What is the purpose of barring the engine?

[LeilaAnn]

Here is an introduction to the purpose of barring the engine: Preventing thermal bending of the wheels: It prevents the turbine rotor from thermal bending caused by uneven heating. Before starting the impulse, steam is generally supplied to the shaft seal. Most of this steam enters the upper part of the cylinder, creating a temperature difference between the upper and lower parts of the cylinder. After shutdown, a temperature difference also exists between the upper and lower parts of the cylinder. If the rotor remains stationary at this time, it will bend and deform. Therefore, the rotor must be rotated to prevent shaft bending. Inspection: Before starting, barring is performed to check whether the turbine meets the operating conditions; for example, whether there is friction between the stationary and moving parts, whether the main shaft is bent or deformed, and whether these exceed the specified values. Inertial force: It reduces the inertial force when starting the rotor.