Huadian wuhu company steam feed water pump bearing damage cause analysis and improvement

Huadian wuhu company steam feed water pump bearing damaged 2018 - root cause analysis and improvement 12 - 13 FuLin ( Wuhu of anhui huadian power generation co. , LTD. , turbine maintenance department) Wuhu of anhui huadian power generation co. , LTD. , 2 * 660 mw ultra supercritical unit, for the domestic first sets of 600 mw and above ultra supercritical units. To form a complete set of auxiliary steam feed pump group chosen HPT300 - power plants in Shanghai co. , LTD 340 - 6 s type pump and Shanghai steam turbine factory production ND ( Z） 84/79/07 type small steam turbine, the equipment of form a complete set of design and operation in use process there is no mature and reference information. Feed water pump and two small steam turbine equipment system design is the first time cooperation, burn tile accident in xinji first appeared during debugging. Determined by way of analysis for the lubricating oil system design is unreasonable, lubricating oil system to the distribution of bearing oil supply system can not meet the requirement of the operation. Profile 1, the accident on April 20, 2008 # 1 unit start-up debugging steam feed pump group, for the first time A steam feed water pump group pump radial bearing bush for not drive on the tile temperature high fever. B steam feed water pump water pump drive end bearing supporting temperature due to a high temperature. 2, the cause of the accident analysis of feed water pump and two small steam turbine equipment system design is the first time cooperation, burn tile accident in xinji first appeared during debugging. Determined by way of analysis for the lubricating oil system design is unreasonable, lubricating oil system to the distribution of bearing oil supply system can not meet the requirement of the operation. According to the Shanghai steam turbine works for the safe operation of the steam turbine bearing lubricating oil hydraulic design requirements of 0. 098 - 0. 147 mpa, Shanghai power plants for the safe operation of the feed water pump bearing lubricating oil hydraulic design requirements: 0. 18MPa―0. 20 mpa, and steam feed water pump group oil system integration design, USES pressure lubricating oil mother tube design is 0. 15MPa。 In the oil system of lubricating oil pump outlet of mother tube Shanghai steam turbine factory design have a throttling orifice plate adjustment pressure welding type, and design on feed mother tube with a pressure relief valve, when the mother tube and the safety of hydraulic pressure more than design pressure when part of the lubricating oil from the relief valve discharge quickly to the lubricating oil tank make the pipe will not run overpressure, on the way of oil inlet pipe of each bearing oil line for the same root, each bearing feed order after the first small turbine feed water pump ( As shown in figure) 。 The feed water pump bearing entrance hydraulic tile burning accident cannot meet the operation requirements. 3, take measures due to the lubricating oil system only small turbine was considered in the design of the bearing oil supply pressure meet the operation requirements, to the design of feed water pump bearing oil supply pressure without further consideration, feed water pump bearing caused by tile burning. So the lubricating oil pump output is not affected on the original lubricating oil system under the condition of technical renovation, after modification, the system should be able to meet the feed water pump bearing oil pressure, small turbine type design, operation requirements, and ensure the steam feed pump group under various operating conditions on the reliability, security. For Shanghai steam turbine factory the lubricating oil system working principle of this design for technical improvement, the lube oil pump outlet pressure adjustment, the throttling orifice plate for replacing manual adjustable throttle valve to adjust the feed water pump bearing pressure lubricating oil mother tube first meet the lubricating oil pressure of 0. 18MPa―0. 20 mpa. At the same time the # 1 and # 2 for steam turbine bearing oil, imports of tubing in each had a manually adjustable throttle valve and to adjust the monitor pressure gauge, adjust the # 1, # 2 bearing oil inlet pressure to zero. 15 mpa, at the same time satisfy the safety of mother tube in the hydraulic pressure relief valve to adjust the setting pressure stress ( As shown in figure) 。 So it can satisfy the feed water pump at the same time, the design of the small turbine running hydraulic needs, maintain the tile burning failure during operation. 4, and end with the steam feed pump group that the flaws of the oil system of steam turbine oil, feed water pump system in terms of design the interface, there is no system, no do it seamlessly. Wuhu company through professional survey, the research on the system, the oil pressure distribution, by adjusting the system satisfy the small turbine, feed water pump bearing shell oil, so as to solve the steam feed water pump process defects, but also for the new unit design in the public system design aspect, want to consider to meet the system as a whole and associated auxiliary equipment performance requirements, have very good reference.