轴流风机和离心风机在机械通风中的作用

Axial flow fan and centrifugal fan in mechanical ventilation effect

1、由于气温和粮温相差较大，第一次通风时间要选在白天，以减小粮温和气温的差距，减轻结露的发生。以后的通风尽量选在晚上进行，因为本次通风是以降温为主，晚上大气湿度相对偏高、温度较低，这样即减少了水份损耗，又充分利用了晚上的低温，提高了降温效果。

1, because the temperature and grain temperature difference is large, the first ventilation time should be selected in the daytime, in order to reduce the gap between grain temperature and temperature, reduce the occurrence of condensation. After the ventilation as far as possible in the evening, because the ventilation is to cool at night, humidity is relatively high, low temperature, so that reduce the water loss, and make full use of the night temperature, improve the cooling effect.

2、用离心风机通风初期有可能会出现门窗、墙壁结露，甚至表层粮面轻微结露，只要停止风机，打开窗户，开启轴流风机，必要时翻动粮面，将仓内的湿热空气排除仓外就可以。而用轴流风机进行缓速通风就不会出现结露现象，只会出现中上层粮温缓慢上升，随着通风的继续进行粮温会平稳下降。

2, in the early days of centrifugal fan there may be a door and window and wall condensation, even slight condensation of surface grain surface, as long as the wind stop machine, open the window, open the axial fan, if necessary, changes the grain surface, the positions within the hot air outside the warehouse can be excluded. When the axial fan is used for slow speed ventilation, no condensation phenomenon occurs, only the upper and middle grain temperature rises slowly, and as the ventilation continues, the grain temperature will decrease steadily.

3、用轴流风机进行缓速通风时，由于轴流风机的风量小，另外粮食是热的不良导体，通风初期容易出现个别部位通风缓慢，随着通风的继续进行全仓粮温会逐渐平衡。

Slow ventilation 3, axial flow fan, the axial fan air volume, and food is a poor conductor of heat, ventilation early prone to individual parts of ventilation ventilation continued to slow, with full grain storage temperature will gradually balance.

4、进行缓速通风的粮食必须经过震动筛的清理，并且入到仓内的粮食必须及时清扫自动分级造成的杂质区，否则易造成局部通风不均。

4. The grain with slow speed ventilation must be cleaned by vibrating screen, and the grain in the warehouse must be cleaned in time and the impurity area caused by automatic grading will be easy to cause partial ventilation uneven.

5、能耗计算：14号仓用轴流风机累计通风50天，平均每天15小时，共用750小时，水份平均降了0.4%，粮温平均降了23.1度，单位能耗为：0.027kw.h/t.℃。28号仓累计通风6天，共用126小时，水份平均降了1.0%，温度平均降了20.3度，单位能耗为：0.038kw.h/t.℃。

5, energy consumption calculation: No. 14 warehouse axial fan accumulated ventilation for 50 days, an average of 15 hours per day, sharing 750 hours, the average water dropped by 0.4%, grain temperature dropped by 23.1 degrees, unit energy consumption is: 0.027kw.h/t. degrees centigrade. No. 28 warehouse accumulated ventilation for 6 days, shared 126 hours, the average water dropped by 1%, the average temperature dropped by 20.3 degrees, the unit energy consumption is: 0.038kw.h/t. degrees centigrade.

6、以轴流风机进行缓速通风的优点：降温效果良好；单位能耗低，在倡导节能的今天尤为重要；通风时机易掌握，不易出现结露；不用单独配备风机，方便灵活。缺点：由于风量小，通风时间长；降水效果不明显，高水份粮不宜用轴流风机进行通风。

6, with the advantages of axial flow fan ventilation: slow cooling effect is good; the unit energy consumption is low, is particularly important in advocating energy conservation today; ventilation time is easy to grasp, not prone to condensation; not alone with a fan, convenient and flexible. Disadvantages: due to the small air volume, long ventilation time, the effect of precipitation is not obvious, high moisture grain should not use axial flow fan for ventilation.

7、离心风机的优点：降温、降水效果明显，通风时间短；缺点：单位能耗高；通风时机掌握不好易出现结露。

7, the advantages of centrifugal fan, cooling, precipitation effect, ventilation time is short; disadvantages: high energy consumption; ventilation timing bad dewing.

8、结论：在以降温为目的的通风中，应用轴流风机进行安全、高效、节能的缓速通风;在以降水为目的的通风中应用离心风机。

8, conclusion: in the ventilation for the purpose of cooling, the axial fan is used for safe, efficient and energy-saving slow speed ventilation, and the centrifugal fan is used in the ventilation for the purpose of precipitation.