Hydroelectric plants, Parker and their distributors / integrators make powerful teams in the area of power generation support and technical expertise. Carter Lake Hydroelectric, adjacent to the 112,000-acre-foot lake of the same name in northern Colorado, has benefited from a custom solution for their hydro dam project. As a Parker hydraulic systems Integrator, Western Integrated Technologies designed and manufactured two hydraulic power units for Gilkes, a UK-based manufacturer of hydro-electric turbines generators (Francis hydro). Western Integrated was able to provide Gilkes and Carter Lake - with a fully integrated and comprehensive solution. They leveraged the broad variety of specialty components, manifolds, fluid conveyance and condition monitoring, and sensors that Parker offers for this hydro dam governance application.
The two Francis hydro turbines are part of a new hydraulic systems integration installation that controls the flow of water to a distribution canal from an existing mountain lake - Carter Lake in Colorado. A large pipe from the lake carries water down to the powerhouse where the two hydro turbines are installed. The power in the flowing water spins the turbine which spins a generator that produces electric power.
After the energy from the flowing water is reduced at the turbine, the water is directed to the distribution canal and onto homes and businesses.
There are several needs at the client level, namely to reduce turbine downtime and maintenance, while optimizing running efficiency:
- Health and operation of the hydro turbine
- Keeping hydraulic oil clean and moisture free
- Eliminating corrosion, and leaks from piping and fittings
- Pressure and overall system condition monitoring
- Wicket gates precise control to control volume of water that flows through turbine.
Each hydraulic power unit is a fully integrated package of controlling all functions of the hydro turbine. Each Francis turbine has a brake, a turbine inlet valve, a turbine bypass valve, and a wicket gate operating assembly that needs hydraulic oil under pressure to control each function.
Parker components have been used in all key areas: valves, accumulators, gear pumps, filters, desiccant breather, transmitters/switches, and ALok fittings. Each function uses the motion from a hydraulic cylinder (servomotor) that is controlled with directional valves, with the wicket gate servomotors being controlled with a precise proportional valve.
The hydraulic oil from the reservoir is pumped to and stored in bladder accumulators from dual redundant electric motor/pump combinations utilizing Parker gear pumps.
Keeping hydraulic oil clean
The hydraulic oil is kept clean by flowing through a Parker WPF pressure filter and the return oil is filtered
through a Parker low pressure tank top return filter. The oil in the reservoir is kept moisture free by using a desiccant breather (Parker) to remove any moisture from the incoming air. The complete hydraulic power unit is plumbed with stainless steel tubing using Parker ALok fittings for interconnections.
Hydraulic system check valves, relief valves, unloading valves are Parker cartridge valves that are machined into custom designed manifolds. For individual pressure monitoring of certain functions, Parker test points are used. Parker electronic pressure transmitter/switches are used for pressure monitoring and lead/lag motor pump control.
The wicket gates must be precisely controlled because their function is to control the volume of water that moves through the turbine. The volume of water equates to turbine speed and the speed must be very accurate for proper generator frequency output. A Parker proportional valve with onboard electronics coupled to a Parker PID module and a position feedback device, “close the loop” to maintain very precise wicket gate position and thus generator frequency. Additional Parker manual valves are used in parallel to the electrically operated valves and can be used in an emergency to operate the turbine in times of power failure.
Article contributed by Todd Yoshioka, Parker Territory Manager and Western Integrated Technologies.
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Carter Lake: Images used with permission. Additional info on this project see link: http://www.poweringthewest.org/tag/carter-lake-hydroelectric-project