Enhancement of Downward-Facing Saturated Boiling Heat Transfer by the Cold Spray Technique

• Published in: Nuclear engineering and technology 2017, 49(1), , pp.124-133
• Main Authors: Faruk A. Sohag, Faith R. Beck, Lokanath Mohanta, Fan-Bill Cheung, Albert E. Segall, Timothy J. Eden, John K. Potter
• Format: Article
• Language: English
• Subjects: 원자력공학
• ISSN: 1738-5733; 2234-358X

In-vessel retention by passive external reactor vessel cooling under severe accident conditionsis a viable approach for retention of radioactive core melt within the reactor vessel. In this study, a new and versatile coating technique known as “cold spray” that can readilybe applied to operating and advanced reactors was developed to form a microporouscoating on the outer surface of a simulated reactor lower head. Quenching experimentswere performed under simulated in-vessel retention by passive external reactor vesselcooling conditions using test vessels with and without cold spray coatings. Quantitativemeasurements show that for all angular locations on the vessel outer surface, the localcritical heat flux (CHF) values for the coated vessel were consistently higher than thecorresponding CHF values for the bare vessel. However, it was also observed for bothcoated and uncoated surfaces that the local rate of boiling and local CHF limit varyappreciably along the outer surface of the test vessel. Nonetheless, results of this intriguingstudy clearly show that the use of cold spray coatings could enhance the local CHF limit fordownward-facing boiling by > 88%. KCI Citation Count: 11