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消防水带在火场内长距离供水时,易受到火场高温的影响,在水带壁面形成气泡核化现象,导致水带内气液两相流动现象的发生,造成水带磨损和水枪的难以掌控,影响灭火救援工作的开展。这篇论文针对核化特性对基本方程进行了相应描述,着重阐述了均质核化与非均质核化的特点,并对气泡核化所需过热度进行了推导,分析了成核过程中气泡的受力状况,在进行合理化假设的基础上,求得气泡脱离直径,并提出了通过加权的方法,计算对流换热与汽化潜热在气泡核化过程中所占的比重,利用数学分析的方法,推导了总热流密度的计算式,并将数值解与实验数据进行了对比分析,提出了气泡核化特性与气泡脱离直径和气泡成核频率相关的指数有关。
When the fire hose is supplied with water for a long distance in the fire, it is easily affected by the high temperature of the fire and bubble nucleation occurs on the wall of the hose, resulting in the occurrence of gas-liquid two-phase flow in the hose, resulting in the hose wear and water cannister being difficult to control , Affecting the fire fighting and rescue work. This paper describes the basic equations for nucleation characteristics, emphasizes the characteristics of homogeneous nucleation and inhomogeneous nucleation, deduces the superheat degree required for nucleation of nuclei, analyzes the nucleation process Based on the assumption of rationalization, the bubble diameter was calculated. Based on the weighted method, the proportion of convective heat transfer and latent heat of vaporization in bubble nucleation process was calculated. By using mathematical analysis Method, the calculation formula of the total heat flux is deduced, and the numerical solution is compared with the experimental data. The relationship between the nucleation characteristics of bubbles and the exponents of bubble diameter and bubble nucleation rate is proposed.