Thermal Hydraulics of Helium-Cooled Finger-Type Divertors at Higher Incident Heat Fluxes
Abstract
Over the last decade, a number of studies at the Georgia Institute of Technology (GT) have evaluated the thermal hydraulics of the design of the helium-cooled modular divertor with multiple jets (HEMJ) originally developed at the Karlsruhe Institute of Technology. Using the GT helium loop, a test section of a single HEMJ finger heated by a radio-frequency (rf) induction heater was studied at near prototypical condition at pressures of ~10 MPa, maximum mass flow rates of 8 g/s, and maximum helium inlet temperatures Ti of 425°C. The area-averaged cooled surface temperature was estimated from embedded thermocouple measurements. This, together with the average incident heat flux , was used to determine the average heat transfer coefficient and the corresponding Nusselt number over the cooled surface. The normalized pressure loss coefficient KL was determined from the pressure drop measured across the test section. The helium loop was modified last year by enclosing the test section and heater within an argon-filled stainless steel chamber to minimize oxidation of the tungsten-alloy test section. Initial results, when extrapolated to prototypical conditions, suggested that was about 20% higher than our previous results. However, the maximum heat flux for these results was less than 3 MW/m2 due to rf coupling with the steel chamber walls. The chamber was then recently upgraded to a glass–stainless steel enclosure with modified feedthroughs for the induction heater connections to minimize this coupling. With this upgrade, a maximum incident heat flux = 8.1 MW/m2 was achieved. This work presents experimental estimates and correlations for and KL at higher heat fluxes. These results provide greater confidence when estimating the maximum heat flux that can be accommodated by the HEMJ at fully prototypical conditions. Lastly, preliminary metrology results for the test section used to experimentally study the simplified flat design variant of the HEMJ are presented as part of an effort to resolve recently reported discrepancies between experimentally estimated and numerically simulated
- Authors:
-
- Georgia Inst. of Technology, Atlanta, GA (United States). G. W. Woodruff School of Mechanical Engineering
- Publication Date:
- Research Org.:
- Georgia Institute of Technology, Atlanta, GA (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Fusion Energy Sciences (FES)
- OSTI Identifier:
- 1593394
- Grant/Contract Number:
- FG02-01ER54656
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Fusion Science and Technology
- Additional Journal Information:
- Journal Volume: 75; Journal Issue: 8; Journal ID: ISSN 1536-1055
- Publisher:
- American Nuclear Society
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Helium-cooled divertors; thermal hydraulics; modular divertor with multiple jets; impinging jets
Citation Formats
Lee, D. S., Musa, S. A., Abdel-Khalik, S. I., and Yoda, M. Thermal Hydraulics of Helium-Cooled Finger-Type Divertors at Higher Incident Heat Fluxes. United States: N. p., 2019.
Web. doi:10.1080/15361055.2019.1593008.
Lee, D. S., Musa, S. A., Abdel-Khalik, S. I., & Yoda, M. Thermal Hydraulics of Helium-Cooled Finger-Type Divertors at Higher Incident Heat Fluxes. United States. https://doi.org/10.1080/15361055.2019.1593008
Lee, D. S., Musa, S. A., Abdel-Khalik, S. I., and Yoda, M. Thu .
"Thermal Hydraulics of Helium-Cooled Finger-Type Divertors at Higher Incident Heat Fluxes". United States. https://doi.org/10.1080/15361055.2019.1593008. https://www.osti.gov/servlets/purl/1593394.
@article{osti_1593394,
title = {Thermal Hydraulics of Helium-Cooled Finger-Type Divertors at Higher Incident Heat Fluxes},
author = {Lee, D. S. and Musa, S. A. and Abdel-Khalik, S. I. and Yoda, M.},
abstractNote = {Over the last decade, a number of studies at the Georgia Institute of Technology (GT) have evaluated the thermal hydraulics of the design of the helium-cooled modular divertor with multiple jets (HEMJ) originally developed at the Karlsruhe Institute of Technology. Using the GT helium loop, a test section of a single HEMJ finger heated by a radio-frequency (rf) induction heater was studied at near prototypical condition at pressures of ~10 MPa, maximum mass flow rates of 8 g/s, and maximum helium inlet temperatures Ti of 425°C. The area-averaged cooled surface temperature was estimated from embedded thermocouple measurements. This, together with the average incident heat flux q ‾ ′′ , was used to determine the average heat transfer coefficient and the corresponding Nusselt number N u ‾ over the cooled surface. The normalized pressure loss coefficient KL was determined from the pressure drop measured across the test section. The helium loop was modified last year by enclosing the test section and heater within an argon-filled stainless steel chamber to minimize oxidation of the tungsten-alloy test section. Initial results, when extrapolated to prototypical conditions, suggested that N u ‾ was about 20% higher than our previous results. However, the maximum heat flux for these results was less than 3 MW/m2 due to rf coupling with the steel chamber walls. The chamber was then recently upgraded to a glass–stainless steel enclosure with modified feedthroughs for the induction heater connections to minimize this coupling. With this upgrade, a maximum incident heat flux q ‾ ′′ = 8.1 MW/m2 was achieved. This work presents experimental estimates and correlations for N u ‾ and KL at higher heat fluxes. These results provide greater confidence when estimating the maximum heat flux that can be accommodated by the HEMJ at fully prototypical conditions. Lastly, preliminary metrology results for the test section used to experimentally study the simplified flat design variant of the HEMJ are presented as part of an effort to resolve recently reported discrepancies between experimentally estimated and numerically simulated N u ‾ .},
doi = {10.1080/15361055.2019.1593008},
journal = {Fusion Science and Technology},
number = 8,
volume = 75,
place = {United States},
year = {Thu May 02 00:00:00 EDT 2019},
month = {Thu May 02 00:00:00 EDT 2019}
}
Web of Science
Works referenced in this record:
He-cooled divertor for DEMO: Status of development and HHF tests
journal, December 2010
- Norajitra, Prachai; Giniyatulin, Radmir; Kuznetsov, Vladimir
- Fusion Engineering and Design, Vol. 85, Issue 10-12
Influence of multiple jet cooling on the heat transfer and thermal stresses in DEMO divertor cooling finger
journal, March 2011
- Končar, Boštjan; Simonovski, Igor; Draksler, Martin
- Fusion Engineering and Design, Vol. 86, Issue 2-3
Experimental and numerical studies of helium-cooled modular divertors with multiple jets
journal, November 2018
- Zhao, Bailey; Musa, Shekaib; Abdel-Khalik, Said
- Fusion Engineering and Design, Vol. 136
Experimental Evaluation of the Thermal Hydraulics of Helium-Cooled Divertors
journal, January 2015
- Yoda, M.; Abdel-Khalik, S. I.; Sadowski, D. L.
- Fusion Science and Technology, Vol. 67, Issue 1
He-cooled divertor development for DEMO
journal, October 2007
- Norajitra, P.; Giniyatulin, R.; Ihli, T.
- Fusion Engineering and Design, Vol. 82, Issue 15-24
An Experimental Study of the Helium-Cooled Modular Divertor with Multiple Jets at Nearly Prototypical Conditions
journal, October 2015
- Mills, B. H.; Zhao, B.; Abdel-Khali, S. I.
- Fusion Science and Technology, Vol. 68, Issue 3
Works referencing / citing this record:
An Experimental Reversed Heat Flux Investigation of the Helium-Cooled Modular Divertor with Multiple Jets
journal, August 2019
- Musa, S. A.; Lee, D. S.; Abdel-Khalik, S. I.
- Fusion Science and Technology, Vol. 75, Issue 8