Designed Water Injection Valve
A major producer of “gas” turbines was having problems with a water injection system used on a large number of their turbines. The water was injected to increase the mass flow through the combustion chamber and also to lower combustion temperatures, which improved emissions.
The system they were using consisted of a number of discrete valves connected to each of the injector nozzles. The problem was that the opening of the valves was difficult to synchronize properly which caused unacceptable levels of vibration.
Our solution was to design a valve that ganged the metering and shut off functions for each nozzle into a common package with one actuator. This simplified synchronizing the opening of the various valves and avoided cost of multiple actuators. The challenge was in selecting the proper materials and surface treatments required to deal with the erosion-corrosion inherent in the use of high velocity de-mineralized water.
The water injection valve met all design and reliability requirements and was approved by the customer. They stated that this approach saved them “hundreds of thousands” of dollars on each turbine and eliminated the vibration problem. We sought and received a patent (US Patent 5,131,426) on the design.