Some characteristics of the mixed flow pump turbine units

Some characteristics of the mixed flow pump turbine units 2019 - 05 - 16 mixed-flow pump turbine is the most widely used type new pumped storage units. Most unit adopts the underground plant, has a long drainage channel, unit of calculation is critical. The aircraft used head range is very wide, from 30 m to 700 m, are successful unit in operation. Due to the different head unit design focuses on the different emphasis, on the overall design difference is bigger also. Below 100 m section head of units like anhui ring HongDian ( Head 27 ~ 64 m) And panjiakou ( 35 ~ 85) Are very representative. Low head pumped storage units the biggest problem is the water flow is big, sometimes with double speed, to improve the hydraulic characteristics when different head. If water flow is not big, adopting single speed and is of simple structure, low cost, and Francis turbine in the structural design of close. The units with a water head of 100 ~ 300 m very much, recently put into production and construction of jilin baishan pumped storage, reed {langya} mountain in anhui, hubei white lotus river pumped storage power station, etc. The head section of the unit due to water head is not high, the unit speed is not high also, the possibility of wheel resonate far less than the high head pump turbine units. Most roof can whole through the inner diameter of the generator stator, on general structure design and the head of Francis turbine. In jilin baishan pumped storage units, for example, the unit structure of half umbrella, two three guide shaft support, the thrust bearing support plane frame of the generator, the unit is on the way down, pit arranged in two straight cylinder relay device through the control loop operation guide water agencies, volute laid elastic layer pouring, stay ring, spiral casing, tail pipes and other components are embedded in the concrete, to reduce the vibration and noise of the unit. 300 m above the head grade of pumped storage units, due to technical and economic indicators are significantly higher than low head unit, made great development in recent years. High speed, large capacity, it is the characteristics of the head section of the unit, the design and manufacture installation operation has the certain difficulty. Look from already running unit, and its overall design difference is very big, each has his strong point. Guangzhou pumped storage power plant first phase ( Guangzhou issue) Unit is the first to introduce high head large pumped storage unit, the unit thrust bearing bracket arrangement on the roof, bottom ring and tail pipe is bare type, under the wheel. Pit two relay device is installed inside, through the control loop operation guide water institutions. The first unit put into operation in 1993. Guangzhou pumped storage power plant phase ii ( Guangzhou phase ii) To sum up the experiences of a period, to reduce hydraulic vibration, the bottom ring and tail water taper pipe buried in concrete, the unit is in the open way, using the unit relay control guide water institutions. Guangzhou first phase ii unit put into operation in 1998. Thrust bearing the Ming tombs pumped storage unit in the next frame, USES the open way, bottom ring and tail water taper pipe buried in concrete volute pressure casting, with two straight cylinders relay operation guide water institutions. （ Source: pumping storage technology exchange)