By Hydro Review staff
The hydropower industry doesn’t move too fast when it comes to new technology, but there are still many companies doing innovative things to bring new products to market. Thus we provide you with a guide to the latest “gear” (products and technology) that has come on the market recently. We’re sure some of these have applications at your hydro plants or dams.
New approaches for dams, civil structures
This article provides information on three products/technologies recently launched that can be used to improve construction, maintenance or safety of dams and civil structures.
Concrete corrosion repair
Cortec offers a High Performance Repair System (HPRS) intended to repair damage to spalling or deterioration of reinforced concrete.
Cortec – based in St. Paul, Minn. – says this system makes it possible to “greatly reduce a structure’s corrosion rate and extend useful service life.”
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| Corrosion repair system from Cortec |
The system uses a special sequence to maximize performance of what it calls Migrating Corrosion Inhibitor (MCI) molecules. First the base surface is prepared to remove all spalled, loose and deteriorated concrete. Rust on exposed rebar is eliminated, two coats of anti-corrosion MCI grout are applied to exposed rebar or metal, and MCI repair mortars are applied to the concrete surface. Once the repair mortar is cured, the company’s MCI-2020 formula is sprayed, brushed or rolled on “to penetrate through concrete and attach to and protect the surface of embedded reinforcing steel.” Other materials, such as coatings or water repellents, may be applied on top.
The HPRS system was used to restore and protect concrete pipelines in Spain for customer Consorci D’Aigues De Tarragona. After application to a network of prefabricated reinforced concrete pipes at least 30 years old, testing showed decreased corrosion rates.
Modular approach to civil works
French Development Enterprises LLC received an award from the U.S. Department of Energy in September 2015 to advance manufacturing and installation of low environmental impact hydropower technologies. French Development will use these funds, given in the category of Rapidly Deployable Hydropower Civil Works Technologies, to advance development of its French Dam.
This modular impoundment technology is intended for the construction of new and retrofit of existing small to medium-head hydroelectric and water control dams. The technology uses interlocking precast segments to allow for rapid in-field installation and removal. The segments are manufactured in a climate-controlled environment and, as they are installed, are interconnected with each other and secured to the river bed using underpinning. They offer the ability to construct “in the wet,” eliminating the need for cofferdams and diversion tunnels.
The Boston-based company estimates this technology will reduce civil costs by up to 60% and reduce construction time by four. The structure comes with a 100-year warranty, and French Development says it is compatible with all major hydropower equipment.
French Development is collaborating with Alden Labs, Maine Drilling and Blasting, and Old Castle Precast, Willis Insurance and Cleantech Analytics to develop this technology.
Remotely measuring and monitoring components
Sensor Networks’ matPIMSâ„¢ ultrasonic transducer array remotely measures and monitors remaining wall thickness in plant components such as piping, pressure vessels and heat exchanger shells.
The company says all of matPIMS’ ultrasonic and digital communications hardware and software are co-located in its sensor array, which improves signal performance. The array is used in connection with Sensor Networks’ smartPIMS Modbus system and optionally with the webPIMS cloud-based data analysis and viewing software.
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| matPIMSâ„¢ ultrasonic transducer array from Sensor Networks |
The company designs and manufacture integrated systems that use ultrasonic sensor arrays and a digital control and communication system architecture that supports handheld, wired and wireless data collection. It says its products can be configured for different installed-sensor applications in the oil and gas, power generation and other process safety management-regulated industries.
Sensor Networks is based in Boalsburg, Pa., and specializes in asset-integrity monitoring solutions for critical components within the energy sector.
Electrical equipment
A couple of new products have recently been released to assist with operations of electrical equipment.
New approach to switchgear
ABB has added AirPlus, an eco-efficient gas mixture and alternative to sulfur hexafluoride (SF6), to its gas-insulated switchgear (GIS).
AirPlus uses a fluoroketone-based gas mixture as the insulation medium for medium- and high-voltage switchgear applications. This chemical compound was developed in collaboration with 3M.
ABB says the global warming potential of new new gas mixture is almost 100% lower than that of SF6, without any compromise on equipment quality and reliability. The company says this can lower CO2 equivalent emissions of the GIS by half through the lifecycle of the equipment, with the other half being attributable to raw materials, manufacturing and thermal losses during operation.
Switchgear is used to control, protect and isolate electrical equipment to boost the reliability of the electrical supply. With GIS technology, key components (such as contacts and conductors) are protected with insulating gas. Pressurized SF6 is a greenhouse gas and its lifecycle management requires careful handling and can entail substantial costs.
This technology was commissioned in a pilot installation in Zurich, Switzerland, for utility ewz in August 2015.
Custom variable frequency drive
Eaton recently released its SC9000® EP medium voltage adjustable frequency drive featuring an encapsulated power pole and modular inverter design. The drive helps reduce downtime during routine maintenance, the company says, and the encapsulated power pole inverter has heat pipe technology, which reduces overall equipment size and helps protect sensitive electronic components in harsh plant environments.
Eaton has placed this solution at the town of Mooresville’s Water Treatment Plant in Mooresville, N.C., to help increase energy efficiency in the plant with a noticeable reduction in power usage, Eaton says. The SC9000 EP series of drives control the pressure from the high-service, 800-hp pumps, allowing the new and old plants to work in tandem, preventing the new pumps from rusting away due to disuse.
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| Medium voltage adjustable frequency drive from Eaton |
The system uses a compact integrated control gear solution, allowing the VFD to remain in one room with no modifications and tying it back to the plant’s existing communications system, Eaton says.
The company has North American regional offices in Cleveland, Ohio.
Bottom profiling systems
Two companies have recently announced technology that allows mapping of reservoir bottoms, among other functions.
Profiling system penetrates difficult sediments
Falmouth Scientific’s line of oceanographic instrumentation has expanded with the addition of its HMS-AT650 Compact ULF Sub-Bottom Profiling System. The Cataumet, Mass.-based manufacturer says the system is ideal for applications requiring high-resolution CHIRP images and deeper penetration in difficult sediments, such as hard-packed sand.
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| Compact sub-bottom profiling system from Falmouth Scientific |
The system generates CHIRP signals in the 200 Hz to 2 kHz frequency range, according to FSI, and is suitable for operation in a variety of array configurations, making it particularly suitable for sub-bottom profiling applications in shallow water.
Components of the system include the HMS-AT650 transducer, a single or dual frequency FSI “CHIRPceiver,” a ULF matching driver and a specialized headphone streamer. The system can be mounted on a rigid support or towed behind a small vessel.
Sonar system shows full spectrum
EdgeTech’s 2300 system combines the company’s line of side scan sonars, sub-bottom profilers and multi-phase echo sounder (MPES) bathymetry into one towable system. The 2300 is ideal for deep water applications, EdgeTech says, with its “Full Spectrum” CHIRP technology able to provide high-resolution imagery from any two user-selected frequencies.
Previous units’ sub-bottom profiler capabilities have been expanded with the ability to incorporate up to four low-frequency transducers as part of EdgeTech’s DW-106 (1-10 kHz) system. The 2300 can also use a large PVDF hydrophone array, while its MPES produces real-time, high-resolution and three-dimensional maps.
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| Sonar system from EdgeTech |
The 2300 also features a remote head USBL beacon, optional Nexus Multiplier, rear magnetometer shackle mount and adjustable trim panels. And it has built-in heading, pitch and roll sensors.
The West Wareham, Mass.-based company says applications include archaeological surveys, geological/geophysical surveys, sediment classification, pre/post dredging surveys and scour/erosion investigation.
New approach to turbine design
Verterra Energy in Minneapolis, Minn., is developing the Volturnus, a low-profile horizontal-axis turbine with a capacity of 5 kW to 10 kW.
The device’s patented design allows it to operate in lower speed flows and much shallower water (20 inches) when compared with conventional horizontal turbines.
Volturnus is being developed for deployment in rivers, oceans and man-made canals. The company thinks individual units could be linked in groups (pods) of five or farms numbering in the hundreds of units.
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| Low-profile turbine from Verterra Energy |
A 0.5-meter-diameter scale prototype was field-tested in the Crow River in Rockford, Minn., and a manmade canal in September 2015. The overall water depth was 20 inches, with the depth over the lip of the device varying between 3 to 7 inches. Verterra saw 29% to 50% efficiency depending on water velocity, as calculated by the forward swept area of the turbine component.
The device provided nearly 32% efficiency in a 1.1 meters per second (mps) flow with turbine rotation approaching 100 rpm. The velocity range of 0.5 to 1.1 mps for the scaled prototype is the equivalent of a commercial scale turbine in 1.5 to 2.5 mps flows, the company says.
ROV offers twice the functionality
Deep Ocean Engineering has an underwater vehicle, the Phantom FlyImager, calling the hybrid drone a “revolutionary” system. Co-developed with EdgeTech, the Phantom FlyImager combines EdgeTech’s 4125 side scan sonar system with a Phantom T5 ROV underwater drone.
Deep Ocean Engineering of San Jose, Calif., says the system is unique in that the side scan sonar system can be pulled behind a powered surface vessel as a towfish while scanning using “wings” that provide stability and constant depth control. The side scan system provides long-range acoustic imaging in the water column to find targets. Once a target is identified, the wings can be retracted and the drone is converted from a towfish to a free-flying ROV that can be used to acquire close-up optical images.
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| Phantom FlyImager from Deep Ocean Engineering |
The unit’s dual capabilities eliminate the need to deploy both a passive side scan sonar system and separate ROV, the company says.
The Phantom T5 ROV features full HD video with 20X optical zoom and an on-screen videographic overlay mounted on a tilt platform with angle feedback; 300 m depth rating and two-person portability; magnetically coupled thrusters; and a non-corroding polypropylene chassis.
