Application of Ultrasound Gas Detectors in Gas Turbine Package

A Gas Turbine (GT) usually has hot surfaces and it is installed with the fuel gas system inside a ventilated acoustic enclosure. Several connections are present in the fuel gas system and in the GT combustion chamber that could become sources of leakage. For this reason, the introduction of hydrogen as fuel for Gas Turbines requires attention in the design phase due to properties such as a large flammability range and low ignition energy. To prevent hazardous events in case of unexpected leakage, it is required to have a Gas Detection system which command an emergency shut down of the GT train. Fundamental characteristics of a gas detection system include its reliability and the response time. Since hydrogen is more reactive than conventional natural gas, the time required to detect gas leaks becomes a crucial factor. For this reason, an intervention as fast as possible is strongly recommended. Ultrasound gas detectors have these features but they regularly work in open environment and there is no evidence of their application in GT enclosures. This work describes some tests of Ultrasonic Gas Leak Detectors carried out in operating GT package. Ultrasound gas detectors were installed in several locations inside a GT enclosure and tested during different GT load conditions up to Full Speed Full Load. Hydrogen leaks have been simulated using helium as surrogate to verify GD performances. Promising results achieved from this test are shown in this paper.