Investigation of nanoparticles enriched phase change materials for improved thermal performance of energy storage applications

The thesis provides a detailed analysis of the integration of nanoparticles into phase change materials (PCMs) to improve thermal energy storage (TES) performance across various applications. By leveraging nanoparticles, the thermal conductivity and heat transfer characteristics of PCMs are improved, enabling faster charging and discharging cycles, reducing thermal losses, and maintaining system stability under varying operational conditions. Through a series of numerical simulations and in-depth analyses, this work investigates the effects of nanoparticles-enhanced PCMs (NPCMs) on the performance of different applications. The first part focuses on using PCMs in passive solar greenhouses in cold climates, incorporating them into the north-facing wall to extend the growing season by up to 48 days. Additionally, it achieves a temperature increase from an average of 12.1°C to 24.8°C. Next, a TES unit is analyzed in the context of energy storage used for CSP applications. Integrating high-quality nanoparticles into PCMs reduces the charging time by 8.6% to 12.5%, significantly improving system responsiveness and stability. Additionally, the cyclic performance of NPCM-based TES is studied. Numerical simulations show that while high concentrations of nanoparticles enhance thermal conductivity during the charging and discharging phases, the solid nanoparticles tend to sediment as the base storage medium liquifies, reducing their thermal effectiveness after the initial cycle. Accordingly, the possible integration of nanoparticles with solid-solid PCMs (S-S PCMs) is investigated. Three designs are modeled for the thermal management of electronic devices with the topology-optimized configuration showing superior thermal performance. Compared to conventional designs, the optimized configuration reduces heat sink and chip temperatures by up to 3.51°C and 2.65°C, respectively. The integration of nanoparticles accelerates the phase transitions within the PCM, resulting in improved heat dissipation and storage. The thesis provides a thermodynamic assessment of a CSP-driven trigeneration system utilizing solar irradiance and NPCM-based thermal energy storage to produce electricity, fresh water via MED, and cooling through absorption refrigeration. The plant operates with an energy efficiency of 56.72% and an exergy efficiency of 31.24%, underscoring the system’s capability to efficiently harness solar energy for multiple outputs.

Name thesis:degree_name

Doctor of Philosophy (PhD)

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Ontario Institute of Technology

Year dc:date.issued

2024

Author dc:creator

• Ismail, Mohamed M.

Advisor dc:contributor.advisor

• Dincer, Ibrahim

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10155/1895

OAI identifier oai:identifier

oai:ontariotechu.scholaris.ca:10155/1895