Experimental analysis of solar thermal storage in a water tank with open side inlets Articles uri icon

authors

  • PALACIOS LORENZO, MARIA ESTHER
  • IZQUIERDO MILLAN, MARCELO
  • ADMIRAAL, D.M.
  • MARCOS, J.D.

publication date

  • January 2012

start page

  • 401

end page

  • 412

issue

  • 1

volume

  • 89

international standard serial number (ISSN)

  • 0306-2619

electronic international standard serial number (EISSN)

  • 1872-9118

abstract

  • Special issue on Thermal Energy Management in the Process Industries. [Resumen]. This paper investigates thermal mixing caused by the inflow from one or two round, horizontal, buoyant jets in a water storage tank, which is part of a thermal solar installation. A set of experiments was carried out in a rectangular tank with a capacity of 0.3 m3, with one or two constant temperature inflows. As a result, two correlations based on temperature measurements have been developed. One of the correlations predicts the size of a zone of homogenous temperature, referred to herein as the mixing zone, which develops when a single hot inflow impinges on the opposite wall of the tank. The other identifies the degree of mixing resulting from the interaction between a hot inflow and a cold inflow located below the hot one. The correlations are combined with energy balances to predict the amount of hot water available in a tank with open side inlets and the corresponding temperatures of the outflows. Outdoor measurements were also performed in a solar installation, in which a commercial water storage tank with a 1.5 m3 capacity, heated by a solar collector array with a useful surface area of 42.2 m2, drives a LiBr&-H2O absorption chiller. Comparison of the predicted and measured outflow temperatures under a variety of weather conditions shows a maximum difference of 3 °C.