Hello,

I am been reading some information from different sources about the IGV position for Westinghouse W501D5 (100MW). but I am a little confused because the first information says that during initial acceleration the IGVs are moved from fully closed position, approximately 37 degrees, to an intermediate starting position (22 degrees), and remain there until turbine reaches nearly synchronous speed (3580 rpm) when they are fully opened to approximately 7 degrees.

The second information says that during initial acceleration the IGVs are moved from fully closed position to intermediate position (22 degrees), then when the turbine reaches 3330 rpm the IGVs returns to fully closed position and remain there until turbine is synchronized and loading more than 8 MW, then then IGVs are fully opened

Which information is correct?

 

Hi,

I am using W501D5A. In our unit, here is the condition:
1. Turbine Not Running: Fully Closed (+38 Deg)
2. Start Up to 3275 rpm: Intermediate (+20 Deg)
3. 3275 rpm to 10 MW: Fully Closed (+38 Deg)
4. Greater than 10 MW to Full Load: Ramped Fully Open (-2 Deg)

I think the second opinion is the valid one if the W501D5 control same with W501D5A

Best Regards;
Sati

>The second information says that during initial acceleration
>the IGVs are moved from fully closed position to
>intermediate position (22 degrees), then when the turbine
>reaches 3330 rpm the IGVs returns to fully closed position
>and remain there until turbine is synchronized and loading
>more than 8 MW, then then IGVs are fully opened
>
>Which information is correct?

 

The second information says that during initial acceleration the IGVs are moved from fully closed position to intermediate position (22 degrees), then when the turbine reaches 3330 rpm the IGVs returns to fully closed position and remain there until turbine is synchronized and loading more than 8 MW, then then IGVs are fully opened

This is correct?

 

Does the last sentence a question or statement?

Best Regards;
Sati

>The second information says that during initial
>acceleration the IGVs are moved from fully closed position
>to intermediate position (22 degrees), then when the turbine
>reaches 3330 rpm the IGVs returns to fully closed position
>and remain there until turbine is synchronized and loading
>more than 8 MW, then then IGVs are fully opened
>
>This is correct?

 

Hello Sati

Thank you for a quick reply now I understand how the IGV operates. I have another quick question if is not too much to ask. What would be the normal temperatures for the disc cavities? and how is prevented the surge protection for the W501D5A.

a) 2-1, 2-2
b) 3-1, 3-2
c) 4-1, 4-2.

I am trying to understand all parameters and features of this kind of turbine

Thank you for your help

 

Hi Jolcan,

In general, here are profile of our disc cavity temp in early 2014.

a) 2-1: 723 Deg F, 2-2: 728 Deg F
b) 3-1: 666 Deg F, 3-2: 664 Deg F
c) 4-1: 626 Deg F, 4-2: 586 Deg F

In mid Q3, we change our disc cavity 2 and 3 orifice (put smaller). This initiative was conducted to gain more power. Unfortunately in the first unit, it's fail. The disc cavity 2 goes up until 900 Deg F. We install the larger orifice on this unit. The second unit have no issue but there is no proven evidence for additional output.

Profile are:
a) 2-1: 750 Deg F, 2-2: 750 Deg F with 80% Disc Cavity Cooling Valve Opening
b) 3-1: 651 Deg F, 3-2: 670 Deg F
c) 4-1: 638 Deg F, 4-2: 595 Deg F

I hope it answer your questions.

Best Regards;
Sati