3.2. Third Stage of Rehabilitation, Boilers4-6 The 'Compact' design selected for Units 4-6 offers 26 1 .6 MWe of output rather than the 235 MWe offered by the fırst CFBs, while stili remaining within the same space restrictions imposed by the old, pulverized coal-based 200 MWe units. The Foster Wheeler CFB boilers for Units 4, 5, and 6 are designed for fıxed-pressure, natural circulation, lignite fıring, with a maximum continuous rating of 1 95.5 kg/s of life steam. Estimated boiler effıciency is 91 %, LHV-based, with a stack temperature of 1 30 °C compared to 1 57 °C for Units 1-3. The required emissions level for these three CFB boilers is achieved exactly same like in boilers 1-3, by low combustion temperature and an even temperature profile throughout the furnace, staged combustion, and good residence times and mixing conditions. The designed stable operation range of the boilers without auxiliary fıring is from 40% to 1 00% MCR. The steam temperature control range is from 60% - 1 00% of full load. The increase in unit capacity was achieved thanks to higher steam parameters, useofthe Compact boilerconcept, INTREX™ heat exchangers [4], and rotary air preheaters. 4. Environmental lmpact of Modernization The region on the border between Germany, the Czech Republic, and Poland where Elektrownia Tur6w is located was badly polluted by the beginning ofthe early 1990s, largely as a result of airborne emissions from the thermal power plants concentrated in the area. Forests were dying because of acid rain precipitation, and the region had begun to be known as the 'Black Triangle'. Thanks to the modernization project, the Tur6w Table 3. Emissions of Units 1-3 power plant now has six modern units that comply with all EU requirements in respect of dust, SOx, and NOx emissions. AII the CFB units also meet the CO emission requirement, although the contract for the fi rst three CFB units does not guarantee CO emissions under to the current legal model in Poland. Guarantee measurements on Unit 6 will be performed injune 2005. Preliminary measurements carried out during the trial run indicated that this unit, like the previous units, will not have any problem in meeting guaranteed emissions levels. Tur6w's new CFB units generate 87,000 t/a less SO2 (93% reduction/ MWe) than the old PC boilers, 5,220 t/a less NOx (50% reduction/MWe), and 36,500 t/a less dust (94% reduction/MWe, 1 00 t/day less). Seven measurement stations are installed in the surrounding area today. These monitor emission levels continuously and send data back both to the power plant and to the state Sox NOx Dust � g/GJ g/GJ Even lower emissions to meet future EU requirements could be easily obtained with only minor adjustments. A NOx limit of 200 mg/Nm3 could be achieved by adding a simple system ofweak water-solution ammonia spray into the separators. Further reducing sulfur dioxide emissions could be achieved by increasing limestone injection into the furnace or Guaranteed in dry gaş 6%02 150* 150** r mg �� m3 by employing an ash activation solution. The units must be compatible with UCPTE and PSE S.A. requirements to ensure they are capable of feeding the grid and operating at house load. Unit 1 %MCR Unit 2 %MCR Unit 3 %MCR • - 371 ıııg/Nm; •• -347 nıg/Nııı3 Table 4. Emissions of Units 4-6 SOx - Guaranteed in dry gas 6%02 mg/Nm3 - 347 371 150 - Unit 4 100 -� %MCR 316 Unit 5 100 %MCR 287 Unit 6 100 %MCR 346 1 14.2 122.5 17.5 126.0 L 126.0 3.5 -- 84.0 1 1 1 .0 6.0 NOx co Dust mg/Nm3 mg/Nm3 mg/Nm3 50 239 6.8 16 275 4.3 21 212 7.5 l 33 1 ENERJi OÜNYASI MAYi$ 2007 ♦ - 66 --l===========.::.:�::c=�================ "Enerjide Sürdürülebilirlik ve Küreselleşme: Verimlilik, Emisyonlar, Yeni Piyasa Oluşumlan"
RkJQdWJsaXNoZXIy MTcyMTY=