Loose-tight-loose twist, twisted-tape insert solar central receiver

摘要

This invention reduces a molten salt, solar central receiver's size, pressure loss and cost by using a loose-tight-loose twist, twisted-tape insert inside the receiver's tubes to enhance the tube's heat transfer coefficient. This twist staging is designed to provide a higher heat transfer coefficient in the receiver's central region where the solar flux is high and a reduced pressure loss at the low solar flux entrance and exit end regions. Because the twisted-tape enhances the tube's heat transfer ability it can be made larger in diameter than a smooth bore tube at an equivalent pressure loss. This reduces the number of tubes which results in a substantial reduction in receiver cost.