Numerical study on combined free-forced convection heat loss of solar cavity receiver under wind environments

Abstract A numerical study has been carried out to investigate the impact of wind on combined free-forced convection loss from a fully open solar cavity receiver for high-temperature dish/engine system. Visualization results, i.e., velocity vector field, temperature and velocity contours are provided to reveal the wind effect. The variations of combined free-forced convection heat loss with wind speed, wind incidence angle as well as the receiver inclinations have been quantitatively analyzed. Results show that, the combined convection heat loss for some wind cases may not decrease monotonically with increasing inclinations as that of no-wind cases. Under some certain wind conditions, the combined convection heat loss may possibly be reduced below the natural convection value, and there exists critical wind speed that minimizes the combined convection heat loss. Moreover, the combined convection heat loss of receiver at different inclinations becomes more and more indistinguishable as wind speed increases. Finally, a simple correlation has been proposed to estimate the convection heat loss variation caused by the environmental wind.

[1]  U. Leibfried,et al.  Convective Heat Loss from Upward and Downward-Facing Cavity Solar Receivers: Measurements and Calculations , 1995 .

[2]  Lan Xiao,et al.  Effect of aperture position and size on natural convection heat loss of a solar heat-pipe receiver , 2011 .

[3]  S. Patankar.  Numerical Heat Transfer and Fluid Flow , 2018, Lecture Notes in Mechanical Engineering.

[4]  P. E. Liley,et al.  Steam and Gas Tables with Computer Equations , 1984 .

[5]  Sawat Paitoonsurikarn,et al.  Experimental Investigation of Natural Convection Heat Loss From a Model Solar Concentrator Cavity Receiver , 2004 .

[6]  Sawat Paitoonsurikarn,et al.  Effect of paraboloidal dish structure on the wind near a cavity receiver , 2006 .

[7]  Nathan P. Siegel,et al.  Wind effect on the performance of solid particle solar receivers with and without the protection of an aerowindow , 2009 .

[8]  Jinjia Wei,et al.  Thermal performance simulation of a solar cavity receiver under windy conditions , 2011 .

[9]  Gregory J. Kolb,et al.  Experimental and simulation study on wind affecting particle flow in a solar receiver , 2010 .

[10]  Yiding Cao,et al.  Convection heat loss from cavity receiver in parabolic dish solar thermal power system: A review , 2010 .

[11]  T. Shih,et al.  A new k-ϵ eddy viscosity model for high reynolds number turbulent flows , 1995 .

[12]  Sawat Paitoonsurikarn,et al.  Estimation of Convection Loss from Paraboloidal Dish Cavity Receivers , 2004 .

[13]  B. Launder,et al.  The numerical computation of turbulent flows , 1990 .

[14]  Shireesh B. Kedare,et al.  Investigations on heat losses from a solar cavity receiver , 2009 .

[15]  A. M. Clausing,et al.  Convective losses from cavity solar receivers--Comparisons between analytical predictions and experimental results , 1983 .

[16]  Reiner Buck,et al.  Dish-Stirling Systems: An Overview of Development and Status , 2003 .

[17]  R. Y. Ma,et al.  Wind effects on convective heat loss from a cavity receiver for a parabolic concentrating solar collector , 1993 .