It is a very effective way to adopt centrifugal air fans with frequency conversion to save energy. However

the energy-saving effect is not ideal in most cases

and even affects the load capacity of the unit. To solve this problem

large amounts of experimental data were collected

and the problems and causes of the frequency conversion and speed regulation of the power plant fans were analyzed and summarized. Moreover

the feasible solutions for both newly built and in-service units were put forward. The analysis shows that

the main reasons for the problems of variable frequency speed regulation of centrifugal fans are as follows. First

the performance of the air fans does not match the resistance characteristics of the flue gas system. Second

there is large rotate speed difference between the inverter and the air fan performance. Therefore

several countermeasures were proposed

such as improving the matching degree between the fan and flue gas system(for example

optimizing the type selection

increasing the impeller width)

controlling the system effect influence and improving the actual performance of the fan(for example

controlling the installation accuracy in site and improving the air intake condition of the fan through flue duct optimization). This conclusion can provide references for the manufacturers

installation and operating enterprises of air fans.