为提高换热器的传热性能，设计了叉排板束换热器，利用Fluent软件中的RNG k-ε模型数值研究了叉排板束的传热特性。分析了叉排板束排数对于整体Nu的影响以及板束的局部传热特性，比较了不同横纵比对整体Nu的影响，并给出不同Re下叉排板束的Nu经验公式。实验结果表明：叉排板束整体传热性能随板排数的增多而增强，当达到一定排数后传热性能趋于稳定，不同Re下趋于稳定的排数不同，当Re=4.3×105时进入稳定阶段需13排，当Re=4.3×103时进入稳定阶段仅需7排；叉排板束局部传热性能在各板排中先增大后减小，在第2~4排局部Nu达到峰值，板的局部传热性能在两个直角处以及撞击点位置大大增强；板束在横纵比为5时传热性能最佳，横纵比大于或小于5时，传热性能均会减弱；给出Re在1~500，500~1 000，1 000~200 000范围内板束整体Nu拟合公式，当Re>30 000时，与叉排圆管束相比，叉排板束传热性能提高25%

In order to improve the heat transfer performance of the heat exchanger, a cross row plate bundle heat exchanger is designed. Using RNG k-ε model in Fluent software, the heat transfer characteristics of cross row plate bundles are studied numerically. The influence of the number of plate rows on the overall Nu and the local heat transfer characteristics of plate bundles are analyzed. The effects of different aspect ratios on the overall Nu are compared, and the Nu empirical formulas of cross row plate bundles at different Re are given. The experimental results show that the overall heat transfer performance of the cross row plate bundle increases with the increase of the number of plate rows. When a certain number of rows are reached, the heat transfer performance tends to be stable, and the number of rows tending to be stable at different Re is different; when Re=4.3×105, rows are required to be 13 to enter the stable stage, and only 7 rows are required to enter the stable stage at Re=4.3×103; the local heat transfer performance of the cross row plate bundle first increases and then decreases in each plate row, and the local Nu reaches the peak approximately from row 2 to 4. The local heat transfer performance of the plate bundle is greatly enhanced at two right angles and the position of the impact point; When the aspect ratio is 5, the heat transfer performance of plate bundle is the best, and when the aspect ratio is greater than or less than 5, the heat transfer performance will be weakened; the overall Nu fitting formula of plate bundle is given when Re is in the range of 1 to 500, 500 to 1 000, 1 000 to 200 000. When Re is greater than 30 000, the heat transfer performance of cross row plate bundle is improved by 25% compared with the cross row circular tube bundle.

TK124

国家自然科学基金（5216060011）