Refine Your Search

Search Results

Technical Paper

Octane Requirement Increase Control - A New Way of Saving

1991-09-01
911739
Due to the accumulation of deposits in the combustion chamber, the “appetite” of an engine for octane increases with mileage. Depending on the type of engine, driving conditions, and gasoline, this octane requirement increase (ORI) ranges from 3 to 10 octane numbers. Because of ORI, national specifications for octane number of gasoline must be based on engines' octane requirement at equilibrium. Applying the incremental analysis technique to refining economics, F. Bernasconi calculated that the incremental cost of producing each extra octane number by refining ranges from $2 to $6 per ton. It is generally well accepted that an increase of one octane number will lead to a loss in refinery yield of 4 to 6%. Octane requirement increase can be controlled with a new type of ashless, non-metallic additive. An ORI reduction of 50 to 80% has been observed, opening the route to decreasing national gasoline octane specifications.
Technical Paper

Potential Savings by Fuel-Economy Engine and Transmission Oils

1991-09-01
911697
Applying lubricants is one of the most important measures to reduce friction and wear. Improving the mechanical efficiency of engines and gears by reducing the frictional losses in the mixed film and in the fluid film lubrication regime in principle facilitates the reduction of fuel consumption of the engine or of the energy needed to operate the cars. The maximum consumption reduction that is theoretically possible with lubricating measures is estimated by means of the efficiency analysis of engines and gears and the proportionate effects of lower viscosity and additives reducing friction are evaluated. The estimate is made on the basis of the given relationship between friction and fuel consumption. Obviously, the possible consumption reductions at partial loads and lower temperatures are higher than at full load and operating temperature. This determines the relevant consequences regarding the possible total energy reductions under political economy aspects.
Technical Paper

Reduction of NOx in the Exhaust Gases of an Automotive Engine Using Methane Gas by Water Injection in the Inlet Manifold

1991-09-01
911738
The main reason for the utilization of methane gas, in the form of natural gas or purified biogas, is as substitute of the diesel oil, aiming to the reduction of the pollution by the exhaust gases from the combustion engines of the urban buses. The largest pollutants of diesel engines are the particulates, originated by the combustion process, and the sulphur oxides. The latter, further, to act as nucleants for the particulates, contribute to the so called “acid rain”. As the natural gas is free from sulphur, and the spark ignition cycle does not originate particulates, these are obvious advantages of the utilization of the methane as fuel in the urban vehicles. But the spark ignition engines burning methane originates much more NOx, nearly twice as much, than the diesel engine equivalent, particularly at high loads. Several processes are being studied for the reduction of the NOx emissions.
Technical Paper

Ceramic Converter Technology for Automotive Emissions Control

1991-09-01
911736
This paper reviews the development and successful application of ceramic catalytic converters for controlling automotive exhaust emissions. It presents the scientific rationale for designing the high surface area substrate to meet both performance and durability requirements. This is followed by a step-by-step design process for each of the converter components. The initial design stage focuses on understanding automaker's requirements and optimizing component design commensurate with them. The intermediate stage involves laboratory testing of converter components in simulated environment and ensuring component compatibility from durability point of view. The final design stage addresses the critical tests on converter assembly to ensure performance and field durability. In addition, it examines the necessary trade-offs and associated design modifications and evaluates their impact on warranty cost for system failure.
Technical Paper

Catalytic Ignition of Methanol in a Diesel Engine with a Platinum-Coated Glow Plug

1991-09-01
911737
In recent years, intensive research has been pursued throughout the world in order to find substitutes to crude oil based fuel in compression-ignition engines. Among the different fuels studied, methanol is probably the primary candidate to substitute diesel fuel in the future. The major problems encountered with methanol in diesel engines are its poor cold startability together with unstable combustion levels under low load. Forced ignition techniques such as glow plugs and spark plugs have been used to overcome these problems. The major disadvantages with the use of glow plugs are their high power requirements as well as their limited lifetime. This paper presents the results from recent work done on the feasibility of catalytically igniting methanol with the use of platinum and platinum/rhodium-coated glow plugs.
Technical Paper

Adsorption-Catalytic Purification by Carbon Fibers

1991-09-01
911735
The possibility of carbon fibers use for the removal of H2S from H2S/H2/Ar and H2S/Ar gas mixtures has been studied. Cu-containing carbon fibers and Cu-containing activated carbon fibers proved to be most efficient materials for removing of H2S small amounts in 298-1173 K temperature range at the atmospheric pressure. Depending on the treatment method and the specific surface area and porosity values carbon fibers have different sorption and catalytic properties at different temperatures. H2S sorption from gas mixtures was observed at room temperature while H2S decomposition to H2 and S occurred at elevated temperatures. Cu-containing activated carbon fibers modified by chemical treatment should be used at room temperature. Less expensive Cu-containing carbon fibers can be used at elevated temperatures.
Technical Paper

Noble Metal Usage Reduction Strategies for Three-Way Emission Control Catalysts

1991-09-01
911732
Strict mobile source emission legislation in many countries throughout the world are motivating research and development efforts to bring forth advanced formulations. Steep rises in the price of rhodium during the past couple of years is resulting in intense efforts to control the costs of the new catalyst technologies being developed. This paper examines some catalyst development strategies being explored to accomplish the above objectives.
Technical Paper

Commercial Vehicles Emission Control for Latin America

1991-09-01
911733
The emission control for commercial vehicles in Latin America has just begun and it brings an exceptional opportunity for the introduction of a common concept towards an air quality program suited for developing countries. The analysis of prior experiences accumulated by countries where legislations on that field have already been settled and improved is a worthy tool to choose the most convenient alternative to deal with the emission control in an affordable way. Steady-state test procedures provide enough information to estimate the engine emission levels on actual operation, avoiding the use of expensive facilities. Through simple and already well-proven methods and considering all aspects concerning the problem, from the fuel quality to the vehicle maintenance, it is possible to reach the main aim, the air preservation, alloting fewer resources and promoting Latin America's integration.
Technical Paper

Effect of Aging and Testing Conditions on Catalyst Performance

1991-09-01
911734
In order to simulate the aging of the emission control system over the life of a vehicle, a variety of engine dynamometer cycles has been developed that accelerate the catalyst aging processes. This paper investigates the sensitivity of automotive emission control catalysts to their aging and testing environments. To show the effects of aging conditions on catalytic performance, three engine stand dynamometer aging cycles were utilized. These aged catalysts were then tested on two test vehicles: one featured multi-point fuel injection; the other, sequential electronic fuel injection. The performance results indicate the sensitivity of a catalyst to aging conditions as well as the various parameters of its operating environment. This sensitivity varied for the two catalyst formulations.
Technical Paper

Development and Optimization of Alcohol Fueled SI-Engines for Passenger Cars for the Brasilian Market

1991-09-01
911730
During the last four years FIAT AUTO has cooperated with AVL in the development of three generations of ethanol vehicles for the Brasilian market for current, 1992 and 1997 Brasilian emission standards. This paper deals with suitability of ethanol as SI-engine fuel combustion system development and calibration strategies for 1992 lean burn engines and 1997 TWC-concepts transient and warm up development single fuel cold start systems TWC emission control requirements vehicle performance, fuel economy, emissions with and w/o catalyst. The paper shows that the concepts chosen allow calibrations with sufficient margin with respect to emission standards. Cold start and driveability can be developed for single fuel operation down to 0 deg. C. Vehicle driveability and performance are on a competitive level. For aldehyde control the TWC is a very good solution. Application problems with TWC can occur if the catalyst is located remote from the engine.
Technical Paper

Mobile Air Conditioning and CFC's - An Update

1991-09-01
911729
Abstract In response to the problem of stratospheric ozone layer depletion, the United Nations Environmental Program has enacted a protocol which places restrictions on the future production and consumption of CFC's. This protocol has been widely ratified throughout the world and further discussions are underway to increase the stringency of its provisions. Automotive air conditioning systems use the compound CFC-12 as a refrigerant and the proposed restrictions will significantly impact this vehicle option. This presentation will provide an update into the issue of automotive air conditioning and the CFC problem. The latest international regulations will be described. The presentation will then review general findings related to the application of new, environmentally-safe, refrigerant R-134a in vehicle air conditioning systems.
Technical Paper

The Influence of Wave Action on Mass Flow Rate Through Pipes

1991-09-01
911724
Abstract The behavior of pressure waves in the exhaust and intake pipes of the internal combustion engine plays an important role in the increase and decrease of the flow rate through these pipes. Using the rotary valve of disc type the effect of the pressure wave on the flow rate through the pipes with junctions or nozzles was studied. It was found that the arrival time of the compression wave at the port of the valve was the important parameter in evaluating the increase and decrease in flow rate.
Technical Paper

A Theoretical and Experimental Study of Water/Engine-Oil Compact Heat Exchangers

1991-09-01
911723
The present study has been performed in order to characterize the compact plate-type heat exchangers that are used to cool the lubricating oil of Internal Combustion Engines. During the work an evaluation model has been developed for water/engine-oil heat exchangers. The evaluation model uses experimental data such as coolant and oil flow rates and the heat exchanger inlet and outlet temperatures. Also a predictive model has been developed, based on the application of the fluid flow and heat transfer equations of the real heat exchanger geometry. This model permits the performance calculation of the heat exchangers in arbitrary conditions. Simultaneously an experimental facility has been projected and built for testing the heat exchangers. The test facility allows to fix oil and coolant flow rates and temperatures over a wide range.
Technical Paper

Influence of Composite Reinforcement on Failure Modes of Steel Tubes

1991-09-01
911720
The previous experimental results on the circular steel tubes reinforced by a FRP composite have shown that the external reinforcement by composite improve their crush strength not only because of its own strength but also through an iteraction with the enveloped tube sheet which reduces the folding wave length and changes the collapse mode from an unstable one to a stable one. Here, the influence of the external reinforcement by composite on the crushing behaviour of square tubes is investigated experimentally. The same trend is obtained for square tubes. The external reinforcement changes the crushing mode from a non compact one to a compact one. The highest relative specific energy of the reinforced tube with respect to that of the non reinforced tube is 2.44.
Technical Paper

A Superior Hard Chromium Plating Method

1991-09-01
911721
Hard chrome plating is used in the automobile industry quite extensively. Cylinder valves, transmission parts, body part dies and molds, are only a few examples. Most automobile companies that have hard chrome plating shops are using methods that have been obsolete for over 50 years. The same is true for their outside chrome plating shop vendors. There is a hard chrome plating method that achieves plating rates of .006 (152) per hour with very even, dense and harder deposits. Even deposits mean less grinding time or no grinding after plating at all. What is considered by most chrome platers impossible to plate is easy to do. Holes and slots as small as .040 (1mm) in diameter can be plated using this system.
Technical Paper

Ceramic Coatings for Aluminum Engine Blocks

1991-09-01
911719
The trend toward lighter vehicles for improved performance has recently introduced the use of aluminum and plastic materials for vehicle bodies and drive trains. In particular, the aluminum alloy block for engine application is certain to reappear. The soft aluminum cylinder liner will require additional treatment before acceptance. Three possible approaches appear to solve the aluminum cylinder liner dilemma. These approaches are: 1. Use of high silicon aluminum such as the 390 aluminum. 2. Insert or cast steel liners into the aluminum engine block. 3. Ceramic coat the low cost standard aluminum engine block. Each has known advantages and disadvantages. It is the purpose of this paper to present the merits of Option 3, the ceramic coated aluminum cylinder bore from the standpoint of low weight, cost, and tribological effectiveness. The advantages of approaches (1) and (2) are obvious. High temperature after treatment of the ceramic engine components is not required.
Technical Paper

Design, Evaluation and Manufacture of Lubricant Additives in Argentina

1991-09-01
911698
Modern engines demand better perfomance from the lubricant. In order to fulfill them it is necessary to add the base oil some products that are called “additives”. Between them the Zinc Dialquilditiophosphate family is worldwide used, and there has not been other product better than this as antioxidant-antiwear-anticorrosive. Such perfomance is very closely related to its thermic stability and chemical structure. Our Research and Development group began to work in a six stages project which covered the deep action mechanism's analysis to a manufacture agreement with a private company. At industrial scale it has been got a product which has been tested not only by standar determinations but also in bench, engine and fleet tests, As a result we got not only a competitive product both in price and quality, but also the growth of local suppliers of critical components to the petroleum industry.
Technical Paper

Use of Alternative Transportation Fuels and Its Environmental Implications in Canada

1991-09-01
911695
Motor vehicles using gasoline and diesel fuel are major contributors to atmospheric pollution. There are several alternative fuels that are potentially cleaner than current gasoline and diesel fuel. Exhaust emission measurements of regulated and non-regulated pollutants using a number of alternative fuels including low level alcohol-gasoline blends, natural gas, propane, and methanol in selected vehicles show certain environmental/air quality benefits and indicate future potential to further reduce the motor vehicle emissions.
Technical Paper

Evaluation and Study on the Heat Release Rate of Swirl Chamber Diesel Engine

1991-09-01
911786
A zero-dimensional computation model for the heat release rate of a swirl chamber diesel engine is established in this paper. With the aid of control volume analysis method of variable mass thermodynamic system, the instantaneous discharge coefficent of the connecting passage of combustion chambers is accurately determined by calculating the motored indicator diagrams of main and swirl chambers. A deeper study is also made on the heat release rate and other combustion characteristics under various conditions of the swirl chamber diesel engine such as connecting passages with different structural parameters, different shapes of main combustion chambers and different operating conditions. Thus some beneficial conclusions are reached, that is, the combustion delay in the main combustion chamber of the swirl chamber diesel engine is an important reason for its fuel economy lower than that of a DI diesel engine besides its greater losses of flow and heat.
X