“不良”结霜现象的分析和对策

Analyses and Solutions to Unfavorable Frosting

空气冷却盘管在冷库制冷过程中结霜是经常发生且不可避免的问题,必须要周期性的除霜。在温湿图上,如果空气降温处理过程穿越了饱和线,就可能发生“不良”结霜的问题。“不良”结霜是一种低密度、蓬松的、雪状霜,与其他结霜的类型相比,“不良”结霜会更快地减少空气流通面积,盘管换热能力迅速下降。通过分析其形成原理,提出了相应的防止措施,能有效的减少“不良”结霜。

Air cooling coils in most refrigerated applications become frostecl and must be penodically defrosted. Unfavorable frost forms if the coll air approach line crosses into the super - saturated region on a psychrometric chart. Unfavorable frost is low density, fluffy, snow- like frost that quickly blocks coil airflow resulting in rapid deterioration in coil performance compared with other frost types. Design and operating conditions to avoid unfavorable frost are defined and quantitative methods to predict unfavorable frost formation arc presented.