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Nano-enhanced phase change materials for improved thermal energy storage and building performance / John Paul Nadakkal

By:

Nadakkal, John Paul [author.]

Material type: Text

text

Media type:

unmediated

Carrier type:

volume

ISBN:

THE0009932 (Local)

Subject(s):

Dissertation note: Thesis (Doctor of Philosophy) -- Universiti Malaysia Pahang – 2024 Abstract: Phase change materials are generally preferred for thermal energy storage applications but are troubled by their poor thermal conductivity, which affects their widespread usage. This research aims to analyze the thermophysical properties of paraffin-based hybrid nano-enhanced phase change material (NePCMs) and optimize the thermal conductivity of nanocomposite using Response Surface Methodology (RSM), followed by a reliability assessment and an annual energetic and environmental performance evaluation of NePCM integrated buildings. Graphene: silver nanofillers were dispersed in low-temperature paraffin under a liquid state with different dispersion rates (0.1%,0.3%,0.5%). They were mixed homogeneously using a probe sonicator (twostep synthesis). Nanocomposites dispersed with 0.3 wt% additives showed a maximum enhancement of 6.7% in latent heat and 6.5% in heat storage efficiency. The thermal conductivities of composites were enhanced by a maximum of 90%. In the second stage, statistical methods were applied for hybrid nanocomposite synthesis to deliver maximal favourable thermophysical properties. RSM with a central composite design was sourced to generate optimal input response conditions for the maximal thermal conductivity of NePCM. The maximal thermal conductivity value for the optimum input response of nanofiller and surfactant concentration was 0.412 W/mK, 0.310%, and 0.313%, respectively. Statistical parameters were used to validate the experimentally developed RSM model. Manual thermal cycling up to 2000 cycles was conducted, equivalent to 7 years of operation, and corrosion compatibility of aluminum against NePCM was also done and found in the permissible range. A mathematical model was developed in Design Builder to analyze performance variation due to NePCM integration in buildings. NePCM integration improved performance indices like maximum indoor temperature difference, decremental factor, average operative temperature reduction, Operational temperature difference, discomfort hours reduction, maximum heat gain reduction, and CO2 savings. The room integrated with NePCM logged almost a stable operational temperature (around 27℃) irrespective of rise or fall in outdoor temperature. The annual CO2 emission is 233 kg CO2 per m2 with NePCM. This research provides insight into the capabilities of hybrid nano-enhanced phase change materials for enhanced thermal energy storage and building performance under Malaysian climatic conditions.

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Holdings ( 2 )
Title notes ( 4 )

Holdings
Item type	Current library	Call number	Copy number	Status	Date due	Barcode
Thesis	UMPLIB PEKAN	FTKMA .P38 2024 r Thesis (Browse shelf(Opens below))	1	Not for loan		T000003237
Thesis	UMPLIB PEKAN	CD13621 (Browse shelf(Opens below))	1	Final Processing		T000003238

Faculty of Mechanical and Automotive Engineering Technology

Thesis (Doctor of Philosophy) -- Universiti Malaysia Pahang – 2024

ncludes bibliographical referencesIncludes bibliographical references

Phase change materials are generally preferred for thermal energy storage applications but are troubled by their poor thermal conductivity, which affects their widespread usage. This research aims to analyze the thermophysical properties of paraffin-based hybrid nano-enhanced phase change material (NePCMs) and optimize the thermal conductivity of nanocomposite using Response Surface Methodology (RSM), followed by a reliability assessment and an annual energetic and environmental performance evaluation of NePCM integrated buildings. Graphene: silver nanofillers were dispersed in low-temperature paraffin under a liquid state with different dispersion rates (0.1%,0.3%,0.5%). They were mixed homogeneously using a probe sonicator (twostep synthesis). Nanocomposites dispersed with 0.3 wt% additives showed a maximum enhancement of 6.7% in latent heat and 6.5% in heat storage efficiency. The thermal conductivities of composites were enhanced by a maximum of 90%. In the second stage, statistical methods were applied for hybrid nanocomposite synthesis to deliver maximal favourable thermophysical properties. RSM with a central composite design was sourced to generate optimal input response conditions for the maximal thermal conductivity of NePCM. The maximal thermal conductivity value for the optimum input response of nanofiller and surfactant concentration was 0.412 W/mK, 0.310%, and 0.313%, respectively. Statistical parameters were used to validate the experimentally developed RSM model. Manual thermal cycling up to 2000 cycles was conducted, equivalent to 7 years of operation, and corrosion compatibility of aluminum against NePCM was also done and found in the permissible range. A mathematical model was developed in Design Builder to analyze performance variation due to NePCM integration in buildings. NePCM integration improved performance indices like maximum indoor temperature difference, decremental factor, average operative temperature reduction, Operational temperature difference, discomfort hours reduction, maximum heat gain reduction, and CO2 savings. The room integrated with NePCM logged almost a stable operational temperature (around 27℃) irrespective of rise or fall in outdoor temperature. The annual CO2 emission is 233 kg CO2 per m2 with NePCM. This research provides insight into the capabilities of hybrid nano-enhanced phase change materials for enhanced thermal energy storage and building performance under Malaysian climatic conditions.