The customer for this application note is an electrical power station with a combined-cycle, natural gas-fired generating unit with two combustion turbines, two heat recovery steam generators and one steam turbine. The output of combustion turbines can vary at different times throughout the year. The nominal output for this facility is 577 megawatts. The station burns natural gas.A combined-cycle power plant uses a gas and a steam turbine together to produce up to 50% more generated electricity, using the same fuel, when compared to a traditional simple-cycle plant. The gas turbine waste heat is routed to the nearby steam turbine which, in turn, generates the extra power.
One of the most common components for managing high-pressure steam in a combined-cycle plant is the HRH bypass valve (HRH stands for "hot reheat"). Since the valve actuator controls the valve’s ability to reliably and accurately respond to system demands, it can be argued it is one of the most important elements in the steam bypass system, and therefore the entire combined-cycle plant.
In this application, the customer had two 18" steam balancing valves using large, high torque, scotch-yoke actuators that had to cycle 20 times a day. These actuators presented significant performance issues (they were failing), plus they were very large which presented maintenance difficulties.The customer approached the local Kinetrol USA Distributor and inquired if they could suggest a better alternative. The goal was to provide replacement actuators that provide very high torque, be highly reliable, and save space.
The Distributor recommended Kinetrol Model 30 pneumatic rotary actuators. The Model 30 provides 168000 lbf ins (19140 Nm) at 100 psi (7 bar) of torque and were significantly smaller and lighter than the legacy scotch-yoke actuators. Most importantly, they carried the world-renowned Kinetrol reputation for outstanding reliability, long life, and maintenance-free operation.
Kinetrol USA
https://kinetrolusa.com
972-447-9443
