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In order to comply with 2002 EPA emissions regulations, cooled exhaust gas recirculation (EGR) will be used by heavy duty (HD) diesel engine manufacturers as the primary means to reduce emissions of nitrogen oxides (NOx). A feedforward controlled EGR cooling system with a secondary electric water pump and proportional-integral-derivative (PID) feedback has been designed to cool the recirculated exhaust gas in order to better realize the benefits of EGR without overcooling the exhaust gas since overcooling leads to the fouling of the EGR cooler with acidic residues. A system without a variable controlled coolant flow rate is not able to achieve these goals because the exhaust temperature and the EGR schedule vary significantly, especially under transient and warm-up operating conditions. Simulation results presented in this paper have been determined using the Vehicle Engine Cooling System Simulation (VECSS) software, which has been developed and validated using actual engine data.

Studies have been conducted at Michigan Technological University (MTU) for over twenty years on methods for characterizing and controlling particulate emissions from heavy-duty diesel engines and the resulting effects on regulated and unregulated emissions. During that time, control technologies have developed in response to more stringent EPA standards for diesel emissions. This paper is a review of: 1) modern emission control technologies, 2) emissions sampling and chemical, physical and biological characterization methods and 3) summary results from recent studies conducted at MTU on heavy-duty diesel engines with a trap and an oxidation catalytic converter (OCC) operated on three different fuels. Control technology developments discussed are particulate traps, catalysts, advances in engine design, the application of exhaust gas recirculation (EGR), and modifications of fuel formulations.

Various measurement techniques were employed to quantify sulfuric acid deposition levels and concentration of sulfuric acid in the condensate from the recirculated exhaust gas heat exchanger of a 1995 Cummins M11 heavy-duty diesel engine. Methods employed included a modified version of the sulfur species sampling system developed by Kreso et al. (1)*, rinsing the heat exchanger, and experiments employing a condensate collection device (CCD). The modified sampling system was applied to the inlet and outlet of the heat exchanger in order to quantify the changes in various sulfur compounds. Doped sulfur fuel (3300 to 4000 ppm S) was used to increase the concentrations of the various oxides of sulfur (SOx). These tests were performed at mode 9 of the old EPA 13-mode test cycle (1800 RPM, 932N*m) with 17-20% exhaust gas recirculation (EGR) at two EGR outlet temperatures: 160°C and 103°C.

The effects of a catalyzed particulate filter (CPF) and Exhaust Gas Recirculation (EGR) on heavy-duty diesel engine emissions were studied in this research. EGR is used to reduce the NOx emissions but at the same time it can increase total particulate matter (TPM) emissions. CPF is technology available for retrofitting existing vehicles in the field to reduce the TPM emissions. A conventional low sulfur fuel (371 ppm S) was used in all the engine runs. Steady-state loading and regeneration experiments were performed with CPF I to determine its performance with respect to pressure drop and particulate mass characteristics at different engine operating conditions. From the dilution tunnel emission characterization results for CPF II, at Mode 11 condition (25% load - 311 Nm, 1800 rpm), the TPM, HC and vapor phase emissions (XOC) were decreased by 70%, 62% and 62% respectively downstream of the CPF II.

The effects of exhaust gas recirculation (EGR) on heavy-duty diesel emissions were studied at two EPA steady-state operating conditions, old EPA mode 9* (1800 RPM, 75% Load) and old EPA mode 11 (1800 RPM, 25% Load). Data were collected at the baseline, 10% and 16% EGR rates for both EPA modes. The study was conducted using a 1995 Cummins M11-330E heavy-duty diesel engine and compared to the baseline emissions from the Cummins 1988 and 1991 L10 engines. The baseline gas-, vapor- and particle-phase emissions were measured together with the particle size distributions at all modes of operation. The total particulate matter (TPM) and vapor phase (XOC) samples were analyzed for physical, chemical and biological properties. The results showed that newer engines with electronic engine controls and higher injector pressures produce TPM decreases from the 1988 to 1991 to 1995 engines with the solids decreasing more than the soluble organic fraction (SOF) of TPM.

An experimental and modeling study was conducted to study the passive regeneration of a catalyzed particulate filter (CPF) by the oxidation of particulate matter (PM) via thermal and Nitrogen dioxide/temperature-assisted means. Emissions data in the exhaust of a John Deere 6.8 liter, turbocharged and after-cooled engine with a low-pressure loop EGR and a diesel oxidation catalyst (DOC) - catalyzed particulate filter (CPF) in the exhaust system was measured and used for this study. A series of experiments was conducted to evaluate the performance of the DOC, CPF and DOC+CPF configurations at various engine speeds and loads.

To meet future NO, heavy-duty diesel emissions standards, exhaust gas recirculation (EGR) technology is likely to be used. To improve fuel economy and further lower emissions, the recirculated exhaust gas needs to be cooled, with the possibility that cooling of the exhaust gas may form sulfuric acid condensate in the EGR cooler. This corrosive condensate can cause EGR cooler failure and consequentially result in severe damage to the engine. Both a literature review and a preliminary experimental study were conducted. In this study, a manually controlled EGR system was installed on a 1995 Cummins Ml l-330E engine which was operated at EPA mode 9* (1800 rpm and 75% load). The Goksoyr-Ross method (1)** was used to measure the particle-phase sulfate and vapor-phase H2SO4 and SO2 at the inlet and outlet locations of the EGR cooler, obtaining H2SO4 and SO2 concentrations. About 0.5% of fuel sulfur in the EGR cooler was in the particle-phase.

Turbocharging, in addition to increasing an engine's power output, can be effectively used to maintain exhaust emission levels while improving fuel economy. This paper presents the emission and performance results obtained from a turbocharged multicylinder spark ignition engine with thermal reactors and exhaust gas recirculation (EGR) operated at steady-state, part-load conditions for four engine speeds. When comparing a turbocharged engine to a larger displacement naturally aspirated engine of equal power output, the emissions expressed in grams per mile were relatively unchanged both with and without EGR. However, turbocharging provided an average of 20% improvement in fuel economy both with and without EGR. When comparing the turbocharged and nonturbocharged versions of the same engine without EGR at a given load and speed, turbocharging increased the hydrocarbon (HC) and carbon monoxide (CO) emissions and decreased oxides of nitrogen (NOx) emissions.

An Andersen Impactor was used to collect particulate samples in both the undiluted and diluted exhaust from a Caterpillar 3150 diesel engine operated on the EPA 13-mode cycle. A total of 24 samples were examined using the transmission electron microscope and approximately 300 photomicrographs were taken. The microscope analysis and photomicrographs revealed details concerning the physical characteristics of the particulate and permitted a direct visual comparison of the samples collected. The photomicrographs were used to obtain diameter measurements of the basic individual spherical particles that comprise the much larger aggregates/agglomerates. Nearly 11,000 basic particles were measured and the observed range of diameters was 70-1200 Å. The mean particle diameters in the undiluted and diluted exhaust samples were 479 Å and 436 Å respectively. respectively. A respectively. 436 A respectively.

Flame arrival data, determined by ionization gaps and a radiation detector, are presented for a multi-hole CFR engine equipped with six spark plugs spaced around the periphery of the combustion chamber, using a shrouded intake valve to produce swirl and with a standard valve to eliminate it. For results with the shrouded valve, path equations for the burnt gases are derived for several velocity distributions that satisfy the Navier-Stokes equations of motion for the unburned gas. Previous velocity distribution and observed flame movement data are presented in support of the derived model for the path of the burnt gases.

The effect of truck dieselization for three levels of diesel penetration into each of the eight classes of trucks is modeled. Diesel and total truck sales, population, mileage and yearly fuel usage data are aggregated by four truck classes representing light, medium, light-heavy and heavy-heavy classes. Four fuel economy scenario's for different technological improvements were studied. Improvement of fuel economy for light and heavy-heavy duty vehicle classes provides significant total fuel savings. Truck dieselization of light and light-heavy duty vehicle classes provides the largest improvement of fuel usage due to the fact that they have large numbers of vehicles and presently have few diesels. Total car and truck fuel usage in the 1980's shows roughly a constant demand with cars decreasing due to improved new fleet fuel economy and trucks increasing due to a larger population with better fuel economy due to dieselization and improved technology.

A 1-D 2-layer model developed previously at MTU was used in this research to predict the pressure drop, filtration characteristics and various properties of the particulate filter and the particulate deposit layer. The model was used along with dilute emission data to characterize two catalyzed particulate filters (CPFs) having different catalyst loading and catalyst application processes. The model was calibrated and validated with data obtained from steady state experiments conducted using a 1995 Cummins M11-330E heavy-duty diesel engine with manual EGR with different fuels for the two different CPFs. The two different catalyzed particulate filters were CPF III (5 gms/ft3 Pt) and CPF V (50 gms/ft3 Pt). Both the CPFs had cordierite substrates with CPF III and CPF V had MEX and NEX catalyst type formulation respectively. The CPF III filter was catalyzed using a solution-impregnated process while the CPF V filter was catalyzed using a wash coat process.

The objective of this research was to study the effect of a catalyzed particulate filter (CPF) with a high loading of catalyst (50 gms/ft3) and ultra low sulfur fuel (ULSF -0.57 ppm of sulfur) on the emissions from a heavy duty diesel engine. The particulate emissions were measured using two different analytical methods, i.e., the gravimetric method and the thermal optical method (TOM). The results from the two different methods of analyses were compared. The experiments were performed at four different operating conditions chosen from the old Environmental Protection Agency (EPA) 13-mode test cycle. A 1995 Cummins M11 heavy-duty engine with manually controlled exhaust gas recirculation (EGR) was used to perform the emission characterization experiments. The emission characterization included total particulate matter (TPM), which is composed of the solids (SOL), soluble organic fractions (SOF) and sulfates (SO4) analyzed using the gravimetric method.

A study was undertaken to investigate the affect of exhaust gas recirculation (EGR) on engine wear and lubricating oil degradation in a heavy duty diesel engine using a newly developed methodology that uses analytical ferrography in conjunction with short term tests. Laboratory engine testing was carried out on a Cummins NTC-300 Big Cam II diesel engine at rated speed (1800 RPM) and 75% rated load with EGR rates of 0, 5, and 15% using a SAE 15W40 CD/SF/EO-K oil. Dynamometer engine testing involved collecting oil samples from the engine sump at specified time intervals through each engine test. These oil samples were analyzed using a number of different oil analysis techniques that provide information on the metal wear debris and also on the lubricating oil properties. The results from these oil analysis techniques are the basis of determining the effect of EGR on engine wear and lubricating oil degradation, rather than an actual engine tear down between engine tests.

The Vehicle Engine Cooling System Simulation (VECSS) computer code has been developed at the Michigan Technological University to simulate the thermal response of a cooling system for an on-highway heavy duty diesel powered truck under steady and transient operation. In Part 1 of this research, the code development and verification has been presented. The revised and enhanced VECSS (version 8.1) software is capable of simulating in real-time a Freightliner FLD 120 truck with a Detroit Diesel Series 60 engine, Behr McCord radiator, Allied signal / Garrett Automotive charge air cooler and turbocharger, Kysor DST variable speed fan clutch, DDC oil and coolant thermostat. Other cooling system components were run and compared with experimental data provided by Kysor Cooling Systems. The experimental data were collected using the Detroit Diesel Electronic Control's (DDEC) Electronic Control Module (ECM) and the Hewlett Packard (HP) data acquisition system.

Heavy-duty diesel engine particulate matter (PM) emissions must be reduced from 0.1 to 0.01 grams per brake horsepower-hour by 2007 due to EPA regulations [1]. A catalyzed particulate filter (CPF) is used to capture PM in the exhaust stream, but as PM accumulates in the CPF, exhaust flow is restricted resulting in reduced horsepower and increased fuel consumption. PM must therefore be burned off, referred to as CPF regeneration. Unfortunately, nominal exhaust temperatures are not always high enough to cause stable self-regeneration when needed. One promising method for active CPF regeneration is to inject fuel into the exhaust stream upstream of an oxidation catalytic converter (OCC). The chemical energy released during the oxidation of the fuel in the OCC raises the exhaust temperature and allows regeneration.