Cutterhead supplied for China’s biggest tunnelling project for 4800 MW hydro station

UK heavy engineering company DavyMarkham has fabricated and shipped a 320 tonne cutterhead for a 12.4 m diameter tunnel boring machine (TBM), being built by The Robbins Company of Ohio, the world’s foremost manufacturer of underground construction machinery.


The 12.4m diameter, 320 tonne cutterhead manufactured at DavyMarkham’s Sheffield works, for Robbins’ tunnel boring project in China.
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It has been despatched to the mountains of Sichuan Province, China, where it will be instrumental in one of the biggest TBM-driven tunnelling projects in the country, i.e. for the new 4800 MW Jinping II hydropower station on the Yalong River. Once completed in 2010, this will be the largest power station in an ambitious project for owners Ertan Hydropower Development Company, and will transmit electricity to many eastern provinces and such cities as Shanghai and Beijing.

Fabricated in six sections and test assembled at DavyMarkham’s Sheffield works prior to despatch, the cutterhead and associated Main Beam TBM are being finally built by Robbins in a massive underground launch chamber, pre-excavated by drill and blast methods. The same on-site assembly technique was also employed on the earlier Niagara Falls TBM contract, for which DavyMarkham again supplied the cutterhead.

In a contract valued at £1.15m ($2.2m), DavyMarkham applied precision engineering standards to the heavy machining and fabrication. In order to improve competitiveness when dealing with such large steel pieces, the firm employed a newly-developed cutting tool for rough machining, which resulted in a metal removal rate five times faster than normal, and deployed the latest carbide U-drill technology, which cut holes eight times faster.

Tunnel boring machines are among the largest, most complex pieces of equipment made and, with 50 years of innovation and experience, Robbins is regarded as the leading exponent, holding 94 per cent of all world records for TBM production. Its Main Beam TBMs bore more than 200 km of tunnel every year, establishing them as the workhorses of hard rock excavation.

The cutterhead is the rotating head at the front of the TBM, which actually cuts through the rock, and DavyMarkham has supplied Robbins with these and many other TBM elements over the years, including the literally groundbreaking Channel Tunnel machine.

For the Jinping II project, the 12.4 m TBM will bore a headrace tunnel almost 17 km long, which will deliver water under pressure to the turbines of the hydropower plant currently under construction.

Vibro-Meter used to protect and remotely monitor the world’s most powerful gas turbine

Siemens Energy has chosen Vibro-Meter to provide the monitoring system for the SGT5-8000H gas turbine.

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Irsching 4 near Ingolstadt, Germany is the test power plant for the new SGT5-8000H, which is the world’s most powerful gas turbine (GT) with a 340 MW simple cycle power output. The GT was first fired in December 2007.

After an 18-month trial operation period, it will be expanded to become a 530 MW combined-cycle power plant (CCPP) and will be handed over by Siemens to German utility E.ON for commercial operation in 2011.

This technologically-leading CCPP will achieve an efficiency of 60 per cent, which is a new world record. As a result, it will emit approximately 40 000 tonnes of carbon dioxide per year less than comparable existing plants.

Monitoring vibrations and combustion is a proven way to contribute to reliable GT operation, with the target of reaching the highest possible efficiency and lowest emissions. Integrated solutions include dynamic pressure sensors, as well as relative and absolute vibration sensors and a VM600 protection & condition monitoring system.

All data collected by the VM600 are continuously transferred to Siemens’ Intranet, interfaced with its Win_TS system (a global networked plant diagnostic platform). With these tools, experts working in Siemens’ Diagnostic Centres (Erlangen and Orlando) and Research and Engineering Centres (Erlangen, Berlin, Muelheim, Orlando and others) can for example remotely calculate balancing for turbines located in plants all over the world.

Using this information, staff on-site can balance a turbine without the need for an on-site visit by experts.

Stud welding gets smarts

A new line of digital arc stud welding equipment – Smart Weld – is available from Image Industries, with advanced data management for statistical process control (SPC) documentation.

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By reporting information, such as date and time, weld tool used, mode used, weld parameters requested (time and current), and actual weld results (time, current, and voltage), users can determine whether quality standards are being consistently upheld with every weld.

SPC limits can also be entered and reported by Smart Weld.

Users determine optimal weld settings, and then enter upper and lower SPC limits, which are based on real world variations.

Cropico DO7 powers ahead at global service provider

Cropico’s DO7 digital microhmmeters have been specified for a company that makes rotating electrical machines and specializes in the repair, maintenance and service of large electric motors and generators for global customers.

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Quartzelec, a leading electrical engineering company with engineering operations based in Rugby, UK, provides a range of specialized service and support solutions for rotating plant installed in power stations, steelworks and paper mills in Europe, North Africa, the Middle East and Far East.

Now, in a move to improve aftersales service and support, the company has equipped its team of electrical and mechanical service engineers with DO7 units to enable them to undertake on-site resistance measurement and status checking of electric motors and generators.

These are replacing Quartzelec’s own ageing in-house testing units and have been specified because of the superior features and benefits provided. Not only is the DO7 highly accurate but the flexibility of the in-built manual default is enabling engineers to rapidly undertake on-site multi-testing of machinery.

Other benefits include high portability and a rugged design, enabling the DO7 to be carried easily from site-to-site and providing high impact resistance.

Ian Martin, Quartzelec’s engineering manager, said: “We have been extremely pleased with the Cropico DO7 units since they were introduced a few months ago.

“It’s a very easy-to-use instrument, even in the harshest of environments, producing very good testing data.

“Because of this we have now gone ahead and ordered further units for our North African operations.”

Cropico DO7 digital microhmmeters come with specially developed handspike test leads to add increased accuracy to the unit’s rugged portable construction.

Alpha Wire’s flexible cable range in extra demand

Alpha Wire International has announced that sales of its highly successful Xtra Guard flexible cables range have doubled year on year in Europe for the last three years.

Sales of this extreme performance cable have increased across the board in terms of industry sector, but is most prevalent in the automation and control environments, where robotics are increasingly being utilized in manufacture.

By increasing flex life cycles, refining cable profile and improving durability in single and multi-axis flexing applications, Alpha Wire has enlarged the ‘performance gap’ between its industry-standard’s Xtra Guard flexible cables and other flex cables.

Sea change for safe discharge of stored energy

Seaward has introduced the first instrument of its kind for the safe discharge of stored energy in large capacitors and electrically charged equipment.

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The portable SD300 is an innovative, self-contained safe discharge device that has been designed to protect the operator or test engineer from danger and the equipment under test from potential damage.

The UL-listed device has been specifically designed to enable engineers to safely discharge high power capacitors used in power factor correction, DC drives and energy storage applications in the petrochemical, oil and gas, processing and other industries.

No official or recognized means of safely discharging large capacitors in these applications exists and the SD300 unit incorporates a number of special features to counter the common but unauthorized and highly dangerous practice of discharging high power capacitors with wires or screwdrivers.

The SD300 is a long-life battery powered tester that has been designed for use in situations with a maximum voltage of 1000 V DC and maximum capacitance of 1200 uF.

The unique fail-safe design of the SD300 incorporates a two-handed push button operation to initiate and maintain the energy discharge, ensuring that the operator cannot come into contact with the live circuit. In addition, the operator is totally isolated from the discharged energy by a fully insulated and robust instrument case rated at IP66.

The totally self-contained instrument comes complete with fully shrouded fused test leads and includes an inbuilt test lead and fuse proving facility. Other safety features include an automatic pre-use self test, protection against prolonged connection to live operating circuits and monitoring of critical component temperatures with automatic cut off.

Once activated, the stored energy is discharged in 30 seconds and both analogue meters and LEDs provide a visual indication of the state of the stored energy.

The displays also indicate whether the discharged current is AC or DC and the polarity. As the first instrument of its type the SD300 provides an innovative and highly effective solution for the safe discharge of electrically charged equipment.

Stroma signs agreement to offer air source heat pumps

Stroma LZC, a leading independent provider of renewable energy products, has agreed an exclusive deal with HeatKing to be its sole supplier of its market leading range of air source heat pumps.

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With extensive experience in helping the construction industry to reduce carbon dioxide (CO2) emissions and achieve energy efficiency requirements, the Stroma LZC will offer a wide range of air source heat pumps which reduce energy costs and cut CO2 emissions by up to 70 per cent, when compared with an all-electric system.

HeatKing’s highly efficient units are renowned for delivering a coefficient of performance (COP) of up to five and can operate in temperatures as low as -20 ºC. All these units are British manufactured, ensuring their quality and performance. HeatKing offers a range of heat pumps covering every size of application from domestic to commercial, and excellent technical support and backup is available through Stroma.

Matthew Ferguson, managing director of Stroma, explains: “We are delighted to be offering one of the most efficient air source heat pump systems on the market. HeatKing’s track record in this field is second-to-none and we see them as the perfect supplier to enable us to develop and expand our business even further into this market.”

Conval release zero leakage valves

Conval, a leader in high-temperature, high-pressure valves for the world’s most demanding applications, offers single and double bellows seal valves in standard sizes from 1/2” to 4” through ASME Class 2500 in Y-pattern, angle-pattern, and T-pattern body styles.

These in-line serviceable, low operating torque valves are often specified when packed valves may not reliably contain fugitive emissions such as light gases or hazardous system fluids. In almost all applications, the 6-ply Inconel, welded bellows stem seal is more reliable than sliding stem seals.

The Inconel bellows has been tested to MSS SP-117, and provides the longest cycle life in the industry. The double-height bellows provides the highest bellows valve flow capacity available per pipe size.

Megger combines speed with accuracy with latest transformer testing equipment

Their unique testing algorithms and integral storage facilities for test results make Megger three-phase transformer turns ratio testers in the new TTR300 range many times faster to use than conventional turns ratio testers, especially when they are used to test difficult three-phase transformers such as those with multiple tap changers and bushing CTs.

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The TTR300 testers have the ability to measure turns ratios up to 45 000:1 with an accuracy of 0.1 per cent, thereby providing dependable condition information for power, distribution and substation transformers of all types. In addition to turns ratio, the units also accurately measure excitation current and phase deviation between the high and low voltage windings.

The TTR300 series testers are designed to take full advantage of Megger’s powerful and versatile PowerDB acceptance and maintenance test data management software, with the TTR330 incorporating the PowerDB ONBOARD package as an integral feature. The other models in the range are supplied with a copy of PowerDB Lite at no extra cost. The full version of PowerDB is available as an option.

Except for the TTR300 base model, which supports remote controlled operation only, all models offer fully automatic testing in both stand alone and remote controlled modes, and all have facilities for storing test results internally in an open XML data format that is compatible with a wide range of software packages. According to the model, the data can be downloaded via RS232, USB or ethernet ports.

The test sets in the range are designed to provide reliable operation even in locations such as substation switchyards, where high levels of electrical interference are present. They are supplied in a robust carrying case, and have a wide operating temperature range, making them well suited for on-site use in harsh conditions. Their speed of operation and convenience, however, mean that the instruments are also an excellent choice for in-plant use by transformer manufacturers.

Four models are currently available in the TTR300 transformer turns ratio test set family. The TTR300 is designed to be completely remote controlled by a PC running PowerDB Lite or the optional full version of PowerDB.

The TTR310 has an LCD display that, in conjunction with the built-in keypad, provides a convenient interface for instrument set up and testing. An optional thermal printer can also be incorporated within the instrument, allowing test results to be printed on site without the need for an external printer.

For users who prefer a graphical interface, the TTR320 offers a 14.5 cm full colour VGA display, together with a QWERTY keyboard for the entry of nameplate and similar alphanumeric data.

Unique array of wave buoys at UK wave hub site

The Peninsula Research Institute for Marine Renewable Energy (PRIMaRE) has ordered eight Fugro Oceanor Seawatch Mini II buoys to form the core of an instrumentation network at the Wave Hub site off the southwest coast of England.

Wave Hub is a groundbreaking renewable energy project that aims to create the UK’s first offshore facility for the demonstration and proving of arrays of wave energy generation devices (WECs).

The Wave Hub facility will provide a well-defined and monitored site with electrical connection to the onshore national grid.

Four different proven commercial WEC manufacturers will each have a berth to connect a number of their devices to the Wave Hub’s sea bed ‘socket’ which is approximately 16 km offshore and at a depth of 50 m.

PRIMaRE, which is directly linked to the Wave Hub project, is tasked to monitor and characterize the wave climate at the site. The eight-directional wave sensor buoys will facilitate this with detailed coverage of the 2 km by 4 km deployment area.

More significantly, as a part of an extensive but highly integrated system of oceanographic, meteorological and environmental monitoring equipment at the Wave Hub site, the buoy array will constitute a world leading facility giving researchers in wave energy a unique opportunity to work with much richer and detailed data sets.

The buoy array will also be an important part of the Wave Hub’s infrastructure, feeding wave information to the WEC devices. In one mode of operation the buoys will be able to deliver synchronized live and continuous data streams that will allow a local description of the sea surface to be computed in near real-time. This data can be provided as a live feed to the WEC devices to help optimize their energy output.

Unifin unveils auxiliary transformer coolers

Unifin, a world-leading supplier of cooling equipment and transformer oil pumps and valves to the power generation industrry, offers ForZair HeatSink auxiliary transformer cooler.

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The strong performance of this portable and highly efficient cooler allows increased overload and extends transformer life. The ForZair HeatSink cooler can be installed on a transformer quickly to immediately reduce the temperature of the dielectric cooling oil.

With its small footprint, low profile and quick-connect hoses, the ForZair HeatSink cooler can be transferred easily from one overloaded substation to another, providing quick relief wherever it is needed most.

The ForZair line of coolers feature Unifin’s unique Mono-Aluminum Extruded Fin-Tubes and the industry’s best plate fin technology, both of which the maker claims provide optimal heat transfer efficiency and exceptional durability.

The ForZair HeatSink coolers employ Cardinal transformer oil pumps, with a glandless design that prevents leaks in demanding transformer oil applications.

To augment cooling on 1 Mva to 60 Mva OA, FA or FOA transformers these rugged portable coolers come ready for fully self-contained operations. The skid-mounted package is mounted on a durable frame designed for easy lifting by forklift or overhead crane.

Versatile circuit-breaker launched for the medium voltage system market

Siemens Energy has launched a recloser that operates with vacuum interrupters and integrated controller aimed at the market in countries with extensive medium voltage overhead systems.

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Installed in an overhead line route or at the transformer substation, this circuit-beaker has the function of selectively disconnecting the system in case of a fault. If the fault is temporary, the system is automatically connected back to load shortly afterwards. Siemens has been delivering its first series-produced reclosers since March 2008.

“Our new vacuum recloser expands our globally successful portfolio of circuit-breakers for medium voltage overhead systems. The outstanding performance of this circuit-breaker is based on modern vacuum interrupters combined with our internationally leading protection and control technology,” said Ralf Christian, CEO of the Power Distribution division in the Siemens Energy.

The Siemens recloser can be used as an efficient way to manage system faults in single-phase and three-phase medium voltage systems. It is generally installed on an overhead line tower, but it can also be used in a transformer substation. These circuit-breakers have been developed for operating currents up to 800 A and rated voltages of 15.5 kV to 38 kV, with short-circuit currents of between 12.5 kA and 16 kA.

In addition to the circuit-breaker, the recloser also comprises integrated sensors and the controller, which is a protection and control device. The controller measures overcurrents, times and voltages and controls the circuit-breaker switching processes on the basis of these data.

The special function which has given the recloser its name is the repeated automatic reclosing after temporary faults in the overhead line system. The controller also has additional remote supervision and measurement functions, as well as its comprehensive protection functions. This includes in particular the functions for measuring system reliability indices.

The Siemens circuit-breaker is also equipped with load management functions to increase supply reliability and to minimize failures. The controller is accommodated in a separate control cabinet which also contains the uninterruptible power supply, the drive electronics and a number of communications interfaces.