Steam turbine performance witr reduction in inlet pressure

[ICECOOL]

Dear All,

I am estimating a future problem while still in erection phase for 60 MW steam turbine. I may need your help to estimate a solution.

Due to some reason my process heater is not able to generate steam at the desired pressure (other parameters including Temperature and Flow rate are remain same). Therefore I want to know the effect of reduce inlet pressure in the HP Steam turbine output. The steam parameters are mention below

Steam Turbine is Superheated, Condensing type with Reheater (HP-LP combination)

1. Normal condition
Manufacturer : GE
HP Steam inlet pressure : 98 bar
HP Steam inlet temperature : 365 Degree C
Inlet Flow rate : 70 kg/s
HP Steam Turbine outlet pressure 23 bar
HP Steam Turbine outlet Temperature 220 Degree C

There is 1 extraction of steam from the turbine to HP Heater

2 Revised condition

HP Steam inlet pressure : 75 bar
HP Steam inlet temperature : 365 Degree C
Inlet Flow rate : 70 kg/s

Can somebody suggest the role of pressure in steam turbine. Will steam turbine able to work properly even at low inlet pressure?

 

[Jobrag]

Ask the OEM what the consequences will be.

 

[ICECOOL]

OEM will not support you after they get the payment. Also, the problem is not in the turbine. It was designed correctly. The only thing changed is the inlet parameter due to Steam Generator limitation.

 

[Jobrag]

If you're in the erection phase isn't there going to be any commissioning, and site testing? Talk to site engineers and ask them to talk to tech support, it may be that you need a redesign of the inlet vanes to get the most out of what you've got.

 

[russ_watters]

OEM will not support you after they get the payment. Also, the problem is not in the turbine. It was designed correctly. The only thing changed is the inlet parameter due to Steam Generator limitation.

Nonsense. Such things never come without warranties and even past the warranty they would help with such a question. Heck, they probably have performance tables ready. Besides, if it is still being built, the OEM still owns it.

[edit] This makes all sorts of no sense: even if the OEM tried to back-out the minute it left the factory, procurement wouldn't have paid for it yet and still has leverage. And you have a whole project/engineering team who's job it is to get the installation right. This is a real-world problem that needs to be dealt with in the real-world.

 

[AlephZero]

Besides, if it is still being built, the OEM still owns it.

These days, the OEM might own it for its entire working life. Customers don't buy the hardware, they buy the functionality that the hardware provides. http://en.wikipedia.org/wiki/Power_by_the_Hour.

 

[ICECOOL]

russ_watters,

The project got delayed due to some reason. The turbine is on site since last 2 years. All the engineering/procurement team is changed now..you are right its a real world problem. It is true that will find out its effect during the commissioning phase. But as an engineer I want to save the turbine life by not exposing it to problematic things.

But its a different story. My question is remain same..if not go that specific for that project can somebody tell me what is the effect of inlet pressure variation in MW output. Also, how to calculate it.

 

[russ_watters]

There is a right way (or two) to do this and a wrong way. You want to do this the wrong way and we aren't going to help you do that.

So:
-What is the model # of the turbine?
-Do you have a submittal for it? If not, call the vendor and get one.
-The catalog cut sheet probably has performance and selection info. Look it up.