Energy Conversion and Management, Vol.132, 119-135, 2017
Modelling of a Stirling engine with parabolic dish for thermal to electric conversion of solar energy
Stirling engines with parabolic dish for thermal to electric conversion of solar energy is one of the most promising solutions of renewable energy technologies in order to reduce the dependency from fossil fuels in electricity generation. This paper addresses the modelling and simulation of a solar powered Stirling engine system with parabolic dish and electric generator aiming to determine its energy production and efficiency. The model includes the solar radiation concentration system, the heat transfer in the thermal receiver, the thermal cycle and the mechanical and electric energy conversion. The thermodynamic and energy transfer processes in the engine are modelled in detail, including all the main processes occurring in the compression, expansion and regenerator spaces. Starting from a particular configuration, an optimization of the concentration factor is also carried put and the results for both the transient and steady state regimes are presented. It was found that using a directly illuminated thermal receiver without cavity the engine efficiency is close to 23.8% corresponding to a global efficiency of 10.4%. The components to be optimized are identified in order to increase the global efficiency of the system and the trade-off between system complexity and efficiency is discussed. (C) 2016 Elsevier Ltd. All rights reserved.
Keywords:Stirling engine;Solar energy;Solar concentration;Numerical modelling;Energy efficiency;Optimization