Assessment of the charging performance in a cold thermal energy storage container with two rows of serpentine tubes and extended surfaces


Afsharpanah F., Pakzad K., Arici M. , Ajarostaghi S. S. M.

JOURNAL OF ENERGY STORAGE, vol.51, 2022 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 51
  • Publication Date: 2022
  • Doi Number: 10.1016/j.est.2022.104464
  • Title of Journal : JOURNAL OF ENERGY STORAGE
  • Keywords: Ice storage, Ice-on-coil, Serpentine tubes, Heat exchanger, PCM, Thermal energy storage, HEAT-TRANSFER, ENHANCEMENT, TEMPERATURE, SYSTEM, SHELL

Abstract

Each year around 1.3 billion tons of food is wasted in the world. Some of this food waste is due to the improper performance of the cold chain, which can be controlled by the means of cold thermal energy storage devices. In this research, the charging performance of a small-scale cuboid-shaped ice container unit with two rows of serpentine tubes equipped with connecting plates has been numerically examined. The container is designed to be utilized as a cooling backup for home refrigeration units in developing countries to compensate for the heat load during the frequent power outages in these regions and to help food preservation during these times. The impacts of various dimensionless parameters regarding the flow and geometric aspects of the serpentine tubes and extended surfaces have been examined in this ice container. These parameters were the Reynolds and modified Stefan numbers of the refrigerant flow, serpentine tube pitch length/container height ratio (gamma(1)), the serpentine tube row distance/container width ratio (gamma(2)), the serpentine tube diameter/container diagonal length ratio (gamma(3)), the plate area/the maximum plate area ratio (gamma(4)), and the plate thickness/tube diameter ratio (gamma(5)). The charging process was monitored using a dimensionless parameter, named, stored energy ratio which considers both sensible and latent energy storage progress. The results suggest that higher gamma(1), gamma(2), gamma(4), and gamma(5), and lower gamma(3) values lead to enhanced charging rates. It was also found that installing the full-coverage thick plates (gamma(4) =1 and gamma(5 )= 0.0081) increases the time-averaged charging rate by 18%.