Back-pressure type heat regenerative system for combined heat and power generation

The invention relates to a back-pressure type heat regenerative system for combined heat and power generation. The back-pressure type heat regenerative system mainly comprises a back-pressure type generator set, a No.1 high pressure heater, a No.2 high pressure heater, a high pressure deaerator, a steam feed pump, a feed pump turbine and a surface type water supplemental heater, wherein most steam exhausted from a back-pressure type steam turbine is used as low pressure heat supply steam for supplying heat outwards through a main steam exhaust pipeline, part of steam exhausted from the back-pressure steam turbine acts as deaeration steam of the high pressure deaerator, and part of steam exhausted from the back-pressure type steam turbine acts as driving steam for the feed pump turbine, that is to say, a pipeline is guided from the main steam exhaust pipeline and is connected with the feed pump turbine through a fourth valve; steam exhausted from the feed pump turbine enters the surface type water supplemental heater, and is used for heating chemical supplemental water discharged from a sealing heater; the surface type water supplemental heater is connected with the high pressure deaerator, and after being deaerated, the chemical supplemental water is connected with the No.2 high pressure heater for further heating fed water, through a water supply pump driven by the steam exhausted from the back-pressure type steam turbine, and then enters a boiler through connecting with the No.1 high pressure heater.