Experimental investigation of heat transport with oscillating liquid column in pulsating heat pipe using forced oscillation system
Experimental investigation of heat transport with oscillating liquid column in pulsating heat pipe using forced oscillation system
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DOI：
10.1016/j.ijheatmasstransfer.2016.10.069
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发表时间：
2017-03-01
影响因子：
5.2
通讯作者：
Ito, Yu
中科院分区：
文献类型：
--
作者：
Miura, Masayoshi;Nagasaki, Takao;Ito, Yu
(T)为了阐明脉动热管的详细传热机理，采用强迫振动系统进行了实验研究。在单组分(液体乙醇和蒸气乙醇)体系和双组分(液体乙醇和空气)体系中，液柱在通道中振荡。在单组分体系中，由于气相中只含有工质蒸汽，因此振荡流动引起的显热输送和相变引起的潜热输送同时发生。在双组分系统中，由于气相由大气压下的空气组成，因此只发生了显热传输。根据单组分体系和双组分体系的有效导热系数的差异，确定了潜热传递的有效导热系数。在相同的振幅和频率下，随着振荡中心向加热段移动，感热输送的有效导热系数单调增加。另一方面，在相同的振幅和频率下，随着振荡中心向冷却段移动，潜热传递的有效导热系数增大，直到振荡液柱尖端到达加热段。根据对单组分体系汽压波动的测量，估算了汽质波动。结果表明，振荡液柱形成的液膜在潜热传递机理中起着重要的作用。结果还表明，当液柱从冷却段向加热段移动时，发生了从工质蒸汽到液柱尖端的直接接触冷凝。(C)2016爱思唯尔有限公司。保留所有权利。
(T)o clarify the detailed heat-transport mechanism of a pulsating heat pipe, an experimental study was conducted using a forced oscillation system. A liquid column was oscillated in a channel for a single component (liquid ethanol and vapor ethanol) system and a two-component (liquid ethanol and air) system. In the single-component system, the sensible heat transport due to the oscillating flow and the latent heat transport due to the phase change occurred simultaneously because the gas phase consisted of only working-fluid vapor. In the two-component system, only sensible heat transport occurred, because the gas phase consisted of air at the atmospheric pressure. The effective thermal conductivity of the latent heat transport was determined according to the difference in effective thermal conductivity between the single-component system and the two-component system. The effective thermal conductivity of the sensible heat transport increased monotonically as the oscillation center moved to the heating section under the same amplitude and frequency. On the other hand, the effective thermal conductivity of the latent heat transport increased as the oscillation center moved to the cooling section under the same amplitude and frequency until the tip of the oscillating liquid column reached the heating section. The vapor-mass fluctuation was estimated according to the measurement of the vapor-pressure fluctuation in the single-component system. The results show that the liquid film formed by the oscillating liquid column played an important role in the mechanism of the latent heat transport. They also show that the direct-contact condensation from the working-fluid vapor to the tip of the liquid column occurred when the liquid column moved from the cooling section to the heating section. (C) 2016 Elsevier Ltd. All rights reserved.