A linear Fresnel reflector as a solar system for heating water: Theoretical and experimental study

This work is concerned with assessing the thermal performances of a solar water heating system which is dependent on a linear Fresnel receiver (LFR) as a solar energy converter. The main objective of this paper is validation the experimental work carried out in the winter of 2015 on the concentrator in the climatic conditions of Algerian city “Blida” by a numerical simulation, where the tap water used as a heat carrier fluid. This simulation was used to solution of the energy balance equations of the absorber tubes and the water, where the solution is based on the finite difference method with an implicit scheme. After the solution of nonlinear equations, the program performed by using the MATLAB language gives the thermal efficiencies, the absorber temperatures, the water temperatures at the absorber tubes outlet, and thermal losses coefficients. The thermal efficiency of the reflector is exceeded 29%. The results obtained proved the existence of substantial convergence between the experimental and the numerical results, where in all cases the water temperature exceeded 347 K.