Numerical simulation on flow boiling heat transfer of R32 in micro/mini-channels

doi:10.11949/j.issn.0438-1157.20160643

Abstract

Abstract:

Two dimensional unsteady numerical simulations of flow boiling heat transfer inside a 1 mm and 2 mm smooth horizontal tubes for R32 were conducted utilizing VOF multiphase model, under the condition of a mass flux of 100 kg·m^-2·s^-1, a heat flux of 12 kW·m^-2, a saturation temperature of 15℃. Single phase flow, bubbly flow, slug flow were observed in the simulation results for R32 flow boiling heat transfer inside a 2 mm channel while single phase flow, bubbly flow, confined bubbly flow, slug flow were observed inside a 1 mm channel. Bubble movement characters and influences on flow boiling heat transfer basic patterns exerted by channel diameter during flow boiling heat transfer inside the tubes for R32 were analyzed based on the distributions of gas phase volume fraction and temperature generated by the simulations. A promising consistency was achieved through the comparison between numerical simulation and experimental results.

Key words: multiphase flow, flow boiling, microchannels, numerical simulation, R32, VOF model

摘要：

利用VOF多相流模型对R32在1、2 mm水平光管内流动沸腾换热进行了二维非稳态数值模拟。模拟的工况为：质量流速100 kg·m²·s^-1，热通量12 kW·m^-2，饱和温度15℃。模拟结果显示：2 mm通道内工质的流动沸腾过程依次经历了液相单相流、泡状流、弹状流；1 mm通道内工质的流动沸腾过程依次经历了液相单相流、泡状流、受限泡状流、弹状流。利用模拟所得气相体积分数分布、温度分布，分析了R32管内流动沸腾过程中的基本规律和气泡运动特点，以及管径对流动沸腾换热过程流型的影响。利用数值模拟结果与实验结果进行对比，显示较好的一致性。

关键词: 多相流, 流动沸腾, 微通道, 数值模拟, R32, VOF模型

CLC Number:

TK124

ZHAO Ran, WU Xiaomin, HUANG Xiujie. Numerical simulation on flow boiling heat transfer of R32 in micro/mini-channels[J]. CIESC Journal, 2016, 67(S1): 33-39.

赵然, 吴晓敏, 黄秀杰. 微细通道中R32流动沸腾换热的数值模拟[J]. 化工学报, 2016, 67(S1): 33-39.

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