Minimum bypass capacity for a Power Plant Load Rejection Test

[hamidun]

Hi All,

In commissioning a Power Plant, if bypass capacity is 40% and we want to do 100% Load Rejection Test, is it recommended to go ahead with Load Rejection Test?

As if I am assuming, the excess load (60%) will go to safety valves? Is my understanding correct?

Kindly share your experience.

Thank you.

 

[RRaghunath]

That's right. 100% Load rejection test is irrespective of the Bypass capacity built in to the boiler /Turbine system.
All power plants are designed to withstand 100% load rejection without trip of the unit.

R Raghunath

 

[bacon4life]

I had heard that hydro generators sometimes exceed 35% overspeed and the some nuclear plants trip the generator for full load rejection. Is the requirement not to trip specific to gas turbines?

 

[hamidun]

RRaghunath,

Appreciate your straightforward answer.

bacon4life,

Hope that others will share their experience for your question.

 

[RRaghunath]

bacon4life, the requirement to be capable of 100% load rejection is there for Gas and Steam Turbines. This calls for fast acting control systems and valves.

R Raghunath