Showing papers on "Alcohol fuel published in 1992"

Alcohol discriminator and fuel control for an internal combustion engine fueled with alcohol-gasoline fuel mixtures

Abstract: An apparatus for discriminating between different types of alcohol contained in alcohol-gasoline fuel mixtures, such as methanol or ethanol, and a fueling system for controlling the quantity of alcohol-gasoline fuel mixture delivered to an internal combustion engine in accordance with type of alcohol determined to be present in the fuel mixture are described. The resistivity of the fuel mixture delivered to the engine is measured using a fuel resistance sensor. Based upon the measured resistivity, the type of alcohol contained in the fuel mixture is determined and indicated. The fuel system then adjusts the quantity of the fuel mixture delivered to the engine based upon the indicated type of alcohol and the sensed alcohol concentration in the fuel mixture.

Method for determining fuel composition using oxygen sensor feedback control

Abstract: A flexible fuel vehicle is a vehicle capable of operating on alcohol, gasoline, or any combination of these two fuels. Because of the unique properties of alcohol fuels, modifications to engine operating characteristics are required to compensate for the varying percentage of alcohol in the fuel. A method is provided for determining the percent alcohol content of the fuel in the fuel tank, utilizing the oxygen sensor feedback control loop to sense changes in air/fuel ratio and relay that information to the engine controller so that dependant variables can be adjusted accordingly. The method includes placing the fuel pump in the fuel tank along with a mixed fuel accumulator so that a known and slowly varying percentage of alcohol in the fuel is provided to the engine, especially during open loop operation.

New generation of automotive sensors to fulfil the requirements of fuel economy and emission control

Abstract: The new passenger car regulations for future emission levels and the increasing demands for fuel economy have led to strong efforts to develop new engine-management systems, exhaust-treatment technologies and new automotive sensors. In this paper a new generation of automotive sensors that help to fuffil the requirements for fuel economy and emission control is presented. The demands on these new sensors include the following improvements: (i) better resolution, higher accuracy and better long-term stability, especially under severe environmental conditions; (ii) good performance at high temperature (e.g., up to 150 °C for rotational speed sensors and 1100 °C for exhaust gas sensors); (iii) short response times for dynamic cylinder-selective measurements; (iv) more efficient compensation methods by measuring different physical parameters. This talk gives an overview on the physical principle, the design, the technology and the application of a new generation of automotive sensors. Representing a potential ‘high-volume’ sensor, we report on an active rotational speed sensor to measure the angular position of the crankshaft. This sensor is based on a newly developed differential Hall IC. The high angular resolution allows more accurate ignition timing as well as ‘misfiring’ detection to be achieved. For the precise control of combustion in future engine-management systems, an ‘air flow sensor’ for cylinder-specific carburation, a ‘combustion pressure sensor’ for thermodynamic calculation of the combustion and a ‘fast exhaust gas sensor’ for cylinderselective exhaust-gas analysis can be used. This report will focus on the development of a fast oxygen sensor to measure the oxygen partial pressure of the exhaust gas. As an example of a smart sensor, an ‘alcohol fuel sensor’ for alternative fuel concepts is introduced. This sensor is a key component of a flexible fuel system which can be run on arbitrary mixtures of gasoline and methanol. This sensor measures three physical parameters: the capacitance, the conductivity and the temperature, in order to determine the methanol/gasoline ratio in the fuel rail with high accuracy.

Low aromatic diesel fuel

Abstract: The invention concerns an improved fuel for use in diesel engines, which comprises mainly a mixture of hydrocarbons containing not more than 1 % by volume of aromatic type hydrocarbons. Preferably the fuel also contains less than 0.05 % by weight of sulphur or sulphur compounds, and essentially no petroleum waxes. Additionally described are methods of producing this fuel, as well as the use of the fuel to reduce unwanted emissions and to improve operational performance.

Catalytic clean-combustion-promoter compositions for liquid hydrocarbon fuels used in internal combustion engines

Abstract: Petroleum derived fuel compositions of improved efficiency for use with finished gasoline and diesel fuels in compression ignition engines and spark ignition engines include a catalytic clean-combustion-promoter composition to improve fuel efficiency and reduce their air polluting effects The catalytic clean-combustion-promoter compositions utilize ketones as solvents, alcohols as cosolvents, ethers as octane supporters, nitroparaffin compounds as combustion supporters, and, to promote the chemical reactions a catalytic medium is used in combination with aromatic amines When all the compounds are combined in the recited quantities, the molecular structure and surface tension of the fuel is transformed through chemical bonding to produce a synergistic effect, which increases the combustion characteristic of the fuels to be burned and reduces the tendency of the fuel to create deposits, and therefore reduces the exhaust emissions Engines operating with the catalytic clean-combustion-promoter compositions added to the fuel do not require the use of fuels with a high cetane or octane number for maximum performance Such compositions may be employed in micro-amount ranging from 400 to 2,500 parts per million relative to the volume of the basic liquid of engine fuel The present catalytic clean-combustion-promoter compounds meet the standards of the EPA "Clean Air Act" as amended in 1990

Feasibility studies of the exhaust-gas reforming of hydrocarbon and alcohol fuels

Abstract: The feasibility of a proposed exhaust-gas reforming process, as applied to hydrocarbon and alcohol spark-ignition engine fuels, has been studied. In the first instance, a theoretical approach is reported. Complex chemical equilibria and energy balance software has been developed, and used to simulate exhaust-gas reforming reactions for n-heptane and methanol feedstocks. Engine combustion of reformed fuel compositions thus predicted has then been modelled by means of in-house developed cycle analysis software. An important preliminary part of the cycle simulation exercise was the calculation of reformed fuel laminar flame speed, and hence heat-release duration and commencement values. The results of the simulations have enabled comparisons of predicted engine thermal efficiency and pollutant emission levels for reformed and conventional fuelling strategies. Conclusions of the theoretical studies were sufficiently encouraging to warrant a practical investigation, and hence the design, construction and commissioning of a prototype reforming reactor and test rig are described. A test programme was then conducted, in order that the effect of various relevant parameters on reformer performance could be established. The findings of this study were encouraging in terms of the fuel compositions which could be produced, and in the case of an n-heptane feedstock, results were found to correlate well with those of the earlier predictive work. Major limitations highlighted by the practical work, however, relate to high reformer temperature requirements, and low reformed fuel generation rates. The findings of the studies are drawn together in a discussion of the practical feasibility of a vehicle installation, and project conclusions.

Air-fuel ratio controller

Abstract: PURPOSE:To prevent troubles even if alcohol steam flowing dack together with blow-by gas increases by lowering the lower limit value of correction range for a fuel supply amount when an engine temperature falls within a predetermined temperature range regulated with reference to the boiling point of alcohol CONSTITUTION:A controller 7 controllably increases and decreases an alcohol fuel injection time within a predetermined range on the basis of an output signal of an oxygen sensor 5 provided on the way of an exhaust pipe line 12, while alcohol steam mixed in engine oil in starting an engine 1 or the like is returned to an intake pipe line 11 through a reflux path 15 When here a temperature of the engine 1 rises to a predetermined temperature range regulated with reference to the boiling point of alcohol, the lower limit value of a correction range for an injection time is lowered Thus, even if a lot of the alcohol steam mixed in the engine oil is returned to an intake system, air fuel ratio can be made proper, so that the normal running condition of the engine 1 can be maintained

Oil performance in a methanol-fueled vehicle used in severe short-trip service

Abstract: A methanol and a gasoline vehicle were each subjected to testing under severe short-trip driving conditions. Results show that the cool oil sump temperatures caused more fuel and water to collect in the oil of the methanol vehicle. Protective properties of both vehicles' oils degraded during short trips but rebounded somewhat during a subsequent long trip. Slightly warmer sump temperatures in longer short-trip driving resulted in no methanol dilution in the methanol vehicle's oil, and higher total volatiles contamination in the gasoline vehicle's oil. Freeway driving following the longer short trips promoted less rebound in the degraded oils' protective properties.

Development and vehicle application of a multi-fuel di-alcohol engine

Abstract: The main objective of the development was to select and optimize the setting parameters, e.g. injection timing, EGR-rate, fuel metering, for operation with various alcohol fuels (methanol, ethanol as well as alcohol/gasoline blends). For this purpose, an electronically controlled engine management was used, selecting the parameters according to the fuel type applied. After steady-state development, the dynamic optimization of the engine installed in a test vehicle was carried out on a chassis dynamometer and during road operation to achieve low exhaust emission levels at best driveability and high power potential. The results show that the application of diesel-cycle alcohol engines can obtain high fuel economy as well as low emissions. (A) For the covering abstract see IRRD 869246.