racookpe1978
Nuclear
- Feb 1, 2007
- 5,984
We are calculating substantially different nozzle movement (hot position of the turbine bleed and inlet piping nozzles) for a repair on an older competitor's turbine. Not many original vendor prints and no engineering design analysis documents readily available.
In particular, our calculations for the hot positions of the steam nozzles are significantly different from the list.
Assume a steel casing, exp coef = 6.4 x 10^-6.
Nozzle 1.
Assume 400 deg F at this particular nozzle, 70 F original cold temp. Delta T = 330 deg F.
The nozzle_1 extends 18 inch above a 36 inch dia turbine casing.
Nozz_1 is on CL, on top of the casing.
Total height_at cold temp z_0 = 36.0 inch
It is on centerline, delta y = 0. (The list does agree with us on that at least!)
To get Z_hot, I am using the total height of the nozzle from CL. 18 in casing radius + 18 nozzle length = 36 in x delta_T x coef of exp.
But this exceeds the list value by 40%.
Could the original list be developed assuming the casing did not expand as a expect?
Nozzle 2.
12 inch to the right of CL.
This nozzle, also at 400 deg F hot conditions, moves outboard and up.
Is not the outward movement also simply y_hot = 12 in x delta T x coef of expansion?
Or is the casing not expanding linearly sideways as I expect? (That I should be taking the sine and cosine of the projected casing expansion from 70 deg to 400 degree?)
In particular, our calculations for the hot positions of the steam nozzles are significantly different from the list.
Assume a steel casing, exp coef = 6.4 x 10^-6.
Nozzle 1.
Assume 400 deg F at this particular nozzle, 70 F original cold temp. Delta T = 330 deg F.
The nozzle_1 extends 18 inch above a 36 inch dia turbine casing.
Nozz_1 is on CL, on top of the casing.
Total height_at cold temp z_0 = 36.0 inch
It is on centerline, delta y = 0. (The list does agree with us on that at least!)
To get Z_hot, I am using the total height of the nozzle from CL. 18 in casing radius + 18 nozzle length = 36 in x delta_T x coef of exp.
But this exceeds the list value by 40%.
Could the original list be developed assuming the casing did not expand as a expect?
Nozzle 2.
12 inch to the right of CL.
This nozzle, also at 400 deg F hot conditions, moves outboard and up.
Is not the outward movement also simply y_hot = 12 in x delta T x coef of expansion?
Or is the casing not expanding linearly sideways as I expect? (That I should be taking the sine and cosine of the projected casing expansion from 70 deg to 400 degree?)
