Experimental investigation on minimum film boiling temperature during reflooding in multi-rectangular narrow channels. (October 2021)

• Record Type: Journal Article
• Authors: Dong, Kejian; Ding, Shuhua; Chen, Deqi; Wu, Dan; Deng, Jian; Liu, Haidong; Liu, Hanzhou
• Is Part Of: International journal of heat and mass transfer. Volume 178(2021)
• Publication Date: 2021-10
• Subjects: Reflooding -- Minimum film boiling temperature -- Experiment -- Nuclear reactor -- Rectangular narrow channel; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2021.121635
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: Bottom reflooding experiment is carried out to investigate T min in rectangular narrow channels. High reflooding velocity has mild effect on T min and quench velocity. Model is proposed to predict T min in rectangular narrow channel during reflooding. Abstract: Determination of minimum film boiling temperature ( T min ) is significant in the nuclear reactor safety analysis. T min represents the start of quenching which is vital to mitigate the severity of the accident. In this paper, a bottom reflooding experiment is carried out to investigate T min and quench velocity in multi-rectangular narrow channels. Effects of working conditions, including inlet subcooling, reflooding velocity, initial wall temperature, and system pressure on T min and quench velocity, are analyzed in detail. It is found that T min and quench velocity distinctly increases with the increase of subcooling, system pressure, and reflooding velocity. However, the effect of reflooding velocity on T min and quench velocity is mild when the reflooding velocity is relatively high. T min increases with the increase of initial wall temperature, while quench velocity drops. T min at the upper position of the heating wall is lower than that at the lower position because the water subcooling changes when flowing along the heating channel. A prediction model of T min during reflooding in rectangular narrow channel is proposed, and very good agreement is achieved comparing with experimental data with ±10% uncertainty.