The invention relates to a combined heat and
power generation system for condensing-extracting-backpressure
heat supply and an operation method thereof. A traditional centralized heating mode can cause great available
energy loss. In the combined heat and
power generation system for condensing-extracting-backpressure
heat supply provided by the invention, a boiler, a
steam turbine high-pressure cylinder, a
steam turbine intermediate-pressure cylinder, a
steam turbine low-pressure cylinder, an
electric generator and a condenser are sequentially connected through a pipeline; a boiler feed
pipe is connected between the condenser and the boiler; the condenser, a
condensate pump, a low-pressure heater, a feed
water heater, a
deaerator, a
feed pump and a high-pressure heater are sequentially arranged on the boiler feed
pipe; a steam inlet of a
heat supply network
heat exchanger is connected with a communicating
pipe between the steam
turbine intermediate-pressure cylinder and the steam
turbine low-pressure cylinder; and a
dewatering outlet is connected with the low-pressure heater. According to the combined heat and
power generation system for condensing-extracting-backpressure heat supply and the operation method thereof provided by the invention, the steam
turbine intermediate-pressure cylinder is structurally improved, or a secondary intermediate-pressure cylinder is additionallyarranged behind so as to be adapt to switching operation among three working conditions, i.e. pure condensing, steam extracting and backpressure of a turboset. According to the combined heat and powergeneration
system for condensing-extracting-backpressure heat supply and the operation method thereof provided by the invention, the original lost energy is converted into high-quality
electric energy through the acting of a turbine, so that the gradient utilization of the energy is realized.