In a non-diesel internal combustion engine, direct injection gasoline (GDI) , also known as direct injection gasoline , direct gasoline injection , spark-ignited direct injection (SIDI) and fuel-stratified injection (FSI) , is a variant of fuel injection used in two-stroke and four-step modern gasoline engines. The gasoline is highly pressurized, and is injected through a common rail fuel line directly into the cylinder's respective combustion chamber, compared to conventional multipoint fuel injection that injects fuel into the intake or cylinder port. Direct insertion of fuel into the combustion chamber requires high-pressure injection, while low pressure is used to inject into the intake or cylinder port.
In some applications, direct injection of gasoline allows the refueling of layers (ultra slim combustion) to improve fuel efficiency, and reduce emissions levels at low loads.
GDI has seen rapid adoption by the automotive industry over the past few years, from 2.3 percent of production for 2008 model vehicles up to more than 45 percent of production expected for model year 2015.
Video Gasoline direct injection
Operating theory
The main advantages of GDI engines are improved fuel efficiency and high power output. The emission levels can also be more accurately controlled with the GDI system. The GDI machine operates into two modes 1) the composition of the overall lean equality ratio during low load and low speed operation. 2) homogenous stoichiometric modes at higher loads and at all higher loads and speeds. On the load of medium slim load area or stoichiometry. The combustion system is classified into an air guided system, guided on the wall and guided by a spray.
The engine management system continues to choose between three burning modes: ultra lean burn , stoichiometry , and full power output. Each mode is characterized by air-fuel ratio. The stoichiometric fuel-air ratio for gasoline is 14.7: 1 weight (mass), but ultra slim mode can involve a ratio as high as 65: 1 (or even higher in some machines, for very limited periods). This mixture is much slimmer than in conventional engines and greatly reduces fuel consumption.
- Ultra lean burn mode or stratified charge is used for light load path conditions, at constant or reduced speeds of roads, where no acceleration is required. Fuel is not injected at the intake step but rather at the last stage of the compression step. The combustion takes place in the cavity on the piston surface which has a toroidal or ovoidal shape, and is placed either in the center (for central injector), or moved to one side of the piston closer to the injector. The cavity creates a swirl effect so that a small amount of fuel-air mixture is positioned optimally near the spark plug. This layered voltage is mostly surrounded by air and residual gas, which makes the fuel and flame away from the cylinder wall. The reduction in combustion temperature allows the lowest emissions and heat loss and increases air quantity by reducing widening, which provides additional power. This technique allows the use of an ultra-lean blend that is not possible with conventional carburetors or fuel injectors. The
- Stoichiometric mode is used for medium load conditions. The fuel is injected during the intake step, creating a mixture of homogeneous air fuel in the cylinder. From the stoichiometric ratio, optimum combustion results in net exhaust emissions, further cleared by catalytic converter. Mode
- Full power is used for fast acceleration and heavy loads (such as when climbing a hill). The air-fuel mixture is homogeneous and the ratio is slightly richer than stoichiometry, which helps prevent ping. The fuel is injected during the intake step.
It is also possible to inject fuel more than once during one cycle. After the first refueling has been turned on, it is possible to add fuel as the piston goes down. The benefits are more electric and economic, however, certain octane fuels have caused the erosion of the exhaust valve.
Maps Gasoline direct injection
Companion technology
Direct injection can also be accompanied by other engine technologies such as turbocharging or supercharging, variable valve timing (VVT) or continuous variable cam phasing, and tuned/multi path or variable length intake manifolding (VLIM, or VIM). Water injection or (more commonly) exhaust gas recirculation (EGR) may help reduce high nitrous oxide emissions (NOx) that can result from the burning of ultra-slim mixtures; Modern turbocharged engines use continuous phasing instead of EGR.
Designing an initial generation FSI power station to generate higher power is difficult, since the only time it is possible to inject fuel during the induction phase. Conventional injection machines can inject a whole 4-stroke sequence, such as an injector spray onto the back of the closed valve. Direct injection machine, where the injector injects directly into the cylinder, is limited to the piston intake step. As RPM increases, the time available to inject fuel decreases. The newer FSI systems that have sufficient fuel pressure to inject even at the final compression stage do not suffer at the same rate. However, they do not inject during the discharge cycle because it will dispose of fuel. Therefore, all other factors are considered equal, the FSI engine requires a high-capacity injector to achieve the same power as a conventional engine. Some engines overcome this limitation by using direct injection and multiport fuel injection, including the Toyota 2GR-FSE V6 and Volkswagen Group TSI Engine.
History
Initial system
The invention of direct gasoline injection was by the inventor of the French configuration of the V8 engine, Leon Levavasseur in 1902. Levavasseur designed the original company Antoinette series from the aero V-form engine, starting with Antoinette 8V to be used by Antoinette built aircraft which Levavasseur also designed, 1906 to the death of the company in 1910, with the world's first V16 engine, using Levavasseur direct injection and generating about 100 hp, flying the monoplane Antoinette VII in 1907.
The first post-World War I example of direct gasoline injection was on a Hesselman machine created by Swedish engineer Jonas Hesselman in 1925. The Hesselman machine used the principle of ultra-slim combustion and injected fuel at the end of the compression step and then turned it on with a spark plug, started on petrol and then switched to run on diesel or kerosene. The Hesselman machine is a low compression design built to run on heavy fuel oil.
Direct gasoline injection was applied during World War II to almost all of the higher output of aircraft production made in Germany (widely used BMW 801 radials, and the popular inline inline V12 Daimler-Benz DB 601, DB 603 and DB 605, along with Junkers Jumo 210G is similar, Jumo 211 and Jumo 213, starting as early as 1937 for Jumo 210G and DB 601), Soviet Union (Shvetsov ASH-82FN radial, 1943, Design Bureau of Chemical Automation - KB Khimavtomatika) and US (Wright R-3350 < i> Duplex Cyclone radial, 1944).
Bosch had been working on DKW-Meisterklasse's mechanical direct injection machine in the late 1930s with good test results. The Second World War stopped further development.
The first automotive direct injection system used to run gasoline was developed under the leadership of Hans Scherenberg, and was introduced by Goliath and Gutbrod in 1952 to ignite some of their two-stroke cars. This system made by Bosch is essentially a high-pressure direct injection pump with an intake throttle valve. (Diesels only convert the amount of fuel injected to varying outputs, there is no throttle.) It uses a normal gasoline fuel pump, to provide fuel to a mechanically driven injection pump, which has a separate plunger per injector to produce an injection pressure very high directly into the combustion chamber. The two-stroke vehicles show excellent performance and fuel consumption up to 30% less than carburetor versions, especially under low engine loads. Cars enjoy additional benefits because the injection system also measures the lubricant into the engine from a special oil tank, negating the owner's need to mix their own two-stroke fuel mixture. Part of the oil is combined with fuel at the injection pump to lubricate the cylinder and piston ring, the rest is ported to the air intake to lubricate the crankcase. But the cars were expensive and difficult to run when the machine was warm because of the steam lock. Also, very few people know about direct injection, and the injection pump needs to be adjusted frequently. Branded workshops and Bosch services become overloaded, and many cars are converted into carburetors. This two-stroke engine was soon replaced by a four-stroke.
The 1955 Mercedes-Benz 300SL, the first production sports car that uses fuel injectors, uses direct injection. The Bosch fuel injector is placed into a hole in the cylinder wall used by spark plugs in another Mercedes-Benz six-cylinder engine (spark plugs are moved to the cylinder head). Later, the main application of fuel injection is preferred to cheaper indirect injection methods.
The study was conducted in the early 1970s with the support of American Motors Corporation (AMC) to develop a Straticharge Continuous Fuel-Injection (SCFI) system. Conventional sparks power up a straightforward AMC straight-6 internal combustion engine with a redesigned cylinder head. The system incorporates a mechanical device that automatically responds to engine airflow and loading conditions with two separate fuel control pressures supplied to two sets of continuous flow injectors. Flexibility is designed into the SCFI system to trim it to a particular machine. The prototype "straticharge" road testing machine was performed using the 1973 AMC Hornet, but the mechanical fuel control had teething problems.
Ford Motor Company developed a stratified stratified machine in the late 1970s called "PROCO" (programmed burning) using a unique high pressure pump and direct injector. At least one hundred and fifteen (115) Crown Victoria cars were built at the Ford Atlanta Assembly in Hapeville, Georgia using PROCO V8 engines. The project was canceled for several reasons: electronic controls, key elements, are in the early stages; the cost of pump and injector is very high; and slim combustion produce nitrogen oxides that exceed the United States Environmental Protection Agency (EPA) limit in the future. Also, the PROCO system was launched in the late 1970s, during the second "gas crisis" in the US, which pushed fuel costs higher. PROCO was originally developed for the Ford 460 Cubic-inch V8 engine, then applied to the 351, and finally 302. Due to the extreme fuel price spike, Ford was not sure about the future market for the V8 engine, and chose not to do expensive technology in the not- stable.
Later system
Direct gasoline injection 1996 reappears in the automotive market. Mitsubishi is the first with the GDI engine in the Japanese market with Galant/Legnum's 4G93 1.8Ã, L inline-four. It was later brought to Europe in 1997 in Carisma. It also developed the first six-cylinder GDI plant, 6G74 3.5Ã, L V6, in 1997. Mitsubishi applied this technology extensively, producing more than one million GDI machines in four families in 2001. Although used for many years, on 11 September 2001 MMC claimed a trademark for 'GDI' (with the uppercase final "I").
In 1997 Nissan released Leopard featuring VQ30DD equipped with direct injection.
At 1998 , Toyota's D4 direct injection system first appeared in various Japanese market vehicles equipped with the SZ and NZ engines. Toyota then introduced the D4 system to the European market with the 1AZ-FSE engine found at Avensis 2006. and the US market in 2005 with the 3GR-FSE engine found at Lexus GS 300 The first-ever V6 found on the Lexus IS 350 uses a more sophisticated direct injection system, which combines direct and indirect injection using two fuel injectors per cylinder, traditional port fuel injector ( low pressure) and direct fuel injector (high pressure) in a system known as D4-S. By 2015 Toyota added an independent self-cleaning cycle that is not used for direct fuel injection, the system only operates during idle with a maximum 10 minute cleaning cycle.
In 1999 , Renault introduced 2.0 IDE (Injection Directe Essence), first on Megane. Rather than following the lean burn approach, the Renault design uses high exhaust recirculation ratios to boost the economy at low engine loads, with direct injection that allows fuel to be concentrated around the spark. Then the gasoline direct injection engine has been tuned and marketed due to its high performance and improved fuel efficiency. PSA Peugeot Citro, Hyundai and Volvo entered into a development and licensing agreement for GDI Mitsubishi technology in 1999. The Mitsubishi engine is also manufactured at the NedCar plant and is used in 1.8 L Carisma and Volvo S40/V40 models supported by GDI.
At 2000 , the Volkswagen Group introduced its gasoline direct injection engine at Volkswagen Lupo, a 1.4-L inline-four unit, under the "Fuel Stratified Injection" (FSI) and "Turbo Fuel Stratified Injection" TFSI). This technology is adapted from the Audi Le Mans R8 prototype racing car. Marques Volkswagen Group uses direct injection in turbocharged 2.0-L TFSI and four-cylinder four FSI engine naturally aspirated. Later, an inline-four 1.6L L unit was introduced at MY 2002 Volkswagen Golf Mk4/Jetta/Bora, a 1.4L at MY 2002 Volkswagen Polo Mk4 and 2.0L in the 2003 Audi A4 model year. PSA Peugeot CitroÃÆ'Â nn introduced its first GDi (HPi) engine in 2000 in CitroÃÆ'¡n C5 and Peugeot 406. It is a 16-valve EW10 D 2.0 liter unit with 140 hp (104 kW), the system is licensed from Mitsubishi.
At 2002 , Alfa Romeo 156 with direct injection engine, JTS (Jet Thrust Stoichiometric) went on sale and now this technology is used on almost all Alfa Romeo engines.
In 2003 , Ford debuted the 1.8-inch Duratec SCi engine L naturally aspirated for Mondeo. Ford introduced its first European Ford engine to use direct injection technology in 2001, SCI notched (Smart Charge injection) for Direct-Injection-Spark-Ignition (DISI). This range will include several turbocharged derivatives, including 1.0, L, three turbocharged cylinders exhibited at the 2002 Geneva Show.
At 2003 , BMW introduced a direct injection of low-pressure gasoline N73 V12. The initial BMW setup could not enter lean-burn mode, but the company introduced a second-generation High Precision Injection (HPI) system on a turbocharged N54 straight-6 in 2006, which uses high-pressure injectors. The system goes beyond many others with a wider envelope of lean-burn time, improving overall efficiency. PSA teamed up with BMW on a new line of machines that made its first appearance in 2007 MINI Cooper S. Honda released their own direct injection system on Stream sold in Japan. Honda's fuel injector is placed directly above the cylinder at an angle of 90 degrees rather than a slanted angle.
In 2003 , General Motors released the 155 hp (116 kW) version of 2.2Ã, L Ecotec for Opel/Vauxhall Vectra and Signum. Several direct injection versions of the Ecotec engine have been introduced, using the SIDI (Spark Ignition Direct Injection) moniker: in 2006, an Ecotec 2.0G Ecotec LNF using Gen II blocks for Pontiac Solstice GXP and Saturn Sky Red Line; in 2010, block Gen II 2.4Ã, L Ecotec LAF ; and in 2012, an Ecotec LCV 2.5 and Ecotec 2.0G L Ecotec LTG in the Gen III block. In 2018 Corvette ZR1 (C7) introduces GM twin ports and direct injector systems.
At 2004 Isuzu produces the first GDi engine sold in American public vehicles, the standard on Axiom 2004 and optionally at Rodeo 2004. Isuzu claims the benefits of GDi is that the evaporated fuel has a cooling effect, enabling a higher compression ratio (10.3: 1 versus 9.1: 1) that increases output by 20 hp (15 kW), and that 0-to-60 mph times down from 8.9 to only 7.5 seconds, with a quarter mile cut from 16.5 to 15.8 seconds.
At 2005 , Mazda began using their own direct injection version at Mazdaspeed6 and later on the CX-7 sports utility, and the new Mazdaspeed3 in the US and European markets. This is called Direct Injection Spark Ignition (DISI).
At 2006 , BMW released a new direct-injection N54 twin-turbo-charge engine for the 335i Coupe and then for the 335i Sedan, the 535i series. and model 135i. Mercedes-Benz released a direct injection system (Charged Gasoline Injection, or "CGI") on the CLS 350 CGI featuring common rail, piezo-electric direct fuel injectors. The CLS 350 CGI offers 292 BHP versus 272 BHP for the CLS 350, with reduced carbon dioxide emissions and improved fuel economy. Audi also released its V8 engine with FSI technology in the Audi R8 that can produce 424 BHP with lower carbon emissions and more fuel economy.
In 2007 , GM released 3.6Ã, L V6 LLT SIDI for Cadillac CTS and redesigned STS and Holden Commodore SV6. 3.6 L has been used in Chevy Camaro 2010, the first for this model. In 2010, SIM 3.0Ã, L LF1 was introduced.
At 2007 , Ford introduced EcoBoost engine technology designed for a variety of vehicles. The machine first appeared in Lincoln MKR Concept 2007 under the name TwinForce . The EcoBoost family of 4-cylinder and 6-cylinder engines features turbocharging and direct injection technology (GTDI - Gasoline Turbocharged Direct Injection). Version 2.0 L was launched in Explorer America Concept 2008.
At 2008 , BMW released the X6 xDrive50i equipped with twin N63 V8 direct injection turbo engine.
At 2009 , Ferrari began selling California front engines with direct injection systems, and announced the 458 Italia will also feature a direct injection system, the first for the Ferrari mid-rear engine setup. Porsche also started selling 997 and Cayman which is equipped with direct injection. Ford produces a new generation of Taurus SHO and Flex with 3.5-L twin-turbo EcoBoost V-6 with direct injection. The Jaguar Land Rover engine AJ-V8 Gen III 5.0Ã, L (introduced in August 2009 for 2010 models) has a direct injection feature guided by sprays.
At 2010 Infiniti generates M56 that includes DI. Motus Motorcycles is growing, with Katech Engines, a direct-injected V4 engine named KMV4 as a powertrain for their MST motorcycles.
At 2011 the 2011 Hyundai Sonata models come with GDI engines, including a 2.0-liter turbo that produces 274 hp.
At 2013 Acura RLX comes with direct injection, becoming the first Honda GDI V6.
The 2014 General Motors LT1 (apart from the 1990s LT1/LT4 engine), 6.2 L V8, will use direct injection as well as VVT and variable displacement (cylinder deactivation). Hyundai Accent 2014 has an aluminum block, 138, I4 GDI engine.
On a two-stroke machine
The benefits of direct injection are even more pronounced on a two-stroke engine, because it eliminates much of the pollution it causes. In all two-strokes apart from those with single-split machines or similarly sophisticated settings, the exhaust and intake ports are both open at the same time, at the bottom of the piston stroke, for "scavenging". In conventional two-stroke, a portion of the fuel/air mixture enters the cylinder from the crankcase through the intake port directly out, not burning, through the exhaust port. With direct injection, only air (and usually some oil) comes from the crankcase, and fuel is not injected until the piston goes up and all ports are closed.
Two types of GDi are used in two-stroke: low-pressure assisted air, and high pressure. The first, developed by Orbital Engine Corporation of Australia (now Orbital Corporation) injects a mixture of fuel and compressed air into the combustion chamber. When the air expands, atomizes the fuel. The Orbital system is used in motor scooters manufactured by Aprilia, Piaggio, Peugeot and Kymco, in outboard motors produced by Mercury and Tohatsu, and in private boats manufactured by Bombardier Recreational Products.
High pressure direct injectors for two-stroke engines were developed in the early 1990s by Ficht GmbH of Kirchseeon Germany. Outboard Marine Corporation (OMC) licensed the technology in 1995 and introduced it to its outboard production engine in 1996. OMC purchased a controlling stake in Ficht in 1998. Supported by extensive warranty claims for Ficht outboard and previous and simultaneous financial management issues, OMC declared bankruptcy in December 2000 and parts of machinery and brand manufacturing (Evinrude Outboard Motors and Johnson Outboards), including Ficht technology, was purchased by Bombardier Recreational Products in 2001.
Evinrude introduced the E-Tec system, an increase in Ficht fuel injection, in 2003, based on US patent 6,398,511. In 2004, Evinrude received the EPA Clean Air Excellence Award for their paddle using the E-Tec system. The recent E-Tec system has also been adapted for use in two-step snowmobile performance.
Yamaha also has a high-pressure direct injection system (HPDI) for two-stroke outboard. This differs from Ficht/E-Tec and Orbital direct injection systems because it uses a separate, belt-driven, high-pressure, fuel-driven mechanical pump to produce the pressure required for injection in enclosed spaces. This is similar to the latest 4-step automotive design and fat pump system.
Husqvarna/KTM developed a DFI system for their two-stroke Enduro motorcycles. In 2011, Ossa developed 300i fuel-injected enduro motorcycles, the company was sold to Gas Gas and the release to the market was thwarted by financial problems.
EnviroFit, a nonprofit corporation sponsored by Colorado State University, has developed a direct injection retrofit kit for two-stroke motorcycles in a project to reduce air pollution in Southeast Asia, using technology developed by Orbital Corporation of Australia. The World Health Organization says air pollution in Southeast Asia and the Pacific causes 537,000 premature deaths each year. 100 million two-stroke cabs and motorcycles in that part of the world are the main cause.
Disadvantages of direct injection of gasoline
Although direct injection provides more power and efficiency, carbon accumulation takes place in the intake valve which over time reduces airflow to the cylinder, and therefore reduces power. Fuel contains various detergents and can keep your intake clean. When the fuel is no longer sprayed on the intake valve, a small amount of dirt from the air comes in and the carbon blowback from the ventilation vessel system on the intake wall, even with an air filter that prevents most dirt from entering the cylinder. This buildup can become quite severe so that pieces can break and have been known to burn holes in the catalytic converter. This can also lead to sporadic ignition failure. These problems have been known for some time and the technology has been improved to reduce carbon buildup.
Twin-fuel Bobcat Machine
Code named Bobcat, Ford's new twin-fuel engine is based on a 5.0L V8 engine block but uses E85 cylinder injection and gasoline port injection. The machine was developed in conjunction with Ethanol Boosting Systems, LLC of Cambridge, Massachusetts, which calls its trademark process DI Octane Boost. Direct injection of ethanol increases the regular gasoline octane from 88-91 octane to a maximum of 130 octane. The Bobcat project was inaugurated to the US Department of Energy and SAE International in April 2009.
Formula One
Among other power unit changes, one of the regulatory changes for the 2014 season is that Direct Injection has been made mandatory, under rule 5.10.2 stating 'There should be only one direct injector per cylinder and no injectors allowed upstream of the intake or downstream valves of the exhaust valve. '
Emissions
In 2013, a study by TÃÆ'Ã… "V NORD found that although direct gasoline injection engines dramatically reduced carbon dioxide emissions, they released about 1,000 times as many particles classified by the World Health Organization as a hazardous material than traditional gasoline engines and 10 times as much rather than a new diesel engine. This release occurs because direct injection results in uneven fuel combustion due to uneven fuel and air mixing (stratification) and because the direct injection engine operates at a higher pressure in the cylinder than the older indirect injection engine.
This pollution can be prevented by relatively inexpensive particulate filters that can significantly reduce particle emissions. However, installing such a filter is not mandatory. Until September 2017, the Euro 6 emission regulations limit the number of particles at a maximum of 6 ÃÆ' - 10 11 per kilometer during the New European Driving Cycle. Some gasoline direct injection engines may require gasoline particulate filters (GPFs) to meet that standard.
See also
References
Source of the article : Wikipedia
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