METHOD FOR TESTING AN OVERSPEED PROTECTION APPARATUS OF A SINGLE-SHAFT SYSTEM

摘要

A method for testing an overspeed protection apparatus of a single-shaft system that includes: a) operating the system at nominal speed and under electrical load, wherein the load is selected to be low enough that, after dropping the load, the speed of the system rises such that the speed remains below steam turbine threshold speed lower than gas turbine threshold speed, such that first overspeed protection is triggered when the speed of the steam turbine reaches the steam turbine threshold speed, and second overspeed protection is triggered when the speed of the gas turbine reaches the gas turbine threshold speed; b) dropping the load; c) increasing the mass flow of the steam introduced into the steam turbine and/or of the fuel introduced into the gas turbine such that the speed of the steam turbine reaches the steam turbine threshold speed; d) testing whether the first overspeed protection is triggered.

主权项

1. A method for testing an overspeed protection apparatus of a single-shaft system having a gas turbine, a generator and a steam turbine, the method comprising:
a) operating the single-shaft system at its rated speed and under an electric load connected to the generator, wherein the load is chosen to be low such that, after the load is shed, the speed of the single-shaft system rises such that the speed remains below a steam turbine limit speed which is lower than a gas turbine limit speed, wherein the overspeed protection apparatus is set up such that a first overspeed protection is triggered as soon as the speed of the steam turbine reaches the steam turbine limit speed, and a second overspeed protection is triggered as soon as the speed of the gas turbine reaches the gas turbine limit speed; b) shedding the load; c) raising the mass flow of the steam fed into the steam turbine and/or of the fuel fed into the gas turbine such that the speed of the steam turbine reaches the steam turbine limit speed; and d) checking whether the first overspeed protection is triggered.