Abstract Fouling is one of the customarily happened, fundamental and expensive problems in heat transfer systems. It causes the reduction in heat transfer performance of the heat exchangers, energy loss and also, damage to the apparatus. Effect of fluid flow rate on the salt deposition was complicated in the previous researches. In this paper, a comprehensive rigorous investigation was performed to make clear the effect of fluid flow rate of calcium sulfate aqueous solution on the heat transfer coefficient and fouling resistance in subcooled flow boiling condition. Large numbers of experiments performed at different flow rates (2.5–11.5 l/min), solution concentrations (1.75–2.20 g/l), fluid bulk temperatures (55–75 °C), and heat fluxes (8–95 kW/m2). Chen model, Gungor and Winterton model, and Kandlikar model approved pure water experimental data. It was found that increasing the heat flux increased the fouling rate and consequently, sharply decreased the heat transfer coefficient. It was also found that increase in the flow rate may cause both increase or decrease of the fouling layer, which depends on the applied heat flux. At low heat fluxes, deposition is mass transfer controlled, and increasing Re enhances the fouling rate while at high heat fluxes the deposition is chemical reaction controlled, and incresing Re decreases the fouling rate.

中文翻译：

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流体流速对过冷流沸腾条件下硫酸钙水溶液抗结垢性能的影响

摘要 结垢是传热系统中经常发生的、基本的和昂贵的问题之一。它会导致换热器的传热性能降低、能量损失以及设备损坏。在以往的研究中，流体流速对盐沉积的影响是复杂的。本文通过全面严谨的研究，明确了硫酸钙水溶液流体流速对过冷流沸腾条件下传热系数和结垢阻力的影响。在不同流速 (2.5–11.5 l/min)、溶液浓度 (1.75–2.20 g/l)、流体整体温度 (55–75 °C) 和热通量 (8–95 kW/m2) 下进行的大量实验）。Chen模型、Gungor和Winterton模型、Kandlikar模型认可了纯水实验数据。结果表明，增加热通量会增加结垢率，从而显着降低传热系数。还发现流速的增加可能导致污垢层的增加或减少，这取决于施加的热通量。在低热通量下，沉积受传质控制，增加 Re 提高结垢率，而在高热通量下，沉积受化学反应控制，增加 Re 降低结垢率。