The flow in volumetric absorbers is investigated using a simple mathematical model. It is found that there are several restrictions and failure mechanisms that are inherent to the volumetric absorber, regardless of the precise structural details, material properties, etc. The heat that the absorber can extract safely is limited by flow-related constraints. Multiple steady solutions exist for certain parameter values: a “fast” solution corresponding to a low exit temperature, a “slow” solution which is unstable, and a “choked” solution for which the absorber is near to stagnation temperature. The existence of multiple solutions may lead to abrupt local “switching” and absorber failure. For a given irradiance applied to the absorber, the existence and the character of the solutions are determined by a single dimensionless parameter, the Blow parameter B. Neglecting the variation of the hydraulic resistivity with temperature may lead to a dangerous overestimate of the receiver’s ability to sustain irradiation. For reasonable efficiencies control of mass flow or outlet temperature of the absorber, rather than pressure control, may be required.

1.
Batchelor, G. K., 1967, An Introduction to Fluid Dynamics, Cambridge University Press, Cambridge, UK.
2.
Bohmer
M.
, and
Chaza
C.
,
1991
, “
The Ceramic Foil Receiver
,”
Solar Energy Materials & Solar Cells
, Vol.
24
, pp.
182
191
.
3.
Buck
R.
,
Muir
J. F.
,
Hogan
R. E.
, and
Skocypec
R. D.
,
1991
, “
Carbon Dioxide Reforming of Methane in a Solar Volumetric Receiver
,”
Solar Energy Materials & Solar Cells
, Vol.
24
, pp.
449
463
.
4.
Buck, R., 1988, “Tests and Calculations for a Volumetric Ceramic Receiver,” Proc. 4th Int. Symp. Solar Thermal Technology, Santa Fe, NM.
5.
Fricker, H. W., Winkler, C, Silva, M., and Chavez, J., 1988, “Design and Tests Results of the Wire Receiver Experiment Almeria,” Proc. 4th Int. Symp. Solar Thermal Technology, Santa Fe, NM.
6.
Heinrich, P., Keintzel, G., and Streuber, C., 1992, “2.5 MWt System Test on Volumetric Air Receiver Technology,” Proc. 6th Int. Symp. Solar Thermal Concentrating Technologies, Almeria, Spain.
7.
Heller, P., Biehler, T., and Buck, R., 1992, “Simulation and Test Results of a 100 kW Volumetric Air Receiver,” Proc. 6th Int. Symp. Solar Thermal Concentrating Technologies, Almeria, Spain.
8.
Karni, J., Kribus, A., Rubin, R., Doron, P., and Sagie, D., 1992, “Development of the Porcupine Absorber and a Novel Directly-Irradiated Pressurized Receiver (DIAPR),” Proc. 1st Meeting SolarPACES Task 3: Solar Technology and Applications, Almeria, Spain.
9.
Landau, L. D., and Lifschitz, E. M., 1983, Physikalische Kinetik, Akademie-Verlag, Berlin.
10.
Menigault
T.
,
Flamant
G.
, and
Rivoire
B.
,
1991
, “
Advanced High-Temperature Two-Slab Selective Volumetric Receiver
,”
Solar Energy Materials & Solar Cells
, Vol.
24
, pp.
192
203
.
11.
Pitz-Paal, R., Feibig, M., and Cordes, S., 1992, “First Experimental Results From the Test of a Selective Volumetric Air Receiver,” Proc. 6th Int. Symp. Solar Thermal Concentrating Technologies, Almeria, Spain.
12.
Posnansky
M.
, and
Pylkkanen
T.
,
1991
, “
Development and Testing of a Volumetric Gas Receiver for High-Temperature Application
,”
Solar Energy Materials & Solar Cells
, Vol.
24
, pp.
204
209
.
13.
Schlichting, H., 1979, Boundary-Layer Theory, McGraw-Hill, New York.
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