Study On Safety Operation Technology Of Niangziguan Water Supply Pump Station

Yangquan city Niangziguan water supply project built in the middle of the taihang mountain.The total length is about 30 km,from the water intake of Niangziguan Power Plant in the east to Maishan of Yangquan City in the west,and the end point is the distribution pool of Yangquan Water Plant.The first,second and third stage pressurized pump stations and lifting pipes have been constructed,with 12 main water pumps,with a total installed capacity of12770 KW and a total toposional head of 419.396 m.Niangziguan pumping station pumps from running up to now,has been nearly three years,the water pump imports and mouth ring junction within the tao and the water pump pump shell,a water level of impeller inlet side in the same place to produce local cavitation,sealing ring arc on the pump shell and cover the different degree of cavitation,which appear on the serious influence to the pump unit economic and safe operation;Many air valves on the water supply pressure pipeline leak water.Therefore,this paper studies the technical problems in the operation of Niangziguan Water Supply Pump Station.The main contents and conclusions are as follows:(1)Research on water pump cavitation1)Through the calculation model of water pump installation elevation,the maximum installation elevation of water pump without cavitation in Niangziguan pump station is calculated to be 386.234 m,while the actual installation elevation exceeds the allowable installation elevation,which is one of the reasons for water pump cavitation in Niangziguan pump station.2)In view of the cavitation damage of the pump in Niangziguan Pump Station,an economic plan for repairing the cavitation parts is put forward through analysis and comparison.(2)Study on water leakage of air valve1)hollow valve niangziguan water supply project is also running water leaking in the operation of the reason is that in the actual engineering,often due to the large flow,flow inside the air valve rapidly,containing trace gas water quickly assembled over the floating ball is easy to form small eddies,lead to float above the pressure is too big,and so cannot be higher than normal,can’t plug the vent,can make the water leak,It leads to the waste of water resources and even endangers the safety of water supply system.2)In view of the leakage of air valve over the water supply line of Niangziguan pumping station,the air valve of DN100 is modeled geometrically by Solid Works modeling software.Based on the finite volume method,a dynamic grid is set to perform numerical simulation and solution.Inlet flow velocity is 5 m/s at the time of the air valve internal floating ball floating every moment in the process of movement speed and pressure increases with time,and in 400 ms time tends to be stable,generated by the pressure and velocity contours can be found that the biggest stress position at the bottom of the buoy and floating ball just outside the location and the fluid domain narrow channels on both sides,The maximum speed is located at the small inlet at the bottom of the buoy.Exploring the position of maximum speed and maximum pressure lays the technical foundation for the technical transformation of air valve.3)By controlling different inlet flow rates,the flow grid was solved by FLUENT to obtain the internal pressure field of the air valve and the pressure values above and below the float ball.The final pressure situation inside the air valve at different flow rates was analyzed to find out that the flow rate range under which the float ball could normally float up was below 35m/s and above 50m/s.When the inlet flow rate is between 35m/s-50m/s,the floating ball will be unable to float due to too much pressure above it,resulting in water leakage phenomenon of DN100 type waterproof hammer air valve,which cannot protect the pipeline.To explore the normal flow rate range of the floating ball of air valve and lay the technical foundation for the safe operation of Niangziguan water supply project.(3)Through the research on the key technical problems in the operation of Niangziguan water supply pumping station,the main objective is to provide technical support for the safe operation of Niangziguan water supply project.