Backpressure steam extraction small steam turbine thermal system coaxially arranged with primary reheating main steam turbine set

The utility model provides a backpressure steam extraction small steam turbine thermal system coaxially arranged with a primary reheating main steam turbine set. The primary reheating main steam turbine set is provided with a high-pressure cylinder, an intermediate-pressure cylinder, a low-pressure cylinder and a reheater. The backpressure steam extraction small steam turbine thermal system comprises a backpressure steam extraction small steam turbine, a steam inlet pipe system, a steam extraction pipe system, a steam exhaust pipe system and back-heating equipment. Steam before reheating of the primary reheating main steam turbine set serves as the steam source of the thermal system to drive the backpressure steam extraction small steam turbine. Steam extraction and steam exhaustion of the backpressure steam extraction small steam turbine are used for heating supplied water and condensed water. The backpressure steam extraction small steam turbine and the primary reheating main steam turbine set are coaxially arranged. The backpressure steam extraction small steam turbine thermal system can reduce system manufacturing cost and improve thermodynamic cycle efficiency.