We were approached by our customer to redesign a steam turbine control system which was necessary to overcome the reliability and safety issues that they were facing. The customer was experiencing oil leaks and linkage wear with the original equipment, consisting of a mechanical hydraulic governor.
We therefore sought a solution to deliver the amount of control they required, to eliminate all safety issues, remove original linkage which had caused major wear problems and reliability issues in addition to looking into the possibility of providing an electronic actuator that can be driven straight to the steam valve thus removing all the problematic interface and damage suffered by the old governor.
There were a number of potential problems and uncertainties within this project such as how the new control would interface with the equipment provided by other suppliers, and the compatibility of older equipment with the new, faster actuator.
A new control was configured to replace the old pneumatic system; this had to be designed in such a way as to ensure its compatibility with the control panel controlling the compressor end driven by the steam turbine. Furthermore, the actuator used for the retrofit was designed exclusively for this application and manufactured to fit in with the original steam valve assembly.
Upon completion of the design phase, a full demonstration was set up to evidence the functionality. This took place with the customer present and is a particularly significant stage due to the fact that the turbine is a critical set; thus, any downtime incurred entails a significant loss to the customer.
During the testing and installation stages, many design changes had to be made in order to meet the customer requirements.
The first year post installation and commission was trouble free, however the customer experienced a problem the electronic actuator which was then examined. Any problems that the customer faced were readdressed as required.