1、中文 4400 字 ， 2700 单词， 14500 英文字符 Diesel Engine Development and Durability ADVANCED DIESEL ENGINE AND AFTERTREATMENT TECHNOLOGY DEVELOPMENT FOR TIER 2 EMISSIONS Rakesh Aneja Detroit Diesel Corporation Brian Bolton Detroit Diesel Corporation Adedejo Bukky Oladipo Detroit Diesel Corporation Zornitza Pav
2、lova-MacKinnon, Detroit Diesel Corporation Amr Radwan Detroit Diesel Corporation ABSTRACT Advanced diesel engine and after treatment technologies have been developed for multiple engine and vehicle platforms. Tier 2 (2007 and beyond) emissions levels have been demonstrated for a light truck vehicle
3、over a FTP-75 test cycle on a vehicle chassis dynamometer. These low emissions levels are obtained while retaining the fuel economy advantage characteristic of diesel engines. The performance and emissions results were achieved by integrating advanced combustion strategies (CLEAN Combustion) with pr
4、ototype after treatment systems. CLEAN Combustion allows partial control of exhaust species for after treatment integration in addition to simultaneous NOx and PM reduction. Analytical tools enabled the engine and after treatment sub-systems development and system integration. The experimental techn
5、ology development methodology utilized a range of facilities to streamline development of the eventual solution including utilization of steady state and transient dynamometer test-beds to simulate chassis dynamometer test cycles. Key Words: diesel engine, Tier 2, SCR, after treatment, emissions, ur
6、ea INTRODUCTION In the late 1990s, fuel use projections were prepared for future transportation requirements. Energy use among automobiles was shown to be fairly steady for the future outlook from 2000 to 2020, while Class 3 through Class 8 trucks (heavy-duty type vehicles) were predicted to increas
7、e marginally over that same twenty-year time frame. However, a significant increase was seen in the Class 1 to Class 2 trucks (pickups, vans and SUVs). In some cases, these are used commercially, but the primary source of increase was seen as a growing part of the passenger car market for use for pe
8、rsonal transportation. This major increase in the use of these vehicles is subsequently increasing the energy use and thereby driving up total energy use in terms of millions of barrels per day of petroleum, from approximately 8 million barrels in the late 1990s up towards 12.5-13 million barrels in
9、 2020 1,2. (See Figure 1.) At that time, it was forecast that the dieselization of the vehicle fleet, primarily these Class 1 and Class 2 light trucks, would have a significant reduction on the U. S. transportation energy use； however, many people questioned whether the diesel engines potential to a
10、chieve future Tier 2 emissions would make it a viable option. Those who considered that the emissions hurdle could be overcome, then questioned what the resulting fuel economy improvement would be after all of the NOx abatement technologies were applied and the fuel efficiency was reduced. As a resp
11、onse to this, a series of collaborative projects with the Department of Energy were initiated including the DELTA program, and later, the LEADER program at Detroit Diesel Corporation. The purpose of these programs was to look at the technical viability of meeting Tier 2 emissions and also the fuel e
12、conomy impact that that would have. The approach that was followed at Detroit Diesel was an integrated analytical and experimental approach that utilized simulation in the early stages of the program to develop the concepts required for engine design as well as strategy development. Figure 1: “Diese
13、lization” of Vehicle Fleet Offers Significant Reduction to U.S. Transportation Energy Use METHODOLOGY AND RESULTS Control systems were integrated along with the engine control system in a fairly dynamic, yet effective way that led to significant advancements in the overall emissions characteristics
14、of the engine while maintaining the inherent fuel economy advantage of the diesel engine over the baseline gasoline engine. Initially, extensive simulation was conducted to design a clean sheet engine. This simulation was validated by actually procuring and building the engine and doing the steady s
15、tate modal development. This effort both validated the simulation and quantified the performance in the steady state mode. Once this activity established calibrations and a robust, repeatable engine performance level, it was used to forecast transient engine performance by characterizing transient c
16、ycles, again still in a steady state type of scenario. Integrating with analytical tools allowed for transient types of situations to be identified and then run in a steady state test cell environment which is highly controlled. This allowed for critical answers to questions such as tradeoffs between air systems, EGR systems and combustion systems to allow an improved engine development scheme to be worked out.
