The oxidation of soot: a review of experiments, mechanisms and models

A premixed charge compression ignition engine, and a control system, is provided which effectively initiates combustion by compression ignition and maintains stable combustion while achieving extremely low nitrous oxide emissions, good overall efficiency and acceptable combustion noise and cylinder pressures. The present engine and control system effectively controls the combustion history, that is, the time at which combustion occurs, the rate of combustion, the duration of combustion and/or the completeness of combustion, by controlling the operation of certain control variables providing temperature control, pressure control, control of the mixture's autoignition properties and equivalence ratio control. The combustion control system provides active feedback control of the combustion event and includes a sensor, e.g. pressure sensor, for detecting an engine operating condition indicative of the combustion history, e.g. the start of combustion, and generating an associated engine operating condition signal. A processor receives the signal and generates control signals based on the engine operating condition signal for controlling various engine components to control the temperature, pressure, equivalence ratio and/or autoignition properties so as to variably control the combustion history of future combustion events to achieve stable, low emission combustion in each cylinder and combustion balancing between the cylinders.

Premixed charge compression ignition engine with optimal combustion control

During the last few decades, concerns have grown on the negative effects that diesel particulate matter has on health. Because of this, particulate emissions were subjected to restrictions and various emission-reduction technologies were developed. It is ironic that some of these technologies led to reductions in the legislated total particulate mass while neglecting the number of particles. Focusing on the mass is not necessarily correct, because it might well be that not the mass but the number of particles and the characteristics of them (size, composition) have a higher impact on health. To eliminate the threat of diesel particulate matter, essentially absolute filtration in combination with the oxidation of all emitted hydrocarbons is what will be required. After two decades of development, the first filters will soon be introduced on a large scale. Many different problems had to be overcome; it was especially important that the filter was robust and its regeneration was controllable. The key technol...

Science and technology of catalytic diesel particulate filters

This handbook presents a state-of-the-art review of vehicle emission standards and testing procedures and attempts to synthesize worldwide experience with vehicle emission control technologies and their applications in both industrialized and developing countries. It is one in a series of publications on vehicle-related pollution and control measures prepared by the World Bank in collaboration with the United Nations Environment Programme to underpin the Bank's overall objective of promoting transport development that is environmentally sustainable and least damaging to human health and welfare. Chapter 1 surveys vehicle emission standards adopted in various countries, emphasizing the international system of standards employed in North America and Europe. Chapter 2 discusses the test procedures used to quantify vehicle emissions in order to verify compliance and estimate emissions actually used. Chapter 3 describes the engine and aftertreatment technologies developed to enable new vehicles to comply with emission standards, as well as the costs and other impacts of these technologies. That measures to control emissions from in-use vehicles are an essential complement to emission standards for new vehicles is the subject explored in Chapter 4. Lastly, the role of fuels in reducing emissions is reviewed in Chapter 5, which discusses both the benefits of reformulating conventional gasoline and diesel fuels and the potential benefits of alternative cleaner fuels.

Air Pollution from Motor Vehicles: Standards and Technologies for Controlling Emissions

Diesel particulate emission control

A filtration system operative to remove oxidizable particulates from the exhaust gas of a diesel engine is disclosed. The system has a filter element to trap and collect particulates in the exhaust gas, ignition means supplied with energy for a period only sufficient to ignite a leading portion of the particulate collection, and means for conducting a flow of gas with excess oxygen thorough the filtration means immediately following ignition without addition of other energy, the flow of gas with excess oxygen being utilized to support the continued oxidation of the ignited particulate collection. The ignition means may comprise (a) apparatus for adding excess hydrocarbon fuel either to (i) the gas flow through the intake manifold of the engine, (ii) the exhaust gas exiting from the engine, or (iii) a separate supply of compressed air, and (b) a supplementary heated catalyst located between the exhaust manifold of the engine and the filter element for acting upon the hydrocarbon rich gas flow, the catalyst being effective to bring about ignition of the hydrocarbon rich gas and produce a heated exhaust gas high enough in temperature to ignite at least a portion of the particulates in the filter element.

Filtration system for diesel engine exhaust-II

A Ceramic Insert Uncooled Diesel Engine

An apparatus for regenerating a filter trap (A) used to collect particulates from the exhaust gas of an internal combustion engine. The apparatus comprises: (a) apparatus (C-2) providing a flow of a heat transfer medium through the filter trap (A), (b) apparatus (C) for heating the heat transfer medium to a temperature effective to incinerate the particulates in the filter trap (A), and (c) a flow mask (22) stationed in the flow of heat transfer medium, upstream from said filter trap (A) effective to divert the heat transfer medium away from the radially inner zone of the filter trap (A) while guiding the heat transfer medium to engage and ignite the particulates along a radially outer region of the filter trap (A). The mask (22) is a circular disc and spaced upstream from the filter trap (A) effective to mask a central core area of the flow of heat transfer medium. The apparatus (C) for heating comprises one or more electrically heated resistance elements (21) arranged in a planar coil configuration extending transversely across the flow of heat transfer medium. A flow diffuser (23) is stationed upstream from the mask (22) and is comprised of a plurality of foraminous plates effective to diffuse and slow down the flow of heat transfer medium for increasing heat exchange. The flow diffuser (23) has a radiation reflective coating to limit heat losses and a member (24) is employed for depressing the temperature required to ignite the particulates.

Apparatus for periodically oxidizing particulates collected from exhaust gases

Possibilites de realiser des economies de carburant avec un moteur diesel a injection directe non refroidi

Fuel economy opportunities with an uncooled Dl diesel engine

A dispensing apparatus is disclosed for adding a fluid agent to the fuel supply of an automotive engine, the agent is effective in depressing the ignition temperature of soot collected in an exhaust trap. The apparatus comprises: (a) a reservoir for containing a supply of the fluid agent such as copper octoate and hexane; (b) an electrically operated pulse pump for positively displacing a measured amount of the agent from the reservoir into the fuel supply; (c) register means for registering the amount of fuel replenished to the engine fuel supply and for transmitting an electrical signal proportional to the amount of fuel so added; and (d) control means responsive to the electrical signal to permit electrical operation of the pulse pump for a number of predetermined pulses to dispense a required amount of the agent for maintaining a desired uniform concentration of the agent throughout the fuel supply.

Wallace R. Wade

Papers

Filtration system for diesel engine exhaust-II

A Ceramic Insert Uncooled Diesel Engine

Apparatus for periodically oxidizing particulates collected from exhaust gases

Fuel economy opportunities with an uncooled Dl diesel engine

Automotive dispensing apparatus for fuel additive