Full Content is available to subscribers

Subscribe/Learn More  >

Effect of Viscosity Variations on Charge and Discharge Time of a Sulfur-Based Thermal Energy Storage System

[+] Author Affiliations
Reza Baghaei Lakeh

California State Polytechnic University, Pomona, CA

Karthik Nithyanandam, Amey Barde, Louis Tse, Richard E. Wirz

University of California, Los Angeles, Los Angeles, CA

Paper No. ES2016-59161, pp. V001T05A002; 5 pages
  • ASME 2016 10th International Conference on Energy Sustainability collocated with the ASME 2016 Power Conference and the ASME 2016 14th International Conference on Fuel Cell Science, Engineering and Technology
  • Volume 1: Biofuels, Hydrogen, Syngas, and Alternate Fuels; CHP and Hybrid Power and Energy Systems; Concentrating Solar Power; Energy Storage; Environmental, Economic, and Policy Considerations of Advanced Energy Systems; Geothermal, Ocean, and Emerging Energy Technologies; Photovoltaics; Posters; Solar Chemistry; Sustainable Building Energy Systems; Sustainable Infrastructure and Transportation; Thermodynamic Analysis of Energy Systems; Wind Energy Systems and Technologies
  • Charlotte, North Carolina, USA, June 26–30, 2016
  • Conference Sponsors: Advanced Energy Systems Division, Solar Energy Division
  • ISBN: 978-0-7918-5022-0
  • Copyright © 2016 by ASME


Most of the renewable energy sources, including solar and wind suffer from significant intermittency due to day/night cycles and unpredictable weather patterns. On the other hand increasing share of renewable sources imposes additional stability risks on the power grid. Increased share of solar energy in power generation during noon along with increased power demand during afternoon peak hours generates a significant risk on the stability of power grid. Energy Storage systems are required to enable the renewable energy sources to continuously generate energy for the power grid and enhance the stability of future grid that benefits from more renewable sources. Thermal Energy Storage (TES) is one of the most promising forms of energy storage. Although round trip efficiency is relatively high in thermal storage systems, heat transfer is a well-known problem of most TES systems that use solid state or phase change. Insufficient heat transfer may significantly impact the performance of the TES system. The TES system of this study utilizes molten sulfur as the storage medium. Although thermal conductivity of molten sulfur is relatively low, the sulfur-based TES system benefits from enhanced heat transfer due to the presence of buoyancy-driven flows. In this study, the effect of natural convection on the heat transfer characteristics of a sulfur-based isochoric TES system is studied computationally and theoretically. It turns out that the viscosity of sulfur in the temperature range of this study (250–400 °C) varies by two orders of magnitude. A computational model was developed to investigate the effect of viscosity variations on the buoyancy-driven flow and corresponding charge and discharge times. The computational model is developed using an unsteady Finite Volume Method by a commercially available CFD package. The results of this study show that the heat transfer process in the isochoric TES element is highly impacted by natural convection. The viscous flow of molten sulfur near the boundaries of the isochoric TES element leads to different charge and discharge times. The discharge time is almost two times longer than the charge time due to formation of a viscous layer of elemental sulfur near the heat transfer surface. The viscous layer of sulfur decreases the activity of the buoyancy-driven flow and decreases the heat transfer rate during discharge cycle. The computational model was validated by comparing the results of a representative case with experimental data.

Copyright © 2016 by ASME



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In