Condensation experiments for counter-current flow limitation in an inverted U-tube. Issue 4 (2nd April 2016)

• Record Type: Journal Article
• Authors: Kusunoki, Takayoshi; Nozue, Takahiro; Hayashi, Kosuke; Hosokawa, Shigeo; Tomiyama, Akio; Murase, Michio
• Is Part Of: Journal of nuclear science and technology. Volume 53:Issue 4(2016)
• Page Start: 486
• Page End: 495
• Publication Date: 2016-04-02
• Subjects: reflux condensation -- steam generator -- U-tube -- CCFL -- Wallis parameter -- condensation experiment; Nuclear engineering -- Periodicals; Nuclear physics -- Periodicals; Nuclear energy -- Periodicals; 621.4805
• DOI: 10.1080/00223131.2015.1057253
• Languages: English
• ISSNs: 0022-3131

Abstract

Abstract : In this study, we measured counter-current flow limitation (CCFL) characteristics in an inverted U-tube (18.4 mm diameter and 1.0 m straight-part length) simulating steam generator (SG) U-tubes under conditions of steam condensation at pressures of 0.1–0.14 MPa. Differential pressure ΔP between the top of the inverted U-tube and the lower tank was measured, and the flow patterns wave estimated by comparing the waveforms of Δ P with those in air–water experiments. As a result, we classified the flow patterns under CCFL conditions into CCFL-P, CCFL-L and CCFL-T. The falling water flow rate under CCFL conditions slightly increased as the pressure increased and the cooling water temperature decreased (subcooling of cooling water increased). In the case of CCFL-L, CCFL characteristics in the inverted U-tube were between those in air–water and saturated steam–water experiments at 0.1 MPa. Furthermore, we derived a Wallis type CCFL correlation and its uncertainty from CCFL data, including previously measured data, i.e., J * 1/2 G + 0.88 JL * 1/2 = 0.76 ± 0.05.