858 MWe supercritical extension for Belchatow

From the early 1990s onwards it was clear that major investment was needed to rehabilitate and/or replace Polish power plants, to improve operating performance and to address the effects of ageing and obsolescent technology.

Furthermore, after a brief period when electricity consumption decreased, due to closure of obsolete production facilities and a decline in the power-intensive sectors of industry, over the past few years power demand has been increasing steadily in tandem with the country’s GDP growth.

The situation in the power sector was exacerbated by Poland’s joining of the European Union in May 2005, which brought the burden of additional emissions reduction obligations, with limitations on emissions by Poland as a whole and by the Polish power sector specifically.

All these factors created the necessity for the Polish power sector to embark on a very large investment programme to meet the requirements of growing power demand, increased market competition and tightening environmental regulations.

Estimates suggest that to meet these requirements some 9 GW of new or radically rehabilitated generating capacity will need to be put in operation between now and 2015.

Indigenous coal remains the mainstay of Polish power, accounting for about 152 TWh of the 162 TWh gross production in 2006 (some 94%, with oil, gas and hydro providing the rest). Lignite accounts for about a third of the coal generation.

The first big project was rehabilitation of units 1-6 of the Turow lignite fired plant, a huge undertaking that started in 1994 (with the awarding to an Alstom-led consortium of a contract to rehabilitate all six LMZ-designed 200 MW units) and continued until 2005. The first three units were uprated to 235 MWe, and the subsequent three units to 262 MWe.

Another significant project was the construction of a 460 MW supercritical lignite fired plant at Patnow (replacing two old 200 MW LMZ designed oil fired units), for which Alstom was awarded the turbine island and boiler contracts in 2001 and which is currently under commissioning.

The next key phase in the replacement of old generating capacity in Poland was the start of construction of the world’s first supercritical CFB plant, at the Lagisza site of PKE (Southern Poland Power Company). Lagisza is scheduled to enter commercial operation in early 2009. The boiler for this 460 MW unit is being supplied by Foster Wheeler, while in December 2003 Alstom received an EPC contract covering the turbine island package (including civil works) and the cooling system, including cooling tower.

The new 858 MWe lignite fired supercritical unit to be built at Belchatow represents a further key stage in the modernisation of Poland’s power generation infrastructure.

Poland’s biggest

The Belchatow extension will be the largest generating unit ever built in Poland and also the most efficient lignite plant, expected to achieve almost 42%.

Alstom is supplying the plant to utility BOT Elektrownia Belchatow SA (which is owned by the state power generation holding company BOT Gornictwo i Energetyka) under a full turnkey EPC (engineering, procurement, construction and commissioning) contract. The contract was signed in December 2004 and the pre-engineering phase started immediately. Financial close and the official launch of the project (notice to proceed) was obtained in October 2006. Commercial operation is scheduled for the last quarter of 2010.

There are already twelve 370 MWe lignite fired units at the Belchatow site, which started operation in the early 1980s and run in baseload mode. There was an urgent need to rehabilitate these units due to their age, emissions and economics.

Ten of the units will be upgraded, over the period 2007 to 2013, while the oldest two will be shut down permanently before 2016, with the new plant more than making up the loss of power production. The end result will be increased electricity production in full compliance with European environmental regulations, including the Large Combustion Plant and Integrated Pollution Prevention and Control Directives.

The total cost of the new plant plus the refurbishment of the existing units is estimated to be around 1.7 billion euros. The EBRD is providing a loan of 125 million euros for the new plant. Other investors include EIB, 220 million euro, Nordic Investment Bank, 150 million euro, and ING and Citibank, which are providing various facilities totalling 604 million euro.

BOT Elektrownia Belchatow decided to build the new 858 MWe unit as an extension of the existing unit in order to secure continuous deliveries of electricity to customers as well as maintaining a constant level of lignite consumption from the local open mine (a major cost factor for the power plant).

Thanks to the project BOT Elektrownia Belchatow will:

• secure its income by maintaining electricity production;

• secure fuel costs by achieving constant lignite demand;

• secure extended lifetimes for the upgraded existing units; and

• meet all EU requirements relating to coal fired plants.

The environmental performance of the new plant can be summarised as follows:

• NOx emissions below 200 mg/Nm3;

• particulate emissions below 30 mg/Nm3 thanks to ESP plus additional effect of wet desulphurisation;

• reduction of SOx emissions to below 200 mg/Nm3 with a removal efficiency of over 96 %, again thanks to the wet desulphurisation system;

• limitation of CO2 emissions thanks to high plant efficiency;

• reduction of raw cooling water consumption through measures such as reuse of cooling tower blowdown water and reuse of water from the nearby mine for ash slurry transport instead of using surface water resources; and

• noise abatement though use of protection systems and special attention to design of sensitive systems, such as coal handling equipment, boiler fans, and cooling tower.

Solid waste consisting of fly and bottom ash will be transported as slurry to a new landfill in the nearby lignite mine. Waste gypsum from the new wet limestone FGD scrubbing system will be used commercially, a practice well established in Poland. In fact the use of power plant gypsum for plasterboard in Poland was pioneered by the existing Belchatow units.

Design features

The Alstom scope of supply includes: a tower type supercritical once through pulverised coal boiler (with low NOx combustion system); five-casing steam turbine with three double flow exhausts (STF100); hydrogen cooled generator (GIGATOP); water cooled condenser; feedheating system with seven heaters; milling system; wet flue gas desulphurisation system; coal and ash handling systems; control system based on Alstom ALSPA technology; and balance of plant. An important feature of the project has been careful integration of all these systems throughout all phases, from development of the concept, through the basic and detailed design up to erection and commissioning.

The new 858 MW unit has been designed to achieve an operating life of about 200 000 hours, ie about 35 years.

It will use local lignite from the existing Belchatow open cast mine, presently supplying fuel to the existing units, as well as from a new open cast lignite mine being constructed at Szczercow.

The design of the unit as well as the equipment selected will allow the new plant to achieve an availability above 88% over the first two years of operation, with scheduled outages reduced to about two weeks for the annual overhaul, with a six week outage every three years.

Thanks to its compact and modular design the new unit, with all auxiliary installations, will cover the relatively small area of 300 m long and 350 m wide, an extension to the area of the existing plant.

The total height of the new turbine building will be 39 m and the boiler will be up to 150 m high.

In addition to the new power block (boiler, turbine and generator) the project consists of: the new desulphurisation plant with auxiliary installations; recirculating cooling system with the cooling tower also used as a chimney; the complete electrical system with two unit transformers; new control system; water treatment system; coal handling system connecting the new unit with the lignite transportation system from the open mine to the existing units; hydraulic ash slurry transport systems; electrostatic precipitator; auxiliary systems and buildings, including administration building.

The majority of deliveries and almost all the on-site work will be provided by Polish companies.

Main components

The main data for the plant are summarised in the table, right.

Key features of the main systems include the following:

Boiler

Supercritical once-through single pass boiler with circulating pump for start up and turn down capability to 40% of boiler load.

There is one 100% boiler feedwater pump driven by an auxiliary steam turbine connected to steam extraction from the main steam turbine and two start up and reserve pumps (35% each) connected to electrical motors via hydrokinetic couplings.

The design of the boiler has been done in Stuttgart, Germany, and production of most of the boiler components is being done in Raciborz, Poland.

Turbine-generator

The five-casing steam turbine (STF100) is of the reaction type and is being manufactured in Elblag, Poland. The GIGATOP generator is being produced in Wroclaw, Poland, and Birr, Switzerland.

Control system

The new unit will be equipped with an ALSPA P320 control system, which includes a CENTRALOG integrated monitoring and supervision system and CONTROBLOCK P320 control blocks.

Integration

With Alstom the single EPC supplier, and through the use of its Plant Integrator capabilities, the project also provides a good example of the benefits of integration between systems, coupled with close co-operation between contractor and utility, during all phases of the project, from conceptual development of the concept, through basic and then detailed design up to erection and commissioning of the new plant.

All major components of the new unit have been analysed as elements of the overall power plant system to achieve the best balance between technology, costs, power production etc.

Also, all major systems and the interfaces between them have been optimised to arrive at the most compact solution, matched to the limited area available for the new unit.

In addition, integration combined with modularisation has contributed to reducing the expected project execution time to 48 months, from notice to proceed (October 2006) to obtaining of the provisional acceptance certificate (PAC) (October 2010).

Ever more stringent environmental regulations and the emergence of open and competitive markets, with the need for increased productivity, are currently strong drivers in Central and Eastern European countries including Poland. The new Belchatow unit can be seen as a product of these combined forces.

BOX 1:

Belchatow, pillar of Polish power – a utility perspective

Piotr Szmaj, chief engineer, new unit, BOT Elektrownia Belchatow

Even before the addition of the new 858 MWe supercritical unit (described in the main article), Belchatow hosted the largest coal (lignite) fired plant in Europe – with a current installed capacity of 4400 MWe (12 x 370 MWe) – and has been called the capital of the Polish power generation industry. Following completion of the modernisation programme started in 1997, which added 120 MWe to the installed capacity (by modernisation of the turbine LP stages), the plant fulfils all EU requirements and standards.

Indeed, BOT Elektrownia Belchatow was the first company in Poland to receive a permit under the EU’s Integrated Pollution Prevention Control (IPPC) scheme to run its installations in line with the IPPC directive.

The power station being the lowest cost and the most efficient electricity producer in the country is a pillar of the Polish power generation industry, helping to stabilise the national energy market. Since the late 1990s, with an annual electricity output of about 28 TWh, Belchatow has provided some 20% of Poland’s power, well ahead of any other power station.

The design of the original Belchatow units was developed in the 1970s and did not anticipate any measures to limit emissions of sulphur oxides emissions because at that time flue gas desulphurisation technologies were largely unknown and only in the development phase. However, in the years 1988 to 1990, BOT Elektrownia Belchatow turned its attention to developments in Polish desulphurisation technologies as well as those being applied worldwide, and subsequently fitted FGD to ten of the 12 Belchatow units (numbers 3 to 12).

To maintain a leading position in the Polish electricity market BOT Elektrownia Belchatow has adopted a strategy for capacity development, which entails comprehensive modernisation of Belchatow units 3 to 12, starting in 2007 – with the aim of enabling them to reach 320 thousand hours of operation, ie to operate until around 2035 – plus construction of the new unit, as described in the main article.

The strategy, which assumes maintenance of high power production capabilities in association with optimal utilisation of available coal deposits (about 1 billion tonnes of lignite) in the Belchatow and Szczercow open cast mines, can be summarised as follows:

• Construction of the new 858 MW power unit, with commercial operation scheduled for October 2010. This represents the largest investment of its kind yet in Poland. In 2001, official acceptance from the Ministry of the Treasury was obtained to commence a project to build a new 833 MW power unit. The capacity was subsequently increased to 858 MW, thanks to improved plant integration by EPC contractor Alstom. The tender procedure began in 2002 resulted in the selection of the Alstom consortium. The design was approved in 2005 and a construction permit issued. Construction work began in October 2006. The power plant will use best available technology (BAT), as required under IPPC, and will also fulfil the requirements of the EU Large Combustion Plant directive. First synchronisation with the Polish national grid is anticipated in February 2010. The project includes a new transmission link to the system switching station in Trebaczew.

• Reconstruction and modernisation programme. Refurbishment of units 1 and 2 (which do not have FGD) was done in 2004 and 2005, while modernisation of units 3-12 will be done according to the following schedule: unit 3 in 2007, unit 4 in 2009, units 5 and 6 in 2010, units 7 and 8 in 2011, units 9 and 10 in 2012, and units 11 and 12 in 2013. The basic goals of the modernisation process include: extension of the operating lifetime of units 1 and 2 (to 2016) and of units 3-12 (to 2030-2035); improvement of operating performance; reduction in environmental impact, including compliance with EU Directive 2001/80/EC; and increase in turbine-generator unit power from 370 MW to 380 MW.

The total investment cost (new build plus refurbishment) is 1.6 billion euro, with banks providing 880 million euro. The project won the Euromoney/Project Finance award for best European power deal of 2006.

The new unit and the refurbishment programme are in line with BOT Elektrownia Belchatow’s policy of striving to continuously upgrade and improve its power technology assets. The management system is also being continuously improved. The power plant holds a PCBC and IQNet certificate for an Integrated Management System for Quality, Environment, Occupational Safety and Information Security (IMS-ISO), compliant with the requirements of the PN-EN ISO 9001:2001, PN-N-18001:1999, PN-EN ISO 14001:1998 and PN-I-07799-2.