Gas Turbine compliance to Standard
Gas Turbine compliance to Standard
(OP)
Hi,
I am auditing a gas turbine unit compliance to a standard (API 616), and item 5.4.3.4 states :The governor for mechanical drive applications shall limit speed to 105% of rated speed.
I found that there is a trip setpoint a 110% of rated speed and no other details on the governor control range; Is there other mechanism to limit the speed to 105% other than tripping the unit? How should I interpret the standard?
I am auditing a gas turbine unit compliance to a standard (API 616), and item 5.4.3.4 states :The governor for mechanical drive applications shall limit speed to 105% of rated speed.
I found that there is a trip setpoint a 110% of rated speed and no other details on the governor control range; Is there other mechanism to limit the speed to 105% other than tripping the unit? How should I interpret the standard?





RE: Gas Turbine compliance to Standard
RE: Gas Turbine compliance to Standard
rmw
RE: Gas Turbine compliance to Standard
Unlike governing, Trip is a safety function. For turbines, trip function is provided by an independant system.Usually trip speed is set at about 105% of MCS. MCS is the "Maximum Continous Speed". MCS is at least 105% of the rated speed.
Operation above 105% is not menat to be continous. For most applications (power gen as well as mechancial drive) such a high speed operation may not even be meaningful. Operators would know something is wrong. The reason why the turbine is not tripped immediately above 105% is to avoid nuisance trips caused by the governor control overshooting beyond 105%.