Double-reheat supercharged steam turbine thermal system

The invention discloses a double-reheat supercharged steam turbine thermal system which is characterized in that a high parameter steam turbine generating set is provided with a back pressure steam extraction cylinder; the back pressure steam extraction cylinder and an ultrahigh pressure cylinder are set into a split or combined structure; a regeneration and double-reheat thermal cycle system is provided with a second high pressure heater for regeneration; steam extraction of the second high pressure heater is led from steam exhaust of the back pressure steam extraction cylinder. The double-reheat supercharged steam turbine thermal system disclosed by the invention further improves thermal efficiency of electricity generation, reduces power supply coal consumption, and obviously increases the unit output.