Jacking oil pump in Gas Turbine

1.)   Startup Phase

·       When the gas turbine is started, the rotor shaft begins to rotate at a low speed. During this initial phase, the jacking oil pump is activated to supply hydraulic pressure to the turbine’s bearings.

·       The jacking oil is directed to the bearings, which are typically hydrodynamic or tilting pad bearings. These bearings are designed to support the weight of the rotating shaft and allow it to rotate smoothly with minimal friction.

·       The pressurized oil creates a film between the rotating shaft and the bearing surfaces. This film of oil serves as a lubricant, preventing direct metal-to-metal contact between the shaft and the bearings.

·       By lifting and supporting the rotor shaft, the jacking oil pump helps to ensure that the turbine starts up smoothly and without excessive wear on the bearings.

 

2.)   Steady-State Operation

·       Once the gas turbine has reached its operating speed and temperature, the jacking oil pump may continue to supply oil to the bearings at a reduced pressure to maintain proper lubrication and support during steady-state operation.

·       The continuous supply of oil helps to dissipate heat generated by friction between the rotating shaft and the bearings, ensuring that the bearings operate within their designed temperature limits.

 

3.)   Shutdown Phase

·       When it is time to shut down the gas turbine, the jacking oil pump plays a crucial role in the process.

·       As the turbine slows down, thermal expansion and contraction occur within the turbine components, including the rotor shaft and bearings.

·       The jacking oil pump continues to supply oil to the bearings during the shutdown phase, ensuring that they remain lubricated and supported as the turbine comes to a stop.

·       By maintaining proper bearing clearance and preventing metal-to-metal contact, the jacking oil pump helps to prevent damage to the bearings and other critical components during shutdown.

 

4.)   Emergency Shutdown

·       In the event of an emergency shutdown or trip of the gas turbine, the jacking oil pump may provide emergency lubrication to the bearings to prevent damage during rapid deceleration.

·       Emergency shutdown procedures typically include activating the jacking oil pump to ensure that the bearings are adequately lubricated and supported as the turbine comes to a sudden stop.

In summary, the jacking oil pump in a gas turbine system serves multiple critical functions throughout the startup, operation, and shutdown phases. By providing lubrication and support to the turbine’s bearing, it helps to minimize friction, reduce wear, and ensure the safe and efficient operation of the turbine over it operational lifespan.