Heat transfer in molten salt direct absorption receivers

Journal Article · Sat Dec 31 23:00:00 EST 1988 · Solar Energy; (USA)

DOI:https://doi.org/10.1016/0038-092X(89)90130-8· OSTI ID:5061564

Bohn, M S; Green, H J ^[1]

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1. Solar Energy Research Institute, Golden, CO (USA)

Efficient absorption of concentrated solar energy in a falling film of molten salt is critical to the success of the direct absorption receiver (DAR) concept. This paper present experimental data on the heat transfer between the molten salt firm and the surface which supports the film. The results demonstrate that operation of the film in the turbulent regime (Reynolds number greater than approximately 3,000) will give heat transfer coefficients high enough to ensure that the support surface temperature will not be excessive. In particular, we conclude that for a commercial receiver delivering 570{degree}C nitrate salt with peak flux of 1380 kW/m{sup 2}, the support surface will not exceed 585{degree}C. These results indicate that the addition of a dopant to the salt to enhance volumetric absorption of the solar flux may not be necessary. Adding 0.25 wt% cobalt oxide particles of nominal 40 {mu} size, increased the apparent heat transfer coefficient by about 140%.

• OSTI ID: 5061564
• Journal Information: Solar Energy; (USA), Journal Name: Solar Energy; (USA) Vol. 42:1; ISSN SRENA; ISSN 0038-092X
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140702* -- Solar Thermal Power Systems-- Central Receiver
CENTRAL RECEIVERS
CHALCOGENIDES
COBALT COMPOUNDS
COBALT OXIDES
DATA
DOPED MATERIALS
ENERGY TRANSFER
EXPERIMENTAL DATA
HEAT TRANSFER
INFORMATION
MATERIALS
MOLTEN SALTS
NITRATES
NITROGEN COMPOUNDS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
REYNOLDS NUMBER
SALTS
SOLAR RECEIVERS
TRANSITION ELEMENT COMPOUNDS