Flow maldistribution in heat exchangers
Flow maldistribution in heat exchangers
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DOI：
10.1016/s1359-4311(98)00090-8
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发表时间：
1999-08
影响因子：
6.4
通讯作者：
S. Lalot;P. Florent;S. K. Lang;A. Bergles
中科院分区：
文献类型：
--
作者：
S. Lalot;P. Florent;S. K. Lang;A. Bergles
本文通过对实验电加热器内流动不均匀现象的研究，探讨了流动不均匀性对换热器性能的影响。首先，研究表明，了解电加热器的不均匀分布比了解双流体换热器的不均匀分布更为重要。对特定加热器内流动分布的研究表明，不良的进口集箱设计可能导致回流。这里提出了一种简单的方法来均匀流动分布和一个简单的规律来计算速度比（管内最高速度与最低速度之比），并且精度很高。将原始流体分布应用于热交换器（冷凝器、逆流式热交换器和横流式热交换器），结果表明，当流速比高达15时，总的流量分布不均匀导致冷凝器和逆流式热交换器的效率损失约为7%，横流式换热器的效率损失高达25%。
Based on the study of gross flow maldistribution in an experimental electrical heater, this paper presents the effect of flow nonuniformity on the performance of heat exchangers. First, it is shown that it is much more important to understand maldistributions for electrical heaters than for two-fluid heat exchangers. The study of the flow distribution in a particular heater shows that reverse flows may occur for poor inlet header design. Suggested here is a simple way to homogenize the flow distribution and a simple law to calculate, with good accuracy, the velocity ratio (ratio of the highest velocity in the tubes to the lowest velocity). The original fluid distribution is applied to heat exchangers (condensers, counterflow and crossflow heat exchangers), and it is shown that gross flow maldistribution leads to a loss of effectiveness of about 7% for condensers and counterflow heat exchangers, and up to 25% for crossflow exchangers, for velocity ratios up to 15.