Why is it necessary to perform a trial run on a steam turbine? How to start it up?

Wow, someone could even ask such a beginner-level question! A turbine relies on steam to drive the blades into rotation, which in turn causes the main shaft to spin and powers rotating equipment or generators to produce electricity. The process of starting a turbine from a stationary state is referred to as startup. Depending on the metal temperature of the turbine’s cylinders before startup, this process can be classified as cold-start or hot-start; however, as this process is relatively complex, it will not be discussed in detail here!

The question is asking why a reverse rotation is needed; could you please read the question carefully? And talk about others too

Hehehe, what an erudite set of accusations.

I really didn’t understand the real intent of the question; it was asking why a turbine rotates after steam is introduced into it, and what is the principle behind its startup It still asks why the engine needs to run at a low speed during warm-up before accelerating, and what the entire acceleration process looks like

Large turbines all have a minimum speed; at too low a speed, an oil film cannot be properly formed at the contact area between the sliding bearings and the shaft journals, leading to wear. Our unit’s turbines are equipped with a minimum speed interlock; it seems to be 350 rpm, and the turbine stops automatically if the speed drops below this value. The spinning speed must be above 500 rpm

It is the startup of the turbine – high-pressure steam is used to spin up the turbine rotor; once the steam enters the turbine, it hits the blades on the rotor, causing the rotor to rotate. Prime rotation is generally carried out alongside warm-up, which is why it is also called prime rotation warm-up. Ramping up is necessary for the unit in order to prevent it from being damaged due to too rapid loading. Taking all factors into account, surge starting is intended to enable the unit to start up in a healthier and safer manner. The impulse rotor is key to the starting process; the actual start takes place here, as all previous steps were merely preparatory. The impulse rotor marks the beginning of the transition of a turbine from a cold state to a hot state, and from rest to rotation. The key to operation is to control the increase in the metal temperature of the turbine and the increase in rotor speed. When the rotor just starts to rotate, fresh steam at near-rated temperature enters the turbine whose metal is at a lower temperature; at this point, the steam undergoes intense condensation and releases heat, which causes rapid changes in the temperature of the turbine’s metal and can lead to significant thermal stresses. As the rotational speed increases, the temperature of the turbine also rises; the contribution of heat transfer by convection of steam within the cylinder to the metal gradually increases, which is why the rate of temperature rise of the metal slows down. The main purpose of starting a turbine manually is to test the interlocks. I haven’t experienced exactly how to perform this reversal, so I hope someone experienced in this area can offer some help.