Evaluation of heat-transfer coefficient at direct-contact condensation of cold water and steam

• Published in: Nuclear engineering and design Vol. 131; no. 1; pp. 17 - 24
• Main Authors: Aya, Izuo, Nariai, Hideki
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.1991; Elsevier
• Subjects: Applied sciences; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; Installations for energy generation and conversion: thermal and electrical energy; Vapor; LOCA; Cold water; Critical study; Direct contact; Condensation; Light water reactor; Heat transfer; Nuclear reactor
• ISSN: 0029-5493; 1872-759X
• DOI: 10.1016/0029-5493(91)90314-8

The estimation of the heat transfer coefficient at the direct-contact condensation of cold water and steam is a very hard task since the phenoma are essentially undsteady and the interface motion is so complicated that an exact estimation of its area is almost impossible. The present study shows the heat transfer coefficient evaluated experimentally by assuming simple interface shapes for complicated surfaces and estimated those through comparison of the numerical analyses to the data of experiments related to the loss of coolant accidents of light water reactors. At chugging, the heat transfer coefficient reached up to 2 × 10 6 W/( m 2 K ). At condensation oscillation, it ranged between 10 5–10 6 W/(m 2 K). At a jet region of cold water injected into the steam flow in a pipe or the stationary steam in a vessel, the value was around 2 × 10 5 W/( m 2 K), and at the surface of stratified flow, it was between 3 × 10 3–3 × 10 4 W/( m 2 K).