共查询到18条相似文献,搜索用时 62 毫秒
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本文对板壳式换热器的换热元件内的流动沸腾传热进行了实验研究,在热虹吸流程的实验装置中流量了充动沸腾传热系数。 相似文献
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本文采用曲线拟合法对立式热虹吸再沸器的传热过程和流体力学进行了模拟计算。将该程序应用于工程实践中,提高了经济效益,取得了令人满意的结果。 相似文献
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釜式再沸器壳侧循环流动与管束传热的分格模型 总被引:4,自引:0,他引:4
通过对管束壳侧循环流动沸腾传热的分析,提出了管束沸腾传热的薄层蒸发传热增强贡献的计算公式,建立了釜式再沸器壳侧循环流动与管束传热的分格模型,利用此模型,对管束传热系数及循环流速进行了模拟计算。验证结果表明,由本模型计算所得管束沸腾传热系数与实验结果吻合较好。 相似文献
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为了提高再沸器的用能效率,特将固体颗粒引入立式热虹吸再沸器的管程形成气-液-固多相流系统,以强化传热,并提出了该节能型立式热虹吸再沸器的数学模型。模拟计算表明,流态化技术的引入能够强化再沸器的传热,减小换热面积或系统的有效能损失。颗粒的密度对传热的影响较大,其增加可使管内传热系数增大;随着固含率的增加,管内传热系数增大;随着粒径的增加,管内传热 数先增加后减小,有一极大值,颗粒密度的增加可使该极值增大并出现得更早。 相似文献
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釜式再沸器传热计算方法的进展 总被引:1,自引:1,他引:1
综述了釜式再沸器传热计算方法的国内外研究现状,并与国内现行釜式再沸器设计方法作以比较,指出目前釜式再沸器设计方法偏于保守,文中提及的设计方法及笔者的分析结论对工程设计有一定的参考作用。 相似文献
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本文研究了内加热式螺旋流流动沸腾传热的传热性能与临界热通量问题,提出了有旁流和无旁流时沸腾传热系数的计算方法,并进行了验证。 相似文献
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In the present study a semi empirical equation has been developed as a modification and extension of the previous analyses of pure fluids for the prediction of wall superheat for six binary liquid mixtures including the effect of liquid submergence. The wall superheat required for the onset of nucleate boiling of binary mixtures was related to thermo physical properties, heat flux and liquid submergence. The results predicted from the theoretical analysis are consistent with the experimental data available in the literature. The results were compared with the available correlations, indicating that the correlations based on the submergence are in better qualitative agreement. A unified correlation for the binary mixtures covering wide ranges of heat flux, submergence, inlet liquid subcooling and surface material was also obtained with enhanced deviation of 20.37%. 相似文献
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立式热虹吸再沸器由于其具有较大的传热系数、较小的占地面积以及安装便捷等优点,在化工行业中得到广泛的应用,本文利用HTRI软件对醋酸仲丁酯装置中醋酸精馏塔再沸器进行设计优化,计算合适的再沸器结构参数,找出合适的静压头,以及最优的进口管径。 相似文献
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在垂直受热通道中气液两相流的传热是一种从单相流、泡状流、弹状流、搅拌流直至环状流的各种流型的气、液两相复杂传热。本文采用了特制的实验研究设备,以水及其蒸汽为介质,研究了各种流型的传热特性及其影响因素(进料质量流速、热通量以及干度等),探讨了成膜条件,并用J.C.Chen双机理传热模型计算、分析了在不同情况下各机理对传热所起的作用。 相似文献
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A model is proposed to predict boiling heat transfer coefficient in a three-phase circulating fluidized bed (CFB), which is a new type of evaporation boiling means for enhancing heat transfer and preventing fouling. To verify the model, experiments are conducted in a stainless steel column with 39 mm ID and 2.0 m height, in which the heat transfer coefficient is measured for different superficial velocities, steam pressures, particle concentrations and materials of particle. As the steam pressure and particle concentrations increase, the heat transfer coefficient in the bed increases. The heat transfer coefficient increases with the liquid velocity but it exhibits a local minimum.The heat transfer coefficient is correlated with cluster renewed model and two-mechanism method. The prediction of the model is in good agreement with experimental data. 相似文献
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以乙醇-水、正丙醇-水、乙醇-正丙醇-水以及乙醇-苯-水作为工质,在热虹吸矩形流道内研究了多元物系流动沸腾传热。使用校正的渐进模型关联式,结合Thome核沸腾传质阻力效应校正,构造出多元物系流动沸腾传热计算方法。 相似文献
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Heat transfer characteristics are studied for gas carrying evaporation with fluidized solid particles in a vertical rectangular conduit. Experimental results show that heat transfer of gas carrying evaporation is enhanced and the superheat of liquid in contact with heating surface lowers remarkably by introducing solid particles. Nucleate boiling on the heating surface is suppressed to a considerable degree. The mechanism of heat transfer enhancement by fluidized solid particles is analyzed with the consideration of collisions of solid particles with the boiling vapor bubbles. 相似文献