Improving Thermal Energy Storage in Solar Collectors: A Study of Aluminum Oxide Nanoparticles and Flow Rate Optimization

1. Research Summary (Abstract):

This study investigates the effect of aluminum oxide (Al₂O₃) nanoparticles and varying flow rates on the thermal storage performance of solar collectors. An indoor experimental setup was used to optimize nanoparticle concentration and flow rate for improved heat storage. Results show a 19% increase in specific heat and optimal performance at 15 L/h flow rate and 0.6% nanoparticle concentration.

2. Background and Motivation:

Context:

Thermal energy storage (TES) is essential for addressing the intermittency of solar energy and improving energy efficiency, especially for space heating in residential and commercial applications.

Gap in Knowledge / Need:

Prior studies introduced nanoparticles into heat transfer fluids or phase change materials, but none explored the direct incorporation of Al₂O₃ nanoparticles into water-contained storage tanks. This study fills that gap.

3. Objectives:

  • 1. Evaluate the effect of Al₂O₃ nanoparticles on the thermal properties of storage water.
  • 2. Identify the optimal flow rate for maximum energy storage.
  • 3. Determine the ideal nanoparticle concentration for maximum specific heat and system efficiency.

4. Methods and Approach:

Approach:

An indoor setup using the ET 202 system simulated solar heating. Nanoparticles were added to the water in a storage tank, and flow rates were varied.

Key Techniques:

  • – Use of halogen lamps to simulate solar radiation
  • – Copper constant thermocouples for temperature measurement
  • – Variation of flow rates (5–30 L/h) and nanoparticle concentrations (0–1.0%)
  • – Specific heat capacity and efficiency calculations using thermodynamic equations.

5. Key Findings:

  • 1. The optimal flow rate for maximum storage temperature was 15 L/h.
  • 2. The highest specific heat (5.65 kJ/kg°C, +19%) was achieved at 0.6% Al₂O₃ concentration.
  • 3. Efficiency peaked at 1.0% nanoparticle concentration due to reduced thermal conductivity from particle agglomeration.

6. Outcomes and Impact Highlights:

Academic:

Contributes to the growing field of nanotechnology-enhanced thermal storage, filling a critical research gap in solar energy systems.

Societal / Economic:

Potential for more efficient and compact solar thermal systems, reducing energy costs and reliance on fossil fuels.

Policy / Practice:

Supports the adoption of advanced materials in renewable energy systems to meet sustainability goals.

7. Evidence of Impact:

  • – Specific heat of water improved by 19%
  • – Experimental system efficiency increased at higher nanoparticle concentrations
  • – Results applicable to residential and industrial solar thermal systems

8. Funding and Support:

This research received no external funding. Institutional support was provided by the participating universities.

9. Supporting Materials / URLs:

– Paper DOI

– Journal page

10. Academic Profile:

Name: Mohammad Hamdan

Affiliation: Department of Renewable Energy Technology, Faculty of Engineering and Technology, Applied Science Private University, Amman, Jordan

ASU Profile URL: https://www.asu.edu.jo/en/Energy/Pages/Mohammad-Hamdan.aspx​

11. Project Partners (if any):