卫星式柔印机中心压印滚筒螺旋流道冷却性能研究

目的 探究卫星式柔印机在印刷过程中，中心压印滚筒内部冷却水流道结构对其冷却效果的影响。方法 以双层中心压印滚筒为研究对象，采用数值模拟方法分析螺旋流道内冷却水的速度场和外滚筒的温度场，并与无螺旋流道的中心压印滚筒进行对比;探究流道截面形状对滚筒表面轴向温差的影响规律。结果 有螺旋流道的滚筒的表面温度整体较低，且轴向温差(4.2 ℃)更小。在相同的入口流速条件下，横截面高宽比大的螺旋流道滚筒表面轴向温差更小。在入口冷却水流速为2.5 m/s的条件下，横截面高宽比为0.6的螺旋流道对应的滚筒表面轴向温差为2.46 ℃。结论 采用高宽比较大的矩形截面螺旋流道，有利于缩小中心压印滚筒表面的轴向温差，从而改善滚筒的冷却效果。

Cooling Performance of Spiral Channels in Central Impression Cylinder of Satellite Flexographic Press

The work aims to investigate the cooling effect of the spiral flow channel in a central impression cylinder of satellite flexographic press during printing process. With double-walled central impression cylinder as the research object, the velocity field and temperature field of cooling water within the channels, and the temperature field of the outer wall of the impression cylinder were analyzed through numerical simulation. The simulated results were compared with those of a double-walled cylinder without spiral flow channels. The effect of rectangular cross-sectional geometries of the spiral flow channel on the axial temperature difference of the cylinder surface was discussed. The cylinder with the spiral flow channel had a lower surface temperature and a smaller temperature difference of 4.2 °C. The spiral flow channel with a greater height/width ratio in cross-sectional dimensions contributed to a smaller axial temperature difference at the same inlet flow velocity. When the inlet flow velocity of the cooling water was 2.5 m/s, and cross-section height/width ratio of the flow channel was 0.6, the axial temperature difference on the surface of the cylinder was 2.46 °C. The rectangular spiral flow channels with a greater cross-section height/width ratio are beneficial to reducing the surface temperature difference of the central impression cylinder, having a better cooling performance.