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Tighter emission limits are discussed and established around the world to improve quality of the air we breathe. In order to control global warming, authorities ask for lower CO2 emissions from combustion engines. Lots of efforts are done to reduce engine out emissions and/or reduce remaining by suitable after treatment systems. Watlow, among others, a manufacturer of high accurate, active temperature sensor ExactSense™, wanted to understand if temperature sensor accuracy can have an influence on fuel consumption (FC). For this purpose a numerical approach was chosen where several non-road driving cycles (NRTCs) were simulated with the data base of a typical Stage IV heavy duty diesel engine. The engine is equipped with an exhaust gas after treatment system consisting of a DOC, CDPF and an SCR. In this work scope, the investigations shall be restricted to the FC benefits obtained in the active and passive DPF regeneration.

Simultaneous particulate and NOx reduction represents the next step to the reduction of diesel emissions. One of the most promising concepts to achieve this target involves the combination of two technologies already in use in the after-treatment technology - Diesel Particulate Filter and NOx Storage Catalyst - in the same component. The major issue to be solved is the design of a complex thermal strategy, for the regeneration of NOx emissions, particulate matter and possibly sulfates. For this set-up to function properly the engine must periodically generate a rich spike to induce the NOx desorption process. The system must also increase the exhaust gas temperature to induce the soot oxidation process. Complicating matters further, the regeneration process of the filter must also be controlled to avoid substrate or washcoat damage.

In order to improve the reputation of diesel engines in terms of environmental friendliness and to reach the legislation limits Diesel Particulate Filters have penetrated the passenger car market in Europe. A fuller understanding of filter characteristics is essential for further system optimization, especially for substrate optimization and improvement of regeneration strategy. The process of filter loading at different engine points and transient conditions has been investigated in depth Studies have also been conducted in regards to filter regeneration with oxygen. Both topics of which are now widely understood. In contrast to that is the NO2 based regeneration. Even though the chemical base reactions have been known and understood for a considerable time, detailed information concerning its application to the automotive industry is missing regarding the NO2 based reaction, which is very slow and temperature sensitive. Therefore causing local effects within the system.

The most critical aspect of the DPF technology is the maximum soot collection limit which is related to the local soot concentration and the thermal stress during regeneration. In order to keep this parameter under control the only method used so far was to manage (periodical operation, back-pressure measurement) the overall soot loading, neglecting the other important factor: soot distribution. Many experiences show that, with the same overall soot amount, a strongly non-homogeneous soot collection can cause much higher temperature peaks than an homogeneous one. The effects on the durability of the substrate are evident. Aim of this work is to investigate the possibility of characterizing the soot distribution in order to improve the durability performances of the DPF System. Indirect measurement methods and a computational tool, which we developed, are investigated, for different loading conditions.

The paper reports on the development of cost effective active regeneration aids as a “worst case solution” for implementation in diesel particulate traps, particularly with respect to long time vehicle operation in the inner-city at very low exhaust gas temperature level. Two different principles of active measures were investigated: heating the entire exhaust gas by fuel burner to initiate the soot burning or applying so called “hot spot” heating by electrical heaters to start the regeneration of the loaded trap. Both methods may be combined with engine management measures to lower the necessary energy input. Based on this investigation, several systems have been developed and tested on modern diesel engines for passenger cars at steady state and dynamic operation at difficult conditions such as low speed and very low load close to idle. Advantages and disadvantages of the systems are reported.

The paper reports on the development of cost effective active regeneration aids as a “worst case solution” for implementation in diesel particulate traps, particularly with respect to long time vehicle operation in the inner-city at very low exhaust gas temperature level. Two different principles of active measures were investigated: heating the entire exhaust gas by fuel burner to initiate the soot burning or applying so called “hot spot” heating by electrical heaters to start the regeneration of the loaded trap. Both methods may be combined with engine management measures to lower the necessary energy input. Based on this investigation, several systems have been developed and tested on modern diesel engines for passenger cars at steady state and dynamic operation at difficult conditions such as low speed and very low load close to idle. Advantages and disadvantages of the systems are reported.

The increased global competition has led to immense interest in the development of new ways of increasing productivity and quality. It is a well known fact that the costs of manufactured products are largely determined at the design stage. It is important to consider manufacturability early in the design. To be able to cut life cycle costs at an early stage the following DFMA-tools have been developed: Design for Manufacture (DFM), Design for Assembly (DFA), Design for Service (DFS) and Design for Environment (DFE). This contribution shows the design for the complete life cycle - with the tools DFM, DFA, DFS, DFE - its present state and some industrial applications. Using an electronic company as an example the implementation of DFMA in an TQM-environment and their integration in the product development process is shown. The value-assessment metric ‘Materials, Energy, Toxicity (MET)’ is also described.

A new analytical method for the automobile industry has been developed using a pulsed tunable laser system and a Reflectron time-of-flight mass spectrometer. The goal was to achieve the following conditions: High time resolution (〈100ms), high sensitivity (down to 1 ppm), high accuracy (10%) and applicability to most exhaust emission components. The main problem is the large number of components with very different and fast varying concentrations. For a preliminary list of 25 exhaust emission components, all necessary parameters have been determined. First results obtained from a real exhaust gas sample will be presented.