集中送风式冷库结霜与除霜性能的研究

Study on frosting and defrosting performance of centralized air supply cold storage

为解决集中送风冷库在不同工况下的除霜问题,系统通过单独的温度控制和电动风阀控制对多间冷库同时进行制冷,利用加湿器使房间相对湿度保持在85%,观察在不同工况下冷风机结霜情况,并采用热空气除霜的方法进行除霜,分析不同热空气温度、不同工况对除霜时间的影响。实验结果表明,库温从-15℃降到-20℃的结霜速率比库温从-10℃降到-15℃的结霜速率降低了25.8%。改变热空气的温度对冷风机进行除霜,当热空气流量不变时,热空气温度越高除霜时间越短。当工况为-20℃时,热空气温度分别是20℃和40℃,前者的除霜时间比后者的除霜时间多19.6min。考虑到冷库的运行性能可以在提高热空气温度的情况下减少结霜时间。

In order to solve the defrosting problem under different working conditions,each cold storage was installed with temperature control and electric air valve control separately. The experiment adopted the method of hot air defrosting to observe the frosting condition of the air cooler under different working conditions,and analyzed the effect of different hot air temperature and different working conditions on defrosting time. The research shows that the frosting rate from-15℃ to-20℃ is 25. 8%lower than the frosting rate during the process from-10℃ to-15℃. Defrosting was carried out at different temperatures of hot air. When the hot air flow is constant,the higher the temperature of the hot air is,the shorter the defrosting time is. For example,when the working condition is-20 ℃,the hot air temperature is 20℃ and 40 ℃ respectively. The defrosting time of the former is 19. 6 min more than that of the latter. It can be seen that we can raise the temperature of hot air to ensure the performance of cold storage.