Search results for "Ignition"
showing 10 items of 50 documents
Gel combustion synthesis and magnetic properties of CoFe2O4, ZnFe2O4, and MgFe2O4 using 6-aminohexanoic acid as a new fuel
2020
Abstract For the first time, 6-aminohexanoic acid is used as an alternative fuel in the synthesis of the spinel ferrites with compositions CoFe2O4, ZnFe2O4 and MgFe2O4 using gel combustion synthesis with different oxidizer-to-fuel (O/F) ratios. The gel precursors were studied by differential thermal analysis and thermogravimetry (DTA/TG), which showed that the ignition temperature depends on the gel precursor, being around 230 °C, 130 °C and 275 °C for CoFe2O4, ZnFe2O4, and MgFe2O4, respectively. These results showed than the 6-aminohexanoic acid has an ignition temperature lower than the urea and the citric acid when were used in the synthesis of the spinel ferrites by gel combustion. More…
Model-based optimization of injection strategies for SI engine gas injectors
2014
A mathematical model for the prediction of the mass injected by a gaseous fuel solenoid injector for spark ignition (SI) engines has been realized and validated through experimental data by the authors in a recent work [1]. The gas injector has been studied with particular reference to the complex needle motion during the opening and closing phases. Such motion may significantly affect the amount of injected fuel. When the injector nozzle is fully open, the mass flow depends only on the upstream fluid pressure and temperature. This phenomenon creates a linear relationship between the injected fuel mass and the injection time (i.e. the duration of the injection pulse), thus enabling efficien…
Design and Implementation of an Electronic Control Unit for a CFR Bi-Fuel Spark Ignition Engine
2017
In this work an Electronic Control Unit for the management of a CFR engine will be described. The engine, which is used both for fuel octane rating (both in terms of RON and MON) and for research purpose, is equipped with a double injection system, with the aim to independently operate both with liquid and gaseous fuels. The developed ECU, hence, is able to control the injections of both kind of fuel, together with the spark ignition. Furthermore the system is also able to measure fuel’s consumption, instantaneous engine speed of rotation and air-fuel ratio, showing all the running parameters both on a local LCD display and on a PC based graphical user interface.
Spark ignition feedback control by means of combustion phase indicators on steady and transient operation
2014
In order to reduce fuel cost and CO2 emissions, modern spark ignition (SI) engines need to lower as much as possible fuel consumption. A crucial factor for efficiency improvement is represented by the combustion phase, which in an SI engine is controlled acting on the spark advance. This fundamental engine parameter is currently controlled in an open-loop by means of maps stored in the electronic control unit (ECU) memory: such kind of control, however, does not allow running the engine always at its best performance, since optimal combustion phase depends on many variables, like ambient conditions, fuel quality, engine aging, and wear, etc. A better choice would be represented by a closed-…
A Study on the Use of Combustion Phase Indicators for MBT Spark Timing on a Bi-Fuel Engine
2007
The performance of a spark ignition engine strongly depends on the phase of the combustion process with respect to piston motion, and hence on the spark advance; this fundamental parameter is actually controlled in open-loop by means of maps drawn up on the test bench and stored in the Electronic Control Unit (ECU). Bi-fuel engines (e.g. running either on gasoline or on natural gas) require a double mapping process in order to obtain a spark timing map for each of the fuels. This map based open-loop control however does not assure to run the engine always with the best spark timing, which can be influenced by many factors, like ambient condition of pressure, temperature and humidity, fuel p…
Misfire Detection System based on the Measure of Crankshaft Angular Velocity
2007
Misfire detection systems are becoming increasingly important in automotive market due to recent environmental issues (Euro rules). An early misfire diagnosis also allows to prevent damages to the exhaust emission system and consequent costs for the user. Today few low cost methods exists in order to precisely detect single misfires in real time, the majority in fact require the use of expensive sensors (e.g. pressure sensors) or dedicated circuits (e.g. ionization current sensing). This work describes a method and electronic system capable of detecting misfires with good accuracy, using parameters such as the speed sensor signal, already available in commercial engines. The proposed method…
Knock onset prediction of propane, gasoline and their mixtures in spark ignition engines
2016
Gaseous fuels, such as Liquefied Petroleum Gas (LPG) and Natural Gas (NG), thanks to their excellent mixing capabilities and high knocking resistance, allow complete and cleaner combustion than gasoline in Spark Ignition (SI) engines, resulting in lower pollutant emissions, above all if particulate matter is considered. In previous works [1,2] the authors proved how the simultaneous combustion of gasoline and gaseous fuel (NG or LPG) may strongly reduce both fuel consumption and pollutant emissions with respect to pure gasoline operation without a significant power loss. These very encouraging results were obtained thanks to the strong knock resistance increase obtained adding gaseous fuel …
Experimental Determination of Liquefied Petroleum Gas–Gasoline Mixtures Knock Resistance
2014
The results of previous experimental researches showed that great advantages can be achieved, both in terms of fuel consumption and pollutant emissions, in bifuel vehicles by means of the double-fuel combustion, i.e., the simultaneous combustion of gasoline and a gaseous fuel, such as liquefied petroleum gas (LPG) or natural gas (NG). The substantial increase in knock resistance pursued by adding LPG to gasoline, which allowed to maintain an overall stoichiometric proportion with air also at full load, is not documented in the scientific literature and induced the authors to perform a proper experimental campaign. The motor octane number (MON) of LPG–gasoline mixtures has been hence determi…
Simple method of estimating consumption of internal combustion engine for hybrid application
2012
This article presents two simple methods to evaluate the fuel consumption of internal combustion engines. Furthermore, it points out the link between piston volume, engine size and fuel consumption as it gives the possibility to visualize the chosen working points inside an internal combustion engine operation points map. This leads to the fact that this approach is a very helpful tool for the design of hybrid systems including internal combustion engines. The two presented methods, one very simple, one more elaborated, are interesting as first approach of internal combustion engine sizing and to evaluate the consumption of internal combustion engine. The results for six pure internal combu…
An NTC zone compliant knock onset prediction model for spark ignition engines
2015
Abstract Pollutant emissions reduction and energy saving policies increased the production of Spark Ignition (SI) engines operated with gaseous fuels. Natural Gas (NG) and Liquefied Petroleum Gas (LPG), thanks to their low cost and low environmental impact represent the best alternative. Bi-fuel engines, which may run either with gasoline or with gas (NG or LPG), widely spread in many countries thanks to their versatility, high efficiency and low pollutant emissions: gas fueled vehicles, as example, are allowed to run in many limited traffic zones. In the last years, supercharged SI engines fueled with either gasoline or gaseous fuel, spread in the market. Thermodynamic simulations, widely …