Low-pressure steam differential pressure power generation system and reuse steam backpressure control method thereof

The invention discloses a low-pressure steam differential pressure power generation system and a reuse steam backpressure control method thereof, and relates to a method and a device for using heat energy in a steam temperature and pressure reduction process. The low-pressure steam differential pressure power generation system comprises a low-pressure steam main pipeline, a main pipeline system, a by-pass system, a generator set system and a control system, wherein the main pipeline system comprises a main stop valve which controls the steam flow of the generator set, and the bypass system is provided with a bypass adjusting valve; according to the steam backpressure control method, the reuse steam backpressure is detected and controlled so that the control system can enter a power control mode, a backpressure control mode or a bypass control mode according to a relationship between a backpressure measured value Pc and an exhaust steam pressure set value Ps; furthermore, the reuse steam backpressure can be co