Decay of thermal stratification in a water body for solar energy storage

Abstract

An experimental study of the temperature decay in a thermally stratiffied water body is carried out. An enclosed water body is initially stratified by the recirculating flow of hot water discharge and also, statically, by the addition of hot water at the top of cold fluid. The time dependent temperature profiles are measured for various initial temperature distributions and ambient conditions. The results obtained indicate the temperature field to be largely one-dimensional and a simple analytical model is formulated to study the basic nature of the process. A fairly good agreement with experiments is obtained. The study discusses the basic mechanisms that arise and considers the decay process in terms of these mechanisms. Several interesting features, with respect to energy storage in stratified fluids, are brought out. © 1982.