Waterside fouling performance in brazed-plate-type condensers for cooling tower applications
Waterside fouling performance in brazed-plate-type condensers for cooling tower applications
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DOI：
10.1080/10789669.2011.555492
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发表时间：
2011-04
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影响因子：
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通讯作者：
L. Cremaschi;J. Spitler;Ellisa Lim;A. Ramesh
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文献类型：
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作者：
L. Cremaschi;J. Spitler;Ellisa Lim;A. Ramesh
本文介绍了结垢运行条件下钎焊式冷凝器水侧热水力性能的新实验方法和结果。开发了高水结垢潜力，以创造在实验期间导致严重降水和颗粒结垢的条件；化学抑制剂有意防止腐蚀和生物污垢。除其他优点外，这种新方法独立于实验室的地理位置和当地的供水源。使用该技术，水的兰格利尔饱和指数达到约 3-3.5，这代表非常严重的污垢状况。对四个钎焊板式换热器进行了测试，热通量最大减少 28%，压降最大增加 250%，说明了换热器热水力性能可能受到严重损害。渐进抗污性对板的内部几何形状有很强的依赖性，而对板的长宽比有较弱的依赖性。 30° 的软波纹角可在清洁条件下提供较低的压降，但会显着增加传热表面上污垢沉积的可能性。测得的软波纹角钎焊板式换热器的抗污垢能力比具有类似几何形状但具有硬波纹角的换热器高约十倍。
This article presents a new experimental methodology and results of the waterside thermal hydraulic performance of brazed-type condensers under fouling operating conditions. High water fouling potential was developed in to create conditions that cause severe precipitation and particulate fouling during the experiments; corrosion and biological fouling were intentionally prevented by chemical inhibitors. Among other advantages, this new methodology is independent from the geographical location of the laboratory and from the local water supply source. Using this technique, a Langelier saturation index of the water of about 3–3.5 was achieved, which represents very severe fouling conditions. Four brazed-plate heat exchangers were tested, and a maximum reduction in heat flux of 28% and a maximum increase in pressure drop of 250% illustrate the potentially critical impairment of the heat exchanger thermal hydraulic performance. The asymptotic fouling resistance had a strong dependence on the internal geometry of the plates and weak dependence on the aspect ratio of the plates. A soft corrugation angle of 30° gives low pressure drop in clean conditions but significantly increases the propensity of fouling deposition on the heat transfer surfaces. The measured fouling resistance for the soft corrugation angle brazed-plate heat exchanger was about ten times higher than those for similar geometries but with hard corrugation angles.