The invention relates to an energy saving
system of an electrically driven
feed pump of a
power frequency-variable frequency switching type liquid
coupling, and belongs to the technical field of energy saving transformation of electrically driven
feed pump sets driven by a liquid
coupling in a
power station. the energy saving
system is characterized in that a frequency converter and a power-frequency bypass is arranged between a power supply frequency converter and a motor on the condition that the
connection type of original electrically driven
feed pump sets are cont changed. According to the energy saving
system, the frequency converter and the power-frequency bypass are mounted between the power supply breaker and the motor, the
power frequency-variable frequency power supply is input in the motor by switching, a front-mounted pump is coaxially driven by one end of the motor, a liquid
coupling input shaft is coaxially driven by the other end of the motor, a feed pump is driven by a liquid coupling output shaft, and a
lubrication pump and a working
oil pump are designed and mounted in a liquid coupling lubricating oil system and a working oil system, so that the same liquid coupling has two operation manners; for meeting requirements of the
power frequency-variable frequency operation manners of the feed pump sets, the front-mounted pump is changed into a front-mounted pump which can operate in both a
constant speed manner and a variable speed manner. The energy saving system of the electrically driven feed pump of the power frequency-variable frequency switching type liquid coupling is simple in structure and rational in design, and has two operation manners including a volume-velocity-regulated speed-regulation type liquid coupling in a power-frequency
constant speed input process and a pump-
pulley-regulated speed-increase gear box in a variable frequency speed-regulation input process.