Four different schemes for a wide-load and high-efficiency regenerative system based on back-pressure steam turbine are studied. The thermo-economic performances of the units for different schemes are analyzed and compared. The results show that

regardless of whether it is a pure back-pressure steam turbine or a back-pressure extraction steam turbine

the thermo-economic performance of the main steam extraction scheme is better than that of the platen superheater extraction steam scheme. In addition

when the economic operation conditions of the backpressure steam turbine are adjusted to low-load side

the efficiency difference between back-pressure steam turbine and main steam turbine cylinder at low load can achieve better energy-saving effect. Especially

at 30% THA load

the coal consumption rate of power supply unit can be reduced by at most 3.21 g/(kW·h). Finally

the regenerative system designed in this study can improve the feed water temperature under low-load operation condition

which is beneficial to improve the cycle thermal efficiency

the inlet flue gas temperature of the economizer and the low-load denitration problem.