An experimental investigation of high performance natural gas engine with direct injection

The meeting of hydrogen and automotive: A review

Advantages of converting Diesel engines to run as dual fuel ethanol–Diesel

Experimental analysis on a spark ignition petrol engine fuelled with LPG (liquefied petroleum gas)

https://biblio.ugent.be/publication/852173/file/944704.pdf

Impact of variable valve timing on power, emissions and backfire of a bi-fuel hydrogen/gasoline engine

The lean burn direct injection jet ignition gas engine

This paper presents a new in-cylinder mixture preparation and ignition system for various gaseous fuels including hydrogen. The system consists of a centrally located direct-injection (DI) injector and a jet ignition (JI) device for combustion of the main chamber (MC) mixture. The fuel is injected in the MC with a new-generation, fast-actuating, high-pressure, high-flowrate DI injector capable of injection shaping and multiple events. This injector produces a bulk lean stratified mixture. The JI system uses a second DI injector to inject a small amount of fuel in a small pre-chamber (PC). A spark plug then ignites a slightly rich mixture. The MC mixture is then bulk ignited through multiple jets of hot reacting gases. Bulk ignition and combustion of the lean jet-controlled stratified MC mixture resulting from coupling DI with JI makes it possible to burn MC mixtures with fuel-to-air equivalence ratios reducing almost to zero for a throttleless control of load diesel-like and high efficiencies over almost the full range of loads. Computations are performed with hydrogen as the PC and MC fuel.

/pdf/computational-analysis-of-the-lean-burn-direct-injection-jet-1zocbxv5vm.pdf

Computational analysis of the lean-burn direct-injection jet ignition hydrogen engine

This paper explores through engine simulations the use of LPG and CNG gas fuels in a 1.5 liter Spark Ignition (SI) four cylinder gasoline engine with double over head camshafts, four valves per cylinder equipped with a novel mixture preparation and ignition system comprising centrally located Direct Injection (DI) injector and Jet Ignition (JI) nozzles. With DI technology, the fuel may be introduced within the cylinder after completion of the valve events. DI of fuel reduces the embedded air displacement effects of gaseous fuels and lowers the charge temperature. DI also allows lean stratified bulk combustion with enhanced rate of combustion and reduced heat transfer to the cylinder walls creating a bulk lean stratified mixture. Bulk combustion is started by a Jet Ignition (JI) system introducing in the main chamber multiple jets of reacting gases for enhanced rate of combustion, initiating main chamber burning in multiple regions with reduced sensitivity to mixture state and composition. Coupling of JI and DI allows the development of a lean burn engine making possible operation up to main chamber overall fuel-to-air equivalence ratios reducing almost to zero and throttle-less load control by quantity of fuel injected as in the diesel engine. Results are presented in terms of maps of brake specific fuel consumption (BSFC) and efficiency and maximum power densities. Load variations are obtained by varying the air to fuel equivalence ratio from ?=1 up to ?=6.6. Maximum power densities running ?=1 are 80 hp/liter (60 kW/liter) with CNG and almost 90 hp/liter (67 kW/liter) with LPG. BSFCs are as low as 200 and 190 g/kWh and brake efficiencies are up to 39 and 37% respectively with LPG and CNG running lean ?=1.65. Low BSFCs and high brake efficiencies are possible from 25 to 100% of engine load.

/pdf/the-lean-burn-direct-injection-jet-ignition-flexi-gas-fuel-5ei895yytp.pdf

The lean burn direct-injection jet-ignition flexi gas fuel LPG/CNG engine

Direct Injection (DI) is believed to be one of the key strategies for maximizing the thermal efficiency of Spark Ignition (SI) engines and meeting the ever-tightening emissions regulations. This paper explores the use of propane and methane gas fuels in a 1.5 liter SI four cylinder gasoline engine with double over head camshafts, four valves per cylinder, and a centrally located DI injector. With DI technology, the injection timing can be set to avoid fuel bypassing the engine during valve overlap into the exhaust system prior to combustion. DI of fuel reduces the embedded air displacement effects of gaseous fuels and lowers the charge temperature. Injection timings and compression ratio are optimized for best performances at Wide Open Throttle (WOT) conditions when configured to achieve homogeneous charge at stoichiometry or run lean jet controlled stratified. Effects of fuel properties on gas exchange, mixture formation, in-cylinder charge cooling, wall-jet interactions, and turbulent combustion evolution and knock occurrence are taken into account. Results are presented in terms of brake mean effective pressure, specific fuel consumption, specific CO 2 production and efficiency. This paper is a contribution to the development of a high flexibility gas fuel SI engine for the Australian market.

Development of a Direct Injection High Flexibility CNG/LPG Spark Ignition Engine

The use of hydrogen as an engine fuel poses several challenges as well as opportunities in engine design and control. These challenges are mainly due to hydrogen's high flame temperatures at near stoichiometric mixtures, as well as the reactant volume fraction which can reduce the engine power output significantly. However, the wide flammability limits of hydrogen combustion in air means that a large part of the engine operation regime can be achieved without the use of the engine throttle or exhaust after treatment. This paper presents results of experiments and computations for a research single cylinder pressure boosted hydrogen fuelled internal combustion engine (H2ICE) fitted with the Hydrogen Assisted Jet Ignition system (HAJI) and running extremely lean mixtures.

/pdf/experimental-and-numerical-study-of-a-hydrogen-fuelled-i-c-1p5nfu2yov.pdf

HC Watson

Papers

The lean burn direct injection jet ignition gas engine

Computational analysis of the lean-burn direct-injection jet ignition hydrogen engine

The lean burn direct-injection jet-ignition flexi gas fuel LPG/CNG engine

Development of a Direct Injection High Flexibility CNG/LPG Spark Ignition Engine

Experimental and numerical study of a hydrogen fuelled I.C. engine fitted with the hydrogen assisted jet ignition system