Study on the Allowable Flux Density for a Solar Central Dual-receiver☆

Abstract Direct steam generating solar power towers begin to develop dual-receiver concept that enables dynamic and accurate solar flux control on boiling and superheating section. The allowable flux density on each receiver is an important parameter to ensure allowable strains of tube material are not exceeded. A physical model is verified and applied to analyse the change of allowable flux density with tube inner diameter, main steam pressure, saturated steam velocity. For both boiling and superheating section, reducing tube inner diameter or increasing saturated steam velocity will enhance allowable flux density. Decreasing main steam pressure of boiling section also makes allowable flux density higher. For superheating section, when pressure less than 10 MPa, increasing allowable flux density with increasing pressure, but result is the opposite when pressure greater than 10 MPa. Last a sensitivity analysis is used to compare the influence of above factors on allowable flux density.