Inherent limitations of volumetric solar receivers

A. Kribus, H. Ries, W. Spirkl

Research output: Contribution to journalArticlepeer-review


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.

Original languageEnglish
Pages (from-to)151-155
Number of pages5
JournalJournal of Solar Energy Engineering, Transactions of the ASME
Issue number3
StatePublished - Aug 1996
Externally publishedYes


Dive into the research topics of 'Inherent limitations of volumetric solar receivers'. Together they form a unique fingerprint.

Cite this