Microchannel parallel flow gas cooler is commonly used in transcritical carbon dioxide automotive air conditioning system. To investigate the influence of the flat tube protrusion depth on fluid distribution, a numerical calculation model of microchannel parallel flow gas cooler with D-shaped header is established. With the object of even flow distribution, a novel stepped protrusion depth header is proposed. The effects of new header on the flow distribution of gas cooler were studied by numerical simulation. The results show that the flow distribution performance of gas cooler can be improved by changing the flat tube protrusion depth. Changing the protrusion depth of three groups of flat tubes simultaneously can achieve a better flow distribution performance of gas cooler than changing the protrusion depth of only one or two groups of flat tubes. When compared with the protrusion depth of all flat tubes is 0, the novel stepped protrusion depth header reduces the total flow distribution nonuniformity of gas cooler by 34–51%. The research in this paper provides a method for improving the flow distribution performance of gas coolers.

中文翻译：

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阶梯式突出深度集管微通道平行流气体冷却器的流量分布性能

微通道平行流气体冷却器常用于跨临界二氧化碳汽车空调系统。为研究扁平管突出深度对流体分布的影响，建立了D型集管微通道平行流气体冷却器的数值计算模型。以流量分布均匀为目标，提出了一种新型阶梯式突出深度集管。通过数值模拟研究了新集管对气体冷却器流量分布的影响。结果表明，通过改变扁平管突出深度，可以提高气体冷却器的配流性能。同时改变三组扁平管的突出深度，比只改变一组或两组扁平管的突出深度，可以获得更好的气体冷却器分流性能。与所有扁平管的突出深度为0相比，新型阶梯式突出深度集管将气体冷却器的总流量分布不均匀性降低了34-51%。本文的研究为提高气体冷却器的流量分配性能提供了一种方法。