Review of the 21st Century Truck Partnership (2008) / Chapter Skim
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3 ENGINE SYSTEMS AND FUELS
3 ENGINE SYSTEMS AND FUELS
Pages 26-55
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From page 26... ...
2) , which can be summarized as follows: The first overarching technology goal of the 21CTP is stated as follows: • Achieve 50 percent thermal efficiency, while meeting 2010 emission standards, by 2010; Develop and demonstrate an emissions compliant engine • Research and develop technologies to achieve 55 per- system for Class 7-8 highway trucks that improves the engine cent thermal efficiency by 2013; and system fuel efficiency by 20 percent (from approximately • By 2010 identify and validate fuel formulations 42 percent thermal efficiency today to 50 percent)
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From page 27... ...
A 20 percent improvement in engine thermal efficiency Energy Audit Shown in Figure 3-1 from the current baseline of 42 percent will yield the 50 percent thermal efficiency objective. Percentage Base Target Reduction Increases in fuel economy, expressed in miles per galTotal Energy Consumption 380 kW 225 kW 40% lon (mpg)
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From page 28... ...
To assess the status of this goal, the trast, Caterpillar and Detroit Diesel used turbocompounding committee summarized the results reported by each industry WHR systems. partner in Table 3-3. The Cummins results, which indicated that 50 percent These results show that none of the industry partners thermal efficiency could be achieved when a Rankine cycle achieved the goal of measuring 50 percent thermal effi- WHR system with a power output of 57 hp was added to the ciency at 2010 emissions from a complete engine system.
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From page 29... ...
Baseline Engine Engine Model MY2000ISX 450 2007 C15 15L Engine Not Specified Rated Power 450 hp @ 2000 rpm 550 hp @ 1800 rpm (est.) Peak Torque 1650 ft-lb @ 1200 rpm 1850 ft-lb @ 1200 rpm and 1534 ft-lb @ 1237 rpm 1850 ft-lb @ 1100 rpm Thermal Efficiency 42% Not Specified Not Specified Test Speed/Load Condition "Typical Cruise"a "Key fuel economy point"a Not Specified Test Conditions SAE J1349 (Net Power)
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From page 30... ...
Furthermore, the committee tee did not receive an explanation of why, after nearly was not informed of the extent to which the absence 7 years with thermal management as a key feature to be of this feature on the engines of the other two indus- included in this project, these items were not included try partners contributed to their failure to achieve the in the Caterpillar test engine. In contrast, the engines of 50 percent thermal efficiency goal.
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From page 31... ...
<0.1 g/bhp-h -- -- -- Exhaust Emission Test Results NMHC -- -- -- 0.14 g/bhp-h CO -- -- -- 15.5 g/bhp-h NOx -- -- -- 0.20 g/bhp-h PM -- -- 0.006 g/bhp-h 0.01 g/bhp-h Exhaust Emission Analytical Calculations NMHC -- -- -- -- CO -- -- -- -- NOx 0.209 g/bhp-h 0.17 g/bhp-h 0.2 g/bhp-h -- PM <0.01 g/bhp-h <0.01 g/bhp-h -- -- Assumptions for Analytical Calculations NOx 85% effectiveness 93-97% conversion 95.3% urea SCR -- with urea-SCR efficiency efficiency assumed, but aftertreatment demonstrated with higher efficiency has been SCR aftertreatment measured (Nelson, 2006a) PM 90% effective PMI -- -- -- filter Aging Used for Aftertreatment System Above Performance "The effect of aging "These are technology -- assumptions was accounted for evaluation/demonstration "consistent with an by only using a projects, and hence, did aged cycle."a 5% degradation not require the protocol factor for the NOx of durability or aging aftertreatment" a required for product development." a DPF Loading Assumed to have -- -- -- average loading Fuel Economy Penalty Reflected in base The fuel economy "The fuel economy -- engine performance.
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From page 32... ...
Instead, the industry partners presented discus DOE should review the original features expected to be sions on potential improvements that might be used to reach included in the 50 percent thermal efficiency engine and the stated goals. These potential improvements, as reported determine the justification for omitting some of the features by the industry partners, are summarized in Table 3-6. As from the demonstration engines.
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From page 33... ...
Some of the technical features used to approach system life target of heavy-duty diesel engines as they are the goal of 50 percent thermal efficiency, as shown in developing experimental, one-off demonstration engines Table 3-4, differed among the three industry partners, and with improved thermal efficiency. At a minimum, a roadmap no explanation or technical analysis was provided to justify of required technical actions to achieve system life targets
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From page 34... ...
to supplement the main engine shaft power, the committee Several of the slides presented indicate the general trends found that an interesting, and potentially relevant, extension of the adverse impact on fuel economy that can occur due of this concept was contained in a Cummins presentation on to the additional emission control systems without further exhaust energy recovery at the 2006 Diesel Engine Emis- improvements in the thermal efficiency of the engine. Engine sion Reduction (DEER)
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From page 35... ...
The data presented for the 50 percent thermal efficiency The peak torque condition where the best thermal goal by the industry partners projected the performance of e fficiency was demonstrated is not consistent with the such emission control systems for the configurations used t ypical 65 mph road load engine operating condition that in the specific engine tests. In some cases, the operating was specified as the focus of Class 8 trucks for the 21CTP.
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From page 36... ...
would appear to be an appropriate choice to approxi mate the 65 mph road load condition, although this would need to be confirmed for each engine under consideration. The 60 percent of rated engine speed for test point A50 is similar to the speed for the peak torque condition that had been used for the demonstration of peak thermal efficiency by the industry partners.
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From page 37... ...
For this to occur in the free marketplace, the ultimate cost of the technology used to achieve the fuel savings must be recovered by the savings in fuel costs within a period of sev eral years. The status of the system costs required to achieve 50 percent thermal efficiency, as reported by the industry partners, is summarized in Table 3-9.
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From page 38... ...
Engine lifetimes for heavy-duty diesel engines partners to make an assessment of cost objectives required are typically 400,000 to 1,000,000 miles. To achieve this to achieve commercial viability.
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From page 39... ...
the 55 percent thermal efficiency goal appears to be low (2010 goal was 50 percent thermal efficiency.) temperature combustion (LTC)
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From page 40... ...
Fuels with lower cetane, or higher octane ratthe diesel combustion chamber. Despite the major advances ings, have a smaller amount of low temperature reactivity in high-pressure diesel fuel injection technology, which has and thus require higher compression ratios to obtain ignireduced both emissions and noise through pulse injection tion.
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From page 41... ...
With really use combinations of multiple combustion modes. The combustion efficiency in the range of 95 percent versus resulting exhaust gas constituents include unburned HC and 99 percent for conventional diesel engines, LTC engines will CO, (normal LTC emissions)
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From page 42... ...
DOE should complete the demonat the maximum engine load, the lean or dilute nature of stration of the 50 percent thermal efficiency goal before this combustion process (to achieve NOx levels capable of embarking on the 55 percent goal. With respect to ongoing meeting 2010 emission levels without aftertreatment)
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From page 43... ...
2 diesel fuel. • New Combustion Regimes and Low Temperature ComRecommendation 3-12.
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From page 44... ...
are increased, Goal 1 and the use of light-duty diesel engines increases because of their inherently higher fuel economy. DOE recently clarified to the committee that this goal The United States has a very extensive and well-devel- deals with advanced nonpetroleum-based fuels and that oped refining, distribution and storage system for provid- future engine designs should operate cleanly and efficiently ing low-sulfur diesel fuel, essentially all of it derived from on fuels with a range of fuel properties, regardless of fuel domestic and imported petroleum.
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From page 45... ...
2 diesel fuel, such as T90, aromaticity and ash, 12Kevin Stork, DOE, FCVT, "Fuel Technologies R&D for Heavy Trucks," are not specified for biodiesel, thereby making transparent Presentation to the committee, February 9, 2007, Washington, D.C. operation in current diesel engines problematic.
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From page 46... ...
and diesel fuel." biodiesel fuels will vary greatly, and their composition will The authors of this report take no stance on the future of determine their effects on engine operation, deposits, emis- biofuels in the United States. However, as pointed out here sions, etc., when blended into conventional diesel fuel.
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From page 47... ...
The discrepancy Replacement of 5 percent petroleum fuel by 2010 is a may be related to the chemistry of the biodiesel fuels used in very aggressive, if not unrealizable goal, especially considerthe various studies. To resolve the impasse between DOE and ing that the most optimistic increase in biodiesel production EPA, an independent body should look at all of the biodiesel capacity could only achieve replacement of 3 percent of studies to see if the chemistry of the fuel can be related to its petroleum fuels by 2010, as previously discussed.
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From page 48... ...
and problem-free use of biodiesel fuels in diesel engines. The history of liquid fuel (both gasoline and diesel fuel)
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From page 49... ...
The authors said that the debate over reducing engine-out There are many potential sources of non-petroleum emissions from diesel engines is tied to whether or not future derived diesel fuel, including; oil shale, coal, tar sands, natuengines, especially light-duty diesel engines, will require ral gas and biomass. Technology exists to make diesel fuel higher cetane number than currently is sold in the United with excellent properties from coal and natural gas.
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From page 50... ...
demonstrate an emissions-compliant engine system"19 and The main computer codes used by the MFC are CHEMKIN stated that among the program's significant accomplishand KINetics, both of which are commercially supported by ments, "collaboration has enabled production diesel engines Reaction Design. to meet stringent 2007 emissions while maintaining high It should be noted that this type of work has been going efficiency."20 on in government and industry laboratories and academic Jim Eberhardt, Chief Scientist of the FCVT, said "DOE institutions for many years and that it is exceedingly difficult with industry is developing more sulfur tolerant catalysts to capture the detailed and complex kinetics of realistic fuels under Combustion and Emission Control and Advanced and their performance in actual engine combustion systems.
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From page 51... ...
High Temperature Materials Laboratory Introduction 27Edgar Lara-Curzio, "The High Temperature Materials Laboratory," The High Temperature Materials Laboratory was estab- Presentation to the committee, Washington, D.C., May 31, 2007. lished 20 years ago as a National User Facility to provide 28Personal communication, Edgar Lara-Curzio, Re: 21st Century Truck Partnership Project Quad Sheets, to the committee, Washington, D.C., May 21, 2007.
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From page 52... ...
Vehicle Materials and Components The objective of the project is to evaluate piezo Friction Stir Welding and Processing of Advanced ceramic materials and stack actuator designs for Materials diesel fuel injectors and develop methods for improv- High Conductivity Carbon Foam for Thermal Control in ing system performance. The project is planned to Heavy Vehicles continue through 2008.
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From page 53... ...
. Both of these classes of pollutants will be and effects as a result of the technology changes, and will reduced with new engine and aftertreatment technologies contribute to the development of a data base to inform future used with cleaner, low-sulfur diesel fuel.
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From page 54... ...
. In addi selecting one heavy-duty diesel engine/aftertreatment tion, a short-term study (3 months exposure duration)
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From page 55... ...
2007. Impact of Test Cycle and Biodiesel Concentra Stability of Biodiesel Fuel, SAE Paper No.
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