoretical correlations have been developed to predict the effective properties of this composite . One commonly used approach is to regard two of components as a new material, which is then mixed with the third component.…”

“…For the PCM and TCEM mixture, the effective specific heat capacity, c m , and density, ρ m , can be respectively determined by the volume average approach, and the effective thermal conductivity, k m , can be evaluated by the Maxwell model: where k PCM and k TCEM represent the PCM and TCEM thermal conductivity, respectively. ε represents the volume ratio of TCEM in the PCM and TCEM mixture.…”

“…A CPCM usually consists of a PCM for heat storage, a ceramic skeleton material (CSM) for shape stabilization and a thermal conductivity enhancement material (TCEM) for heat transfer enhancement. Such an approach has been shown to give an outstanding combination of thermophysical and mechanical properties . However, little work has been found on the use of the CPCM in the design of electrical storage heaters.…”

“…Such an approach has been shown to give an outstanding combination of thermophysical and mechanical properties. [19][20][21][22][23] However, little work has been found on the use of the CPCM in the design of electrical storage heaters. Lin et al 24,25 proposed an underfloor electrical storage system containing a shape-stabilized CPCM made of paraffin (PCM) and polyethylene (CSM) with a mass ratio of 75:25.…”