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Ähnlich wie 2010 Nuking The N Ox
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2010 Nuking The N Ox
- 1. SELECTIVE CATALYTIC REDUCTION “ Nuking the NOx”
- 2. Emission Development NOx with Credits
- 3. Reducing Particulates 0.25 0.1 .01 Units: g/hp-hr aftertreatment
- 4. Reducing Oxides of Nitrogen (NOx) 6 5 2.5 4 1.2 0.5 0.2 “ The technology does not exist to achieve 0.2 without aftertreatment” Units: g/hp-hr aftertreatment
- 5. Near-Zero Emissions from Truck Diesels CO Carbon Monoxide HC Hydrocarbons PM Particulate Matter Carbon (Soot) NOx Oxides of Nitrogen NEAR ZERO NEAR ZERO NEAR ZERO NEAR ZERO
- 7. NOx: At Odds with Fuel Economy In general, the more efficient the combustion, the higher the NOx output. The lower the NOx output, the lower the efficiency Efficiency, % more more less less EFFICIENCY vs. NOx NOx Reduction, %
- 9. More Exhaust Gas Recirculation?? 35% - 50+% 20% - 35% 10% - 20% EGR Flow Massive EGR Heavy EGR Light EGR Industry Definition
- 10. Keeping Everything in Balance is a Challenge… Peak Cylinder Pressure NOx to Soot Ratio Displacement Fuel Injection Pressure Air/Fuel ratio Regeneration Power Density “ Not to Exceed” Emission Window Boost Pressure
- 13. EPA’10 Hardware: Injector and Catalyst
- 14. EPA’10 Hardware
- 15. EPA’10 Hardware
- 16. DEF Indicator – a Real Gage
- 20. Comparing EGR & SCR MORE LESS Fuel Efficiency LESS MORE Heat Rejection MORE LESS Power Density EGR + SCR MASSIVE EGR
- 23. Diesel Exhaust Fluid Water Diesel Exhaust Fluid Crystalline Solid Slurry 12 o F Ice
- 25. 3000 Mile Coast-to-Coast Trip Los Angeles New York Here are the Numbers (Worst Case, as of this date) You can travel coast to coast And still have 1/3 tank of DEF left over 13 gallons DEF
- 28. Potential DEF Sale Locations
- 29. Diesel Exhaust Fluid Dispensers
- 30. As Close As Your Nearest Travel Center Convenience Store D
- 31. EPA’10 Testing Experience October 2, 2007 -- FIRST FIVE EPA’10 TEST TRUCKS DELIVERED
- 33. On Board Diagnostics (OBD) Engine EGR Fuel Fuel Mixing zone DPF Diesel Exhaust Fluid Reservoir Sensors: 3 Temperature sensors 1 Differential Pressure sensor 2 NOx-sensors OBD DEF Mixing zone SCR Exhaust Outlet
Hinweis der Redaktion
- Since 1975, emission standards for U.S. and Canadian heavy trucks have gotten progressively tighter
- By 1994 we had a ‘no visible smoke’ – a 90% reduction in black smoke (particulate matter, or ‘soot’) from original levels. To meet the 2007 standard required another 90% reduction on top of that, to a 99% total reduction . The technology everybody used to meet the standard was ‘aftertreatment’ – treating the exhaust after it came out of the engine. All manufacturers adopted the DPF, or diesel particulate filter.
- By 1998 we had gotten NOx down to 4 g/hp-hr. EPA’02 required truck engines to drop NOx by 40% more to 2.5. For most manufacturers, this required the use of ‘light EGR’. Wow, what an effort that was! EPA’07 required us to cut that level of NOx in half, to 1.2. Most manufacturers employed ‘Heavy EGR’. We made it look easy, but it wasn’t. To restore fuel economy, Volvo went to 35,000 psi fuel injection. We also moved the gearing to the rear of the engine to help keep the torsional vibrations from being a problem. Now EPA’10 requires us to drop yet another 83%, to 0.2. This will be a 99% drop from original levels . IF you apply earned credits from selling another engine below standard, you are permitted to only drop to 0.5. This level is 2.5 times more NOx than without credits. The technology does not exist to get to 0.2, or near-zero NOx, without the use of aftertreatment. Manufacturers meeting 0.2 will employ SCR, or Selective Catalytic Reduction. They will also still use some EGR, but to a lesser extent. Manufacturers using credits will employ ‘Massive EGR’. This is the term the scientific community has for EGR rates approaching or even exceeding 50%.
- Now with NOx emissions reduced to near-zero, the heavy truck diesel is a near zero emission engine. Ninety-nine percent reductions in every regulated pollutant. That’s lower emissions than even T. Boone Pickens’ natural gas engine, until such time as particulate filters are developed and used for natural gas engines.
- The next step in the evolution of the low-emission diesel was Exhaust Gas Recirculation. Some of the exhaust gas is recycled back through the engine under certain circumstances. The purpose of the EGR is not to ‘re-burn the exhaust’ – rather it is to use the spent exhaust as a heat sink. Since it is mostly nitrogen and available in large quantities, re-introducing exhaust back into the engine dilutes the amount of oxygen in the intake charge. This reduces the temperature of combustion and lowers formation of NOx. EGR lowers the combustion temperature which lowers the formation of NOx. But EGR makes fuel economy worse. Other things must be done to recover fuel economy. We will use EGR into 2010 -- just not as much as today.
- Oxides of Nitrogen: Approximately 80% of the air we breathe is nitrogen gas, N2. Nitrogen is totally inert – it does not support a flame. However, when air gets extremely hot – as with a bolt of lightning, or in diesel engine combustion – trace amounts of nitrogen combine with oxygen to form NOx. Over time, it adds up to a lot. NOx elimination presents a dilemma. Unlike soot or other gaseous hydrocarbons, which are reduced by making combustion more efficient, oxides of nitrogen are actually produced in direct proportion to efficient combustion. In general, the more efficient the engine, the higher the NOx output. And t he lower the NOx output, the lower the efficiency .
- Further improvements in NOx came with fuel injection. Higher fuel injection pressure, which gives finer atomization for better combustion Shaped fuel injection delivery, which allows pressure rise to be controlled for best possible release of power. Volvo Dual Solenoid Fuel Injector Today, Volvo group engines use a Dual Solenoid fuel injection system with Ultra-High Fuel Injection Pressure. The pressures are currently 35,000 psi (2400 bar) – among the highest in the world. Multiple events during a single cycle are possible. Our engineers have used this injection system since October ’02 and have had plenty of experience in getting the most out of it.
- There are several levels of EGR that can be discussed: Light EGR (~10%-20%%) Heavy EGR (~20%-35%) Massive EGR (~35%-50%+) Volvo used ‘Light EGR’ with the US’02 ‘V-Pulse’ solution on the D12D. Major design changes included the revised cooling system. For US’07, Volvo uses ‘Heavy EGR’. Major changes include a variable geometry turbocharger to provide the higher rates of flow needed; precision EGR flow control using a new EGR valve and closed loop flow measurement; And Ultra-High Fuel Injection Pressure with our Dual Solenoid fuel injection system. A third level of EGR, ‘Massive EGR’, is being promoted by one engine manufacturer for EPA’10.
- It is a difficult process to keep all relevant engine performance factors in balance. Changing one thing affects another…
- The Solution for 2010: Ultra High Pressure Fuel Injection to Reduce the Soot Light-Heavy EGR to knock Down the NOx DPF aftertreatment for Near-Zero Soot SCR aftertreatment for Near-Zero NOx
- Why use SCR? SUPERIOR fuel economy, compared to other solutions for EPA’10. Total fuel costs will be significantly reduced, even allowing for the DEF. Improved engine performance. Less EGR needed, less heat rejection into cooling system results, greater power density, and higher efficiency. Very little maintenance required Reliable, proven approach (High volume production in other markets) What additions to the truck will be included? DEF tank, on the driver’s side. Heated. Various sizes depending on fuel capacity. Includes pump and filter. Heated lines, pump to injector DEF injector, mounted to today’s frame-mounted Diesel Particulate Filter SCR catalyst, behind DPF or vertically mounted
- Here are the elements of the SCR system: Diesel Particulate Filter similar to today DEF injector SCR catalyst DEF tank with pump and filter Heated lines Control system
- As you can see we retained the technology of our Compact Diesel Particulate Filter. It is mounted close to the turbocharger for more ‘Passive Regeneration.’ The blue lines are coolant lines to avoid overheating of the DEF spray injector. Grey line is the heated DEF supply hose.
- Driver’s side - here is the DEF tank. The regulations say you must have enough DEF to last through two complete fuelings. We will have two sizes, 18.5 gallons for dual 150 fuel tanks and smaller, and 12 gallons for dual 100’s and smaller. The larger DEF tank will be good for 4000 miles or more. Under the blue cap, the throat of the DEF tank is only 19mm, too small for diesel or even gasoline hose nozzles.
- Another component of the 2010 system is the DEF gage. The driver can follow the progress of the DEF consumption using a real gage, a twin to the truck’s diesel fuel gage on the right. As a DEF supply will last 4000 miles or more, the needle moves more slowly than the fuel tank’s, but the driver always has a good indication as to how much DEF he has remaining.
- The Volvo In-Tank Heater and Pickup Extremely high design quality Fits inside DEF tank from top Circulates engine coolant through the Diesel Exhaust Fluid to maintain proper temperature – 60 o F All stainless steel, high-quality manufacture DEF level gage float (in center), with wiring harness (one plug) DEF pickup with intake filter No tank insulation is required By the way – Volvo Group has already delivered over 150,000 of this part. Like the rest of the SCR system, it’s proven. It works.
- PLAIN AND SIMPLE: WITH UREA YOU SIMPLY “NUKE THE NOx” YOU CAN MAKE ALL THE ENGINE-OUT NOX YOU WANT AND NUKE IT IN THE AFTERTREATMENT YOU CAN REDUCE THE EGR AND TUNE THE ENGINE TIMING AND PRESSURE RATIOS THE WAY THEY USED TO BE AND STILL HAVE A GENUINE NEAR-ZERO EMISSION ENGINE
- What about the base engine? Base engine will only experience minor changes. Same proven injection system Same camshaft Same cylinder head Same block Volvo is the only manufacturer who is going into 2010 with essentially the same engine as 2007
- There are good and bad consequences of EGR. On the plus side is emission reduction. On the negative side there are: Power Density LESS Heat Rejection MORE Efficiency LESS Power Density means less horsepower can be produced from a given displacement. Or, put another way, greater displacement may be needed to maintain horsepower. Heat rejection can be dealt with a larger cooling system. Volvo increased the cooling capacity in October 2002. And finally efficiency, which can be improved by fuel injection improvements. Volvo has achieved 35,000 psi in 2007. This is approximately the level of pressure in the common rail systems.
- The after-treatment system utilizes an injection of a solution of urea. Urea is a compound of nitrogen that turns to ammonia when heated. In a catalyzed reaction, the urea combines with the NOx and the byproducts of this reaction are simply nitrogen gas and water vapor.
- The main component of DEF is an organic nitrogen-rich compound called urea . Urea is synthesized from natural gas and carbon dioxide. Urea is very widely used in agriculture as a fertilizer, most often distributed in wax-coated pellets. (Not a water solution) Urea is a compound of nitrogen that turns to ammonia (NH 3 ) when heated. Why call it DEF? Automotive industry wanted a generic name What is Diesel Exhaust Fluid made from? 32.5% urea, 67.5% demineralized water Must be kept extremely pure Why 32.5%? Water solution with lowest freezing point, 12 o F. AUS32. Will also be an API standard.
- Because DEF is a solution of urea crystals and water, it freezes more slowly than pure water and at a lower temperature.
- DEF Freezes at 12 o F. THERE IS NO DELAY IN DRIVING A TRUCK WITH A FROZEN DEF TANK. You can walk up to a truck that has been standing over a frigid weekend and drive it away with no additional warm-up time. A few cc’s will melt immediately due to the heat from the exhaust. The tank heater will eventually melt the rest as you drive. Oh, by the way – one of the other uses for urea is as a de-icer. Google it.
- Here are the fuel numbers: On a 3000 mile trip, you will only consume 13 gallons of Diesel Exhaust Fluid You can travel coast to coast And still have 1/3 tank of DEF left over
- The engine using DEF can be made more fuel efficient. Our engine will be about 5% less in cost than a D12 even after the cost of DEF. In the end, the savings in fuel costs should be greater than the cost of the DEF -- do much so that ‘you get double your money back’.
- How much Diesel Exhaust Fluid is required? Volvo is optimizing the amount of Diesel Exhaust Fluid (DEF) to be injected for US’10 standards, but the rate will probably fall in the 2-4% range. The more DEF, the lower the diesel fuel consumption. The less DEF, the more diesel fuel consumption. We will optimize for the lowest total cost. How much will Diesel Exhaust Fluid cost? According to Volvo’s information, it is estimated at about 3/4 the price per gallon of diesel fuel. The exact price will, as always, be set by the market. Can the UREA infrastructure meet the additional demand? Easily. Globally over 100 million tons of urea were produced last year, primarily for agriculture, and also for cosmetics.
- Truck Dealerships Truck Stops / Travel Plazas Companies with their own facilities: Truck leasing companies Regional Fleets LTL Fleets Truckload Fleets Construction companies
- The long-tern common solution will be the pump on the fuel island. In cold climates the hose will be in an insulated cabinet. DEF will also be available in a multitude of sizes. Near term, the 275 gallon IBC, or ‘tote’, will become common at fleets who provide their own DEF.
- A 2.5 gallon DEF container, good for 500 miles or more, will become a common sight at the cash register of most truck plaza convenience stores.
- Where are we on testing? We have had test trucks in customer hands in North America longer than anyone else. We delivered these 5 production-similar EPA’10 test trucks in October 2007. They have now been through two complete winters - and without problems.
- We know what we’re doing We are ahead of previous emission generations. At VTNA, we already have more than 10 million miles of experience with SCR in North American service. We have our European experience with over 150,000 Volvo group heavy trucks already on the road using SCR. These trucks now have over two billion miles of in-use experience in Europe, in Australia, and in Japan.
- Future emission systems will include OBD - or On-Board Diagnostics. OBD will act as an umbrella over the engine and exhaust emission control systems. Cars have had OBD for some time and is what they use at vehicle inspection time to have the car tell the computer whether or nor it passes emissions rather than use a sniffer or some instrument in the tailpipe. The system is more accurate and ensures compliance on a continuing basis. On heavy trucks, it means the accuracy of the sensors we use in the combustion process must be extremely high.