Abstract
The new research projects in Australia into direct
utilisation of solar energy and into measurements of global
radiation are reviewed against the background of the awakened
world-wide research interest. The design of a small thermosyphon
operated domestic solar water heater without auxiliary
heating is described and curves are presented showing the effect
of the relevant variables on flow rate through the solar
collector system.
Performance of the solar water heater during winter,
autumn and summer is analysed from records made on the domestic
unit. Comparisons are made between the useful heat output
under various operating conditions and the available solar
energy on the collector surface, computed from simultaneous
observations of global radiation using multiplying factors for
angular position of the surface developed later in the thesis.
The installation of the global radiation measuring instrument
is also described.
The importance of satisfactory estimates of available
solar energy to permit economic design of solar water heaters
is noted, and some existing methods of estimation studied.
A new method of estimation is proposed and checked against
observations at seven Australian stations, and the accuracy of
the estimates for monthly averages is compared to the observed
variations in monthly mean values of global radiation at Mount
Stromlo over 12 years.
The effect of angles of bearing and inclination of the
collector surface on solar energy gain is studied, taking into
account distribution of solar energy during the day and the
effect of energy losses through the glass collector covers.
Curves are presented to allow determination of gross and nett
solar energy on inclined surfaces for average days in each
month of the year at Sydney.
A list is given of the detailed studies considered for
future research as a result of experience gained in the operation
of the domestic solar water heater.