# How does the pressure in a steam header react to a sudden load change?

#### Chandrakanth_balusa

Gold Member
Hello People,
I have querry regarding the pressure variation in the steam header in the steam power plant.
if there is a sudden change in the load and the mass flow through the turbine has to be increased, i would like to know how it effects the pressure value? if yes how does this change influence the process?

could you also suggest me a nice resoure where I can study about the header and it operation.

BR

Chandu

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#### anorlunda

Mentor
Gold Member
This is probably a drum type boiler.

A simplified model would be to think of pressure as the integral of the mismatch between energy in and energy out. Actually, energy storage depends on both temperature and pressure, but in a simplified model, imagine temperature to be constant.

So what happens when you make a step change in energy out?

How does the control system respond to change the energy in? How long does that take?

#### Chandrakanth_balusa

Gold Member
This is probably a drum type boiler.

A simplified model would be to think of pressure as the integral of the mismatch between energy in and energy out. Actually, energy storage depends on both temperature and pressure, but in a simplified model, imagine temperature to be constant.

So what happens when you make a step change in energy out?

How does the control system respond to change the energy in? How long does that take?
so I understand from you response that the pressure is a function of energy in and out.
but if the pressure in the header varies, does it effect the process? I know that this variation is going to be for a very short time since the control system triggers the energy in based on the energy out value.

i am a bit curious to know what if the boiler takes a bit long to serve the energy in and the pressure in the header goes on reducing. mathematically is there any relation between pressure drop in the header and the output f turbine or torque or speed.

#### anorlunda

Mentor
Gold Member
mathematically is there any relation between pressure drop in the header and the output f turbine or torque or speed.
Yes. Again speaking in very approximate numbers, turbine power is proportional to presssure times mass flow rate

"How does the pressure in a steam header react to a sudden load change?"

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