More sediment improvement of water turbine main shaft seal

More sediment 2020 - turbine main shaft seal of improvement 04 - Chen bo (30 Danzhou city and celebrates the power plant) Abstract: in this paper, and their power plant no. 1 turbine main shaft seal to improve as an example, the application of several kinds of water turbine main shaft seal in sediment hydropower station design idea and implementation method are discussed in detail. The practical operation shows that the main shaft seal reliable operation, can satisfy the needs of the unit safe and stable operation. Key words: and their power station; Seal; Wear and tear; Leaking and celebrates the power station is located in danzhou and igawa flows within the territory of east road, for the administration of the pines of the second largest hydropower station, was built in 1975. Models for ZD510 - turbine LH - 180, design head is 11. 10 m, rated flow of 14. 2 m3 / s, the rated speed of 250 r/min, the runaway speed of 527 r/min, the rated output of 1360 kw. Models for TS260/40 - generator 24, rated power is 1562. 5 kva, unit type is three hanging structure. Power plant capacity 3 & times; 1250 kw, 13 years average output GWH. More than 30 years of relatively stable operation condition. But when the flood season comes, channel float on the surface of a large number of urban living garbage, such as foam, plastic bags, and the branches of rotten leaves washed down the mountain, the channel water turbidity, sediment concentration is far greater than zero. 41 kg/m3, small water diversion system is designed, failed to make the sediment in the settling basin precipitation well, cause water turbine main shaft seal in a short time by serious wear and tear, leaking, was forced to stop. For this, and celebrates the power organization technical force in early 2008 to no. 1 turbine main shaft seal is improved. 1 the structure of sealing and old celebration of power station early use carbon seal. In carbon seal between the comb and pressure water is piped in, but can't completely prevent the mix water into the carbon seal. Due to serious wear and tear, and multiple water flooded outage of guide bearing. Therefore, have to dismantle carbon sealing, and use the nylon end face seal. Use nylon end face seal, due to uneven spring pressure, corrosion fracture and tray and seal between the resistance of the rubber packing, coupled with the sediment blocking and corrosion of parts, when the load changes caused by the rotating part up move up and down, because sealing frame cannot with free movement up and down, and cause a lot of water. Although has made some improvements, but stuck with wear issues not solved, still exists the possibility of a large number of leaking. Therefore, have to dismantle the nylon end face sealing, and use rubber plate seal. But the thickness of the rubber plate co. , LTD. , short service life, easy tear, causing a lot of water. After scheme comparison, believe that only adopt new structural form of seal: to thoroughly solve the turbine main shaft seal wear leaking problem. 2 new sealing structure of u-shaped rubber end face seal is a new kind of structure form of the improved, its structure is shown in figure 1. This kind of sealing structure characteristics are as follows. U type rubber seal piece of 3, 100 mm high, 52 mm wide, at a height of 100 mm stainless steel seal groove 2. In a sealed at the bottom of the rubber block access to 0. 1 to 0. 15 mpa water pressure, the sealing rubber piece of jacking, produce friction surfaces in contact with the swivel 4, stop leakage. The sealing device to replace spring water pressure to adjust seal clearance. Because the rubber seal piece of elastic, sealed performance is good, can not only prevent leakage inside the stainless steel tank, and flexible moving up and down, makes the rubber piece under the action of water pressure, can with the swivel joint in any condition, achieve good seepage effect. Rubber seal height of 100 mm, the erosion rate of up to 70 mm to the left or right, thus greatly extend the service life of the sealing piece. Rubber seal itself good anti-wear performance, installation and maintenance, replacement is more convenient. U clear water can be directly used in the rubber seal continuously into the middle cavity, ensures the lubrication. U the diameter of the rubber seal should be as small as possible, in order to reduce leakage end face and lower wear rate. No. 1 turbine main shaft seal adopts after U rubber end face seal, not seen in water flooded outage of guide bearing. 3 conclusion operation practice has proved that U wear rubber end face seal is small, load changes, water leakage is not big. Therefore, think U rubber seal as much sediment water turbine main shaft seal is more appropriate. Source: 'the rural electrification'