Solar Hot Air for Industrial Applications Using Linear Fresnel Concentrating Collectors and Open Brayton Cycle Layout

Abstract

Many industrial processes use hot air as a medium. This is especially relevant for drying. Nowadays, most of them consume fossil energy. This study analyses an innovative facility for direct solar heating of air up to 400 °C. For this aim, a medium-scale solar field of linear Fresnel collectors is proposed to heat ambient air inside it. No other dedicated heat transfer fluid is necessary. A simpler layout avoids costs, hurdles, and risks of heat transfer liquids and the related machinery. A Brayton cycle configuration avoids auxiliary energy consumption for pumping air through the collectors by coupling the solar field with a turbocharger. A mathematical model simulates a system of industrial size along a typical meteorological year. It confirms the feasibility of the proposal and the high potential of helping the energy transition to sustainability.