The Importance of a Running Turning Gear in TG Rolling

In the world of power generation, the turning gear plays a crucial role in the operation of turbine generators (TG). It is a mechanical device that rotates the turbine at a slow speed during shutdown periods to prevent distortion of the rotor due to uneven cooling. The turning gear is engaged before the turbine generator starts rolling, and its importance cannot be overstated. This article will delve into the reasons why a turning gear runs before TG rolling and why it is required.

What is a Turning Gear?

A turning gear, also known as a barring gear, is a device used in power plants to rotate large turbines at a slow speed when they are not in service. This slow rotation helps to prevent the rotor from warping due to uneven cooling. The turning gear is usually engaged when the turbine is shut down and disengaged before the turbine is started up.

Why Does a Turning Gear Run Before TG Rolling?

The turning gear is engaged before TG rolling for several reasons. Firstly, it helps to ensure that the rotor is evenly cooled. When a turbine is shut down, the heat it has generated does not dissipate evenly. The top of the rotor cools faster than the bottom because heat rises. This uneven cooling can cause the rotor to warp or bend, which can lead to serious damage. By rotating the rotor slowly, the turning gear helps to distribute the heat evenly, preventing warping.

Secondly, the turning gear helps to distribute lubricating oil evenly across the bearings. This ensures that all parts of the bearing are adequately lubricated before the turbine starts up, reducing the risk of bearing failure.

Why is a Turning Gear Required?

The turning gear is required for several reasons. As mentioned earlier, it helps to prevent rotor warping due to uneven cooling. This is crucial because a warped rotor can cause serious damage to the turbine, leading to costly repairs and downtime.

Furthermore, the turning gear helps to ensure that the bearings are adequately lubricated before the turbine starts up. This reduces the risk of bearing failure, which can also lead to serious damage and downtime.

Finally, the turning gear helps to reduce the risk of thermal stress. When a turbine is started up, it heats up rapidly. If the rotor is not rotating, this rapid heating can cause thermal stress, which can lead to cracking and other forms of damage. By rotating the rotor slowly, the turning gear helps to distribute the heat evenly, reducing the risk of thermal stress.

In conclusion, the turning gear plays a crucial role in the operation of turbine generators. It helps to prevent rotor warping, ensure adequate lubrication of the bearings, and reduce the risk of thermal stress. Therefore, it is engaged before the turbine generator starts rolling and is an essential component of any power plant.