Subcooled boiling in narrow channels with different sizes

doi:10.11949/j.issn.0438-1157.20160641

Abstract

Abstract:

In present paper, the heat transfer characteristics of subcooled flow boiling in vertical rectangular narrow channels of different size at atmospheric pressure were investigated experimentally by using deionized water as working fluid, under the working conditions that width δ from 3 mm to 4 mm, mass flux G=143 & 300 kg·m^-2·s^-1, inlet subcooling ΔT_sub=17 &25℃, heat flux q from 1 W·cm^-2 to 20 W·cm^-2. The visualization experiments were conducted to study the characteristics of bubble nucleation on the heating wall in the same area, then obvious channel size effects were found out, including effects on onset of boiling, heat transfer coefficient, active nucleation site density, bubble departure diameter and bubble departure frequency, etc.

Key words: narrow channel, subcooled boiling, wall nucleation, two-phase flow, bubble, model

摘要：

以去离子水为实验工质，在窄缝宽度δ=3、4 mm，质量流速G=143、300 kg·m^-2·s^-1，主流过冷度ΔT_sub=17、25℃，热通量q=1～20 W·cm^-2的参数范围内，对常压下竖直窄缝通道内向上流动过冷沸腾的换热规律进行了实验研究。对不同宽度窄缝通道内的同一区域过冷沸腾气泡演变过程进行了可视化实验分析，发现窄缝宽度因素对过冷流动沸腾的流动换热特性和壁面核化特性影响显著，其中包括沸腾起始点ONB，压降ΔP，传热系数h，汽化核心密度N_a，气泡脱离直径D_d，气泡脱离频率f等。

关键词: 窄缝通道, 过冷沸腾, 壁面核化, 两相流, 气泡, 模型

CLC Number:

TK124

ZHAO Nan, ZHANG Wang, YANG Lixin. Subcooled boiling in narrow channels with different sizes[J]. CIESC Journal, 2016, 67(S1): 47-56.

赵楠, 张旺, 杨立新. 不同宽度窄缝通道过冷沸腾[J]. 化工学报, 2016, 67(S1): 47-56.

References 22

[1]	王增辉, 贾斗南, 刘瑞兰. 狭缝通道两相流强化换热研究综述[J]. 热能动力工程, 2002, 17(4):329-331. WANG Z H, JIA D N, LIU R L. An overview of the intensified heat exchange research of two-phase flows in a narrow-gap channel[J]. Journal of Engineering for Thermal Energy and Power, 2002, 17(4):329-331.
[2]	KARMAKAR A, GOSWAMI N, PARUYA S. Subcooled boiling oscillations in natural circulation boiling loop at low pressure[J]. AIChE Journal, 2014, 60(1):375-386.
[3]	KEW P A, CORNWELL K. Correlations for the prediction of boiling heat transfer in small-diameter channels[J]. Applied Thermal Engineering, 1997, 17(8/9/10):705-715.
[4]	CHEN L, TIAN Y S, KARAYIANNIS T G. The effect of tube diameter on vertical two-phase flow regimes in small tubes[J]. International Journal of Heat and Mass Transfer, 2006, 49(21/22):4-4230.
[5]	LIE Y M, LIN T F. Subcooled flow boiling heat transfer and associated bubble characteristics of R-134a in a narrow annular duct[J]. International Journal of Heat & Mass Transfer, 2006, 49(s14):2077-2089.
[6]	思勤, 王会军, 黄鸿鼎. 垂直矩形窄缝通道内气液两相流型的研究[J]. 化工学报, 1990, 41(6):745-753. SI Q, WANG H J, HUANG D H. Gas-liquid two phase flow patterns in thin rectangular channels[J]. Journal of Chemical Industry and Engineering (China), 1990, 41(6):745-753.
[7]	STEPHAN K. Heat transfer during boiling of pure substances in forced flow[M]//Heat Transfer in Condensation and Boiling. Berlin Heidelberg:Springer, 1992:174-261.
[8]	管鹏, 贾力, 银了飞, 等. 环形小通道内过冷沸腾的气泡行为研究[J]. 工程热物理学报, 2011, 32(11):1929-1931. GUAN P, JIA L, YIN L F, et al. Bubble behavior of subooled flow boiling in small annular channel[J]. Journal of Engineering Thermophysics, 2011, 32(11):1929-1931.
[9]	WARRIER G R, DHIR V K, BASU N. Onset of nucleate boiling and active nucleation site density during subcooled flow boiling[J]. Journal of Heat Transfer, 2002, 124(4):717-728.
[10]	RONG S, TAKASHI H, MAMORU I, et al. Bubble lift-off size in forced convective subcooled boiling flow[J]. International Journal of Heat and Mass Transfer, 2005, 48(25/26):5536-5548.
[11]	BASU N, WARRIER G R, DHIR V K. Wall heat flux partitioning during subcooled flow boiling(Ⅰ):Model development[J]. Journal of Heat Transfer, 2005, 127(1):131-139.
[12]	郭昂. 竖直矩形窄缝通道内过冷流动沸腾的实验研究与数值模拟[D]. 北京:北京交通大学, 2014. GUO A. Experimental and numerical investigation of subcooled flow boiling in vertical rectangular narrow channel[D]. Beijing:Beijing Jiaotong University, 2014.
[13]	徐慧强, 孙中宁, 谷海峰, 等. 水平管内纯饱和蒸汽强制对流冷凝局部换热特性[J]. 化工学报, 2015, 66(1):92-98. XU F Q, SUN Z N, GU H F, et al. Local heat transfer characteristics of saturated steam forced convection condensation inside horizontal tube[J]. CIESC Journal, 2015, 66(1):92-98.
[14]	THORNCROFT G E, KLAUSNER J F, MEI R. An experimental investigation of bubble growth and detachment in vertical up flow and down flow boiling[J]. International Journal of Heat Mass Transfer, 1998, 41:3857-3871.
[15]	SATISH G, KANDIKAR. Fundamental issues related to flow boiling in minichannels and microchannels[J]. Experimental Thermal and Fluid Science, 2002, 26(2):389-407.
[16]	RAHMAN M L, SULTAN R A, ISLAM T, et al. An experimental investigation on the effect of fin in the performance of closed loop pulsating heat pipe (CLPHP)[J]. Procedia Engineering, 2015, 105:137-144.
[17]	朱恂, 谢建, 王宏, 等. 微小通道内液体扰流微孔逸出气泡串的迁移行为[J]. 化工学报, 2014, 65(10):3805-3810. ZHU X, XIE J, WANG H, et al. Migration behavior of bubble cluster emerging from micro-orifice with liquid cross flow in mini-channel[J]. CIESC Journal, 2014, 65(10):3805-3810.
[18]	YEOH G H, VAHAJI S, CHEUNG S C P, et al. Modeling subcooled flow boiling in vertical channels at low pressures(Ⅱ):Evaluation of mechanistic approach[J]. International Journal of Heat & Mass Transfer, 2014, 75(16):754-768.
[19]	BENJAMIN R J, BALAKRISHNAN A R. Nucleation site density in pool boiling of saturated pure liquids:effect of surface microroughness and surface and liquid physical properties[J]. Experimental Thermal & Fluid Science, 1997, 15(1):32-42.
[20]	NILANJANA B. Modeling and experiment for wall heat flux partitioning during subcooled flow boiling of water at low pressures[D]. California:University of California Los Aneles, 2003.
[21]	HUA S, HUANG R, ZHOU P. Numerical investigation of two-phase flow characteristics of subcooled boiling in IC engine cooling passages using a new 3D two-fluid model[J]. Applied Thermal Engineering, 2015, 90(2):648-663.
[22]	MUNRO T R, BAN H. Flow and heat flux behavior of micro-bubble jet flows observed in thin, twisted-wire, subcooled boiling in microgravity[J]. Microgravity Science and Technology, 2015, 27(1):49-60.