CFBC, preferred Technology for lignite fuel - Experiences - Infraline

More documents

Recommendations

Info

separate norms in respect of Auxiliary Power Consumption, reimbursement of complete fuel additive charges, if necessary. Introduction India has total estimated usable lignite reserves of 97,000 MMT , concentrated in the states of Tamilnadu, Gujarat and Rajasthan. Tamilnadu has 70,000 million Tones, Rajasthan has15,000 million Tones, Gujarat has 12,000 million Tones. All these states are far away from coal reserves located in India. It is economical to use lignite for power generation in these areas. These are more than 30% of coal reserves available in India. Estimated power generation capacity addition with this lignite reserves is around 3,00,000 MW for 50 years. India has not exploited lignite reserves available for power generation as it has to be considering the available resources. Performance of units with PF technology using lignite has been low. Performance of Units with CFBC technology using lignite is encouraging. CFBC operates with combustor temperatures in the region of 850 – 900 deg C. These combustor temperatures are much lower than ash fusion temperature. So, in CFBC boilers problem of any clinker formation is not encountered with lignite as primary fuel. General quality of lignite fuel available for using in boilers in India is as follows: Parameter Range Total Moisture 40 to 52% Ash 8 to 20 % VM 21 to 34% FC 11 to 20 % CV 2500 to 4000 Kcal/kg Sulphur 1 % to 6% Chloride 0.20 % to .35% ADVANTAGES OF CFBC TECHNOLOGY Environment Friendly Sulfur emissions are effectively controlled by adding lime stone to the fluidized bed, eliminating the need for an external desulfurization process such as SO2 scrubbers, which are costly. Because of reduced combustion temperatures, Nox emissions are inherently low or negligible. Fuel Flexibility FBC units were touted as being “fuel flexible”, with the capability of firing a wide range of solid fuels with varying heating value, ash content, and moisture content. Combustion in FBC units takes place at temperatures below the ash fusion temperatures of most fuels. Consequently, tendencies for slagging and fouling are greatly reduced with FBC.
Simplified Fuel Preparation And Feeding Normally crushers are sufficient for fuel preparation. A top size, in the range of 5 – 12 mm is required for sub-bituminous coals. Pulverizes and associated maintenance are eliminated. Compact Plant Design CFBC boilers require less floor space than conventional steam generators with down stream flue gas cleaning equipment. Sustainability Under Cyclic Loading Minimizes stress on boiler tube material with low variation of combustor temperatures under cyclic loading of boiler particularly under varying grid frequencies. High Reliability Low flue gas velocities in combustor minimizes erosion and hence the boiler tube failures leading to very high reliability of the boiler. Comparison of CFBC technology with PF technology on some parameters Description CFB Boiler PF Boiler Benefits of CFB Fuel Size 12-6 mm >70%
Page 1: CFBC, preferred Technology for lign
Page 5 and 6: Other General operation problems be
Page 7: India has good reserves of lignite

CFBC, preferred Technology for lignite fuel - Experiences - Infraline

Create successful ePaper yourself

Delete template?

Save as template?