TCL have developed a transducer that monitors the angular position of the variable inlet guide vanes (VIGV) of a turbine and converts this into an electrical signal that can be used as an input to a SCADA system or chart recorder. The device was specifically developed for the RR Avon gas generator but can be modified to fit most gas turbines.
The control of some types of VIGV system is hydro-mechanical and is prone to wear and drift. Changes in the scheduling of the VIGV's can not only cause drop in engine efficiency but can also lead to compressor stall/surge and consequent catastrophic failures of blading.
Monitoring the positioning of the VIGV's is therefore essential for long-term reliability and maintenance.
Bleed Valve Moniter
TCL have also developed bleed valve position monitors which provide a positive indication of the bleed valves. The VIGV and bleed valve monitors can be connected to the TCL Avon health monitor which provides historical and real-time trending facilities.