Optimization control method of power station steam turbine set shaft seal and door rod steam leakage system

Abstract

The invention discloses an optimization control method of a power station steam turbine set shaft seal and door rod steam leakage system. The optimization control method comprises the following stepsthat during the initial stage of a unit, the inlet temperature is automatically adjusted through a shaft seal steam supply electric heater, and the pressure of a shaft seal mother tube is automatically controlled to be 3.5 kPa by a shaft seal steam supply control valve; a first pneumatic door and a fourth pneumatic door are opened, a third electric door is closed, a pneumatic drain valve is opened, and a shaft seal overflow valve automatically tracks the pressure of the shaft seal mother tube; when the load of the unit grid-connected belt is 20% THA, and the five-section steam extraction pressure is greater than 0.04 MPa, and at the moment, a third electric door starts to be automatically started, and meanwhile, a pneumatic hydrophobic valve is kept full open; when the unit load is gradually increased to 70% THA or higher, a shaft seal system is in a sealed state, the shaft seal steam supply control valve is automatically closed, and the shaft seal overflow valve is automatically started. According to the method, safe, reliable, efficient and energy-saving operation of the shaft seal system and the door rod steam leakage in the whole process stage of unit starting, grid connectionoperation, load shedding and the like can be ensured.

Description

technical field [0001] The invention belongs to the technical field of steam turbine shaft seal system and door lever steam leakage reconstruction optimization technology, and relates to an optimization control method for a steam turbine unit shaft seal and door lever steam leakage system in a power station. Background technique [0002] The steam turbine shaft seal and door stem leakage system is an important part of the steam turbine. Its main function is to provide sealing steam to the shaft seal of the steam turbine, the main steam valve, and the stem seal of the control valve. In the high and medium pressure cylinder section of the steam turbine, the function of the shaft sealing system is to prevent the steam from leaking out, so as to ensure the high efficiency of the steam turbine. In the low-pressure cylinder area of ​​the steam turbine, the function of the shaft seal system is to prevent outside air from entering the inside of the steam turbine, so as to ensure the...

AI Technical Summary

Problems solved by technology

However, in the actual operation of the unit, accidental tripping conditions cannot be avoided. After the unit trips, if the difference between the shaft seal steam supply temperature and the rotor temperature is too large, it may cause the risk of major shaft lockup.

In addition, the existence of the gap between the main steam valve and the door lever of the adjustment valve will inevitably cause some steam to leak out, and if the steam leakage of the door lever is not properly controlled during the recovery process, it will cause the erosion loss of the sealing surface of the door lever packing. Therefore, a new method is proposed. An effective and reliable control strategy of the shaft seal and door lever steam leakage system is very important to realize the safety and reliability of the steam turbine unit during the entire start-up operation stage

Images