Heat transfer performance of graphene nano-platelets laden micro-encapsulated PCM with polymer shell for thermal energy storage based heat sink. (25th June 2019)

• Record Type: Journal Article
• Authors: Praveen, B.; Suresh, S.; Pethurajan, Vignesh
• Is Part Of: Applied thermal engineering. Volume 156(2019)
• Page Start: 237
• Page End: 249
• Publication Date: 2019-06-25
• Subjects: Micro-encapsulated PCM -- Graphene nano-platelets -- TES based heat sink -- Temperature rise rate -- Thermal conductance; PCM phase change material -- ME PCM micro encapsulated PCM -- GnP graphene nano-platelets -- ME/GnP PCM GnP laden micro-encapsulated PCM -- TES thermal energy storage -- RT room temperature -- DSC differential scanning calorimetric -- TGA thermo-gravimetric analysis -- PSD particle size Distribution -- SEM scanning electron microscope -- TRR temperature rise rate, °C/min -- C thermal conductance, W/K; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2019.04.072
• Languages: English
• ISSNs: 1359-4311

Abstract

Graphical abstract: Illustrates the steps involved in the process of micro encapsulation of PCM by In-situ polymerization. To enhance the heat transfer, Graphene nanoplatelets of 0.5, 1 and 3 wt% was added and dispersed homogenously by low energy ball milling process. The morphology, shape and the size of the micro capsules were characterized by SEM analysis. The shape stability of the prepared microcapsules was tested with same temperature exposure. The presence of GnP reduces the internal heat resistance by filling the voids between the microcapsules. The heat sink temperature rise rate gets delayed by the composite PCM and the rate is depend up on the GnP wt% in the PCM. Highlights: Paraffin is microencapsulated with polymer shell by In-situ polymerization. Graphene nano-platelets (GnP) of 0.5, 1 and 3 wt% added to enhance the heat transfer between the encapsulated PCM. The thermal conductance the heat sink increased with GnP wt%. The temperature rise rate (TRR) of heat sink reduced from 1.1 °C/min to 0.85 °C/min at the temperature range of 40–60 °C. The GnP in the encapsulated PCM reduced the recovery time of heat sink. Abstract: Encapsulation of phase change material (PCM) prevents from leakage and can evade the adverse effect of bulk volume expansion. In this study, experimental results on the heat transfer performance of graphene nano-platelets laden microencapsulated PCM (ME/GnP PCM) in a finned thermal energy storage based heat sink are presented. In-situ polymerization method was used to prepare the capsules with paraffin/polyurethane as core/shell material. The samples were characterized by its morphology, capsule size, phase change properties, thermal and chemical stability. To enhance the heat transfer within the microcapsules, GnP of 0.5, 1 and 3 wt% were incorporated. The performance of PCM was compared with a finned heat sink under constant heat load condition of 10 W, 15 W and 20 W. The performance was evaluated based on the heat sink base temperature with time for set point temperatures and the temperature rise rate (TRR). The thermal conductivity increased from 0.192 to 0.379 W/m K and the TRR of the heat sink was delayed due to the enhanced the heat transfer within the ME/GnP PCM. Moreover, the recovery time of the heat sink also declined due to reduced thermal resistance and nucleation effect in the MEPCM by the GnP.