Industrial Turbo-Assisted Direct Solar Air Heater Using Linear Fresnel Concentrating Collectors
Abstract
Among the solar technologies nowadays considered as renewable energy sources for industrial processes, concentrating solar collectors are receiving growing attention due to their capability of providing heat at higher temperatures than other solar collectors. This study focuses on the application of linear Fresnel collectors to directly produce hot air in the medium temperature range 150 °C - 400 °C for industrial processes, aiming at low cost. An innovative layout is proposed. Air is used as heat transfer fluid inside the solar receiver, a low-cost commercial turbocharger is used to compress ambient air through the plant, extracting from the solar source the required pumping power with the attached turbine, minimizing auxiliary energy consumption. A turbo-assisted direct solar air heater of medium-scale size is designed and simulated along representative days of a typical meteorological year, in order to assess the concept, its performances and relevant technical aspects. The study confirms its technical feasibility either in summer and winter season for the selected location (Madrid, Spain). The system provides an hot air stream between 300°C and 400°C without external energy consumption for pumping, avoiding the receiver tube overheating.