Study On The Influence Of Graphene Modified Turbine Oil On The Performance Of The Lubrication System Of The Hydropower Unit

The lubrication performance of the lubrication system of the hydrogenerator unit is directly related to the wear and safety of the whole unit shafting.The author sets out to provide a new way to solve the problem of abnormal temperature of the bearing bush of the hydropower unit by improving the turbine oil with graphene,to reduce wear in order to protect the bearing bush and reduce the temperature of the bearing bush.By comparing the effects of different dimensions of carbon nanoparticles as the main additive to modify turbine oil on the performance of anti-wear and extreme pressure;As the additive,graphene is the best in anti-wear.the best content is 0.3wt%.The maximum P_B value increased by 52.38%compared with the base oil.The friction coefficient decreased by 24.75%,the wear spot diameter decreased by 28.7%,and the wear spot surface area decreased by 73.7%.By comparing different dispersing processes,it is determined that the best mass fraction of redox graphene RGO is 0.3wt%,and the friction reducing and antiwear performance of modified turbine oil is the best.The P_B value is 607.6 N,which is 47.61%higher than that of base oil(411.6 N);the friction coefficient of long-term wear experiment is 0.0807,which is20.1%lower than that of base oil.The best mass fraction of high alkali value synthetic calcium sulfonate is 2wt%,and the friction reducing and antiwear performance of modified turbine oil is the best,P_B value is 607.6 N,which is 47.61%higher than that of base oil(411.6 N),and the friction coefficient of long wear experiment is 0.0797,which is 21.09%lower than that of base oil.When the optimum ball milling time is 2 hours,the friction reducing and antiwear performance of modified turbine oil is the best,P_B value reaches the maximum value(627.2 N),which is 52.38%higher than that of base oil(411.6 N),which improves the protection effect of lubricating oil on friction pair under extreme conditions;the friction coefficient of long-term wear experiment is 0.0729,which is 27.82%lower than that of base oil.In the later stage,the field test of hydropower unit was carried out.By comparing the temperature and temperature rise of bearing bush between before and after adding,the influence of modified turbine oil with graphene additive on the performance of bearing lubrication system of hydropower unit was analyzed and summarized.For the vertical unit,take the water guide bearing as an example.After adding graphene additive,the temperature of the water guide bearing pad of the unit at the same power dropped from 59~60℃to 57~58℃,a decrease by about 2~3℃;for small horizontal hydropower unit,take thrust bearing as an example.After adding graphene additive,the unit has obvious cooling performance(or the temperature rises slowly);the decrease of bearing pad temperature shows that the additive has obvious anti-wear effect on water guide bearing pad lubrication system,and has obvious protection and repair effect on bearing pad clearance friction pair.