Consumption map

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Consumption map of a 1.5-litre three-cylinder diesel engine Brake specific fuel consumption.svg
Consumption map of a 1.5-litre three-cylinder diesel engine

A consumption map or efficiency map [1] is a chart that displays the brake-specific fuel consumption of an internal combustion engine at a given rotational speed and mean effective pressure, in grams per kilowatt-hour (g/kWh).

The map contains each possible condition combining rotational speed and mean effective pressure. The contour lines show brake-specific fuel consumption, indicating the areas of the speed/load regime where an engine is more or less efficient.

A typical rotation power output, P (linear to ), is reached on multiple locations on the map that differ in the amount of fuel consumption. Automatic transmissions are therefore designed to keep the engine at the speed with the lowest possible fuel consumption for a given power output under standard driving conditions.

Overall thermal efficiency can depend on the fuel used; diesel and gasoline engines can reach up to 210 g/kWh and about 40% efficiency. Natural gas can yield an overall efficiency of about 200 g/kWh. [2] Average fuel consumption values are 160–180 g/kWh for slower two-stroke diesel cargo ship engines using fuel oil, reaching up to 55% efficiency at 300 rpm; 195–210 g/kWh for turbodiesel passenger cars; 195–225 g/kWh for trucks; and 250–350 g/kWh for naturally aspirated Otto cycle gasoline passenger cars. [3]

Literature

Related Research Articles

<span class="mw-page-title-main">Diesel engine</span> Type of internal combustion engine

The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is called a compression-ignition engine. This contrasts with engines using spark plug-ignition of the air-fuel mixture, such as a petrol engine or a gas engine.

<span class="mw-page-title-main">Wankel engine</span> Combustion engine using an eccentric rotary design

The Wankel engine is a type of internal combustion engine using an eccentric rotary design to convert pressure into rotating motion. The concept was proven by German engineer Felix Wankel, followed by a commercially feasible engine designed by German engineer Hanns-Dieter Paschke. The Wankel engine's rotor, which creates the turning motion, is similar in shape to a Reuleaux triangle, with the sides having less curvature. The rotor spins inside a figure-eight-like epitrochoidal housing around a fixed-toothed gearing. The midpoint of the rotor moves in a circle around the output shaft, rotating the shaft via a cam.

<span class="mw-page-title-main">Four-stroke engine</span> Internal combustion engine type

A four-strokeengine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either direction. The four separate strokes are termed:

  1. Intake: Also known as induction or suction. This stroke of the piston begins at top dead center (T.D.C.) and ends at bottom dead center (B.D.C.). In this stroke the intake valve must be in the open position while the piston pulls an air-fuel mixture into the cylinder by producing a partial vacuum in the cylinder through its downward motion.
  2. Compression: This stroke begins at B.D.C, or just at the end of the suction stroke, and ends at T.D.C. In this stroke the piston compresses the air-fuel mixture in preparation for ignition during the power stroke (below). Both the intake and exhaust valves are closed during this stage.
  3. Combustion: Also known as power or ignition. This is the start of the second revolution of the four stroke cycle. At this point the crankshaft has completed a full 360 degree revolution. While the piston is at T.D.C. the compressed air-fuel mixture is ignited by a spark plug or by heat generated by high compression, forcefully returning the piston to B.D.C. This stroke produces mechanical work from the engine to turn the crankshaft.
  4. Exhaust: Also known as outlet. During the exhaust stroke, the piston, once again, returns from B.D.C. to T.D.C. while the exhaust valve is open. This action expels the spent air-fuel mixture through the exhaust port.
<span class="mw-page-title-main">Fuel efficiency</span> Form of thermal efficiency

Fuel efficiency is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical potential energy contained in a carrier (fuel) into kinetic energy or work. Overall fuel efficiency may vary per device, which in turn may vary per application, and this spectrum of variance is often illustrated as a continuous energy profile. Non-transportation applications, such as industry, benefit from increased fuel efficiency, especially fossil fuel power plants or industries dealing with combustion, such as ammonia production during the Haber process.

<span class="mw-page-title-main">Junkers Jumo 204</span>

The Jumo 204 was an opposed-piston, inline, liquid-cooled 6-cylinder aircraft Diesel engine produced by the German manufacturer Junkers. It entered service in 1932. Later engines in the series, the Jumo 205, Jumo 206, Jumo 207 and Jumo 208, differed in stroke, bore, and supercharging arrangements.

<span class="mw-page-title-main">Variable-pitch propeller (marine)</span> Propeller with blades that can be rotated to control their pitch while in use

In marine propulsion, a variable-pitch propeller is a type of propeller with blades that can be rotated around their long axis to change the blade pitch. Reversible propellers—those where the pitch can be set to negative values—can also create reverse thrust for braking or going backwards without the need to change the direction of shaft revolution.

<span class="mw-page-title-main">Gasoline direct injection</span> Mixture formation system

Gasoline direct injection (GDI), also known as petrol direct injection (PDI), is a mixture formation system for internal combustion engines that run on gasoline (petrol), where fuel is injected into the combustion chamber. This is distinct from manifold injection systems, which inject fuel into the intake manifold.

Manifold vacuum, or engine vacuum in an internal combustion engine is the difference in air pressure between the engine's intake manifold and Earth's atmosphere.

A microturbine (MT) is a small gas turbine with similar cycles and components to a heavy gas turbine. The MT power-to-weight ratio is better than a heavy gas turbine because the reduction of turbine diameters causes an increase in shaft rotational speed. Heavy gas turbine generators are too large and too expensive for distributed power applications, so MTs are developed for small-scale power like electrical power generation alone or as combined cooling, heating, and power (CCHP) systems. The MT are 25 to 500 kW (34 to 671 hp) gas turbines evolved from piston engine turbochargers, aircraft auxiliary power units (APU) or small jet engines, the size of a refrigerator. Early turbines of 30–70 kW (40–94 hp) grew to 200–250 kW (270–340 hp).

<span class="mw-page-title-main">Variable-geometry turbocharger</span> Type of turbocharging technology

Variable-geometry turbochargers (VGTs), occasionally known as variable-nozzle turbochargers (VNTs), are a type of turbochargers, usually designed to allow the effective aspect ratio of the turbocharger to be altered as conditions change. This is done with the use of adjustable vanes located inside the turbine housing between the inlet and turbine, these vanes affect flow of gases towards the turbine. The benefit of the VGT is that the optimum aspect ratio at low engine speeds is very different from that at high engine speeds.

<span class="mw-page-title-main">Aircraft diesel engine</span> Aircraft engine operating on the Diesel principle

The aircraft diesel engine or aero diesel is a diesel-powered aircraft engine. They were used in airships and tried in aircraft in the late 1920s and 1930s, but were never widely adopted until recently. Their main advantages are their excellent specific fuel consumption, the reduced flammability and somewhat higher density of their fuel, but these have been outweighed by a combination of inherent disadvantages compared to gasoline-fueled or turboprop engines. The ever-rising cost of avgas and doubts about its future availability have spurred a resurgence in aircraft diesel engine production in the early 2010s.

<span class="mw-page-title-main">Fuel economy in automobiles</span> Distance traveled by a vehicle compared to volume of fuel consumed

The fuel economy of an automobile relates to the distance traveled by a vehicle and the amount of fuel consumed. Consumption can be expressed in terms of the volume of fuel to travel a distance, or the distance traveled per unit volume of fuel consumed. Since fuel consumption of vehicles is a significant factor in air pollution, and since the importation of motor fuel can be a large part of a nation's foreign trade, many countries impose requirements for fuel economy.

<span class="mw-page-title-main">Turbo-diesel</span> Diesel engine with a turbocharger

The term turbo-diesel, also written as turbodiesel and turbo diesel, refers to any diesel engine equipped with a turbocharger. As with other engine types, turbocharging a diesel engine can significantly increase its efficiency and power output, especially when used in combination with an intercooler.

Engine efficiency of thermal engines is the relationship between the total energy contained in the fuel, and the amount of energy used to perform useful work. There are two classifications of thermal engines-

  1. Internal combustion and
  2. External combustion engines.

The energy efficiency in transport is the useful travelled distance, of passengers, goods or any type of load; divided by the total energy put into the transport propulsion means. The energy input might be rendered in several different types depending on the type of propulsion, and normally such energy is presented in liquid fuels, electrical energy or food energy. The energy efficiency is also occasionally known as energy intensity. The inverse of the energy efficiency in transport is the energy consumption in transport.

<span class="mw-page-title-main">Energy-efficient driving</span> Driving using techniques that reduce fuel consumption

Energy-efficient driving techniques are used by drivers who wish to reduce their fuel consumption, and thus maximize fuel efficiency. Many drivers have the potential to improve their fuel efficiency significantly. Simple things such as keeping tires properly inflated, having a vehicle well-maintained and avoiding idling can dramatically improve fuel efficiency. Careful use of acceleration and deceleration and especially limiting use of high speeds helps efficiency. The use of multiple such techniques is called "hypermiling".

<span class="mw-page-title-main">Electronic Diesel Control</span> Diesel engine fuel injection control system

Electronic Diesel Control is a diesel engine fuel injection control system for the precise metering and delivery of fuel into the combustion chamber of modern diesel engines used in trucks and cars.

Brake-specific fuel consumption (BSFC) is a measure of the fuel efficiency of any prime mover that burns fuel and produces rotational, or shaft power. It is typically used for comparing the efficiency of internal combustion engines with a shaft output.

<span class="mw-page-title-main">Internal combustion engine</span> Engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber

An internal combustion engine is a heat engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine, the expansion of the high-temperature and high-pressure gases produced by combustion applies direct force to some component of the engine. The force is typically applied to pistons, turbine blades, a rotor, or a nozzle. This force moves the component over a distance, transforming chemical energy into kinetic energy which is used to propel, move or power whatever the engine is attached to.

The Graflight V-8 is an aircraft diesel engine developed by Wisconsin-based Engineered Propulsion Systems

References

  1. Dieter Lohse und Werner Schnabel: Grundlagen der Straßenverkehrstechnik und der Verkehrsplanung: Band 1, Beuth Verlag, 2011, ISBN   9783410172710.
  2. Rainer Golloch, Downsizing bei Dieselmotoren, Abschnitt 2.1.3 Verbrennung, 1.
  3. Table 1 in Konrad Reif, "Dieselmotor-Management im Überblick", Abschnitt Springer Fachmedien Wiesbaden 2014, ISBN   978-3-658-06554-6