The TESTING
Thermal Energy STorage and INsulation Group

Faculty:
Dr. Shahin Shafiee
Tel: (936) 261-9792
Email: shshafiee@pvamu.edu

Research Interest:
Heat Transfer under Anomalous Boundary Conditions, Hydrogen and Energy Storage, Non-Conventional Refrigeration Systems, Transformational Insulation Technologies

Research Activities:

  1. Heat Transfer under Anomalous Boundary Conditions

Heat transfer

Enhancing heat transfer has a wide range of applications from energy systems to thermal management of electronics and can significantly improve their efficiency. Ability of a material to conduct heat and its extent are among thermophysical properties of the material. External forces like electrical fields and magnetic fields can influence some of these properties including its ability in conducting heat. In a similarly way, the convective heat transfer in fluids with certain properties can change by external forces. As an example, convective heat transfer is augmented in ferro-nanofluids (nanofluids generated by ferro-nanoparticles) in presence of external magnetic fields. Verifying the effective parameters that enhance the heat transfer, understanding the involved mechanism, and measuring their impact and extent is the aim of this research. The current work is focused on developing, designing, and fabricating experimentations based on different measurement techniques to study the conductive and convective heat transfer enhancement under the effect of magnetic fields. The experimental results will help better understand the micro-scale mechanism of heat transfer in magnetic fields and leads to developing applications in different areas of heat transfer.

  1. Hydrogen and Energy Storage

Hydrogen is an abundant element with high gravimetric energy density that is three times higher than gasoline. This makes it a proper candidate to be considered as an alternative fuel. Meanwhile, it suffers from low volumetric energy density, which necessitates efficient storage methods for it to remain competitive with conventional (fossil) fuels. Hydrogen storage can be done in gaseous state (compressed gas), liquid state (liquefied H2), or solid state (in absorbing materials). By utilizing the latent heat of chemical reactions, the latter can provide higher energy density compared to the former two methods. Storing hydrogen is absorbing materials like metal hydrides includes exothermic/ endothermic absorption/desorption reactions. This gives the absorption-based storage the capability to serve as energy storage and hydrogen storage system simultaneously. This work focuses on addressing some issues associated with hydrogen storage like low rates of heat transfer and reaction kinetics for solid state storage, and improved tank design for gaseous storage. Developing applications of solid state hydrogen storage in energy systems like grid scale energy storage and heat pumps is another aim of this work.

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Figure 2. Different Thermal Storage Methods Figure 3. Schematic Diagram of an Integrated Metal
Hydrides Thermal Storage in a Solar Power System
  1. Non-Conventional Refrigeration Systems

A paradigm for conventional refrigeration is the systems based on vapor compression cycle. Vapor-compression systems transport heat through a closed-loop cycle by compressing, condensing, expanding, and evaporating a working fluid (refrigerant – dominantly Hydrofluorocarbons). These systems are energy extensive and their refrigerants have detrimental environmental impacts when released into the atmosphere through leaks and other losses during installation, repair, and removal. Although work is underway to make these system as energy efficient as possible, develop alternative refrigerants and improve refrigerant management strategies, the phase-down of Hydrofluorocarbons will impose constraints on vapor-compression equipment that will require trade-offs among cost, efficiency, and safety. These constraints could present market opportunities for alternative space-conditioning technologies. This work is on addressing the issues of excessive energy consumption, carbon footprint, and environmental hazards with conventional refrigeration. The focus is on developing alternative refrigeration system based on thermochemical refrigeration like metal hydride heat pumps; and magnetic refrigeration.

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Figure 4. Exothermic/Endothermic Hydrogen Absorption/Desorption Figure 5. Magnetic Refrigeration
  1. Transformational Insulation Technologies

Conventionally, building envelop relies on sealing and insulating external surfaces to maintain a constant internal climate. Inevitably, insulations play an important role in minimizing the heat transfer between the internal and external environments of a building. In this regard, high thermal resistance materials are desired to be developed for insulating the building envelop. Meanwhile, minimizing heat transfer between the inside and outside space can be achieved by minimizing the temperature gradient on the inner and outer surface of a typical building wall. This work is focused on dynamic control of the heat flux in building envelop through different means including active temperature control of building structure.

Selected Publications:

Book Chapter

  1. H. McCay, and S. Shafiee, “Hydrogen: An Energy Carrier”, Future Energy, improved, Sustainable and Clean Options for Our Planet, 3rd Edition, Elsevier, ISBN 9780081028865, 2020.

Journal Papers

  1. S. Shafiee, “Operational Principles and Effect of Operating Parameters on Performance of Metal Hydride Heat Pumps”, International Journal of Refrigeration, 2020.
  2. S. Shafiee, M. H. McCay, and S. Kuravi, “The Effect of Magnetic Field on Thermal-Reaction Kinetics of a Paramagnetic Metal Hydride Storage Bed”, Applied Sciences, vol. 7, no. 10, p. 1006, 2017.
  3. S. Shafiee, M. H. McCay, and S. Kuravi, “Effect of Magnetic Fields on Thermal Conductivity in a Ferromagnetic Packed Bed,” Experimental Thermal and Fluid Science, vol. 86, pp. 160–167, 2017.
  4. S. Shafiee and M. H. McCay, “Different Reactor and Heat Exchanger Configurations for Metal Hydride Hydrogen Storage Systems – A Review,” International Journal of Hydrogen Energy, vol. 41, no. 22, pp. 9462–9470, 2016.

Conference Papers

  1. S. Shafiee, and M. H. McCay, “Comparison of Different Energy Storage Systems for a Small Airport Facility”, in Proceedings of the ASME 2018 12th International Conference on Energy Sustainability, 2018.
  2. S. Shafiee, and M. H. McCay, “A Hybrid Energy Storage System Based on Metal Hydrides for Solar Thermal Power and Energy Systems,” in Proceedings of the ASME 2016 10th International Conference on Energy Sustainability, 2016.

Research Facilities:
The TESTING (Thermal Energy STorage and INsulation Group) lab and facilities are currently under development.