Abstract

Non-uniform flow distribution among the channels of a heat exchanger (HX) can adversely affect its thermo-hydraulic performance. In this research, various header designs for a plate-fin heat exchanger (PFHX) and a flow data acquisition system were constructed to study the water flow distribution among the channels of the PFHX. These different header configurations were installed at the entrance of the PFHX operating under different flow conditions to evaluate the impact of header structure on flow distribution within the HX and its thermal-hydraulic performance. The conventional header was found to cause severe flow maldistribution at the inlet of the PFHX. The Reynolds number based on channel flow and geometry was seen to significantly affect the flow distribution, which in turn drastically reduced its effectiveness. To improve the conventional header, new headers with different perforated plates were designed and built. Experimental results showed that an improved version of the header is very effective in mitigating the flow maldistribution in the PFHX and thereby enhancing its thermal performance. Engineering correlations relating the flow distribution non-uniformity, HX effectiveness, and the Reynolds number for different header designs were also developed.

中文翻译：

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集管配置对板翅式换热器流量分布不均的影响

摘要

热交换器 (HX) 通道之间的不均匀流量分布可能对其热工水力性能产生不利影响。在本研究中，构建了板翅式换热器 (PFHX) 的各种集管设计和流量数据采集系统，以研究 PFHX 通道之间的水流分布。这些不同的集管配置安装在在不同流动条件下运行的 PFHX 的入口处，以评估集管结构对 HX 内的流量分布及其热工水力性能的影响。发现传统集管会导致 PFHX 入口处出现严重的流量分布不均。基于通道流量和几何形状的雷诺数被认为会显着影响流量分布，从而大大降低其有效性。为了改进传统集箱，设计并建造了具有不同穿孔板的新集箱。实验结果表明，改进版的集管可以非常有效地缓解 PFHX 中的流量分布不均，从而提高其热性能。还开发了与不同集管设计的流量分布不均匀性、HX 有效性和雷诺数相关的工程相关性。