Dual-fuel retrofit lowers emissions and adds flexibility
MAN Diesel recently completed the first retrofit of its advanced dual-fuel technology on an existing heavy-fuel engine in a stationary application.
Executed by MAN Diesel’s rapidly expanding PrimeServ aftersales organization, a twelve cylinder, vee configuration 48/60 engine operating in an industrial cogeneration plant in Portugal was converted to full 51/60DF specification. “We recently handed over the converted 51/60DF engine to operator Tàƒªxtil Manuel Gonàƒ§alves, Sociedade de Producao de Electricidade e Calor S.A. (TMG SPE) which runs an adjacent textile works in the town of Vila Nova de Famalicàƒ£o,” notes Manfred Gallersdàƒ¶rfer, leader of the 51/60DF retrofit team at PrimeServ, which handles all engine and turbocharger upgrades.
In over 11 years of operation the 48/60 engine had logged over 88 000 hours in grid parallel baseload mode at the cogeneration plant, where its thermal output is used to raise process steam for the textile works. “Since the 51/60DF dual-fuel engine is based on MAN Diesel’s successful 48/60 medium speed engine platform à‚— and since a major overhaul was due à‚— TMG SPE decided it was the perfect opportunity to convert to dual-fuel gas operation,” Gallersdàƒ¶rfer states.
Converting to natural gas as the main fuel had several distinct advantages for TMG SPE. Notably, the engine achieves compliance with European Union emissions legislation and, due to its application in a high efficiency industrial cogeneration plant, the TMG SPE installation qualifies for preferential prices for the power it feeds to the Portuguese grid. Moreover, dual-fuel technology still allows TMG SPE a high degree of independence from Portugal’s gas supply infrastructure, since liquid fuel is still stored on-site for pilot injection and can serve as a backup.
As well as exchange of the original cylinder liners and pistons of 480 mm diameter to new 510 mm bore components, other major changes were: new piston crowns with piston bowls adapted to gas combustion, new cylinder heads with pilot injectors and gas admission valves (in the inlet ports), new inlet cams and the common rail pilot injection pumps, pressure accumulators and solenoid valve system.
The conversion also included turbocharger re-matching for gas engine operation via the fitting of new nozzle rings and further adaptation of the exhaust system.
The converted engine has also been equipped with MAN Diesel’s SaCoS DF safety and control system, specifically developed for its dual-fuel gas engines.
As well as comprehensive control functions, including remote on-line monitoring capability and extensive redundancy, in combination with the common rail pilot fuel injection system, SaCoS DF allows the outputs of the 51/60DF’s individual cylinders to be precisely matched and engine settings to respond to combustion knock signals on a cylinder-to-cylinder basis. In gaseous fuel mode, the gas engine readily achieves emissions of oxides of nitrogen (NOx) of 500 mg/mn3 at 5 per cent O2 and complies with legislation based on Germany’s TA Luft clean air code and the World Bank Pollution Prevention and Abatement Handbook.
For land-based power generation, the 51/60DF is offered in a nine-cylinder in-line version and in vee configuration versions with 12, 14, and 18 cylinders. It has a standard mechanical rating of 1000 kW per cylinder for 60 Hz power generation (514 rpm) and 975 kW for 50Hz applications (500 rpm), giving an overall generator-set rating range of 8560 to 17,550 kWe. In the TMG SPE application the output of the retrofitted 51/60DF is adapted to a local gas supply with a nominal methane number of 75, the thermal-versus-electrical energy requirements of the specific 50 Hz cogeneration application and ambient air conditions.
It equates to 950 kW/cyl under ISO conditions. As the global natural gas supply infrastructure grows and more areas of the world are subject to emissions regulations, MAN Diesel expects diesel to dual-fuel conversions of this kind to become increasingly popular.
CRE Technology’s most advanced genset control unit
CRE Technology has launched what it claims is the most advanced genset control unit on the market, with its Gensys 2.0.
Gensys 2.0 in its standard version allows static paralleling, also known as black start synchronization, which enables a power plant to go from a stand-by position and be up and running in parallel in less than 10 seconds.
This Gensys 2.0 feature is particularly useful when a fast response to a heavy load request is required, such as for large electric motors or turbines. It is also useful when it is not possible to shed load in situations such as hospitals or in certain heavy industries.
In less sensitive industries, static paralleling also allows the use of smaller uninterruptible power sources, reducing investment and maintenance costs, without extra investment on the genset power plant side.
The second main advantage of static paralleling is the magnetization of the step-up transformers without any amps rush. The transformer can be magnetized with a low voltage before it receives the power from the genset.
Power plant benefits from important cost gains (i.e. less cabling, lower transformer consumption) and a better efficiency (quick power plant availability and more stable power).
Static paralleling, which is widely used in some European countries, is now being requested worldwide. CRE Technology has been familiar with this particular specification for a long time, enabling it to develop the necessary functions that have been incorporated into the Gensys 2.0.
With dynamic synchronization, the first genset closes on a dead bus before other genset enter into the synchronization mode to close their breakers. The synchronizers will individually adjust frequency, phase and voltage to match those of the first genset. This, however, can take time because it depends on the engine, the generator and a number of installation-related factors. Thus, a possible delay cannot be removed from the system.
With static paralleling, all sets are ready to take the load right after the starting phase, reducing the time to have 100 per cent of the power plant nominal capacity available.
The Gensys 2.0 unit can control both modes. The dynamic synchronization is even available as a back-up to static paralleling, if required by the application.
According to CRE technology, Gensys 2.0 is the only unit on the market offering a diverse programming capacity. All the internal logic sequences are programmable by equations without the requirement of any software tools. This feature allows the control system to fit any applications, from simple paralleling to complex cogeneration plants.
The Gensys 2.0 also offers the latest communication technology to the genset industry. In addition to Canbus and USB ports, the Ethernet port cab offer important time gains and ease of information transfer.
Shahjibazar Power orders 32 GE Jenbacher engines
Independent electricity generator Shahjibazar Power has ordered 32 of GE’s natural gas fuelled J620 GS Jenbacher engines, which will be installed at a site, located about 180 km north of Dhaka, Bangladesh.
The project will be developed by independent power producers (IPPs) that are rapidly building new power plants, with government support, to improve electricity supplies in rural areas of Bangladesh that do not have reliable transmission grids.
The units for the Shahjibazar project will be contained in two powerhouses and will generate 92.8 MW of electricity for the local grid. The engines are scheduled to be commissioned by the beginning of 2009.
Prady Iyyanki, CEO of GE Energy’s Jenbacher gas engine business, said: “As Bangladesh’s economy continues to grow, the government and private sectors are seeking solutions to improve the country’s energy infrastructure.
“GE’s fuel-flexible Jenbacher engines are a cost efficient, highly reliable power generation solution, making them suitable for a variety of projects in Bangladesh and throughout South Asia.”
Tognum expands Asian energy business with major order
Tognum group is expanding their Asian business in the area of on-site energy generation with a substantial contract: a consortium led by Tognum subsidiary MTU Friedrichshafen GmbH will deliver ten emergency power supply gensets for two Chinese nuclear power stations.
The order value is at approximately €65 million. Consortium partners include the joint venture between MTU and the Chinese Norinco Group, Shanxi North MTU Diesel Co. Ltd., and energy generation supplier AREVA NP.
Before this contract was awarded by the Chinese nuclear power plant operator, it was important to ensure the necessary local content. The joint venture agreed in December 2007 and MTU and their Chinese partner Norinco Group ensured that MTU complied with this particular prerequisite. The MTU consortium can command a significant share in the highly coveted Chinese market for emergency power supply gensets in nuclear power plants.
The Chinese nuclear power station market is buzzing à‚— a considerable number of new plants are scheduled to be built in the near future.
“This contract both serves to expand our on-site energy business, as well as providing a significant contribution to our Asian operations,” explains Volker Heuer, Chairman of the Executive Board and CEO of Tognum AG. “It goes to show that our strategic growth initiatives are paying off.” Other strategic Tognum group drivers include the expansion of the product portfolio in the area of drive and propulsion systems and the focus on the high-margin after sales business.
At the core of the MTU on-site energy emergency power supply gensets, you will find Series 20V956TB33 diesel engines with an electrical power output of 6000 kW. Upon initiation of the start signal, the gensets run up to their nominal speed within ten seconds, ready to pick up maximum performance. This is how they ensure the power supply for coolant pumps or the electronic control system of the nuclear power plant in a potential emergency scenario.
Growing global demand for diesel gensets
As global market dynamics begin to shift, genset companies are making a number of strategic alterations. They are placing greater focus on developing regions, where the bulk of new opportunities will be concentrated, as well as on providing gensets that comply with current and impending emission regulations.
New analysis from Frost & Sullivan finds that the global market for diesel gensets earned revenues of $7.16 billion in 2007 and estimates this to reach $10.28 billion by 2014. Frost & Sullivan finds that gensets below 60 KW are the dominant market driver, with this sector worth $2.1 billion in 2007 and forecasted to reach $3.8 billion in 2014.
“The bulk of new opportunities will come from emerging markets in Asia, the Middle East and Latin America,” notes Frost & Sullivan Research Analyst Nathan Laryea. “As countries in these regions modernize and develop, there will be a significant increase in demand for gensets.”
The European and North American markets are dominated by established international companies with a vast and loyal customer base. In contrast, brand loyalty is very low in the developing world and companies armed with quality products and an effective marketing strategy will have a chance of achieving market penetration.
In addition, countries in regions such as Asia and Latin America are recording economic growth far in excess of most Western nations, and the demand for power has increased considerably as a result. Moreover, Frost & Sullivan expects that the global financial turmoil will have a lower impact on these regions than the developed European and North American economies.
The increasing emphasis on eco-friendly power generation means diesel genset market participants are also entering a testing period. In the longer term, genset participants will face the challenge of complying with emission regulations and, more broadly, the task of surviving in a market that will be increasingly inhospitable to so-called ‘old’ energy companies. In such a climate, diesel gensets face the threat of being substituted by more energy-efficient forms of power generation.
“In the United States, stringent regulations relating to stationary power equipment already exist, while in Europe genset participants are preparing for Stage 3A regulation, which will render some of their product portfolios redundant,” notes Laryea. “The market conditions will become very favourable for engines running on natural gas and biofuels, while fuel cells are also anticipated to eat into the market share of diesels.”
However, the demand for diesel-powered gensets will continue to be strong, even though the market environment may appear less favourable. Diesel remains an excellent means of power generation, and the market for ‘built to comply’ gensets will be lucrative.
“Companies that demonstrate technological innovation in producing ‘built to comply’ engines with similar levels of performance will continue to experience growth,” concludes Laryea.
Rolls-Royce power increases efficiency for SPE in Belgium
SPE, the second largest electrical utility in the Belgium, has commissioned its Rolls-Royce Trent 60 powered electrical generating plant at the Ham power station in the centre of Ghent.
The simple cycle plant, which is the most powerful and fuel-efficient of its type in the world, is also environmentally friendly due to the high efficiency of the Rolls-Royce engines.
Charles Athanasia, Vice President of Power Generation for the Rolls-Royce energy business said: “This represents a significant achievement for Rolls-Royce. The Trent 60 delivers performance levels to SPE that are not available from any other aero derivative gas turbine. Our experience, together with our technology, will enable SPE to run its plant at peak efficiency.”
The Rolls-Royce gas turbines have made a significant improvement to the plant’s environmental impact and were a key factor in the decision to replace the diesel engines used at the station for the past 40 years. Two Trent 60 aero derivative gas turbines will provide over 100 MW of power during times of peak demand at the Meuse River site, where a power station has been sited for over 80 years.
The noise level of the new plant is now even lower than the ambient noise level on the streets of Ghent. Vibrations from the plant when the diesel engines were running have almost completely disappeared. This environmental improvement was one of the main drivers for the project, given its city centre location.
Following on from this successful installation in Ghent, SPE and Rolls-Royce have joined forces to build another Trent 60 power station on an existing SPE site at Angleur near Liàƒ¨ge.
Rolls-Royce has now installed eleven Trent gas turbine generating sets at power station sites in Europe with an additional 12 units on order.
The Trent 60 gas turbine, derived from the Rolls-Royce Trent aero engine for the Boeing 777, is currently the most powerful aero derivative gas turbine available in the world with a power output up to 64 MW.
Wärtsilä: O&M award in Pakistan
Wärtsilä has been awarded an operations and maintenance (O&M) agreement to operate and maintain the Attock Gen Ltd power plant, located at the Attock Refinery site near Rawalpindi, Pakistan.
The 156 MW power plant, which was supplied and installed by Wärtsilä, will start commercial operations this year.
Wärtsilä has O&M agreements in three other power plants in Pakistan, supplying a total of 317 MW of electricity.
The Attock Gen power plant, which is connected to the national grid, utilizes nine Wärtsilä 18V46 type generating sets, with heat recovery boilers on each. Wärtsilä also supplied the plant with an 11.6 MWe steam turbine plant and a 132 kV switch-yard.
“This new power plant will contribute significantly to ensuring that our refinery operations run smoothly. This will speed sales of heavy fuel oil, thus boosting to the economy of energy-starved Pakistan. We want to operate the plant at the highest efficiency and we are confident that Wärtsilä’s team will achieve this,” says Mr M Adil.