Environmentally Oriented Modernization of Power Boilers

1. INTRODUCTION

2. BOILER EFFICIENCY AND THERMAL LOSSES

3. MODERNISATION TO REDUCE THE FLUE GAS LOSS 3.1. Lowering of flue gas temperature 3.2. Selection of the minimum flue gas temperature at the boiler outlet 3.3. Optimisation of flue gas outlet temperature 3.4. Lowering the air excess number in the boiler

4. REDUCTION OF NITROGEN OXIDE EMISSIONS 4.1. Formation of nitrogen oxides 4.2. Impact of operating conditions of the furnace on emissions of nitrogen oxides 4.3. Methods of reduction of nitrogen oxide emissions in PF boilers 4.4. Secondary methods of NOx reduction 4.5. NOx reduction methods without the use of ammonia or urea 4.6. Combined methods of NOx control 4.7. The future of NOx emission reduction methods

5. MODERNISATION OF FUEL GRINDING SYSTEMS 5.1 Quality of pulverised coal 5.2 Coal mills 5.3 Modernisations of coal mills arising from low-NOx combustion 5.4 Modernisation to improve the operating conditions of pulverisers in dynamic states 5.5 Modernisation of pulverisers to reduce harmful emissions

6. REPLACING COAL WITH OTHER FUELS6.1. Introduction 6.2. Replacement of coal with natural gas 6.3. Replacement of coal with blast furnace gas and low quality syngas 6.4. Replacement of coal with fuel oil 6.5. Replacement of hard coal with lignite 6.6. Modernisation for the combustion of various fuels in the same boiler

7. ADAPTATION OF BOILERS FOR BIOMASS BURNING 7.1. Types of biomass used in the power industry 7.2. Adaptation of PF boilers for biomass burning 7.3. Complete replacement of coal with biomass

8. HARMFUL PHENOMENA IN MODERNISED BOILERS8.1. HT corrosion on the flue gas side 8.2. LT corrosion on the flue gas side 8.3. Fly-ash erosion 8.4. Fouling 8.5. Slagging 8.6. Condensation of sulphates

9. CONVERSION OF AN EXISTING BOILER TO A CONDENSING BOILER 2.1. Condensing technology 2.2. Industrial applications

10. INCREASING FLEXIBILITY OF BOILER OPERATION 10.1. Adaptation of the boiler to work with a load higher than nominal 10.2. Lowering the minimum boiler load 10.3. Frequent start-ups and large and rapid load changes 10.4. Increasing flexibility of boiler pressure parts

11. INTERACTIONS BETWEEN EMISSION REDUCTION SYSTEMS11.1. Introduction 11.2. Interactions between NOx reduction systems and dust removal systems 11.3. Interactions between SOx reduction systems and dust removal systems 11.4. Influence of flue gas dedusting and NOx reduction systems on wet FGD