Split-cycle engine

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The split-cycle engine is a type of internal combustion engine.

Contents

Design

In a conventional Otto cycle engine, each cylinder performs four strokes per cycle: intake, compression, power, and exhaust. This means that two revolutions of the crankshaft are required for each power stroke. The split-cycle engine divides these four strokes between two paired cylinders: one for intake and compression, and another for power and exhaust. Compressed air is transferred from the compression cylinder to the power cylinder through a crossover passage. Fuel is then injected and fired to produce the power stroke.

History

The Backus Water Motor Company of Newark, New Jersey was producing an early example of a split cycle engine as far back as 1891. The engine, of "a modified A form, with the crank-shaft at the top", was water-cooled and consisted of one working cylinder and one compressing cylinder of equal size and utilized a hot-tube ignitor system. It was produced in sizes ranging from 1/2 to 3 horsepower (2.2 kW) and the company had plans to offer a scaled-up version capable of 25 horsepower (19 kW) or more. [1]

The Atkinson differential engine was a two piston, single cylinder four-stroke engine that also used a displacer piston to provide the fuel air mixture for use by the power piston. However, the power piston did the compression.

The twingle engine (U.S. English) or split-single engine (British English) is a twin cylinder (or more) two-stroke engine; more precisely, it has one or more U-tube cylinders that each use a pair of pistons, one in each arm of the U. However, both pistons in each pair are used for power (and the underside of both supplies fuel air mixture, if crankcase scavenging is used), and they only differ in that one piston works the transfer port to provide the fuel air mixture for use in both cylinders and the other piston works the exhaust port, so that the burnt mixture is exhausted via that cylinder. Unlike the Scuderi both cylinders are connected to the combustion chamber. As neither piston works as a displacer piston at all, this engine has nothing whatsoever to do with the split cycle engine apart from a purely coincidental similarity of the names.

The Scuderi engine is a design of a split-cycle, internal combustion engine invented by Carmelo J. Scuderi. [2] The Scuderi Group, an engineering and licensing company based in West Springfield, Massachusetts and founded by Carmelo Scuderi’s children, said that the prototype was completed and was unveiled to the public on April 20, 2009. [3] [4]

The Tour Engine [5] is an opposed-cylinder split-cycle internal combustion engine that uses a novel Spool Shuttle Crossover Valve (SSCV) to transfer fuel/air charge from the cold to hot cylinder. The first prototype was completed on June, 2008. Tour Engine was funded by grants from the Israel Ministry of National Infrastructures, Energy and Water Resources [6] and ARPA-E [7]

Another split-cycle design, using an external combustion chamber, is the Zajac engine. [8]

New Zealand scam - Rick Mayne's Split Cell engine

In 2009 investigative journalist Gerard Ryle reported a scam by New Zealander Rick Mayne that lost investors 100Ms of NZ dollars. Rick Mayne claimed success with a Split Cycle engine that used a multitude of small cylinders arranged in a radial arrangement with pistons operated by a Geneva mechanism. This scam engine was never successfully run in a meaningful demonstration, but significant capital was raised from unsuspecting investors and lost, through a share plan.

Ryle reported on the Rick Mayne scam, along with other scams involving fuel saving, in his book Firepower; and on ABC radio in 2009: [9] [10]

Even British newspaper the Independent was taken in by the scam, as was British racing driver Jack Brabham [11]

Related Research Articles

<span class="mw-page-title-main">Compression ratio</span> Ratio of the volume of a combustion chamber from its largest capacity to its smallest capacity

The compression ratio is the ratio between the volume of the cylinder and combustion chamber in an internal combustion engine at their maximum and minimum values.

<span class="mw-page-title-main">Reciprocating engine</span> Engine utilising one or more reciprocating pistons

A reciprocating engine, also often known as a piston engine, is typically a heat engine that uses one or more reciprocating pistons to convert high temperature and high pressure into a rotating motion. This article describes the common features of all types. The main types are: the internal combustion engine, used extensively in motor vehicles; the steam engine, the mainstay of the Industrial Revolution; and the Stirling engine for niche applications. Internal combustion engines are further classified in two ways: either a spark-ignition (SI) engine, where the spark plug initiates the combustion; or a compression-ignition (CI) engine, where the air within the cylinder is compressed, thus heating it, so that the heated air ignites fuel that is injected then or earlier.

<span class="mw-page-title-main">Miller cycle</span> Thermodynamic cycle

In engineering, the Miller cycle is a thermodynamic cycle used in a type of internal combustion engine. The Miller cycle was patented by Ralph Miller, an American engineer, U.S. Patent 2,817,322 dated Dec 24, 1957. The engine may be two- or four-stroke and may be run on diesel fuel, gases, or dual fuel.

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

A two-strokeengine is a type of internal combustion engine that completes a power cycle with two strokes of the piston during one power cycle, this power cycle being completed in one revolution of the crankshaft. A four-stroke engine requires four strokes of the piston to complete a power cycle during two crankshaft revolutions. In a two-stroke engine, the end of the combustion stroke and the beginning of the compression stroke happen simultaneously, with the intake and exhaust functions occurring at the same time.

A stratified charge engine describes a certain type of internal combustion engine, usually spark ignition (SI) engine that can be used in trucks, automobiles, portable and stationary equipment. The term "stratified charge" refers to the working fluids and fuel vapors entering the cylinder. Usually the fuel is injected into the cylinder or enters as a fuel rich vapor where a spark or other means are used to initiate ignition where the fuel rich zone interacts with the air to promote complete combustion. A stratified charge can allow for slightly higher compression ratios without "knock," and leaner air/fuel ratio than in conventional internal combustion engines.

<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.

William Hall Barnett, is described as a 'founder' in his 1836 patent, and an 'ironfounder' in his 1838 patent, and later as an engineer and gas engineer, working in Brighton, UK. He worked for many years for the Brighton and Hove General Gas Company.

<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.

<span class="mw-page-title-main">Crankcase</span> Crankshaft housing in reciprocating combustion engines

In a piston engine, the crankcase is the housing that surrounds the crankshaft. In most modern engines, the crankcase is integrated into the engine block.

In the context of an internal combustion engine, the term stroke has the following related meanings:

hot-bulb engine Internal combustion engine

The hot-bulb engine is a type of internal combustion engine in which fuel ignites by coming in contact with a red-hot metal surface inside a bulb, followed by the introduction of air (oxygen) compressed into the hot-bulb chamber by the rising piston. There is some ignition when the fuel is introduced, but it quickly uses up the available oxygen in the bulb. Vigorous ignition takes place only when sufficient oxygen is supplied to the hot-bulb chamber on the compression stroke of the engine.

<span class="mw-page-title-main">Scuderi engine</span>

The Scuderi engine, in 2005–2013 was a claimed new type of engine with claimed benefits. No engine to date has been produced commercially.

<span class="mw-page-title-main">Model engine</span>

A model engine is a small internal combustion engine typically used to power a radio-controlled aircraft, radio-controlled car, radio-controlled boat, free flight, control line aircraft, or ground-running tether car model.

The term six-stroke engine has been applied to a number of alternative internal combustion engine designs that attempt to improve on traditional two-stroke and four-stroke engines. Claimed advantages may include increased fuel efficiency, reduced mechanical complexity, and/or reduced emissions. These engines can be divided into two groups based on the number of pistons that contribute to the six strokes.

<span class="mw-page-title-main">Scavenging (engine)</span> Process used in internal combustion engines

Scavenging is the process of replacing the exhaust gas in a cylinder of an internal combustion engine with the fresh air/fuel mixture for the next cycle. If scavenging is incomplete, the remaining exhaust gases can cause improper combustion for the next cycle, leading to reduced power output.

<span class="mw-page-title-main">Free-piston engine</span>

A free-piston engine is a linear, 'crankless' internal combustion engine, in which the piston motion is not controlled by a crankshaft but determined by the interaction of forces from the combustion chamber gases, a rebound device and a load device.

Two-and-four-stroke engines are engines that combine elements from both two-stroke and four-stroke engines. They usually incorporate two pistons.

<span class="mw-page-title-main">Split-single engine</span> Type of two-stroke internal combustion engine

In internal combustion engines, a split-single design is a type of two-stroke where two cylinders share a single combustion chamber.

Internal combustion engines come in a wide variety of types, but have certain family resemblances, and thus share many common types of components.

<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.

References

  1. ↑ "The Backus Gas Engine". American Machinist. 15 January 1891. (p. 1, top of left column)
  2. ↑ Steve Tripoli (August 1, 2006). "Carmelo Scuderi's legacy just revving up". Marketplace. American Public Media. Archived from the original on May 29, 2007.
  3. ↑ Wrinn, Bill (9 Feb 2009). "Podcast: First Scuderi Engine Prototype Assembled". Air Hybrid Blog. Scuderi Group. Archived from the original on 2009-02-16.
  4. ↑ Murray, Charles (23 Sep 2011). "Will Split-Cycle Engine Compete With EV Powertrains?". Design News. Archived from the original on 2016-06-06.
  5. ↑ "Tour Engine, Inc" . Retrieved 30 October 2017.
  6. ↑ "Research and Development 2012-2014" (PDF). Retrieved 30 October 2017.
  7. ↑ "High Efficiency Split-cycle Engine For Residential Generators" . Retrieved 30 October 2017.
  8. ↑ "The Zajac Technology - Step by Step".
  9. ↑ Rick Mayne (Aug 29, 2009). "Fuel saving follies?". ABC Australia.
  10. ↑ Tony Davis (May 19, 2012). "Frequently unasked questions: What are some other big scams?". Drive.com.au. Fairfax Media.
  11. ↑ Nigel Cope (5 July 1993). "Power in miniature is backed by a champion: Revolutionary engine wins the Brabham seal of approval" . The Independent. Archived from the original on 2022-05-24.
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