The heat transfer during the crystallisation in a slurry of a stable mixtur
e of water with a water-soluble polymerised and cross-linked monomer, suspe
nded in oil is investigated. Some experimental data are presented which emp
hasize that such a suspension of millimetric particles of a phase change ma
terial allows both a high capacity of heat storage and limited super coolin
g phenomena. A phenomenological description of the crystallisation process
is proposed which permits to predict the duration of the plateau of crystal
lisation as a function of the weight fraction and the temperature of the co
ld spring. The results compare very well with the experimental data thus gi
ving a new impulse to the design of new complex fluids for both storage and
heat transport. (C) 2000 Elsevier Science Ltd.