The ``Porcupine``: A novel high-flux absorber for volumetric solar receivers

Journal Article · Fri May 01 04:00:00 EDT 1998 · Journal of Solar Energy Engineering

DOI:https://doi.org/10.1115/1.2888060· OSTI ID:619662

Karni, J; Kribus, A; Rubin, R; Doron, P ^[1]

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1. Weizmann Inst. of Science, Rehovot (Israel). Dept. of Environmental Sciences and Energy Research

A new volumetric (directly irradiated) solar absorber, nicknamed Porcupine, is presented. It was tested over several hundreds of hours at the Weizmann institute`s Solar Furnace, using several flow and geometric configurations, at various irradiation conditions. The experiments, which were conducted at a power level of about 10 kW, showed that the new absorber can accommodate different working conditions and provide a convective cooling pattern to match various irradiation flux distributions. The capability of the Porcupine to endure a concentrated solar flux of up to about 4 MW/m{sup 2}, while producing working gas exit temperatures of up to 940 C, was demonstrated. In comparative tests, the Porcupine sustained an irradiation solar flux level about four times higher than that sustained by other volumetric absorbers (foam and honeycomb matrices). Due to its ability to sustain and transport a much higher energy fluxes, the Porcupine yielded twice the power output of the other absorbers while its exit gas temperature was 300--350 C higher. The Porcupine design is highly resistant to thermal stresses development; none of the Porcupine absorbers tested showed any sign of deterioration after hundreds of operating hours, although temperature gradients of several hundreds C/cm developed in some experiments. The basic Porcupine structure provides convective and radiative energy transport between the matrix elements, therefore alleviating the development of flow instabilities; this phenomenon causes local overheating and restricts the operation of other volumetric matrices. A Porcupine absorber was subsequently incorporated into the directly irradiated annular pressurized receiver (DIAPR), where it has been operating flawlessly at an incident flux of several MW/m{sup 2} and temperatures of up to 1,700 C.

• Sponsoring Organization: USDOE
• OSTI ID: 619662
• Journal Information: Journal of Solar Energy Engineering, Journal Name: Journal of Solar Energy Engineering Journal Issue: 2 Vol. 120; ISSN JSEEDO; ISSN 0199-6231
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
CONVECTION
DESIGN
PERFORMANCE
RADIANT HEAT TRANSFER
SOLAR ABSORBERS
SOLAR RECEIVERS
SOLAR THERMAL CONVERSION