In order to find out the amplitude and speed change laws of back pressure of direct air cooling units caused by environmental wind

field survey on three fossil fuel-fired power plants in Ningxia

Hami and Tuo Kexun area with relatively strong wind conditions was carried out. The actual operation data of the air cooled condenser system were collected and a large amount of statistics was performed. The results show that

the law of change rate of the back pressure of units in each area is basically the same as that of the annual average and maximum monthly mean ambient wind speed. When the cumulative time is over 20 s

the trend curve of the maximum rate of back pressure variation of the units in each area and the cumulative time is similar to straight line

and is basically parallel. The research provides a basis for type selection of water feed pump turbine and operating control of power plants

and also can be referentially used for design of water feed pump turbine outflow to ACC directly and the study of transient mathematical simulation.