MINIMUM MAINTENANCE SOLAR PUMP

Abstract

A minimum maintenance solar pump (MMS?), Fig 1,
has been simulated for Addis Ababa, taking solar
meteorological data of global radiation, diffuse
radiation and ambient air temperature as input to a
computer program that has been developed. To
increase the performance of the solar pump, by
trapping the long-wave light rays leaving the
absorber - the water tank, two glass covers have been
employed. Basic heat transfer equations for double
glass glazing and storage tank (absorber plate) along
with side and bottom insulations are derived and
techniques for the solution of these equations are
presented. The minimum quantity of residual water
that should remain in the storage tank after the
previous day's pumping process, for producing the
required maximum vacuum pressure, has been
determined. The maximum possible pumping head
which depends on the vacuum pressure created within
the storage tank and which in turn depends on the
quantity oftesidual water evaporated has then been
predicted and preselTted for representative days of
the year.