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The work presented here describes the pre-development of a new diesel particulate filter that features an easy set-up. The system is based on a sintered metallic fibre fleece as filtering material. The filter set-up consists of a simple folded arrangement. In this folded configuration the entire filter structure can be set up without one single weld. In addition the filter concept offers a mass flow adapted cross section of the channels which allows very compact filters with a low pressure drop. Another development of the structure with a corrugated arrangement of the filtering walls results in an intensive mixing characteristic of the flow in the structure. By that a homogeneous temperature profile within the structure can be achieved which ensures homogeneous regeneration conditions throughout the structure and thereby avoids partial regenerations.

This study aims at a new concept for a fast catalyst light-off in combining a latent heat storage with a catalyst. The arrangement of a latent heat storage device into the exhaust system offers significant benefits for the catalyst light-off. Different arrangements have been examined. The first arrangement, called the sequential arrangement, comprises a latent heat storage device and a subsequent catalyst. This offers a significantly faster heat up of the catalyst compared to the standard arrangement. By that emissions during the cold start phase can be significantly reduced. The setup of the latent heat storage device is designed for a high heat transfer between storage material and the exhaust gas. A second integrated arrangement of a latent heat storage and a catalyst into one common substrate has also been set up and investigated. The main advantage of this arrangement is that the catalyst itself is kept on its operation temperature during the engine off time.

Active engine-based measures are currently used to assist the exhaust aftertreatment. This paper presents the current predevelopment of a system for active exhaust aftertreatment of diesel engines which enables exhaust aftertreatment to be decoupled from engine-based measures. At the heart of the system, the Fuel Processor is the active component which is used to combust, reactively evaporate or partially oxidise the fuel, as required. Active catalytic converter heating, active particulate filter regeneration or heating of a SCR catalytic converter are possible without engine-based measures.

Published investigations on the calculation of pressure drop of diesel particulate filters consider the contribution of substrate, soot, channel flow and inertial effects at the inlet and outlet of the channels. The model presented in this work considers further contributions as the oil ash and additive ash and their effects on the DPF pressure drop. It is shown that different types of ash deposit which are caused by different driving cycles and different regeneration modes, will result in a significantly different pressure drop even at the same total amount of ash. It will be shown that in the case without soot load the ash deposit at the wall will result in a higher pressure drop than the same amount of ash being deposited at the rear end of the channels. It is also shown that at a higher soot load this behaviour will be inverted. In addition this work considers a variable permeability of the soot layer varying with the soot load of the filter.

Based on the results achieved with the progressive spin element in previous work [1], the focus in this paper is on the loading and regeneration behaviour with a spin element during different engine operating conditions and driving cycles. The temperature distribution inside the diesel particulate filter, the ash and soot loading and regeneration behaviour during different driving cycles have been examined. It can be shown that the use of a progressive spin element leads to superior performance of the DPF through better usage of the available filter volume and minimises the disadvantages e.g. for catalytic coated filters concerning aging. Through careful design of the available parameters of the progressive spin element the additional backpressure due to the spin element can be reduced without loosing the positive influence onto the flow distribution.

A new concept for achievement of homogeneous flow distributions in catalytic converters and particulate traps is presented. New applications such as NOx-adsorbers, SCR-catalysts and diesel particulate filters call for more homogeneous flow distributions. The new concept of the progressive spin inlet serves for homogeneous flow distribution within a short inlet cone. A spin is imposed on the flow at the outer radius of the catalyst inlet using helical-type flow elements. It is essential that the centre part of the flow is almost free of spin. Best results can be obtained when the spin elements are designed to impose a progressive spin. The combination of a progressive slope angle and a progressive height serves for a relative minimum in pressure drop. It is shown, that the progressive spin element also proves very good results with eccentric arrangements of the catalyst inlet cone. The parameters are optimised using CFD-calculations.

The European Union’s 2020 target aims to be producing 20 % of its energy from renewable sources by 2020, to achieve a 20 % reduction in greenhouse gas emissions and a 20 % improvement in energy efficiency compared to 1990 levels. To reach these goals, the energy consumption has to decrease which results in reduction of the emissions. The transport sector is the second largest energy consumer in the EU, responsible for 25 % of the emissions of greenhouse gases caused by the low efficiency (<40 %) of combustion engines. Much work has been done to improve that efficiency but there is still a large amount of fuel energy that converts to heat and escapes to the ambient atmosphere through the exhaust system. Taking advantage of thermoelectricity, the heat can be recovered, improving the fuel economy.