Waiting in the wings

In 2006 Lithuanian utility AB Lietuvos Elektrine will embark on a €252 million ($308 million) project to modernize the 1800 MW Elektrenai power plant. The project will bring the plant in line with national and EU environmental requirements, and above all, ensure that it will be able to serve as the country’s main source of electricity after the closure of the Ignalina power plant.

Siàƒ¢n Green, Managing Editor

As actors in the Lithuanian power market go, there are really just two: the Ignalina nuclear power plant and an 1800 MW supercritical plant in Elektrenai, 50 km west of Vilnius. But while Ignalina has played the lead role, generating the majority of the country’s electricity supplies, it now faces retirement. Stepping into the limelight will be Elektrenai, which, starting in 2009, will generate 70 per cent of Lithuania’s power supply.

For over a decade, the Elektrenai power plant has played understudy to Ignalina, serving as reserve capacity in the Lithuanian power system and operating at just five per cent of installed capacity. But times have changed in Lithuania and its accession to the European Union (EU) means that the Soviet-era Ignalina nuclear plant must close.

As part to its EU Accession Treaty, the government of Lithuania agreed to close Ignalina in two phases: Unit 1 before 2005 and Unit 2 before 2010. Unit 1, which was commissioned in 1983, was shut down at the end of 2004, and Unit 2, commissioned in 1987, is due to close in 2009. Between 1987 and 2004, Ignalina generated 80 per cent of Lithuania’s power supplies, and now Elektrenai must step into its shoes.

Figure 1. The 1800 MW Elektrenai power plant in Lithuania is undergoing a major modernization programme
Click here to enlarge image

But in order to serve as Lithuania’s main electricity generator, Elektrenai needs considerable upgrading. It is therefore due to undergo a major modernization that will improve its environmental performance, efficiency and reliability. Its owner, Lithuanian utility AB Lietuvos Elektrine, is embarking on a major investment programme that will ensure that Elektrenai meets environmental requirements and can operate flexibly within a liberalising electricity market.

Soviet style

Elektrenai was built between 1960 and 1972 and was designed as a base load power plant, producing both heat and power. It consists of eight units: four 150 MW units and four 300 MW units. Each of the 150 MW units (Units 1-4) are 500 t/h, front wall fired units. Units 5-8 each have a capacity of 950 t/h, and feature two opposed fired 150 MW units supplying steam to a single steam turbine.

Although the Elektrenai power plant was designed to burn heavy fuel oil and natural gas, it now also uses a third fuel: orimulsion, imported from Venezuela via the Baltic Sea. Orimulsion was introduced in order to diversify fuel sources at the plant.

The existing environmental abatement equipment at the plant is insufficient to comply with the EU directive on large combustion plants, which will come into force in January 2008. Two boilers are equipped with low NOx burners, and one with an electrostatic precipitator (ESP). There is no desulphurisation equipment installed at the plant.

The modernization

The modernization project, which will be completed in a number of phases between 2006 and 2009, will therefore involve the installation of environmental control equipment, including ESPs and flue gas desulphurization (FGD) equipment. In addition, the plant’s control systems are to be modernised to improve reliability as well as enable it to meet the demands of a liberalized market environment. The project consists of:

  • Installation of five FGD plants for Units 1 and 2, 5, 6, 7 and 8A, with common facilities for reagent, end-product and waste handling
  • Installation of eight ESPs for Units 1, 5 (A and B), 6 (A and B), 7 (A and B), and 8A, with orimulsion and heavy fuel oil ash handling plants, and an orimulsion ash densification system
  • Low NOx burners for Units 1, 2, 5, 7 and 8, and new burner management systems for Units 5 and 8. The burner management systems on Units 1, 2, 6, and 7 will be modified
  • Complete new control systems for Units 5, 7 and 8
  • Rehabilitation of regenerative air preheaters for Units 5-8.

Units 3 and 4 are not included in the project, as Lietuvos Elektrine does not envisage using them in the foreseeable future.

Take control

According to Andrzej Koba, Emerson Process Management’s director of projects and responsible for Lithuanian project implementation, much of the plant’s main equipment is in good shape, largely due to the fact that the plant has been barely used since 1992. However, the plant’s control systems require updating.

“Lithuania wants its power system to meet EU and UCTE standards. The Elektrenai power plant does not currently meet these, partly due to its control system,” said Koba. “The replacement of the current control system with a modern, computerized system will enable the plant to meet these standards, and be a reliable source of power.”

Figure 2. The modernization will improve the plant’s efficiency, reliability and environmental performance
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In December last year, Emerson announced that it had won the EBRD-sponsored bid to modernise Elektrenai’s control systems on Units 5, 7 and 8. Its €15.6 million contract will involve removing and replacing the old control system for the boilers and turbines, including the cables, transmitters, valves, turbine control systems, control room equipment and measuring devices.

Emerson will install its PlantWeb digital plant architecture with the Ovation expert control system. The PlantWeb architecture has predictive intelligence capabilities, enabling problems to be detected before they occur and helping operators to avoid unplanned outages and optimize performance. Under the contract, Emerson will also install new vibration monitoring equipment, instrumentation, valves, actuators, switchgear and electrical protection equipment.

“We have subcontracted much of the field work to a Czech company that we have worked with before, and we have contracted Bentley Nevada to supply the vibration monitoring equipment,” said Koba.

“After the modernization, this plant will be the primary electricity supplier in Lithuania,” said Pranas Noreika, Elektrenai’s plant general manager. “We selected Emerson because of its proven superior experience in advanced control solutions relating to the commissioning and start up of supercritical units. Emerson demonstrated an understanding of our units, as well as extensive capabilities to execute such significant turnkey projects. With the PlantWeb architecture, we expect operating and maintenance savings of up to two per cent.”

Unit 5 will be the first to be modernized, according to Koba, and will be shut down on April 15, 2006. The work will take approximately five months. Units 7 and 8 will follow in 2007 and 2008, respectively.

Burning issues

Under contract to Alstom, Emerson is also supplying the burner management systems to the plant. In 2005, Alstom won the contract to install low-NOx burners at Elektrenai, having previously installed low NOx burners to Unit 6 in 1999/2000. Alstom will install 52 low NOx burners. The burners are designed and built specifically for the project and Alstom is working with a local company in Lithuania for their manufacture. The burners are 2 m high, 2.5 m in length and weigh around 2.5 t. In addition to supplying the burners, Alstom is also carrying out other work such as modifying fuel and ducting systems.

In November 2005 Alstom announced that it had been awarded the contract to supply air pollution control equipment to Elektrenai. Under its contract, it will supply eight new ESPs for the removal of particulate emissions, and will also upgrade the existing ESP at Unit 2 of the plant.

Figure 3. Emerson will install its PlantWeb digital plant architecture with the Ovation expert control system
Click here to enlarge image

Lietuvos Elektrine also awarded Alstom the contract for FGD systems at the plant. Alstom will supply its Flowpac FGD system, with the contract split in two phases: in phase one, valued at €94 million, it will supply FGD equipment for two of the 300 MW units, while in phase two, which will come into force in 2007, it will supply FGD equipment for the remaining units. The total value of the contract is over €200 million.

Alstom will supply five Flowpac plants. Flowpac is a turbulent bed, limestone forced oxidation wet flue gas desulphurisation technology that meet requirements for the removal of sulphur dioxide, sulphur trioxide and particulate matter. The technology can treat emissions with a wide range of sulphur content, and it has a more compact design and lower operation and maintenance costs compared with conventional wet FGD designs.

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