Auxiliary steam drainage mode automatic switching system

The invention relates to the technical field of auxiliary steam drainage, and discloses an auxiliary steam automatic switching drainage mode system which is applied to an auxiliary steam system comprising high-pressure auxiliary steam and low-pressure auxiliary steam. The auxiliary steam drainage mode automatic switching system comprises a sewage condensation water tank used for collecting and storing condensation water, a high-pressure drainage part connected to high-pressure auxiliary steam and a low-pressure drainage part connected to low-pressure auxiliary steam, and the tail ends of pipelines of the high-pressure drainage part and the low-pressure drainage part are each provided with two paths of drainage water connected in parallel. The auxiliary steam drainage mode automatic switching system automatically switches auxiliary steam drainage by receiving different control valve signals, guarantees steam fluidity at the tail end of the auxiliary steam main pipe, prevents water accumulation at the tail end