Heat and fluid flow analysis in Cylindrical Solar Cavity Receiver having Parabolic dish application

1. Presented By-Anwesa Kar
Department of Mechanical engineering
CET, Bhubaneswar

2.  INTRODUCTION
 DESCRIPTION OF THE CAVITY RECEIVER
 NUMERICAL STUDY
 RESULTS AND DISCUSSION
 SUMMARY
 CONCLUSION

3.  Parabolic dish systems use a antenna with mirrors
to direct and concentrate sunlight onto the
receiver system
Fig.1 Schematics of parabolic dish
system(source : wikimedia)

4. Cavity Receiver
 Incoming heat flux into the aperture quickly raise the
temperature of the aperture;
 Initiate a series of heat transfer exchanges amongst
the surfaces in the cavity system enclosure
Fig. 2 Schematics of a
Cavity receiver

5.  To Investigate temperature distribution inside the
cylindrical cavity receiver
 To study the effect of various parameters affecting
the performance of the cavity receiver

6.  Mesh-tetrahedral type and smooth medium size
 The inlet temp. and pressure- 300K and 3 bar
 HTF-ethylene glycol
 Highly insulation material receivers cavity walls
 The outlet -atmospheric pressure
 No inclination in receiver geometry was
considered. All cases were in 90o only.
Fig.3 Designed model of
the cavity receiver

7.  The continuity equation, energy equation and the
Navier-Stokes momentum equation simultaneously
govern the flow of the fluid in the curve tubes
 Three-dimensional, steady, turbulent flow (k-ε model)
 In the cases where radiation is considered, only
surface radiation is considered, while air is non-
participating medium.
 Viscous heat dissipation and compressibility effects
are considered to be negligible.

8. Fig.4 Temperature distribution in a cylindrical cavity
receiver
Fig.5 Position vs.Temp (pipe wall)

9. Fig.6 Position vs. Temp (pipe wall)
Fig.7 Position vs. Pressure
Fig.8 Heat transfer coeff. vs. outlet temp.

10. Fig.9 Emissivity vs. Outlet Temperature Fig.10 Opening ratio vs. outlet temperature
Fig.11 Conc. Ratio vs. Total Heat loss

11.  3D model of cylindrical solar cavity receiver
carrying a helical tube is designed
 computational study (CFD, ANSYS 16.0) used to
investigate parameters affecting heat loss and
temperature distribution in the receiver.
 Heat transfer and flow simulation are proposed
for the cavity receiver with receiver inclination
angle of 90° (vertically downward facing receiver).

12.  Temperature of HTF increases with each turn
of the tube and becomes maximum at the
outlet of the tube
 increase in the emissivity and heat transfer
coefficient causes increased heat loss and
reduced outlet temp

13.  Heat flux gained through the opening of the
cavity receiver increases with increase in
concentration ratio.
 Outlet temperature increases with the
opening ratio up to a certain point. It
remains nearly constant afterwards even
after the further increase in the opening
ratio (d/D).

14.  The thermal performance of the receiver
tubes can be analyzed with different heat
transfer fluids.
 The receiver cavity can be further modified
having different shapes and materials of Fins
attached with cavity.