Abstract

The aim of this study is to model, optimize and analyze the performance of a micro power solar of 3 kW in order to meet the priority needs of Mauritania rural people in electric power and contribute to the reduction of greenhouse gases. The proposed system is composed of a Fresnellinear concentrator which is coupled to an Organic Rankine cycle with a regenerator. Several working fluids (R134a, R152a, R290 and R717) were used for better optimizing the system. Thus, many thermodynamic and physical parameters which are influent on the performance of the overall system were analyzed. This analysis shows that the R152a and R134a fluids are the best candidates for the applications of ORC solar at low temperatures. Indeed, a 5°C superheating, the overall system efficiency, the energy and exergy efficiency of the ORC cycle has been respectively improved to 7.7%, 16.1% and 14.4%. The Optimization made on the overall system allowed a 26% and 12% reduction of the surface of the concentrator and the volume flow out of the micro-turbine respectively. The minimum surface and volumetric flow rate required to produce 3 kW is respectively 21.25 m² and 21.421 m³/h, this last result is achieved from the operating conditions: working fluid R152a, evaporation temperature which is 90°C and the direct normal radiation 1800 W/m².

Keywords:

Areas rural, EES (engineering equation solver), energetic efficiency, fresnel linear concentrator, optimisation, organic rankine cycle, working fluids,

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Competing interests

The authors have no competing interests.

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