OCR Text |
Show Ansaldo Energia s.p.a. The successful accomplishment of this task requires the availability of: i) analytical tools, with different sophistication level, ranging from overall ID to detailed 3 D C F D codes, supplemented by suitable post processors for a friendly elaboration of the results and coping with both flue gas side (mixing, thermal field) and water-steam side, (waterwall metal temperature) [1] ii) experimental results at lab scale and at pilot scale for developing process knowledge and validating the analytical tools against the data of "ad hoc" planned test campaigns performed under controlled conditions [2] [3] hi) field experience for a full scale demonstration of the combustion system performance, jointly with the assessment of the impact on the whole plant behavior [4] [5] [6]. This paper summarizes the experience gained in Italy and abroad by Ansaldo related to the Italian E N E L park applying technologies jointly developed with E N E L. Table 1 Emission Standards for new and existing Plants (data in mg/Nm3 at 3% 02 oil-gas and 6% coal) ANSALDO ENERGIA Pollutant SOi NOx Solid Particulate CO X Size FuelsX Solid Liquid Gaseous Solid Liquid Gaseous Solid Liquid Gaseous All NEW PLANTS 50 => 100 2000 100 => 200 2000=>1600 1700 200 => 300 300 => 500 1600-400 1700-400 35 650 450 350 650 - 200 450 - 200 350 - 200 >500 400 200 50 50 5 150 EXISTING PLANTS <50 2000 1700 35 650 500 350 50-150 100-150 5 50 => 500 1700 650 50 >500 400 200 50 250 EXPECTED EUROPEAN STANDARDS > 500 MWth 200 200 30 100 The Ansaldo/ENEL Strategy As known Italian power production is mainly based on oil/gas firing (~ 28.000 M W e ) with only marginal role played by coal (~ 6500 M W e ) (some 2 0 % of electric energy demand is covered by import from France and another 2 0 % is produced by hydro). ENEL/Ansaldo strategy for oil/gas fired boilers is to make resort to in-furnace N O x reduction techniques and to use low sulphur oils (S < 0,25%) for contemporary N O x / S O x control. For coal fired boilers high dust SCR's coupled with F G D are installed but also introducing combustion modifications (Low N O x burners, B O O S , OFA, Reburning) to reduce both size and operating costs of the SCR's. For oil fired boilers the use of the reburning technology, in both versions: gas over oil and oil over oil, has proven to be the best mean to comply with regulations and over 9000 M W e have been retrofitted up now. Recently O R I M U L S I O N has entered in the E N E L fuels with the scope of using it in coal designed -2- |