This paper presents experimental studies on thermal stratification in chilled-water storage systems. A fibreglass storage tank in static and dynamic modes of operation is used. The parameters varied are aspect ratio, flow rates, initial temperature difference and thickness of insulation. Emphasis is given to the effects of mixing at the inlet, leading to the definition of the mixing coefficient. The thermocline decay increases with the value of mixing coefficient, which is expressed as a function of Reynolds number and Richardson number.

J. E.B. Nelson

Arcot R. Balakrishnan

Aspect ratio

Glass fibers

Heat convection

Reynolds number

Temperature distribution

Thermal stratification

Water tanks

STRATIFIED CHILLED-WATER TANKS

Refrigeration

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Experiments on stratified chilled-water tanks

International Journal of Refrigeration

This paper investigates the accelerated mixing of hot and cold liquid layers in storage tanks of different physical dimensions by the application of high-frequency, high-intensity pulsed ultrasound. In pulsed operation, the ultrasonic field is switched on for a few seconds and then switched off. This cycle is repeated several times. Pulsed mixing of hot and cold water due to ultrasonics was measured in this study. Acoustic streaming and cavitation phenomena associated with the ultrasonic field can induce enhanced mixing in the storage containers leading to de-stratification of liquid. The experimental results indicate that dual frequency operation, which combines one high-frequency mode with one low-frequency mode, is optimal in enhancing mixing compared to other frequencies. Mixing efficiency increases with cavitation intensity and the introduction of acoustic streaming augments it further. The experimental result indicates that as the height of the cylinder increases, the mixing time also increases. The ultrasonic mixing times obtained for different frequencies indicate that as the frequency increases, the time required to reach the steady state temperature also increases, due to decrease in cavitation intensity. © 2008 The Institution of Chemical Engineers.

Chemical Engineering Research and Design

Pulsed ultrasonic mixing: An experimental study

Applied Thermal Engineering

Parametric studies on thermally stratified chilled water storage systems

International Journal of Energy Research

STUDY OF CHARGING OF STRATIFIED STORAGE TANKS WITH FINITE WALL THICKNESS

Analytical and experimental investigation of thermal stratification in storage tanks

Experimental investigation of chilled water storage technique for peak power shaving

Science

Nuclear Energy in Canada: Nucleus.

Journal	Data powered by TypesetInternational Journal of Refrigeration
Publisher	Data powered by TypesetElsevier Science Ltd
ISSN	01407007
Open Access	No