Research And Application Of Cooling And Noise Reduction Technology For Large Horizontal Shaft Axial Pump

In recent years,domestic scholars have carried out a lot of research work on hydraulic optimization design of horizontal axial flow pump device,put forward some new design methods,and become mature.However,the research on temperature and noise reduction of horizontal units is still weak,which has become a bottleneck restricting the construction of high-level pumping stations.As we know,the heat source of the pump station comes from the main pump unit,auxiliary equipment,electrical equipment,lighting and sunshine,among which the main pump unit is the main heat source.If the heat generated by the heat source cannot be exchanged out in time,the load capacity of the unit will be significantly reduced,the efficiency will be reduced,the aging of mechanical and electrical equipment will be accelerated,and even serious accidents such as tile burning and insulation breakdown will occur,and excessive temperature rise is not suitable for project management.The main source of noise is the main pump set,bearing support,auxiliary equipment,electrical equipment and water flow sound.Some of these noise sources are natural to the equipment and water flow of the unit,while others can be reduced by optimizing the design,such as the design of the cooling system of the motor,the design of the bearing structure,etc.To sum up,the key to cooling and noise reduction of large horizontal axial flow pump station is to construct a reasonable cooling system(technical water supply system)and a reasonable supporting structure.In this paper,the key technology of cooling and noise reduction for large horizontal axial flow pump unit is studied based on the technical transformation of Qinhuai xinhe pump station.From energy consumption,reliability,installation and maintenance,equipment investment and other aspects of different technical water supply systems such as air-cooled water cooling units,plate heat exchangers,coil heat exchangers,etc.Based on the analysis of motor cooling,thrust bearing cooling and motor bearing structure,the new cooling methods of motor and thrust bearing and the new structure of motor bearing are studied to solve the key technical problems of cooling and noise reduction.A scientific and reasonable closed cooling cycle technology water supply system is put forward.Based on the basic principles of fluid mechanics,heat transfer,combined with air-cooled water chilling unit,the characteristics of circulating water pump and pipeline system,etc.,using Flowmaster software construction unit cooling cooling system(technical water supply system)model,the research in different lift,different seasons(summer and winter),the running characteristics of large horizontal axial flow pump unit cooling cooling system.Finally,according to the research results,the axial flow pump unit in Qinhuai xinhe pumping station is reformed in an economical and feasible way.Through on-site testing of the unit's temperature rise,noise,efficiency,etc.,and comparing the measured parameters before technical transformation,the following results were obtained:the motor winding temperature rise decreased by 26K,the motor bearing temperature rise decreased by 15K,and the thrust bearing temperature rise decreased by 27K.The operating noise of the unit is reduced by 6dB,and the motor efficiency is improved by 4.7%.It shows that after the motor is changed to water cooling,the motor bearing is changed to three-bearing structure,and the thrust bearing is changed to water cooling,the unit achieves obvious effects in cooling,noise reduction and efficiency improvement.According to the simulation modeling of the technical water supply system of qinghuai xinhe pumping station with Flowmaster software,the simulation results obtained show that the transformation of the cooling and noise reduction technology and the technical water supply system of the pumping station is successful.