Solar energy may be practically utilized directly through transformation into
heat, electrical or chemical energy. A physical and mathematical model is
presented, as well as a numerical procedure for predicting thermal
performances of the P2CC solar concentrator. The demonstrated prototype has
the reception angle of 110? at concentration ratio CR = 1.38, with the
significant reception of diffuse radiation. The solar collector P2CC is
designed for the area of middle temperature conversion of solar radiation
into heat. The working fluid is water with laminar flow through a copper pipe
surrounded by an evacuated glass layer. Based on the physical model, a
mathematical model is introduced, which consists of energy balance equations
for four collector components. In this paper, water temperatures in flow
directions are numerically predicted, as well as temperatures of relevant
P2CC collector components for various values of input temperatures and mass
flow rates of the working fluid, and also for various values of direct
sunlight radiation and for different collector lengths. The device which is
used to transform solar energy to heat is referred to as solar collector.
This paper gives numerical estimated changes of temperature in the direction
of fluid flow for different flow rates, different solar radiation intensity
and different inlet fluid temperatures. The increase in fluid flow reduces
output temperature, while the increase in solar radiation intensity and inlet
water temperature increases output temperature of water. Furthermore, the
dependence on fluid output temperature is determined, along with the current
efficiency by the number of nodes in the numerical calculation.
The results of field measurements of the solar radiation intensity in Kiev
