The impact of crystallization fouling on a microscale heat exchanger
The impact of crystallization fouling on a microscale heat exchanger
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DOI：
10.1016/j.expthermflusci.2012.02.007
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发表时间：
2012-07-01
影响因子：
3.2
通讯作者：
Scholl, Stephan
中科院分区：
文献类型：
--
作者：
Mayer, Moriz;Bucko, Juergen;Scholl, Stephan
由于其非常高的表面积与体积比，微型换热器在传热和传质操作中提供了可能的优势。除了工艺强化和低投资的潜力外，这些微结构器件的工艺稳定性是工业应用的必要标准。微结构化装置对不需要的沉积非常敏感，例如表面上的反溶性盐的结晶（结垢）。通常，结垢导致（i）压降增加，（ii）热交换器性能降低，（iii）微结构中的流动分布不均，以及（iv）停留时间行为的改变。研究了结晶污垢对微型换热器传热性能的影响。污垢实验与碳酸钙（CaCO 3）进行了分析，关于热和流体动力学行为。所观察到的污垢发展从微通道中的过饱和溶液的非均匀性，并导致传热性能的下降和压降的强烈增加。污垢热阻R-f在10（-5）-10（-3）m（2）K W-1范围内。一般而言，微尺度下的污垢行为与宏观尺度下的污垢行为相当。(C)2012 Elsevier Inc. All rights reserved.
Due to their very high surface-to-volume ratios micro heat exchangers provide possible advantages in heat and mass transfer operations. Besides the potential of process intensification and low investment the process stability of these micro structured devices is a required criterion for industrial applications. Micro structured devices are very sensitive to unwanted deposition such as crystallization of inverse soluble salts on the surface (fouling). In general, fouling results in (i) an increase of the pressure drop, (ii) a decrease of the heat exchanger performance, (iii) a maldistribution of the flow in the micro structures and (iv) a change of the residence time behavior. This paper presents investigations about the impact of crystallization fouling on the heat transfer performance of a micro heat exchanger. Fouling experiments with calcium carbonate (CaCO3) were analyzed regarding thermal and fluid dynamic behavior. The observed fouling developed heterogeneously from a supersaturated solution in micro channels and caused a decrease of the heat transfer performance and a strong increase of the pressure drop. The extracted fouling resistances R-f were in the range of 10(-5)-10(-3) m(2) K W-1. In general, the fouling behavior in microscale is comparable to that in macroscale. (C) 2012 Elsevier Inc. All rights reserved.