BEST small machine system started in multiple modes and operation method of BEST small machine system

Abstract

The invention discloses a BEST small machine system started in multiple modes and an operation method of the BEST small machine system. The BEST small machine system comprises a booster pump, a gearbox, a water feeding pump, a BEST small machine, a high-speed synchronous motor and a converter which are sequentially connected. The water feeding pump, the BEST small machine and the high-speed synchronous motor are connected through the same shaft system. The booster pump is connected with the water feeding pump through the gearbox, and the converter is respectively connected with an auxiliary power 10kV busbar and the high-speed synchronous motor. The converter and the high-speed synchronous motor are utilized, the advantages of a steam-driven BEST small machine driving water feeding pump and an electric water feeding pump are combined, the unit starting time is shortened, the auxiliary power consumption is reduced, and meanwhile, the efficiency of the BEST small machine is obviously improved.

Description

technical field [0001] The invention belongs to the technical field of steam turbines in coal-fired power plants, and in particular relates to a multi-mode start-up BEST small machine system and an operating method thereof. Background technique [0002] In the current 660MW and 1000MW units, most of them use pure condensing steam-driven small machines to drive feed water pumps or choose electric feed water pumps to supply water to boilers. However, if the electric feed water pump is selected, the power consumption of the factory will be increased, and the coal consumption of the unit will be increased. If you choose a pure condensing steam-driven feed water pump, you need enough start-up steam during the start-up phase. In addition, the exhausted steam that has done work is directly discharged to the condenser, resulting in waste of steam waste heat. [0003] In order to reduce steam extraction from the high and medium pressure cylinders of the steam turbine, increase the ...

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Problems solved by technology

In addition, exhausted steam that has done work is directly discharged to the condenser, resulting in waste of steam waste heat

[0003] In order to reduce steam extraction from the high and medium pressure cylinders of the steam turbine, increase the flow through the high and medium pressure, improve the efficiency of the unit, and improve the efficiency of the small feed water pump, the BEST dual-machine regenerative system came into being. However, in the existing BEST dual-machine regenerative system, the steam Due to the large throttling loss caused by the adjustment of the BEST small machine, it affects the efficiency of the small machine

In addition, at the initial stage of unit start-up, the electric feed water pump needs to be used to supply water to the boiler, which increases the power consumption of the plant.

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