Abstract

Solar energy can be absorbed by simple and long-life solar collectors set in a garden. The heated water is pumped to a shower directly or through a boiler. This paper focuses on the simulation of performances of some simple collectors combined with a tank of water pre-heated by ambient air and a boiler. The behaviour of the system has been simulated: water temperatures over a day are calculated as a function of the dimensions and the exposure of the pipes and of the surfaces of the reflective panels, of weather data and of water consumption.
The numerical solution of the partial differential equation is obtained by a discrete approximation. The temperature field is approximated by values at discrete points where elements are concentrated.
Numerical results of some different hot water systems are presented. The consumption of gas and CO2 emissions are compared with an instantaneous boiler, a combi-storage boiler and an electric boiler.