Stationary Diesel Engines In the Arctic. David Light Research Engineer University of Alaska Fairbanks

Transcription

1 Stationary Diesel Engines In the Arctic David Light Research Engineer University of Alaska Fairbanks

2 Introduction Source, Wartsila-Sulzer Inc.

3 Diesel Engine Cycle Basic 4 Stroke Sequence Variables Involved During Combustion Effects on Emissions

4 Chemistry of Combustion Exhaust Gasses Non-Hazardous O 2 N 2 Oxygen Nitrogen CO 2 Carbon Dioxide H 2 O Water NWT Canada

5 Chemistry of Combustion Exhaust Gasses Hazardous, Regulated NO X CO HC Nitrogen Oxides Carbon Monoxide Hydrocarbons HCHO Formaldehyde PM Particulate Matter

6 NO x Nitrogen Oxides Formed by reaction between nitrogen and oxygen Created by high combustion temperatures NOx Reacts with volatile organic compounds, in the atmosphere, and in the presence of sunlight causes the formation of ozone. EMD

7 CO Carbon Monoxide Formed during the intermediate stage of combustion Result of incomplete combustion Highly toxic compound 3516 Tok, Alaska

8 HC Hydrocarbons Hydrocarbons are elements of unburned fuel Result of low combustion temperature Often formed in areas along cylinder walls Can be caused by poor air/fuel mixtures Major contribution to formation of smog 3516 Galena, Alaska

9 PM Particulate Matter Direct cause of Black Carbon formation Consists of Carbon core 10 microns Contains outer Hydrocarbon layer Thin coating of Sulfuric Acid on surface Composition ratios can vary greatly depending on engine operating conditions, and fuel supply

10 PM Particulate Matter Hydrocarbon Carbon Diameter 10 microns Sulphuric Acid Misc. Metals Oil Residue

11 Carbon Reduction Solutions 1. Improved maintenance of existing equipment 2. Improve utilization of fuel source, incorporate heat recovery systems 3. Review, and upgrade existing engine installations 4. Replace engines with new models that incorporate latest technology combustion systems 5. Upgrade fuel supply to reduce sulfur content, ULSD Ultra Low Sulfur Diesel 6. Installation of exhaust after-treatment systems, SCR Selective Catalytic Reduction DPF Diesel Particulate Filters

12 Heat Recovery Systems Maximum utilization of heat from jacket water, and exhaust Automated control systems Bethel, Alaska Galena, Alaska

13 Diesel Technology Present, and Future Improvements to After-Coolers Variable Geometry Turbochargers Electronic Timing, and controls High Pressure Fuel Injection Common Rail Fuel Systems Multi-Shot Fuel Injection Technology Exhaust Gas Recirculation, EGR Systems C175 Tok, Alaska

14 Diesel Fuel Sulfur Reduction United States Tiered Reduction of Diesel Sulfur Content for Stationary Engines in Urban, and Rural Alaska Region Fuel Use Before After 2010 Urban Alaska Non- Road High Sulfur High Sulfur 500 PPM 15 PPM 15 PPM Rural Alaska Non- Road High Sulfur High Sulfur High Sulfur 15 PPM 15 PPM High Sulfur Diesel: > 500 ppm Low Sulfur Diesel: 500 ppm Ultra Low Sulfur Diesel: 15 ppm

15 Stationary Emissions Standards USA, and Europe Tiered Emissions Levels Emissions reduced by model year, and power level

16 Emissions Compliance Strategy Tier Levels 1, and 2 can be achieved with improvements to engine technology, and operating conditions Tier Level 3 requires the use of low sulfur fuels as well as continued updated engine improvements Tier Level 4 Interim, and 4 Final will require high level of exhaust after-treatment EMD Bethel, Alaska

17 EGR Exhaust Gas Recirculation EGR Is an engine mounted system that injects a stream of cooled exhaust gas into the combustion chamber Resultant lowering of combustion temperatures reduces NO X formation Source, Navistar Inc.

18 DOC Diesel Oxidation Catalyst DPF Diesel Particulate Filter DOC Catalyst core reacts with, and reduces CO, HC, and PM DPF Contains remaining, PM in the exhaust stream. Source, Navistar Inc.

19 SCR Selective Catalytic Reduction SCR Will provide a reduction of NO X by up to 90% NO X is converted to N 2 H 2 O and CO 2 Ammonia in the form of Urea is injected into the exhaust stream The mixture then passes through a catalyst core assembly

20 Exhaust After-Treatment Equipment Multiple filter DPF housings Serviceable elements Source, Custom Catalyst and Exhaust Products Source, Access Science.com

21 Diesel Engines, Upgrade or Replace? What are the options, what level of emissions can be achieved? Discussion of arctic issues.