Thermodynamic analysis has been carried out in detail, to predict the perfo
rmance of a solar thermal water pump working at different discharge heads.
It is shown that the heating time of the working fluid and the condensation
time of the spent vapour play an important role in determining the number
of cycles that a pump can perform in a day. The heating time in turn depend
s on the amount of working fluid being loaded in the system initially. Simi
larly, it is observed that an optimal cooling coil area dictates the effect
ive condensation time. Hence, in the present work, an optimum design has be
en outlined for a solar thermal water pump, both in terms of the amount of
the working fluid to be loaded in the system and the optimum cooling coil a
rea. (C) 2001 Elsevier Science Ltd. All rights reserved.