A NUMERICAL AND EXPERIMENTAL ANALYSIS ON HEAT TRANSFER IN A SOLAR COLLECTOR FOR DSG

This paper is aimed to investigate on the heat loss by a DSG solar collector for Fresnel power plants. Numerical modeling as well as experimental tests have been made in order to assess the rate of heat transferred by the device to the surrounding environment in working conditions. To this goal, both experimental tests and numerical simulations have been performed holding the absorber pipe at a chosen thermal state and quantifying the heat lost in steady conditions. Numerical results refer to a FE model of the physical system, keeping into account conduction, internal and external convection, surface-to-surface radiation and surface-to-ambient radiation. Otherwise, experimental measures have been acquired by two different facilities: the first one is a test set-up, mainly consisting in a short portion of the absorber pipe heated by an electrical resistance; the second one consists in a prototypal solar plant. Exploiting these facilities, numerical models have been successfully validated by means of a cross-comparison between acquired data and computed results. Then, several design configurations and working conditions of the CPC have been simulated.