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本文综述了近十年来发表的有关混合物池沸腾、流动沸腾、降膜沸腾、管内外自然对流冷凝及强制对流冷凝传热研究的成果和现状,详述了混合工质沸腾,冷凝的现象、机理及其传热强化的方法,并对该领域的深入研究提出了新建议。 相似文献
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纳米流体沸腾传热研究进展 总被引:1,自引:0,他引:1
介绍了纳米流体沸腾传热的最新研究,从纳米流体特性和沸腾表面特性两个方面阐述纳米流体沸腾传热的作用机制,指明纳米颗粒和沸腾表面特性以及两者之间的交互关系是目前研究结果存在分歧的主要原因。对纳米颗粒在制冷系统中的应用基础研究进行了展望,并指明了纳米流体沸腾传热的研究方向。 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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多组分流动沸腾传热研究 总被引:1,自引:0,他引:1
多组分混合物流动沸腾传热系数算式中的液相传质系数,是描述传质阻力的关键参数,但是,当前既无合适的计算方法也无经验数据,只能借用物理和化学吸收传质系数的经验值。本文给出一个简化计算方法。用此法对有机水溶液系统进行预测计算,所得传热系数与实测值比较,其平均绝对偏差为10.72%。 相似文献
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引言由于热泵技术发展的需要,多组分混合物流动沸腾传热的计算方法已成为当前传热研究的前沿课题.经研究发现当前的流动沸腾传热模型并非都能适用于多组分的计算.比如,加和模型由于抑制因子S与混合工质的种类及组成有关,而当前又尚未研究出一个通用算式,故使该模型在用于多组分混合物流动沸腾传热时遇到困难.造成困难的主要原因是混合物流动沸腾传热过程中传质阻力的影响不容忽视,然而混合物传质系数的计算又非常困难,目前尚无可用于实际系统的理论方法,实验数据也很少,还停留在经验阶段.近些年虽然对流动沸腾传质阻力的校正提… 相似文献
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二元液体混合物的沸腾传热 总被引:1,自引:0,他引:1
一、混合物沸腾传热特点及机理沸腾是一种具有相变的传热过程,由于它在工业应用中的重要性,引起许多学者开展研究。在过去的几十年中,对单组分沸腾特性的研究作了不少努力。然而在实际工作中涉及的往往是混合物的沸腾问题,尤其是 相似文献
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Boiling of water/triethyleneglycol (TEG) binary solution has a wide-ranging application in the gas processing engineering. Design, operation and optimization of the involved boilers require accurate prediction of boiling heat transfer coefficient between surface and solution. In this investigation, nucleate pool boiling heat transfer coef-ficient has been experimentally measured on a horizontal rod heater in water/TEG binary solutions in a wide range of concentrations and heat fluxes under ambient condition. The present experimental data are correlated using major existing correlations. In addition a correlation is presented for prediction of pool boiling heat transfer for the system in which the vapour pressure of one component is negligible. This model is based on the mass transfer rate equation for prediction of the concentration at the bubble vapor/liquid interface. Based on this prediction, the temperature of the interface and accordingly, the boiling heat transfer coefficient could be straightforwardly calculated from the known concentration at the interface. It is shown that this simple model has sufficient accuracy and is acceptable below the medium concentrations of TEG when the vapor equilibrium concentration of TEG is almost zero. The presented model excludes any tuning parameter and requires very few physical properties to apply. 相似文献
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本文分析了近年来流动沸腾传热的计算方法,探讨了纯组分及混合物在大尺寸圆管内的流动沸腾传热计算。对目前窄缝通道内流动沸腾传热问题的解决办法给予了介绍。 相似文献
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流动沸腾传热的新模型 总被引:1,自引:1,他引:1
利用矢量分析,导出一个普遍适用于流动沸腾传热系数计算的模型方程并进行了实验验证,吻合较好。作者同时探讨了流动沸腾中核沸腾项被抑制的原因并在新模型的基础上关联了抑制因子的表达式。 相似文献
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An experimental study has been carried out to investigate systematically the effects of acoustic cavitation parameters and fluid subcooling on boiling of acetone around a horizontal circular tube. The experimental results show that acoustic cavitation enhanced remarkably the boiling heat transfer and decreased the incipient boiling superheat and that cavitation bubbles effect on boiling heat transfer reduced with cavitation distance. For boiling curves in a form of h-q“, elevated cavitation distance shift nucleate boiling curves to the right of the corresponding ordinary pool boiling curve. The associated mechanism of heat transfer enhancement is analyzed with the consideration of cavitation bubble influence on vapor embryo. 相似文献
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沸腾传热强技术及方法 总被引:1,自引:0,他引:1
介绍了旨腾传热强化技术的方法,对影响沸腾传热强的因素进行了分析,并对几种典型的工业用传热强化管理及其性能做了介绍,最后对强化沸传热的研究方向进行了讨论。 相似文献
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沸腾传热强化技术及方法 总被引:1,自引:0,他引:1
介绍了沸腾传热强化技术的方法,对影响沸腾传热强化的因素进行了分析,并对几种典型的工业用传热强化管及其性能做了介绍,最后对强化沸腾传热的研究方向进行了讨论。 相似文献
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垂直管内三相流化床沸腾传热特性 总被引:14,自引:1,他引:14
研究了三相流化床沸腾传热的特性和影响传热系数的诸因素。在传热过程中,由于固体粒子的存在,强化了传热。以玻璃球粒子为固相的三相流化床沸腾传热系数,是相同条件下汽液两相流沸腾传热的二倍。以铜粒子为固相的三相流化床沸腾传热系数,是相同条件下汽液两相流沸腾传热系数的3倍。 相似文献