Let’s discuss the effects of scaling on turbine blades
Thread Content
Let me first mention my doubts: 1. With fouling on the blades, the pressure drop before and after the blades should increase, right? So why does the wheel chamber pressure increase? With the increase in pressure drop, the pressure after the speed control stage should decrease compared to before scaling occurred! !
Dear, I think there are variables involved here. If the load remains constant, the amount of air intake will naturally increase; if the air intake volume stays the same, then the pressure in the wheel chamber will decrease
Due to blade fouling, with the load remaining unchanged, it is necessary to increase the opening degree of the throttle valve; this leads to an increased steam consumption. When the excess steam does not perform its function effectively in the nozzles, it results in a higher temperature in the wheel chamber.
Scaling should occur on the blades behind the speed control stage; therefore, the pressure in the wheel housing behind that stage should increase. The pressure drop across the speed control stage decreases, resulting in a reduction in efficiency. It is the pressure drop on the rear blades that increases
Scaling occurs on both the nozzles and the stationary and rotating blades; the main consequence is a significant drop in the efficiency of the turbine chamber, which leads to reduced working efficiency. As a result, the air intake volume increases, and the shaft displacement also increases accordingly.
If the blades are severely fouled, there will definitely be significant changes in steam volume, flow rate, and temperature. This ultimately led to the shutdown of the unit for maintenance.