FAG online condition monitoring system prevents costly failure of a power generation turbine at a Corus steel plant

An FAG DTECT X1 online vibration monitoring system has prevented the failure of a steam turbine, which could have cost the Corus plant in Scunthorpe, UK many thousands of pounds in lost power generation.

The Central Power Station on the Corus site in Scunthorpe provides 53 MW from a total of six steam turbines for the plant. The remaining required energy is drawn from the National Grid.

It was only when Turbine No. 5 was taken off-line for routine maintenance that serious cracks in the generator’s retaining rings were discovered. The resident maintenance engineers realized that the risk of a failure of this turbine would not only result in lengthy downtime and lost production, but in safety serious risks to plant personnel.

To ensure the continued safe operation of an identical generator, the maintenance team decided to act fast and conducted a HAZOP (Hazard & Operability Analysis) study on Turbine No. 4. If this sister unit was discovered to have the same problem as Turbine No. 5 a more serious failure could have easily occurred.

Following the study, a protective cover was put in place immediately, but it was clear that early failure detection was also required. “We needed a quick response vibration monitoring unit to provide protection not only for the equipment but for our personnel,” says Maintenance Engineer, Josh Mortimer.

It was decided to install the DTECT X1 system on the exciter end bearing and the turbine end bearing of Turbine No. 4. Shortly afterwards the online vibration monitoring device detected a problem with one of the rotor blades. “Our attempts to protect this generator paid off,” says Chris Smith, Scunthorpe’s PCM Engineer. “By picking up the blade failure early on, we were able to prevent the failure of the whole turbine. In lost generation alone, this machine is worth à‚£35 000 ($56 700) a day. Minimal damage and a quick return to service is obviously the preferred option.”


VT secures reactor manufacturing contract from British Energy


VT Group has made its first foray into the sector of manufacturing parts for nuclear reactors by winning a prestigious order from British Energy to supply high integrity new reactor bio-thermal assemblies for the Dungeness power station.

The contract represents a significant expansion of VT’s nuclear manufacturing capabilities, which have previously focused mainly on Intermediate Level Waste containers.

VT will manufacture the biothermal units, which are used specifically for Advanced Gas-Cooled Reactors, at its facility near Chester over a period to summer 2010.

The units are critical items for British Energy as they are essential to ensuring continued operation of its Dungeness B facility. VT Group Environment Managing Director John Chubb explained: “This contract demonstrates the confidence that British Energy have in our capabilities by entrusting us to support them with business critical work.

VT Group said that its nuclear fabrication and welding facility has demonstrated the highest quality standards demanded by the nuclear sector

“The replacement of the bio-thermal assemblies is a key element in ensuring that Dungeness B can continue to operate for many years to come. This work clearly demonstrates our capability to be a valued, high quality contributor in the UK new build programme.”

John Sexton, head of Supply and Quality for fleet critical programmes recovery for British Energy, added: “VT has demonstrated its readiness and capabilities to produce these bio-thermals in a very short period of time.

“VT is to be congratulated on this achievement, and we look forward to the company delivering the high quality of product that we demand.”


Optek’s long distance reflective switch employed in wind turbines


Providing alternative energy design engineers with a means of reliably and accurately detecting the speed of wind turbines, Optek Technology’s OPB732 Series long distance infrared reflective switch has been employed in a 6 kW wind turbine for RPM sensing.

Placed at the turbine rotor, the switch is used internally to sense RPMs, and that data is then transmitted to a customer-accessible website via GPRS. In addition to wind turbines, the OPB732 reflective switch is ideal for use in assembly line and machine automation, equipment security, door sensor, machine safety, end of travel sensor, and non-contact reflective object sensor applications.

The OPB732 Series switch has a reflective distance of more than one inch, depending on circuitry. The reflective switch configuration includes an infrared LED and phototransistor, and uses an opaque housing to reduce the sensor’s ambient light sensitivity.

When infrared light strikes the phototransistor, it becomes forward biased and is considered to be in the “on” state, providing an IC(ON) current proportional to the light striking the phototransistor. When the infrared light from the LED is not reflected to the phototransistor, the device turns “off,” minimizing the IC(ON) current.

The OPB732 Series infrared LED features an 850 nm wavelength and a power dissipation of 100 mW. Maximum forward current is 50mA and maximum forward voltage is 1.8 V (If=20mA).


Siemens supplies world’s most powerful 800kV HVDC transformer


Following successful final acceptance tests Siemens Energy has delivered the world’s largest and most powerful 800-kilovolt converter transformer to China.

The transformer produced at the Siemens manufacturing plant in Nuremberg is destined for the Xiangjiaba-Shanghai link, a high-voltage direct-current transmission link (HVDC) recently under construction. Spanning a distance of over 2000 km and with a transmission capacity of 6400 MW, this direct-current link is currently the longest and most powerful in the world.

The HVDC link, which is scheduled to come on line in 2010, will connect the hydropower plants on the Jinsha river on the upper reaches of the Yangtze in central China with the coastal city of Shanghai. Siemens will supply ten converter transformers, five of which are rated at 800 kV, for the Fulong converter station in the vicinity of the Xiangjiaba hydropower plant.

The single-phase 800 kV converter transformer scheduled for delivery is the first of five with a rated capacity of 321 MVA and a shipping weight of 380 metric tonnes.

“With this transformer we’ve become best in class in this field of technology. Our whole range of products will benefit from the innovations implemented,” said Jàƒ¼rgen Vinkenflàƒ¼gel, CEO of the Transformers Business Unit.

The insulation systems of this high-tech transformer had to meet extremely stringent requirements. For example, the two valve-side bushings of the HVDC transformer are approximately 16 metres long because of the requisite insulation clearances. Furthermore, the dimensions specified by the carriers and the transformer’s shipping weight will call for superlative logistics achievements ” for example, shipping by sea on a special heavy-load ocean-going vessel from Antwerp to Shanghai.

For the State Grid Corporation of China, the future operator and the world’s largest utility with approximately one billion customers, the HVDC systems will form the backbone of its power transmission network.

Meanwhile, Siemens has introduced the world’s first 24 kV vacuum circuit-breaker – 3AH37 – for generator switching applications that carries 6300 amperes (A) without forced cooling. This circuit-breaker is designed for an operating voltage of 17.5 kV and operating currents up to 4000 A.

High-current and generator circuit-breakers are used above all in power plants and in industry, for example for generator switching operations and high power ratings. The maintenance-free circuit-breakers are exposed to high thermal and mechanical loadings.

To be able to accommodate these loadings the new circuit-breaker is of modular design. The best materials can thus be used for the current path, power flux and cooling. The modular design also enables horizontal installation of the circuit-breaker. For this purpose the cooling elements are fitted rotated through 90à‚° and enable optimum cooling in this configuration through free convection.

Above and beyond the type tests to IEC 62271-100, which are mandatory for circuit-breakers, the 3AH37 and the smaller 3AH38 generator breakers are tested in accordance with IEEE Std C37.013.

This North American ANSI standard is the only standard worldwide that takes the stringent demands into account, to which the breakers are exposed during generator switching operations. It has thus also become the lead standard for generator circuit-breakers among IEC-oriented experts.


ABB Turbo Systems signs joint development agreement with Schaeffler on fully variable valve control technology


The Schaeffler Group and turbocharger specialist ABB Turbo Systems has signed a cooperation agreement with regard to Schaeffler’s fully variable valve control system, UniAir, which is now in series production.

The collaboration agreement will see ABB contribute its knowledge of efficient, single- and two-stage turbocharger technology, as well as marketing and sales of large, high-performance engines.

The cooperation applies to units with a performance of 400 kW (544 PS) per cylinder or higher. The applications of these large engines are typically in marine, machinery and stationary operation.

“The fully variable valve control system [VVT] is the perfect match for our modern high pressure- and two-stage turbocharging systems,” said Oliver Riemenschneider, Head of Sales and Marketing at ABB Turbo Systems.

The advantages of the VVT system in conjunction with high pressure turbocharging are in the fields of both emission and fuel consumption reduction and in the improvement of the start, part load and acceleration behaviour. The UniAir fully variable, hydraulic valve control system is behind the VVT system. It enables the variation of both valve timing and valve lift.

The UniAir valve control system, which was jointly developed by Fiat Powertrain and the Schaeffler Group and is manufactured by the Schaeffler Group, has already been launched in the automotive sector. The Alfa MiTo 1.4 MultiAir is the first vehicle to utilise this groundbreaking technology. The fully variable valve control system reduces fuel consumption and CO2 emissions ” in conjunction with downsizing ” by up to 25 per cent.


Clyde Bergemann awarded contract to supply AE&E’s 800 MW coal plant in Làƒ¼nen, Germany with dry bottom ash handling system


German-based AE&E Inova has awarded the contract for a dry bottom ash handling system at the new 800 MW hard coal fired Làƒ¼nen power plant, located in North Rhine Westphalia, Germany to Clyde Bergemann.

As an eco-friendly alternative to water, Drycon uses fresh air to cool bottom ash while conveying. Worldwide, the wet bottom ash handling is still the predominant procedure but growing environmental awareness in industrialised countries and increasing water shortage at many power plant sites are causing more and more a shift to the dry technique.

An advantage of Drycon is the additional gain of heat energy from ash by using the re-burning effect. For this purpose, Clyde Bergemann applies a hydraulic driven Jaw Type Crusher/Slide Gate combination, located between the furnace and the Drycon system, which crushes hot ash lumps directly where they appear.

The hot cores of ash lumps are reduced to many small ones at once, falling down at the Drycon conveyor belt where air in counter-current flow fans the re-burning effect. This reduces the unburned carbon level and frees up additional thermal energy which is returned to the steam generating process within the boiler. This arrangement increases boiler efficiency, reduces coal usage and CO2 emissions.

Compared to wet bottom ash handling, Drycon has lower life-cycle costs and as no precious water is wasted for ash cooling and conveying, all related water treatment costs are avoided. By using dry bottom ash handling, the ash quality is ready for re-use as cement.

The scope of supply comprises engineering, delivery, erection and commissioning of Drycon, crusher plant, ash conveying system, ash silo including steel works for storage and unloading facilities as well as supply of a control system which will be connected to the control room.

The Drycon system’s modular design ensures that the length-width ratio of the conveyor can be adjusted flexibly to the individual plant and process conditions. This guarantees efficient ash cooling at maximum extraction rate making Drycon to a technologically advanced solution for dry bottom ash handling.


Purolite unleashes latest nuclear grade resins onto the market


Purolite has announced the introduction of both new and improved products to the NRW family of nuclear grade resins, which meet the very high quality and performance requirements of the nuclear industry.

The nuclear industry is reliant on ion exchange resins to maintain the lowest level of impurities in reactor coolant in primary and secondary circuits and to assist in the reduction of radwaste,” said Don Brodie, Vice President of operations, Purolite.

“In order to accomplish this reliably, the industry has very stringent resin quality and performance specifications and Purolite is very pleased to introduce an advanced family of resins able to meet the nuclear industry’s needs.”

Purolite Corporation was founded in 1981 and is a leading manufacturer of ion exchange, catalyst, absorbent and specialty resins and is the only company to focus exclusively on this market. Headquartered in Bala Cynwyd, Pennslyvania, the company also has a dedicated central research and development facility in the United Kingdom.


Yokogawa to supply control system for Trinidad 720 MW CCGT plant


Yokogawa Deutschland has received an order from MAN Ferrostaal Industrial Projects to supply an automation and control system for the La Brea combined-cycle power plant being built by MAN Ferrostaal Industrial Projects and Eisenbau Essen for Trinidad Generation Unlimited (TGU).

The power plant is being built near La Brea, a town on the south side of Trinidad Island. With a capacity of 720 MW, this will be the largest power plant in Trinidad and Tobago, a country with a vibrant economy that is rich in oil and natural gas resources. Scheduled to be completed in July 2011, the plant will meet Trinidad and Tobago’s rising demand for electricity.

This new power plant will have six gas turbines, six exhaust gas heat recovery steam generators, two steam turbines, and auxiliary facilities.

Yokogawa will provide a range of systems and products including a Centrum series integrated production control system to control all of these facilities, the ProSafe Safety Instrumented System for detecting abnormal conditions and safely initiating emergency shutdowns, the Exaquantum Plant Information Management System for recording and retrieving historical data, and the PRMT integrated device management software package. Yokogawa will also provide engineering services.

The PRM software remotely monitors the status of various types of plant measurement and control devices and executes diagnostic routines that detect potential faults before a malfunction can occur. PRM gives the plant operators a comprehensive overview of the measuring devices used throughout the plant. PRM supports the Foundation fieldbus, HART, and Profibus digital communication protocols. HART is used in the La Brea project.


Emerson to automate Czech Republic’s first supercritical coal plant


Emerson Process Management has won a contract to apply its PlantWeb digital plant architecture with the Ovation expert control system to CEZ’s supercritical coal fired unit being built at Ledvice, Czech Republic.

The new unit will reduce CO2 emissions by 20 per cent and is being built as a replacement for the older Ledvice units 2 and 3. When complete, it will be the largest coal fired unit in the Czech Republic, with a generating capacity of 660 MW.

CEZ is one of Europe’s top ten power utilities with a strong market position in the Czech Republic. As part of a coal power plant modernisation programme, CEZ is investing in Ledvice and other selected power plants located near the Czech lignite mines.

As well as delivering high-efficiency electrical power, the new unit at Ledvice will use the latest technology for flue gas desulphurization (FGD) and ash handling to meet new European environmental standards. Operation of the new plant is scheduled for December 2012.

CEZ named Emerson as the main automation contractor for the new unit’s instrumentation and control systems.

This role includes engineering design, instrument and equipment procurement, control system supply, site installation, commissioning and start-up. Emerson’s Power & Water Solutions industry centre will manage this turnkey instrumentation and control project.

The automation strategy for the Ledvice supercritical unit is based on Emerson’s PlantWeb digital plant architecture with the Ovation expert control system, Rosemount intelligent field devices, Fisher valves and AMS Suite: Intelligent Device Manager predictive maintenance software.

Emerson’s Ovation system will monitor and control the supercritical boiler and balance-of-plant processes. An Ovation Safety Instrumented System will be used for the boiler protection system and burner management system.

As part of the PlantWeb architecture, the Ovation system will use HART communications to network Emerson’s intelligent devices throughout the plant. The Ovation system will also communicate with the intelligent Motor Control Centres using Profibus DP and with other equipment and applications using Modbus, OPC and IEC 61850 links.

“We are delighted that CEZ has chosen Emerson’s leading digital technologies for the new Ledvice plant, which will be the first supercritical unit in the Czech Republic,” said Bob Yeager, president of the Power & Water Solutions division of Emerson.

“A key factor in our ongoing partnership with CEZ was our ability to demonstrate our considerable experience in automating supercritical units as well as managing complex projects of this scale. CEZ also recognized the benefits of local support from our team of specialists at our power expertise centre in Prague,” said Yeager.

Emerson’s Ovation system was designed specifically for the power generation industry and is proven in thousands of installations. Well-established as a leading control system for plants using supercritical technologies, the Ovation system enables operation at elevated steam and temperature levels, making electricity generation more efficient, while also reducing fuel-related emissions.

The Ledvice Power Plant began operation in the second half of the 1960s. Originally consisting of five units, only three are currently in operation. Units 2 and 3 will be shut down when the new unit is operational and Unit 4, which was converted to a fluidised bed boiler construction ten years ago, will remain operational.

Managing Director of VT Group Environment John Chubb (left) and British Energy Head of Supply and Quality John Sexton (right)


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