Measurement of Condensation Heat Transfer Coefficient inside a Vertical Tube in the Presence of Noncondensable Gas

• Published in: Journal of nuclear science and technology Vol. 32; no. 6; pp. 517 - 526
• Main Authors: AKAKI, Hidefumi, KATAOKA, Yoshiyuki, MURASE, Michio
• Format: Journal Article
• Language: English
• Published: Tokyo Taylor & Francis Group 01.06.1995; Atomic Energy Society of Japan; Taylor & Francis Ltd
• Subjects: analogy; Applied sciences; condensation; Cooling systems; correlations; degradation; Energy; Energy. Thermal use of fuels; Exact sciences and technology; experimental data; Fission nuclear power plants; heat transfer coefficient; Installations for energy generation and conversion: thermal and electrical energy; noncondensable gas; nuclear power plants; Nuclear reactors; partial pressure; passive containment cooling system; passive safety; Q1; vertical tube; Measurements; Non condensable gas; Cooling systems; Nuclear reactors; Passive system; Heat transfer coefficients; Condensation; Vertical tube
• ISSN: 0022-3131; 1881-1248
• DOI: 10.1080/18811248.1995.9731739

Degradation of condensation HTC (Heat Transfer Coefficient) under an air presence in a vertical tube was explored both experimentally and analytically, with the aim of developing evaluation methods for the design of passive containment cooling systems in the next generation reactors. Measurements were done using a stainless steel tube of 49.5 mm I. D. and 2.0 m length, enclosed by a cooling jacket. Flow rates of steam, air and cooling water, and the system pressure were varied as the experimental parameters. First, condensation HTC was correlated to a function of mixture Reynolds number and air partial pressure ratio, in which thermal resistance of the condensate film was excluded. Secondly, an analogy between heat and mass transfer was applied. The calculated values agreed well with the measured values of condensation HTCs in turbulent flow, while an obvious underestimation was observed for the flow in which mixture Reynolds number was lower than 2.300. Finally, ratios of calculated to experimental HTCs. which include thermal resistances of the condensate film, averaged 1.01 for turbulent steam flow.