The role of the oil injector in the lubricating oil tank of the steam turbine

The oil injector of Lianyungang Lingdong Electromechanical Equipment Co., Ltd. is a device used for supplying lubricating oil to internal steam turbines using an oil injector system. Its power oil comes from an independent oil pump (starting from an AC high-pressure oil pump), and the main oil pump is a centrifugal pump. To avoid accidents caused by self suction and air leakage, positive pressure oil injection is required. Therefore, the oil supply system is a dual oil injector system with an oil injector for lubrication and an oil injector for the main oil pump. But there are also single jet oil systems that combine the above two functions, which are used in smaller units. In recent years, large units have also used single jet oil systems, such as N300-16.7-537/537 units:

The occurrence of low lubricating oil pressure or low oil injection pressure in the steam turbine unit is a common phenomenon and an unsafe working condition that needs improvement. Lianyungang Lingdong Electromechanical Equipment Co., Ltd. has the ability to do this work and has solved the problem of oil injectors, which is a successful example of cooperation with a lubrication box manufacturer.

For example, the lubricating oil pressure of a 50MN unit in a large petrochemical enterprise in Northeast China is only 0.06MPA, and the on-site requirement is 0.1 MPA or slightly higher. According to the original size of the oil injector, the oil supply capacity is 1050l/min. Taking into account factors such as level difference, resistance of the oil cooler, and the relationship between flow rate and resistance, the required oil volume (should be 1420l/min) was calculated. The improved oil injector designed based on this has successfully met the requirements. Lubricating oil pressure is 0.11MPA. The safety of unit operation is also guaranteed.

A certain 300MW unit is a different type of problem, as there is a "dangerous" speed zone during the start-up and acceleration process. At this point, the outlet oil pressure of the oil injector drops to a low of 0.135 MPA, and it should be greater than 0.2 MPA to be safe. The reason is that at this speed, the main oil pump has a considerable amount of oil pressure, which impacts the check valve of the main oil pump and reduces the outlet check valve of the high-pressure AC oil pump. The two affect each other, reducing the amount of oil input and lowering the oil pressure. The method of encountering such problems in the manufacturing plant is to install an oil injector to start the pressure reducing slide valve, in order to avoid the "dangerous" speed. Under this working condition, the main oil pump also discharges oil according to the speed, without impacting the AC oil pump supply oil, until it reaches the safe speed (which is 500-600 rpm higher than the dangerous speed). The function of starting the pressure reducing slide valve is automatically released, and the oil injector also has a supplementary function until it is fully linked with the main oil pump to supply lubricating oil.

In addition, Lianyungang Lingdong Electromechanical Equipment Co., Ltd. also supplies generator air side sealing oil injectors.

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