109-500: Fuel injection is the introduction of fuel in an internal combustion engine , most commonly automotive engines , by the means of a fuel injector. This article focuses on fuel injection in reciprocating piston and Wankel rotary engines. All compression-ignition engines (e.g. diesel engines ), and many spark-ignition engines (i.e. petrol (gasoline) engines , such as Otto or Wankel ), use fuel injection of one kind or another. Mass-produced diesel engines for passenger cars (such as
218-420: A cold start . In order to ensure an adequate supply at all times, carburetors include a reservoir of fuel, called a "float chamber" or "float bowl". Fuel is delivered to the float chamber by a fuel pump . A floating inlet valve regulates the fuel entering the float chamber, assuring a constant level. Unlike in a fuel injected engine, the fuel system in a carbureted engine is not pressurized. For engines where
327-404: A hot-bulb engine used a 'jerk pump' to dispense fuel oil at high pressure to an injector. Another development in early diesel engines was the pre-combustion chamber, which was invented in 1919 by Prosper l'Orange to avoid the drawbacks of air-blast injection systems. The pre-combustion chamber made it feasible to produce engines in size suitable for automobiles and MAN Truck & Bus presented
436-400: A nuclear fission reactor ; nuclear fuel can refer to the material or to physical objects (for example fuel bundles composed of fuel rods ) composed of the fuel material, perhaps mixed with structural, neutron moderating , or neutron reflecting materials. When some of these fuels are struck by neutrons, they are in turn capable of emitting neutrons when they break apart. This makes possible
545-608: A spark plug . The Cummins Model H diesel truck engine was introduced in America in 1933. In 1936, the Mercedes-Benz OM 138 diesel engine (using a precombustion chamber) became one of the first fuel-injected engines used in a mass-production passenger car. During World War II , several petrol engines for aircraft used direct-injection systems, such as the European Junkers Jumo 210 , Daimler-Benz DB 601 , BMW 801 , and
654-467: A venturi (aka "barrel"). Fuel is introduced into the air stream through small tubes (the main jets ) at the narrowest part of the venturi, where the air is at its highest speed. Downstream of the venturi is a throttle (usually in the form of a butterfly valve ) which is used to control the amount of air entering the carburetor. In a car, this throttle is connected to the vehicle's throttle pedal, which varies engine speed. At lesser throttle openings,
763-451: A carburettor. Many of the carburettor's supporting components—such as the air filter, intake manifold, and fuel line routing—could be used with few or no changes. This postponed the redesign and tooling costs of these components. Single-point injection was used extensively on American-made passenger cars and light trucks during 1980–1995, and in some European cars in the early and mid-1990s. In the US,
872-578: A central injector instead of multiple injectors. Single-point injection (also called 'throttle-body injection') uses one injector in a throttle body mounted similarly to a carburettor on an intake manifold . As in a carburetted induction system, the fuel is mixed with the air before entering the intake manifold. Single-point injection was a relatively low-cost way for automakers to reduce exhaust emissions to comply with tightening regulations while providing better "driveability" (easy starting, smooth running, no engine stuttering) than could be obtained with
981-429: A flexible diaphragm on one side of the fuel chamber, connected to a needle valve which regulates the fuel entering the chamber. As the flowrate of the air in the chamber (controlled by the throttling valve/butterfly valve) decreases, the diaphragm moves inward (downward), which closes the needle valve to admit less fuel. As the flowrate of the air in the chamber increases, the diaphragm moves outward (upward) which opens
1090-572: A fuel injection system are described in the following sections. In some systems, a single component performs multiple functions. Fuel injection is operated by spraying pressurised fuel into the engine. Therefore a device to pressurise the fuel is needed, such as a fuel pump. The system must determine the appropriate amount of fuel to be supplied and control the fuel flow to supply this amount. Several early mechanical injection systems used relatively sophisticated helix-controlled injection pump(s) that both metered fuel and created injection pressure. Since
1199-701: A fuel injection system in 1941 and by 1956 it was used in the Jaguar racing cars. At the 1957 24 Hours of Le Mans , the 1st to 4th placed cars were Jaguar D-Type entries using a Lucas fuel injection system. Also in 1957, General Motors introduced the Rochester Ramjet option, consisting of a fuel injection system for the V8 engine in the Chevrolet Corvette. During the 1960s, fuel injection systems were also produced by Hilborn , SPICA and Kugelfischer . Up until this time,
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#17329170726911308-440: A low-pressure area in the idle passage/port thus causing fuel to flow through the idle jet. The idle jet is set at some constant value by the carburetor manufacturer, thus flowing a specified amount of fuel. Many carburetors use an off-idle circuit, which includes an additional fuel jet which is briefly used as the throttle starts to open. This jet is located in a low-pressure area behind the throttle. The additional fuel it provides
1417-403: A mixture of propane and butane , both of which are easily compressible gases under standard atmospheric conditions. It offers many of the advantages of compressed natural gas (CNG) but is denser than air, does not burn as cleanly, and is much more easily compressed. Commonly used for cooking and space heating, LP gas and compressed propane are seeing increased use in motorized vehicles. Propane
1526-570: A passenger car was released the following year, in the Mercedes-Benz 300SL sports car. However the engine suffered lubrication problems due to petrol diluting the engine oil, and subsequent Mercedes-Benz engines switched to a manifold injection design. Likewise, most petrol injection systems prior to the 2000s used the less-expensive manifold injection design. Throughout the 1950s, several manufacturers introduced their manifold injection systems for petrol engines. Lucas Industries had begun developing
1635-478: A patent for a "gas or vapor engine", which had a carburetor that mixed turpentine and air. The design did not reach production. In 1875 German engineer Siegfried Marcus produced a car powered by the first petrol engine (which also debuted the first magneto ignition system). Karl Benz introduced his single-cylinder four-stroke powered Benz Patent-Motorwagen in 1885. All three of these engines used surface carburetors, which operated by moving air across
1744-436: A pivotal part of our contemporary society, with most countries in the world burning fossil fuels in order to produce power, but are falling out of favor due to the global warming and related effects that are caused by burning them. Currently the trend has been towards renewable fuels, such as biofuels like alcohols. Chemical fuels are substances that release energy by reacting with substances around them, most notably by
1853-477: A pulsed flow system which used an air flow meter to calculate the amount of fuel required. L-Jetronic was widely adopted on European cars during the 1970s and 1980s. As a system that uses electronically-controlled fuel injectors which open and close to control the amount of fuel entering the engine, the L-Jetronic system uses the same basic principles as modern electronic fuel injection (EFI) systems. Prior to 1979,
1962-425: A reservoir). The first known use of fuel was the combustion of firewood by Homo erectus nearly two million years ago. Throughout most of human history only fuels derived from plants or animal fat were used by humans. Charcoal , a wood derivative, has been used since at least 6,000 BCE for melting metals. It was only supplanted by coke , derived from coal, as European forests started to become depleted around
2071-918: A self-sustaining chain reaction that releases energy at a controlled rate in a nuclear reactor , or at a very rapid uncontrolled rate in a nuclear weapon . The most common fissile nuclear fuels are uranium-235 ( U) and plutonium-239 ( Pu). The actions of mining, refining, purifying, using, and ultimately disposing of nuclear fuel together make up the nuclear fuel cycle . Not all types of nuclear fuels create energy from nuclear fission. Plutonium-238 and some other elements are used to produce small amounts of nuclear energy by radioactive decay in radioisotope thermoelectric generators and other types of atomic batteries . In contrast to fission, some light nuclides such as tritium ( H) can be used as fuel for nuclear fusion . This involves two or more nuclei combining into larger nuclei. Fuels that produce energy by this method are currently not utilized by humans, but they are
2180-406: A single carburetor shared between all of the cylinders, though some high-performance engines historically had multiple carburetors. The carburetor works on Bernoulli's principle : the static pressure of the intake air reduces at higher speeds, drawing more fuel into the airstream. In most cases (except for the accelerator pump ), the driver pressing the throttle pedal does not directly increase
2289-399: A sophisticated common-rail injection system. The latter is the most common system in modern automotive engines. During the 20th century, most petrol engines used either a carburettor or indirect fuel injection. Use of direct injection in petrol engines has become increasingly common in the 21st century. In a common rail system, fuel from the fuel tank is supplied to a common header (called
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#17329170726912398-463: A source of energy. The International Energy Agency (IEA) predicts that fossil fuel prices will decline, with oil stabilizing around $ 75 to $ 80 per barrel as electric vehicle adoption surges and renewable energy expands. Additionally, the IEA anticipates a notable increase in liquefied natural gas capacity, enhancing Europe’s energy diversification. The amount of energy from different types of fuel depends on
2507-512: A way to make heavy oil fractions usable as liquid fuels. Many liquid fuels play a primary role in transportation and the economy. Some common properties of liquid fuels are that they are easy to transport and can be handled easily. They are also relatively easy to use for all engineering applications and in home use. Fuels like kerosene are rationed in some countries, for example in government-subsidized shops in India for home use. Conventional diesel
2616-412: Is always intermittent (either sequential or cylinder-individual). This can be done either with a blast of air or hydraulically, with the latter method being more common in automotive engines. Typically, hydraulic direct injection systems spray fuel into the air inside the cylinder or combustion chamber. Direct injection can be achieved with a conventional helix-controlled injection pump, unit injectors, or
2725-546: Is called a manifold injection system. There exist two types of manifold injection systems: multi-point injection (or port injection) and single-point injection (or throttle body injection). Internal mixture formation systems can be separated into several different varieties of direct and indirect injection, the most common being the common-rail injection system, a variety of direct injection. The term "electronic fuel injection" refers to any fuel injection system controlled by an engine control unit . The fundamental functions of
2834-424: Is decreasing as heating technology and the availability of good quality fuel improves. In some areas, smokeless coal is often the only solid fuel used. In Ireland, peat briquettes are used as smokeless fuel. They are also used to start a coal fire. Liquid fuels are combustible or energy-generating molecules that can be harnessed to create mechanical energy , usually producing kinetic energy . They must also take
2943-416: Is easily mechanized, and thus less laborious. As there is a general movement towards a low carbon economy, the use of liquid fuels such as hydrocarbons is coming under scrutiny. Carburettor A carburetor (also spelled carburettor or carburetter ) is a device used by a gasoline internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to
3052-456: Is equivalent to 44 ⁄ 12 (this is the ratio of the molecular/atomic weights) or 3.7 tonnes of CO 2 . Carbon dioxide is one of the greenhouse gases that enhances radiative forcing and contributes to global warming , causing the average surface temperature of the Earth to rise in response, which the vast majority of climate scientists agree will cause major adverse effects . Fuels are
3161-415: Is held shut by engine vacuum, is often used to do so. As the airflow through the carburetor increases the reduced manifold vacuum pulls the power valve open, allowing more fuel into the main metering circuit. In a two-stroke engine , the carburetor power valve operates in the opposite manner: in most circumstances the valve allows extra fuel into the engine, then at a certain engine RPM it closes to reduce
3270-530: Is injected at the same time to all the cylinders; or cylinder-individual , in which the engine control unit can adjust the injection for each cylinder individually. Multi-point injection (also called 'port injection') injects fuel into the intake ports just upstream of each cylinder's intake valve , rather than at a central point within an intake manifold. Typically, multi-point injected systems use multiple fuel injectors, but some systems, such as GM's central port injection system, use tubes with poppet valves fed by
3379-400: Is limited mainly by the fuel's viscosity so that the fuel flow tends to be proportional to the pressure difference. So jets sized for full power tend to starve the engine at lower speed and part throttle. Most commonly this has been corrected by using multiple jets. In SU and other (e.g. Zenith-Stromberg ) variable jet carburetors, it was corrected by varying the jet size. The orientation of
Fuel injection - Misplaced Pages Continue
3488-405: Is often used to prevent icing. This system consists of a secondary air intake which passes around the exhaust, in order to heat the air before it enters the carburetor. Typically, the system is operated by the pilot manually switching the intake air to travel via the heated intake path as required. The carburetor heat system reduces the power output (due to the lower density of heated air) and causes
3597-399: Is similar to gasoline in that it is a mixture of aliphatic hydrocarbons extracted from petroleum . Kerosene is used in kerosene lamps and as a fuel for cooking, heating, and small engines. Natural gas , composed chiefly of methane , can only exist as a liquid at very low temperatures (regardless of pressure), which limits its direct use as a liquid fuel in most applications. LP gas is
3706-641: Is spelled "carburetor" in American English and "carburettor" in British English . Colloquial abbreviations include carb in the UK and North America or Carby in Australia. Air from the atmosphere enters the carburetor (usually via an air cleaner ), has fuel added within the carburetor, passes into the inlet manifold , then through the inlet valve(s) , and finally into the combustion chamber . Most engines use
3815-409: Is the third most commonly used motor fuel globally. Fuel gas is any one of a number of fuels that are gaseous under ordinary conditions. Many fuel gases are composed of hydrocarbons (such as methane or propane ), hydrogen , carbon monoxide , or mixtures thereof. Such gases are sources of potential heat energy or light energy that can be readily transmitted and distributed through pipes from
3924-399: Is used to compensate for the reduced vacuum that occurs when the throttle is opened, thus smoothing the transition from the idle circuit to the main metering circuit. In a four-stroke engine it is often desirable to provide extra fuel to the engine at high loads (to increase the power output and reduce engine knocking ). A 'power valve', which is a spring-loaded valve in the carburetor that
4033-1006: Is widespread public debate about how carbon neutral these fuels are. Fossil fuels are hydrocarbons , primarily coal and petroleum ( liquid petroleum or natural gas ), formed from the fossilized remains of ancient plants and animals by exposure to high heat and pressure in the absence of oxygen in the Earth's crust over hundreds of millions of years. Commonly, the term fossil fuel also includes hydrocarbon-containing natural resources that are not derived entirely from biological sources, such as tar sands . These latter sources are properly known as mineral fuels . Fossil fuels contain high percentages of carbon and include coal, petroleum, and natural gas. They range from volatile materials with low carbon: hydrogen ratios like methane , to liquid petroleum to nonvolatile materials composed of almost pure carbon, like anthracite coal. Methane can be found in hydrocarbon fields, alone, associated with oil, or in
4142-524: The Carter Carburetor WCFB and the identical Rochester 4GC, introduced in various General Motors models for 1952. Oldsmobile referred the new carburetor as the "Quadri-Jet" (original spelling) while Buick called it the "Airpower". In the United States, carburetors were the common method of fuel delivery for most US-made gasoline (petrol) engines until the late 1980s, when fuel injection became
4251-413: The Mercedes-Benz OM 138 ) became available in the late 1930s and early 1940s, being the first fuel-injected engines for passenger car use. In passenger car petrol engines, fuel injection was introduced in the early 1950s and gradually gained prevalence until it had largely replaced carburetors by the early 1990s. The primary difference between carburetion and fuel injection is that fuel injection atomizes
4360-547: The Shvetsov ASh-82FN (M-82FN) . The German direct-injection systems were based on diesel injection systems used by Bosch, Deckel, Junkers and l'Orange. By around 1943, the Rolls-Royce Merlin and Wright R-3350 had switched from traditional carburettors to fuel-injection (called "pressure carburettors" at the time), however these engines used throttle body manifold injection , rather than the direct-injection systems of
4469-494: The Volkswagen 1.4 FSI engine introduced in 2000. However, the stratified charge systems were largely no longer in use by the late 2010s, due to increased exhaust emissions of NOx gasses and particulates, along with the increased cost and complexity of the systems. Fuel A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work . The concept
Fuel injection - Misplaced Pages Continue
4578-474: The Wankel engine . In a manifold injection system, air and fuel are mixed outside the combustion chamber so that a mixture of air and fuel is sucked into the engine. The main types of manifold injections systems are multi-point injection and single-point injection . These systems use either a continuous injection or an intermittent injection design. In a continuous injection system, fuel flows at all times from
4687-665: The accumulator ), and then sent through tubing to the injectors, which inject it into the combustion chamber. The accumulator has a high-pressure relief valve to maintain pressure and return the excess fuel to the fuel tank. The fuel is sprayed with the help of a nozzle that is opened and closed with a solenoid-operated needle valve . Third-generation common rail diesels use piezoelectric injectors for increased precision, with fuel pressures up to 300 MPa or 44,000 psi . The types of common-rail systems include air-guided injection and spray-guided injection . Used by diesel engines, these systems include: This injection method
4796-441: The stoichiometric ratio , the chemically correct air and fuel ratio to ensure complete combustion of fuel, and its specific energy , the energy per unit mass. 1 MJ ≈ 0.28 kWh ≈ 0.37 HPh . (The fuel-air ratio (FAR) is the reciprocal of the air-fuel ratio (AFR).) λ is the air-fuel equivalence ratio, and λ =1 means that it is assumed that the fuel and the oxidising agent (oxygen in air) are present in exactly
4905-436: The throttle body . Fuel injectors which also control the metering are called "injection valves", while injectors that perform all three functions are called unit injectors . Direct injection means that the fuel is injected into the main combustion chamber of each cylinder. The air and fuel are mixed only inside the combustion chamber. Therefore, only air is sucked into the engine during the intake stroke. The injection scheme
5014-464: The 18th century. Charcoal briquettes are now commonly used as a fuel for barbecue cooking. Crude oil was distilled by Persian chemists , with clear descriptions given in Arabic handbooks such as those of Muhammad ibn Zakarīya Rāzi . He described the process of distilling crude oil/petroleum into kerosene , as well as other hydrocarbon compounds, in his Kitab al-Asrar ( Book of Secrets ). Kerosene
5123-548: The 1950 Goliath GP700 small saloon, it was also added to the Gutbrod Superior engine in 1952. This mechanically-controlled system was essentially a specially lubricated high-pressure diesel direct-injection pump of the type that is governed by the vacuum behind an intake throttle valve. A Bosch mechanical direct-injection system was also used in the straight-eight used in the 1954 Mercedes-Benz W196 Formula One racing car. The first four-stroke direct-injection petrol engine for
5232-426: The 1954-1959 Mercedes-Benz 300 SL - all used manifold injection (i.e. the injectors located at the intake ports or throttle body, instead of inside the combustion chamber). This began to change when the first mass-produced petrol direct injection system for passenger cars was a common rail system introduced in the 1997 Mitsubishi 6G74 V6 engine. The first common-rail system for a passenger car diesel engine
5341-414: The 1970s. EEC legislation required all vehicles sold and produced in member countries to have a catalytic converter after December 1992. This legislation had been in the pipeline for some time, with many cars becoming available with catalytic converters or fuel injection from around 1990. A significant concern for aircraft engines is the formation of ice inside the carburetor. The temperature of air within
5450-452: The 1980s, electronic systems have been used to control the metering of fuel. More recent systems use an electronic engine control unit which meters the fuel, controls the ignition timing and controls various other engine functions. The fuel injector is effectively a spray nozzle that performs the final stage in the delivery of fuel into the engine. The injector is located in the combustion chamber , inlet manifold or - less commonly -
5559-569: The Electrojector system, becoming the first cars known to use an electronic fuel injection (EFI) system. The Electrojector patents were subsequently sold to Bosch, who developed the Electrojector into the Bosch D-Jetronic . The D-Jetronic was produced from 1967-1976 and first used on the VW 1600TL/E . The system was a speed/density system, using engine speed and intake manifold air density to calculate
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#17329170726915668-496: The G10 engine in the 2000 Chevrolet Metro became the last engine available on an American-sold vehicle to use throttle body injection. In indirect-injected diesel engines (as well as Akroyd engines), there are two combustion chambers: the main combustion chamber, and a pre-chamber (also called an ante-chamber) that is connected to the main one. The fuel is injected only into the pre-chamber (where it begins to combust), and not directly into
5777-599: The German engines. From 1940, the Mitsubishi Kinsei 60 series engine used a direct-injection system, along with the related Mitsubishi Kasei engine from 1941. In 1943, a low-pressure fuel injection system was added to the Nakajima Homare Model 23 radial engine. The first mass-produced petrol direct-injection system was developed by Bosch and initially used in small automotive two-stroke petrol engines. Introduced in
5886-558: The absorption of a proton or neutron . In most stars the fuel is provided by hydrogen, which can combine to form helium through the proton-proton chain reaction or by the CNO cycle . When the hydrogen fuel is exhausted, nuclear fusion can continue with progressively heavier elements, although the net energy released is lower because of the smaller difference in nuclear binding energy. Once iron-56 or nickel-56 nuclei are produced, no further energy can be obtained by nuclear fusion as these have
5995-413: The air speed through the venturi is insufficient to maintain the fuel flow, therefore the fuel is instead supplied by the carburetor's idle and off-idle circuits . At greater throttle openings, the speed of air passing through the venturi increases, which lowers the pressure of the air and draws more fuel into the airstream. At the same time, the reduced manifold vacuum results in less fuel flow through
6104-570: The amount of fuel to be injected. In 1974, Bosch introduced the K-Jetronic system, which used a continuous flow of fuel from the injectors (rather than the pulsed flow of the D-Jetronic system). K-Jetronic was a mechanical injection system, using a plunger actuated by the intake manifold pressure which then controlled the fuel flow to the injectors. Also in 1974, Bosch introduced the L-Jetronic system,
6213-568: The area around modern Baku , Azerbaijan . These fields were described by the Arab geographer Abu al-Hasan 'Alī al-Mas'ūdī in the 10th century, and by Marco Polo in the 13th century, who described the output of those wells as hundreds of shiploads. With the development of the steam engine in the United Kingdom in 1769, coal came into more common use, the combustion of which releases chemical energy that can be used to turn water into steam. Coal
6322-450: The barrels consist of "primary" barrel(s) used for lower load situations and secondary barrel(s) activating when required to provide additional air/fuel at higher loads. The primary and secondary venturi are often sized differently and incorporate different features to suit the situations in which they are used. Many four-barrel carburetors use two primary and two secondary barrels. A four-barrel design of two primary and two secondary barrels
6431-420: The carburetor can be reduced by up to 40 °C (72 °F), due to a combination of the reduced air pressure in the venturi and the latent heat of the evaporating fuel. The conditions during the descent to landing are particularly conducive to icing, since the engine is run at idle for a prolonged period with the throttle closed. Icing can also occur in cruise conditions at altitude. A carburetor heat system
6540-537: The carburetor is a key design consideration. Older engines used updraft carburetors, where the air enters from below the carburetor and exits through the top. From the late 1930s, downdraft carburetors become more commonly used (especially in the United States), along with side draft carburetors (especially in Europe). The main metering circuit consists of a pipe which reduces to a narrows before widening again, forming
6649-466: The choke based on the temperature of the engine's coolant liquid, an electrical resistance heater to do so, or air drawn through a tube connected to an engine exhaust source. A choke left closed after the engine has warmed up increases the engine's fuel consumption and exhaust gas emissions, and causes the engine to run rough and lack power due to an over-rich fuel mixture. However, excessive fuel can flood an engine and prevent it from starting. To remove
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#17329170726916758-408: The compression-based combustion of diesel requires the greater precision and pressure of fuel-injection. The name "carburetor" is derived from the verb carburet , which means "to combine with carbon", or, in particular, "to enrich a gas by combining it with carbon or hydrocarbons ". Thus a carburetor mixes intake air with hydrocarbon-based fuel, such as petrol or AutoGas (LPG). The name
6867-600: The correct proportions so that they are both fully consumed in the reaction. Nuclear fuel is any material that is consumed to derive nuclear energy . In theory, a wide variety of substances could be a nuclear fuel, as they can be made to release nuclear energy under the right conditions. However, the materials commonly referred to as nuclear fuels are those that will produce energy without being placed under extreme duress. Nuclear fuel can be "burned" by nuclear fission (splitting nuclei apart) or fusion (combining nuclei together) to derive nuclear energy. "Nuclear fuel" can refer to
6976-555: The diesel engine, but also improved it. He increased the air blast pressure from 4–5 kp/cm (390–490 kPa) to 65 kp/cm (6,400 kPa). In the meantime, the first manifold injection system was designed by Johannes Spiel in 1884, while working at Hallesche Maschinenfabrik in Germany. In 1891, the British Herbert-Akroyd oil engine became the first engine to use a pressurised fuel injection system. This design, called
7085-593: The earliest fuel employed by humans is wood. Evidence shows controlled fire was used up to 1.5 million years ago at Swartkrans , South Africa. It is unknown which hominid species first used fire, as both Australopithecus and an early species of Homo were present at the sites. As a fuel, wood has remained in use up until the present day, although it has been superseded for many purposes by other sources. Wood has an energy density of 10–20 MJ / kg . Recently biofuels have been developed for use in automotive transport (for example bioethanol and biodiesel ), but there
7194-411: The electronics in fuel injection systems used analogue electronics for the control system. The Bosch Motronic multi-point fuel injection system (also amongst the first systems where the ignition system is controlled by the same device as the fuel injection system) was the first mass-produced system to use digital electronics . The Ford EEC-III single-point fuel injection system, introduced in 1980,
7303-485: The engine in steady-state conditions, the inertia of fuel (being higher than that of air) causes a temporary shortfall as the throttle is opened. Therefore, an accelerator pump is often used to briefly provide extra fuel as the throttle is opened. When the driver presses the throttle pedal, a small piston or diaphragm pump injects extra fuel directly into the carburetor throat. The accelerator pump can also be used to "prime" an engine with extra fuel prior to attempting
7412-418: The excess fuel, many carburetors with automatic chokes allow it to be held open (by manually, depressing the accelerator pedal to the floor and briefly holding it there while cranking the starter) to allow extra air into the engine until the excess fuel is cleared out. Another method used by carburetors to improve the operation of a cold engine is a fast idle cam , which is connected to the choke and prevents
7521-438: The first direct-injected diesel engine for trucks in 1924. Higher pressure diesel injection pumps were introduced by Bosch in 1927. In 1898, German company Deutz AG started producing four-stroke petrol stationary engines with manifold injection. The 1906 Antoinette 8V aircraft engine (the world's first V8 engine) was another early four-stroke engine that used manifold injection. The first petrol engine with direct-injection
7630-433: The float chamber is located close to the engine, heat from the engine (including for several hours after the engine is shut off) can cause the fuel to heat up to the point of vaporization. This causes air bubbles in the fuel (similar to the air bubbles that necessitate brake bleeding ), which prevents the flow of fuel and is known as 'vapor lock'. To avoid pressurizing the float chamber, vent tubes allow air to enter and exit
7739-407: The float chamber. These tubes usually extend into the carburetor throat, placed to prevent fuel from sloshing out of them into the carburetor. If an engine must be operated when the carburetor is not in an upright orientation (for example in a chainsaw or airplane), a float chamber and gravity activated float valve would not be suitable. Instead, a diaphragm chamber is typically used. This consists of
7848-414: The flow of air at the entrance to the carburetor. This increases the vacuum in the main metering circuit, causing more fuel to be supplied to the engine via the main jets. Prior to the late 1950s the choke was manually operated by the driver, often using a lever or knob on the dashboard . Since then, automatic chokes became more commonplace. These either use a bimetallic thermostat to automatically regulate
7957-634: The form of methane clathrates . Fossil fuels formed from the fossilized remains of dead plants by exposure to heat and pressure in the Earth's crust over millions of years. This biogenic theory was first introduced by German scholar Georg Agricola in 1556 and later by Mikhail Lomonosov in the 18th century. It was estimated by the Energy Information Administration that in 2007 primary sources of energy consisted of petroleum 36.0%, coal 27.4%, natural gas 23.0%, amounting to an 86.4% share for fossil fuels in primary energy consumption in
8066-426: The fuel entering the engine. Instead, the airflow through the carburetor increases, which in turn increases the amount of fuel drawn into the intake mixture. The main disadvantage of basing a carburetor's operation on Bernoulli's Principle is that being a fluid dynamic device, the pressure reduction in a venturi tends to be proportional to the square of the intake airspeed. The fuel jets are much smaller and fuel flow
8175-465: The fuel entering the engine. This is done in order to extend the engine's maximum RPM, since many two-stroke engines can temporarily achieve higher RPM with a leaner air-fuel ratio. This is not to be confused with the unrelated exhaust power valve arrangements used on two-stroke engines. A metering rod or step-up rod system is sometimes used as an alternative to a power valve in a four-stroke engine in order to supply extra fuel at high loads. One end of
8284-626: The fuel injection systems had used a mechanical control system. In 1957, the American Bendix Electrojector system was introduced, which used analogue electronics for the control system. The Electrojector was intended to be available for the Rambler Rebel mid-size car, however reliability problems meant that the fuel injection option was not offered. In 1958, the Chrysler 300D , DeSoto Adventurer , Dodge D-500 and Plymouth Fury offered
8393-572: The fuel injectors, but at a variable flow rate. The most common automotive continuous injection system is the Bosch K-Jetronic system, introduced in 1974 and used until the mid-1990s by various car manufacturers. Intermittent injection systems can be sequential , in which injection is timed to coincide with each cylinder's intake stroke; batched , in which fuel is injected to the cylinders in groups, without precise synchronization to any particular cylinder's intake stroke; simultaneous , in which fuel
8502-420: The fuel itself, or to physical objects (for example bundles composed of fuel rods ) composed of the fuel material, mixed with structural, neutron moderating , or neutron-reflecting materials. Nuclear fuel has the highest energy density of all practical fuel sources. The most common type of nuclear fuel used by humans is heavy fissile elements that can be made to undergo nuclear fission chain reactions in
8611-633: The fuel through a small nozzle under high pressure, while carburetion relies on suction created by intake air accelerated through a Venturi tube to draw fuel into the airstream. The term "fuel injection" is vague and comprises various distinct systems with fundamentally different functional principles. Typically, the only thing all fuel injection systems have in common is a lack of carburetion . There are two main functional principles of mixture formation systems for internal combustion engines: internal mixture formation and external mixture formation. A fuel injection system that uses external mixture formation
8720-431: The generation of renewable energy is therefore under way to help meet increased energy needs. The burning of fossil fuels produces around 21.3 billion tonnes (21.3 gigatonnes ) of carbon dioxide (CO 2 ) per year, but it is estimated that natural processes can only absorb about half of that amount, so there is a net increase of 10.65 billion tonnes of atmospheric carbon dioxide per year (one tonne of atmospheric carbon
8829-459: The highest nuclear binding energies. Any nucleii heavier than Fe and Ni would thus absorb energy instead of giving it off when fused. Therefore, fusion stops and the star dies. In attempts by humans, fusion is only carried out with hydrogen ( H (deuterium) or H (tritium)) to form helium-4 as this reaction gives out the most net energy. Electric confinement ( ITER ), inertial confinement (heating by laser) and heating by strong electric currents are
8938-424: The idle and off-idle circuits. During cold weather fuel vaporizes less readily and tends to condense on the walls of the intake manifold, starving the cylinders of fuel and making cold starts difficult. Additional fuel is required (for a given amount of air) to start and run the engine until it warms up, provided by a choke valve . While the engine is warming up the choke valve is partially closed, restricting
9047-641: The illumination that accompanies combustion . Fuels are also used in the cells of organisms in a process known as cellular respiration , where organic molecules are oxidized to release usable energy. Hydrocarbons and related organic molecules are by far the most common source of fuel used by humans, but other substances, including radioactive metals, are also utilized. Fuels are contrasted with other substances or devices storing potential energy , such as those that directly release electrical energy (such as batteries and capacitors ) or mechanical energy (such as flywheels , springs, compressed air, or water in
9156-409: The intake air filter to be bypassed, therefore the system is only used when there is a risk of icing. If the engine is operating at idle RPM, another method to prevent icing is to periodically open the throttle, which increases the air temperature within the carburetor. Carburetor icing also occurs on other applications and various methods have been employed to solve this problem. On inline engines
9265-597: The intake air is through the Venturi tube in the main metering circuit, though various other components are also used to provide extra fuel or air in specific circumstances. Since the 1990s, carburetors have been largely replaced by fuel injection for cars and trucks, but carburetors are still used by some small engines (e.g. lawnmowers, generators, and concrete mixers) and motorcycles. In addition, they are still widely used on piston engine driven aircraft. Diesel engines have always used fuel injection instead of carburetors, as
9374-411: The intake air travelling through the carburetor is pressurized (such as where the carburetor is downstream of a supercharger ) the entire carburetor must be contained in an airtight pressurized box to operate. However, this is not necessary where the carburetor is upstream of the supercharger. Problems of fuel boiling and vapor lock can occur in carbureted engines, especially in hotter climates. Since
9483-490: The intake and exhaust manifolds are on the same side of the head. Heat from the exhaust is used to warm the intake manifold and in turn the carburetor. On V configurations, exhaust gases were directed from one head through the intake cross over to the other head. One method for regulating the exhaust flow on the cross over for intake warming was a weighted eccentric butterfly valve called a heat riser that remained closed at idle and opened at higher exhaust flow. Some vehicles used
9592-500: The main combustion chamber. Therefore, this principle is called indirect injection. There exist several slightly different indirect injection systems that have similar characteristics. Types of indirect injection used by diesel engines include: In 1872, George Bailey Brayton obtained a patent on an internal combustion engine that used a pneumatic fuel injection system, also invented by Brayton: air-blast injection . In 1894, Rudolf Diesel copied Brayton's air-blast injection system for
9701-468: The main source of fuel for stars . Fusion fuels are light elements such as hydrogen whose nucleii will combine easily. Energy is required to start fusion by raising the temperature so high that nuclei can collide together with enough energy that they stick together before repelling due to electric charge. This process is called fusion and it can give out energy. In stars that undergo nuclear fusion, fuel consists of atomic nuclei that can release energy by
9810-480: The needle valve to admit more fuel, allowing the engine to generate more power. A balanced state is reached which creates a steady fuel reservoir level, that remains constant in any orientation. Other components that have been used on carburetors include: The basic design for a carburetor consists of a single venturi (main metering circuit), though designs with two or four venturi (two-barrel and four-barrel carburetors respectively) are also quite commonplace. Typically
9919-452: The point of origin directly to the place of consumption. Fuel gas is contrasted with liquid fuels and from solid fuels, though some fuel gases are liquefied for storage or transport. While their gaseous nature can be advantageous, avoiding the difficulty of transporting solid fuel and the dangers of spillage inherent in liquid fuels, it can also be dangerous. It is possible for a fuel gas to be undetected and collect in certain areas, leading to
10028-509: The popular methods. Most transportation fuels are liquids, because vehicles usually require high energy density . This occurs naturally in liquids and solids. High energy density can also be provided by an internal combustion engine . These engines require clean-burning fuels. The fuels that are easiest to burn cleanly are typically liquids and gases. Thus, liquids meet the requirements of being both energy-dense and clean-burning. In addition, liquids (and gases) can be pumped, which means handling
10137-475: The preferred method. One of the last motorsport users of carburetors was NASCAR, which switched to electronic fuel injection after the 2011 Sprint Cup series . NASCAR still uses the four-barrel carburetor in the NASCAR Xfinity Series . In Europe, carburetors were largely replaced by fuel injection in the late 1980s, although fuel injection had been increasingly used in luxury cars and sports cars since
10246-779: The process of combustion . Chemical fuels are divided in two ways. First, by their physical properties, as a solid, liquid or gas. Secondly, on the basis of their occurrence: primary (natural fuel) and secondary (artificial fuel) . Thus, a general classification of chemical fuels is: Solid fuel refers to various types of solid material that are used as fuel to produce energy and provide heating , usually released through combustion. Solid fuels include wood , charcoal , peat , coal , hexamine fuel tablets , and pellets made from wood (see wood pellets ), corn , wheat , rye and other grains . Solid-fuel rocket technology also uses solid fuel (see solid propellants ). Solid fuels have been used by humanity for many years to create fire . Coal
10355-575: The risk of a gas explosion . For this reason, odorizers are added to most fuel gases so that they may be detected by a distinct smell. The most common type of fuel gas in current use is natural gas . Biofuel can be broadly defined as solid, liquid, or gas fuel consisting of, or derived from biomass . Biomass can also be used directly for heating or power—known as biomass fuel . Biofuel can be produced from any carbon source that can be replenished rapidly e.g. plants. Many different plants and plant-derived materials are used for biofuel manufacture. Perhaps
10464-489: The rods is tapered, which sits in the main metering jets and acts as a valve for fuel flow in the jets. At high engine loads, the rods are lifted away from the jets (either mechanically or using manifold vacuum), increasing the volume of fuel can flow through the jet. These systems have been used by the Rochester Quadra jet and in the 1950s Carter carburetors. While the main metering circuit can adequately supply fuel to
10573-499: The shape of their container; the fumes of liquid fuels are flammable, not the fluids. Most liquid fuels in widespread use are derived from the fossilized remains of dead plants and animals by exposure to heat and pressure inside the Earth's crust. However, there are several types, such as hydrogen fuel (for automotive uses), ethanol , jet fuel and bio-diesel , which are all categorized as liquid fuels. Emulsified fuels of oil in water, such as orimulsion , have been developed as
10682-399: The throttle from closing fully while the choke is in operation. The resulting increase in idle speed provides a more stable idle for a cold engine (by better atomizing the cold fuel) and helps the engine warm up quicker. The system within a carburetor that meters fuel when the engine is running at low RPM. The idle circuit is generally activated by vacuum under the throttle plate, which causes
10791-544: The top of a vessel containing the fuel. The first float-fed carburetor design, which used an atomizer nozzle , was introduced by German engineers Wilhelm Maybach and Gottlieb Daimler in their 1885 Grandfather Clock engine . The Butler Petrol Cycle car—built in England in 1888—also used a float-fed carburetor. The first carburetor for a stationary engine was patented in 1893 by Hungarian engineers János Csonka and Donát Bánki . The first four-barrel carburetors were
10900-550: The world. Non-fossil sources in 2006 included hydroelectric 6.3%, nuclear 8.5%, and others ( geothermal , solar , tidal , wind , wood , waste ) amounting to 0.9%. World energy consumption was growing about 2.3% per year. Fossil fuels are non-renewable resources because they take millions of years to form, and reserves are being depleted much faster than new ones are being made. So we must conserve these fuels and use them judiciously. The production and use of fossil fuels raise environmental concerns. A global movement toward
11009-420: Was a two-stroke aircraft engine designed by Otto Mader in 1916. Another early spark-ignition engine to use direct-injection was the 1925 Hesselman engine , designed by Swedish engineer Jonas Hesselman. This engine could run on a variety of fuels (such as oil, kerosene, petrol or diesel oil) and used a stratified charge principle whereby fuel is injected towards the end of the compression stroke, then ignited with
11118-438: Was also produced during the same period from oil shale and bitumen by heating the rock to extract the oil, which was then distilled. Rāzi also gave the first description of a kerosene lamp using crude mineral oil, referring to it as the "naffatah". The streets of Baghdad were paved with tar , derived from petroleum that became accessible from natural fields in the region. In the 9th century, oil fields were exploited in
11227-405: Was another early digital fuel injection system. These and other electronic manifold injection systems (using either port injection or throttle-body injection ) became more widespread through the 1980s, and by the early 1990s they had replaced carburettors in most new petrol-engined cars sold in developed countries. The aforementioned injection systems for petrol passenger car engines - except for
11336-527: Was commonly used in V8 engines to conserve fuel at low engine speeds while still affording an adequate supply at high. The use of multiple carburetors (e.g., a carburetor for each cylinder or pair of cylinders) also results in the intake air being drawn through multiple venturi. Some high-performance engines have used multiple two-barrel or four-barrel carburetors, for example six two-barrel carburetors on Ferrari V12s. In 1826, American engineer Samuel Morey received
11445-592: Was later used to drive ships and locomotives . By the 19th century, gas extracted from coal was being used for street lighting in London. In the 20th and 21st centuries, the primary use of coal is to generate electricity , providing 40% of the world's electrical power supply in 2005. Fossil fuels were rapidly adopted during the Industrial Revolution , because they were more concentrated and flexible than traditional energy sources, such as water power. They have become
11554-433: Was originally applied solely to those materials capable of releasing chemical energy but has since also been applied to other sources of heat energy, such as nuclear energy (via nuclear fission and nuclear fusion ). The heat energy released by reactions of fuels can be converted into mechanical energy via a heat engine . Other times, the heat itself is valued for warmth, cooking , or industrial processes, as well as
11663-448: Was previously used in many diesel engines. Types of systems include: The M-System , used in some diesel engines from the 1960s to the 1980s, sprayed the fuel onto the walls of the combustion chamber, as opposed to most other direct-injection systems which spray the fuel into the middle of the chamber. Manifold injection systems are common in petrol-fuelled engines such as the Otto engine and
11772-464: Was the Fiat Multijet straight-four engine, introduced in the 1999 Alfa Romeo 156 1.9 JTD model. Since the 2010s, many petrol engines have switched to direct-injection (sometimes in combination with separate manifold injectors for each cylinder). Similarly, many modern diesel engines use a common-rail design. Stratified charge injection was used in several petrol engines in the early 2000s, such as
11881-409: Was the fuel source which enabled the Industrial Revolution , from firing furnaces , to running steam engines . Wood was also extensively used to run steam locomotives . Both peat and coal are still used in electricity generation today. The use of some solid fuels (e.g. coal) is restricted or prohibited in some urban areas, due to unsafe levels of toxic emissions. The use of other solid fuels as wood
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