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113-514: Robert Stirling 's innovative contribution to the design of hot air engines of 1816 was what he called the 'Economiser'. Later known as the regenerator, it stored heat from the hot portion of the engine as the air passed to the cold side, and released heat to the cooled air as it returned to the hot side. This innovation improved the efficiency of the Stirling engine enough to make it commercially successful in particular applications, and has since been

226-447: A fuel cell without side production of NO x , but this is an electrochemical engine not a heat engine. The word engine derives from Old French engin , from the Latin ingenium –the root of the word ingenious . Pre-industrial weapons of war, such as catapults , trebuchets and battering rams , were called siege engines , and knowledge of how to construct them

339-482: A chemical reaction, but are not heat engines. Examples include: An electric motor uses electrical energy to produce mechanical energy , usually through the interaction of magnetic fields and current-carrying conductors . The reverse process, producing electrical energy from mechanical energy, is accomplished by a generator or dynamo . Traction motors used on vehicles often perform both tasks. Electric motors can be run as generators and vice versa, although this

452-434: A closed circuit. It was to it that the inventor devoted most of his attention. A two horse-power Stirling hot air engine, built in 1818 for pumping water at an Ayrshire quarry, continued to work for some time, until a careless attendant allowed the heater to become overheated. This experiment proved to the inventor that, owing to the low working pressure obtainable, the engine could only be adapted to small powers for which there

565-412: A closed cycle heat engine, which was powered by air, a contrast to the steam engines that were predominant at the time. This updated version of the heat engine was used to pump water from a quarry. Stirling's heat engine was able to run well but was limited by the weaker metals available at the time. Due to the flimsiness of the materials used, the air vessels were eventually crushed by the high pressure of

678-454: A cold cylinder, which are attached to reciprocating pistons 90° out of phase. The gas receives heat at the hot cylinder and expands, driving the piston that turns the crankshaft . After expanding and flowing through the recuperator, the gas rejects heat at the cold cylinder and the ensuing pressure drop leads to its compression by the other (displacement) piston, which forces it back to the hot cylinder. Non-thermal motors usually are powered by

791-414: A component of every air engine that is called a Stirling engine. In boilers , economizers are heat exchange devices that heat fluids, usually water, up to but not normally beyond the boiling point of that fluid. Economizers are so named because they can make use of the enthalpy in fluid streams that are hot, but not hot enough to be used in a boiler, thereby recovering more useful enthalpy and improving

904-441: A cycle optimizer able to stabilize the temperature of the liquid line and allow either an increase in the refrigeration capacity of the system, or a reduction of the power consumption . Such systems have the advantage of not interfering with the original design of the refrigeration system and are a way to expand a single staged system that does not possess an economizer compressor . Subcooling may also be produced by superheating

1017-544: A few limited-production battery-powered electric vehicles have appeared, they have not proved competitive owing to costs and operating characteristics. In the 21st century the diesel engine has been increasing in popularity with automobile owners. However, the gasoline engine and the Diesel engine, with their new emission-control devices to improve emission performance, have not yet been significantly challenged. A number of manufacturers have introduced hybrid engines, mainly involving

1130-412: A gas as in a Stirling engine , or steam as in a steam engine or an organic liquid such as n-pentane in an Organic Rankine cycle . The fluid can be of any composition; gas is by far the most common, although even single-phase liquid is sometimes used. In the case of the steam engine, the fluid changes phases between liquid and gas. Air-breathing combustion engines are combustion engines that use

1243-459: A heat difference to induce high-amplitude sound waves. In general, thermoacoustic engines can be divided into standing wave and travelling wave devices. Stirling engines can be another form of non-combustive heat engine. They use the Stirling thermodynamic cycle to convert heat into work. An example is the alpha type Stirling engine, whereby gas flows, via a recuperator , between a hot cylinder and

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1356-425: A heat engine). Chemical heat engines which employ air (ambient atmospheric gas) as a part of the fuel reaction are regarded as airbreathing engines. Chemical heat engines designed to operate outside of Earth's atmosphere (e.g. rockets , deeply submerged submarines ) need to carry an additional fuel component called the oxidizer (although there exist super-oxidizers suitable for use in rockets, such as fluorine ,

1469-460: A large scale required efficient electrical generators and electrical distribution networks. To reduce the electric energy consumption from motors and their associated carbon footprints , various regulatory authorities in many countries have introduced and implemented legislation to encourage the manufacture and use of higher efficiency electric motors. A well-designed motor can convert over 90% of its input energy into useful power for decades. When

1582-489: A majority of the models. Several three-cylinder, two-stroke-cycle models were built while most engines had straight or in-line cylinders. There were several V-type models and horizontally opposed two- and four-cylinder makes too. Overhead camshafts were frequently employed. The smaller engines were commonly air-cooled and located at the rear of the vehicle; compression ratios were relatively low. The 1970s and 1980s saw an increased interest in improved fuel economy , which caused

1695-438: A more powerful oxidant than oxygen itself); or the application needs to obtain heat by non-chemical means, such as by means of nuclear reactions . All chemically fueled heat engines emit exhaust gases. The cleanest engines emit water only. Strict zero-emissions generally means zero emissions other than water and water vapour. Only heat engines which combust pure hydrogen (fuel) and pure oxygen (oxidizer) achieve zero-emission by

1808-516: A natural inclination for engineering, he began attending Edinburgh University in 1805 at the age of fifteen to study divinity in hopes of becoming a minister. His brother James, who would play a major role in Stirling's future engineering endeavours, also attended Edinburgh at the age of 14. He finished his studies at University of Edinburgh and continued in November 1809 to study at Glasgow University where, according to Keith Laidler, he studied

1921-560: A nuclear power plant uses the heat from the nuclear reaction to produce steam and drive a steam engine, or a gas turbine in a rocket engine may be driven by decomposing hydrogen peroxide . Apart from the different energy source, the engine is often engineered much the same as an internal or external combustion engine. Another group of noncombustive engines includes thermoacoustic heat engines (sometimes called "TA engines") which are thermoacoustic devices that use high-amplitude sound waves to pump heat from one place to another, or conversely use

2034-559: A pressure just above atmospheric to drive the piston helped by a partial vacuum. Improving on the design of the 1712 Newcomen steam engine , the Watt steam engine, developed sporadically from 1763 to 1775, was a great step in the development of the steam engine. Offering a dramatic increase in fuel efficiency , James Watt 's design became synonymous with steam engines, due in no small part to his business partner, Matthew Boulton . It enabled rapid development of efficient semi-automated factories on

2147-556: A previously unimaginable scale in places where waterpower was not available. Later development led to steam locomotives and great expansion of railway transportation . As for internal combustion piston engines , these were tested in France in 1807 by de Rivaz and independently, by the Niépce brothers . They were theoretically advanced by Carnot in 1824. In 1853–57 Eugenio Barsanti and Felice Matteucci invented and patented an engine using

2260-608: A railroad electric locomotive , rather than an electric motor. Some motors are powered by potential or kinetic energy, for example some funiculars , gravity plane and ropeway conveyors have used the energy from moving water or rocks, and some clocks have a weight that falls under gravity. Other forms of potential energy include compressed gases (such as pneumatic motors ), springs ( clockwork motors ) and elastic bands . Historic military siege engines included large catapults , trebuchets , and (to some extent) battering rams were powered by potential energy. A pneumatic motor

2373-555: A return to smaller V-6 and four-cylinder layouts, with as many as five valves per cylinder to improve efficiency. The Bugatti Veyron 16.4 operates with a W16 engine , meaning that two V8 cylinder layouts are positioned next to each other to create the W ;shape sharing the same crankshaft. The largest internal combustion engine ever built is the Wärtsilä-Sulzer RTA96-C , a 14-cylinder, 2-stroke turbocharged diesel engine that

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2486-724: A small gasoline engine coupled with an electric motor and with a large battery bank, these are starting to become a popular option because of their environment awareness. Exhaust gas from a spark ignition engine consists of the following: nitrogen 70 to 75% (by volume), water vapor 10 to 12%, carbon dioxide 10 to 13.5%, hydrogen 0.5 to 2%, oxygen 0.2 to 2%, carbon monoxide : 0.1 to 6%, unburnt hydrocarbons and partial oxidation products (e.g. aldehydes ) 0.5 to 1%, nitrogen monoxide 0.01 to 0.4%, nitrous oxide <100 ppm, sulfur dioxide 15 to 60 ppm, traces of other compounds such as fuel additives and lubricants, also halogen and metallic compounds, and other particles. Carbon monoxide

2599-453: A source of water power to provide additional power to watermills and water-raising machines. In the medieval Islamic world , such advances made it possible to mechanize many industrial tasks previously carried out by manual labour . In 1206, al-Jazari employed a crank - conrod system for two of his water-raising machines. A rudimentary steam turbine device was described by Taqi al-Din in 1551 and by Giovanni Branca in 1629. In

2712-429: A strict definition (in practice, one type of rocket engine). If hydrogen is burnt in combination with air (all airbreathing engines), a side reaction occurs between atmospheric oxygen and atmospheric nitrogen resulting in small emissions of NO x . If a hydrocarbon (such as alcohol or gasoline) is burnt as fuel, CO 2 , a greenhouse gas , is emitted. Hydrogen and oxygen from air can be reacted into water by

2825-407: A system that normally would require bigger compressors, increases the capacity of a system that without economizer would produce less refrigeration, or allows the system to produce the same amount of refrigeration using less power. The economizer concept is linked to subcooling as the condensed liquid line temperature is usually higher than that on the evaporator , making it a good place to apply

2938-431: A torque include the familiar automobile gasoline and diesel engines, as well as turboshafts . Examples of engines which produce thrust include turbofans and rockets . When the internal combustion engine was invented, the term motor was initially used to distinguish it from the steam engine—which was in wide use at the time, powering locomotives and other vehicles such as steam rollers . The term motor derives from

3051-510: A ventilator, allow all or part of the combustion products to pass through the economizer, depending on the demand for make-up water and/or process water. The temperature of the gases can be lowered from the boiling temperature of the fluid to little more than the incoming feed water temperature while preheating that feed water to the boiling temperature. High pressure boilers typically have larger economizer surfaces than low pressure boilers. Economizer tubes often have projections like fins to increase

3164-550: A water-powered mill was built in Kaberia of the kingdom of Mithridates during the 1st century BC. Use of water wheels in mills spread throughout the Roman Empire over the next few centuries. Some were quite complex, with aqueducts , dams , and sluices to maintain and channel the water, along with systems of gears , or toothed-wheels made of wood and metal to regulate the speed of rotation. More sophisticated small devices, such as

3277-659: Is a machine designed to convert one or more forms of energy into mechanical energy . Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power generation ), heat energy (e.g. geothermal ), chemical energy , electric potential and nuclear energy (from nuclear fission or nuclear fusion ). Many of these processes generate heat as an intermediate energy form; thus heat engines have special importance. Some natural processes, such as atmospheric convection cells convert environmental heat into motion (e.g. in

3390-418: Is a "walk-in cooler economizer" or "outside air refrigeration system". In such a system outside air that is cooler than the air inside a refrigerated space is brought into that space and the same amount of warmer inside air is ducted outside. The resulting cooling supplements or replaces the operation of a compressor-based refrigeration system. If the air inside a cooled space is only about 5 °F warmer than

3503-416: Is a machine that converts potential energy in the form of compressed air into mechanical work . Pneumatic motors generally convert the compressed air to mechanical work through either linear or rotary motion. Linear motion can come from either a diaphragm or piston actuator, while rotary motion is supplied by either a vane type air motor or piston air motor. Pneumatic motors have found widespread success in

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3616-703: Is buried in Galston Cemetery where a new gravestone was erected in December 2014 by public subscription replacing the original stone which was in a ruined state. It was rededicated on Sunday 3 May 2015. On 11 January 1840, Stirling was awarded the title Doctor of Divinity by the University of St. Andrews for his excellence in ministry. On 3 October 2014 Stirling was inducted into the Scottish Engineering Hall of Fame. Engine An engine or motor

3729-534: Is highly toxic, and can cause carbon monoxide poisoning , so it is important to avoid any build-up of the gas in a confined space. Catalytic converters can reduce toxic emissions, but not eliminate them. Also, resulting greenhouse gas emissions, chiefly carbon dioxide , from the widespread use of engines in the modern industrialized world is contributing to the global greenhouse effect – a primary concern regarding global warming . Some engines convert heat from noncombustive processes into mechanical work, for example

3842-468: Is improved when the highest temperatures near the combustion sources are used for boiling and superheating, while using the residual heat of the cooled combustion gases exhausting from the boiler through an economizer to raise the temperature of feed water entering the steam drum. An indirect contact or direct contact condensing economizer will recover the residual heat from the combustion products. A series of dampers, an efficient control system, as well as

3955-417: Is no need to install two compressors and still benefit from the booster concept. There are two types of economizer setups for these compressors, flash and subcooling . The latter works like a two staged booster with subcooling. The flash economizer is different because it doesn't use a heat exchanger to produce the subcooling. Instead, it has a flash chamber or tank, in which flash gas is produced to lower

4068-710: Is not always practical. Electric motors are ubiquitous, being found in applications as diverse as industrial fans, blowers and pumps, machine tools, household appliances, power tools , and disk drives . They may be powered by direct current (for example a battery powered portable device or motor vehicle), or by alternating current from a central electrical distribution grid. The smallest motors may be found in electric wristwatches. Medium-size motors of highly standardized dimensions and characteristics provide convenient mechanical power for industrial uses. The very largest electric motors are used for propulsion of large ships, and for such purposes as pipeline compressors, with ratings in

4181-452: Is not measured on an absolute temperature scale, only on a relative scale as a temperature difference. Robert Stirling Robert Stirling (25 October 1790 – 6 June 1878) was a Scottish clergyman and engineer . He invented the Stirling engine and was inducted into the Scottish Engineering Hall of Fame in 2014. Robert Stirling was born at Cloag Farm, a location in Scotland near

4294-461: Is not taken in their design and material selection. A building's HVAC (heating, ventilating, and air conditioning) system can make use of an air-side economizer to save energy in buildings by using cool outside air as a means of cooling the indoor space. When the temperature of the outside air is less than the temperature of the recirculated air, conditioning with the outside air is more energy efficient than conditioning with recirculated air. When

4407-459: Is notorious when taking in account that the evaporation temperature for a walk-in freezer at −20 °F (−29 °C) may be around −35 °F (−37 °C). Systems with economizers aim to produce part of the refrigeration work on high pressures, condition in which gas compressors are normally more efficient. Depending on the application, this technology either allows smaller compression capacities to be able to supply enough pressure and flow for

4520-428: Is reached with a coolant temperature of around 110 °C (230 °F). Earlier automobile engine development produced a much larger range of engines than is in common use today. Engines have ranged from 1- to 16-cylinder designs with corresponding differences in overall size, weight, engine displacement , and cylinder bores . Four cylinders and power ratings from 19 to 120 hp (14 to 90 kW) were followed in

4633-539: Is said to be a two staged set-up if two gas compressors work together in serial to produce the compression. A normal booster installation is a two staged system that receives fluid to cool down the discharge of the first compressor, before it is input to the second compressor. The fluid that arrives at the interstage of both compressors comes from the liquid line and is normally controlled by expansion , pressure and solenoid valves. A standard two staged cycle of this kind has an expansion valve that expands and modulates

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4746-688: Is the Claymills Pumping Engines Trust in Staffordshire, England, which is in the process of restoring one set of economisers and the associated steam engine which drove them. Another such example is the British Engineerium in Brighton & Hove, where the economiser associated with the boilers for Number 2 Engine is in use, complete with its associated small stationary engine. A third site is Coldharbour Mill Working Wool Museum , where

4859-438: Is the case of subcooling the liquid line by any other means that draws the heat out of the main system. For example, a heat exchanger that preheats cold water needed for another process or human use, may take heat from the liquid line, effectively subcooling it and increasing the system's capacity. Recently, machines exclusively designed for this purpose have been developed. In Chile, the manufacturer EcoPac Systems developed

4972-534: Is then cooled, compressed and reused (closed cycle), or (less commonly) dumped, and cool fluid pulled in (open cycle air engine). " Combustion " refers to burning fuel with an oxidizer , to supply the heat. Engines of similar (or even identical) configuration and operation may use a supply of heat from other sources such as nuclear, solar, geothermal or exothermic reactions not involving combustion; but are not then strictly classed as external combustion engines, but as external thermal engines. The working fluid can be

5085-411: Is to capture the waste heat from boiler stack gases ( flue gas ) and transfer it to the boiler feedwater. This raises the temperature of the boiler feedwater, lowering the needed energy input, in turn reducing the firing rates needed for the rated boiler output. Economizers lower stack temperatures which may cause condensation of acidic combustion gases and serious equipment corrosion damage if care

5198-402: Is used to chill a chamber that normally has a series of pipes for the liquid running through it. The superheated gas then proceeds on to the compressor. The subcooling term refers to cooling the liquid below its boiling point. 10 °F (5.6 °C) of subcooling means it is 10 °F colder than boiling at a given pressure. As it represents a difference of temperatures, the subcooling value

5311-693: The Antikythera Mechanism used complex trains of gears and dials to act as calendars or predict astronomical events. In a poem by Ausonius in the 4th century AD, he mentions a stone-cutting saw powered by water. Hero of Alexandria is credited with many such wind and steam powered machines in the 1st century AD, including the Aeolipile and the vending machine , often these machines were associated with worship, such as animated altars and automated temple doors. Medieval Muslim engineers employed gears in mills and water-raising machines, and used dams as

5424-649: The Volkswagen Beetle , the Citroën 2CV , some Porsche and Subaru cars, many BMW and Honda motorcycles . Opposed four- and six-cylinder engines continue to be used as a power source in small, propeller-driven aircraft . The continued use of internal combustion engines in automobiles is partly due to the improvement of engine control systems, such as on-board computers providing engine management processes, and electronically controlled fuel injection. Forced air induction by turbocharging and supercharging have increased

5537-407: The club and oar (examples of the lever ), are prehistoric . More complex engines using human power , animal power , water power , wind power and even steam power date back to antiquity. Human power was focused by the use of simple engines, such as the capstan , windlass or treadmill , and with ropes , pulleys , and block and tackle arrangements; this power was transmitted usually with

5650-733: The combustion of a fuel causes rapid pressurisation of the gaseous combustion products in the combustion chamber, causing them to expand and drive a piston , which turns a crankshaft . Unlike internal combustion engines, a reaction engine (such as a jet engine ) produces thrust by expelling reaction mass , in accordance with Newton's third law of motion . Apart from heat engines, electric motors convert electrical energy into mechanical motion, pneumatic motors use compressed air , and clockwork motors in wind-up toys use elastic energy . In biological systems, molecular motors , like myosins in muscles , use chemical energy to create forces and ultimately motion (a chemical engine, but not

5763-405: The gas compressor needs is strongly correlated to both the ratio and the difference, between the discharge and the suction pressures (as well as to other features like the refrigerant's heat capacity and the type of compressor). Low temperature systems such as freezers move less fluid in same volumes. That means the compressor's pumping is less efficient on low temperature systems. This phenomenon

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5876-399: The oxygen in atmospheric air to oxidise ('burn') the fuel, rather than carrying an oxidiser , as in a rocket . Theoretically, this should result in a better specific impulse than for rocket engines. A continuous stream of air flows through the air-breathing engine. This air is compressed, mixed with fuel, ignited and expelled as the exhaust gas . In reaction engines , the majority of

5989-429: The pistons or turbine blades or a nozzle , and by moving it over a distance, generates mechanical work . An external combustion engine (EC engine) is a heat engine where an internal working fluid is heated by combustion of an external source, through the engine wall or a heat exchanger . The fluid then, by expanding and acting on the mechanism of the engine produces motion and usable work . The fluid

6102-467: The 13th century, the solid rocket motor was invented in China. Driven by gunpowder, this simplest form of internal combustion engine was unable to deliver sustained power, but was useful for propelling weaponry at high speeds towards enemies in battle and for fireworks . After invention, this innovation spread throughout Europe. The Watt steam engine was the first type of steam engine to make use of steam at

6215-499: The Green's economiser is in working order, complete with the drive shafts from the Pollit and Wigzell steam engine. Modern-day boilers , such as those in coal -fired power stations , are still fitted with economizers which are descendants of Green's original design. In this context they are often referred to as feedwater heaters and heat the condensate from turbines before it is pumped to

6328-547: The Institution of Civil Engineers in 1845. The first engine of this kind which, after various modifications, was efficiently constructed and heated, had a cylinder of 12 inches (approx. 30 cm) in diameter, with a length of stroke of 2 feet (approx. 61 cm), and made 40 strokes or revolutions in a minute (40 rpm). This engine moved all the machinery at the Dundee Foundry Company's works for eight or ten months, and

6441-517: The Latin verb moto which means 'to set in motion', or 'maintain motion'. Thus a motor is a device that imparts motion. Motor and engine are interchangeable in standard English. In some engineering jargons, the two words have different meanings, in which engine is a device that burns or otherwise consumes fuel, changing its chemical composition, and a motor is a device driven by electricity , air , or hydraulic pressure, which does not change

6554-462: The amount of refrigerant incoming at the interstage. As the fluid arriving at the interstage expands, it will tend to evaporate , producing a temperature drop and cooling the second compressor's suction when mixed with the fluid discharged by the first compressor. This kind of set-up may have a heat exchanger between the expansion and the interstage, which may be a second evaporator to produce an additional refrigeration effect, though not as cool as

6667-399: The appropriate controls, economizers can be used in climates which experience various weather systems. When the outside air's dry- and wet-bulb temperatures are low enough, a water-side economizer can use water cooled by a wet cooling tower or a dry cooler (also called a fluid cooler) to cool buildings without operating a chiller . They are historically known as the strainer cycle , but

6780-536: The atmosphere is instead used to heat the water and/or air that will go into the boiler, thus saving fuel. The most successful feature of Green's design of economizer was its mechanical scraping apparatus, which was needed to keep the tubes free of deposits of soot . Economizers were eventually fitted to virtually all stationary steam engines in the decades following Green's invention. Some preserved stationary steam engine sites still have their Green's economisers although usually they are not used. One such preserved site

6893-483: The atmosphere, and so obtained an engine of greater power in the same compass. James Stirling followed this same idea when he built the famous Dundee engine. The Stirling patent of 1827 has been the base of the Stirling third patent of 1840. The changes against the 1827 patent were minor but essential. It was this third patent that gave the birth to the Dundee engine. James Stirling gave a presentation of his engine before

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7006-410: The boiler's efficiency. They are a device fitted to a boiler which saves energy by using the exhaust gases from the boiler to preheat the cold water used to fill it (the feed water ). Steam boilers use large amounts of energy raising feed water to the boiling temperature, converting the water to steam and sometimes superheating that steam above saturation temperature . Heat transfer efficiency

7119-430: The boilers. Economizers are commonly used as part of a heat recovery steam generator (HRSG) in a combined cycle power plant. In an HRSG, water passes through an economizer, then a boiler and then a superheater . The economizer also prevents flooding of the boiler with liquid water that is too cold to be boiled given the flow rates and design of the boiler. A common application of economizers in steam power plants

7232-418: The burners need a flow of excess air in order to operate. Combustion produces water steam, and the quantity depends on the amount of natural gas burned. Also, the evaluation of the dew point depends on the excess air. Natural gas has different combustion efficiency curves linked to the temperature of the gases and the excess air. For example, if the gases are chilled to 38 °C and there is 15% excess air, then

7345-436: The chemical composition of its energy source. However, rocketry uses the term rocket motor , even though they consume fuel. A heat engine may also serve as a prime mover —a component that transforms the flow or changes in pressure of a fluid into mechanical energy . An automobile powered by an internal combustion engine may make use of various motors and pumps, but ultimately all such devices derive their power from

7458-776: The classics, philosophy, theology and mathematics, but probably very little science. In 1814, he returned to Edinburgh University studying divinity for a final time. Robert was licensed to preach in the Church of Scotland in 1816 by the Presbytery of Dumbarton . In September 1816, the commissioner of the Duke of Portland granted Stirling the title of Minister as the second charge for the Laigh Kirk parish in Kilmarnock. Finally, in February 1824, Stirling

7571-447: The combustion energy (heat) exits the engine as exhaust gas, which provides thrust directly. Typical air-breathing engines include: The operation of engines typically has a negative impact upon air quality and ambient sound levels . There has been a growing emphasis on the pollution producing features of automotive power systems. This has created new interest in alternate power sources and internal-combustion engine refinements. Though

7684-485: The cost of a refrigeration system. A two staged system also needs synchronization, pressure control and lubrication. To reduce these costs, specialized equipment has been developed. Economizer screw compressors are built by several manufacturers like Refcomp, Mycom, Bitzer and York. These machines merge both compressors of a two staged system into one screw compressor with two inputs: the main suction and an interstage side entrance for higher pressure gas. This means there

7797-552: The economizer concept is applied when a particular design or feature on the refrigeration cycle , allows a reduction either in the amount of energy used from the power grid, in the size of the components (basically the gas compressor's nominal capacity) used to produce refrigeration, or both. For example, for a walk-in freezer that is kept at −20 °F (−29 °C), the main refrigeration components would include: an evaporator coil (a dense arrangement of pipes containing refrigerant and thin metal fins used to remove heat from inside

7910-489: The efficiency of a motor is raised by even a few percentage points, the savings, in kilowatt hours (and therefore in cost), are enormous. The electrical energy efficiency of a typical industrial induction motor can be improved by: 1) reducing the electrical losses in the stator windings (e.g., by increasing the cross-sectional area of the conductor , improving the winding technique, and using materials with higher electrical conductivities , such as copper ), 2) reducing

8023-420: The efficiency will be 94%. The condensing economizer can thus recover the sensible and latent heat in the steam condensate contained in the flue gases for the process. The economizer is made of an aluminium and stainless steel alloy. The gases pass through the cylinder, and the water passes through the finned tubes. It condenses about 11% of the water contained in the gases. The first successful economizer design

8136-496: The electrical losses in the rotor coil or casting (e.g., by using materials with higher electrical conductivities, such as copper), 3) reducing magnetic losses by using better quality magnetic steel , 4) improving the aerodynamics of motors to reduce mechanical windage losses, 5) improving bearings to reduce friction losses , and 6) minimizing manufacturing tolerances . For further discussion on this subject, see Premium efficiency ). By convention, electric engine refers to

8249-527: The engine was abandoned for a time. Stirling patented a second hot air engine, together with his brother James , in 1827. They inverted the design so that the hot ends of the displacers were underneath the machinery and they added a compressed air pump so the air within could be increased in pressure to around 20 atmospheres. The two Stirling brothers were followed shortly after in 1828 by Parkinson & Crossley and in 1829 and Arnott. These precursors, to whom John Ericsson should be added, have brought to

8362-404: The engine. Another way of looking at it is that a motor receives power from an external source, and then converts it into mechanical energy, while an engine creates power from pressure (derived directly from the explosive force of combustion or other chemical reaction, or secondarily from the action of some such force on other substances such as air, water, or steam). Simple machines , such as

8475-415: The fire tubes of a boiler; there the hot gases usually pass through tubes immersed in water, whereas in an economizer the water passes through tubes surrounded by hot gases. While both are heat exchange devices, in a boiler the burning gases heat the water to produce steam to drive an engine , whether piston or turbine, whereas in an economizer , some of the heat energy that would otherwise all be lost to

8588-636: The first half of the 20th century, a trend of increasing engine power occurred, particularly in the U.S. models. Design changes incorporated all known methods of increasing engine capacity, including increasing the pressure in the cylinders to improve efficiency, increasing the size of the engine, and increasing the rate at which the engine produces work. The higher forces and pressures created by these changes created engine vibration and size problems that led to stiffer, more compact engines with V and opposed cylinder layouts replacing longer straight-line arrangements. Optimal combustion efficiency in passenger vehicles

8701-408: The fluid, and maximizes the volume in which the refrigerant changes its phase (phenomena involving much more heat flow, the base principle of vapor-compression refrigeration). An internal heat exchanger is simply a heat exchanger that uses the cold gas leaving the evaporator coil to cool the high-pressure liquid that is headed into the beginning of the evaporator coil via an expansion device. The gas

8814-674: The forces multiplied and the speed reduced . These were used in cranes and aboard ships in Ancient Greece , as well as in mines , water pumps and siege engines in Ancient Rome . The writers of those times, including Vitruvius , Frontinus and Pliny the Elder , treat these engines as commonplace, so their invention may be more ancient. By the 1st century AD, cattle and horses were used in mills , driving machines similar to those powered by humans in earlier times. According to Strabo ,

8927-403: The form of rising air currents). Mechanical energy is of particular importance in transportation , but also plays a role in many industrial processes such as cutting, grinding, crushing, and mixing. Mechanical heat engines convert heat into work via various thermodynamic processes. The internal combustion engine is perhaps the most common example of a mechanical heat engine in which heat from

9040-524: The free-piston principle that was possibly the first 4-cycle engine. The invention of an internal combustion engine which was later commercially successful was made during 1860 by Etienne Lenoir . In 1877, the Otto cycle was capable of giving a far higher power-to-weight ratio than steam engines and worked much better for many transportation applications such as cars and aircraft. The first commercially successful automobile, created by Karl Benz , added to

9153-408: The freezer), fans to blow air over the coil and around the box, an air-cooled condensing unit sited outdoors, and valves and piping. The condensing unit would include a compressor and a coil and fans to exchange heat with the ambient air. An economizer display takes advantage of the fact that refrigeration systems have increasing efficiencies at increasing pressures and temperatures. The power

9266-400: The gas leaving the evaporator and heading to the gas compressor . These systems withdraw heat from the liquid line and heat up the gas compressor's suction line. This is a very common solution to insure that gas reaches the compressor and liquid reaches the valve . It also allows maximum heat exchanger use as minimizes the portion of the heat exchangers used to change the temperature of

9379-463: The heat engine after altering the design in a new attempt to increase durability. The improvements added by Stirling included the addition of rods or plates in the passage through which hot air travelled to the cold section of the engine. By having these surfaces, the air was able to be cooled to a lower temperature when travelling from the hot section of the engine to the cold section of the engine. Additionally, Stirling added cupped leather collars around

9492-411: The heat of a combustion process. The internal combustion engine is an engine in which the combustion of a fuel (generally, fossil fuel ) occurs with an oxidizer (usually air) in a combustion chamber . In an internal combustion engine the expansion of the high temperature and high pressure gases, which are produced by the combustion, directly applies force to components of the engine, such as

9605-448: The heat transfer surface on the combustion gas side. On average over the years, boiler combustion efficiency has risen from 80% to more than 95%. The efficiency of heat produced is directly linked to boiler efficiency . The percentage of excess air and the temperature of the combustion products are two key variables in evaluating this efficiency. The combustion of natural gas needs a certain quantity of air in order to be complete, so

9718-479: The heated air. In 1824 Stirling sought to improve the efficiency of the heat engine by attempting to separate the air present in the economizer. This was done by making the plungers in the air engine from thin plates of metal. This was to improve airflow and offer better heating and cooling of the engine. Although this idea received a patent, it was ultimately unsuccessful in improving the heat engine's overall efficiency. In 1840 Stirling received another patent for

9831-452: The high temperatures at which the engine was running. After replacing the air vessel a couple times, the air engine was dismantled in 1847 after Stirling left the Dundee iron foundry. In 1876 Robert Stirling wrote a letter acknowledging the importance of Henry Bessemer 's new invention, the Bessemer process for the manufacture of steel. Stirling was optimistic that the new steel would improve

9944-518: The interest in light and powerful engines. The lightweight gasoline internal combustion engine, operating on a four-stroke Otto cycle, has been the most successful for light automobiles, while the thermally more-efficient Diesel engine is used for trucks and buses. However, in recent years, turbocharged Diesel engines have become increasingly popular in automobiles, especially outside of the United States, even for quite small cars. In 1896, Karl Benz

10057-420: The main evaporator (for example to produce air conditioning or for keeping fresh products). A two staged system is said to be set-up as a booster with subcooling , if the refrigerant arriving at the interstage passes through a subcooling heat exchanger that subcools the main liquid line arriving at the main evaporator of the same system. The need to use two compressors in a booster set-up tends to increase

10170-622: The notion of increasing efficiencies. Recalling the walk-in freezer example, the normal temperature of the liquid line in that system is around 60 °F (16 °C) or even higher (it varies depending on the condensing temperature). That condition is by far less hostile to produce refrigeration, than the evaporator at −35 °F (−37 °C). Several configurations of the refrigeration cycle incorporate an economizer, and benefit from this idea. The design of these systems requires expertise and extra components. Pressure drop, electronic valve control, and oil drag, must all be considered. A system

10283-462: The operation being one of simple mixture only, no heating surface of metal is required, the air to be heated being brought into immediate contact with the fire. Stirling came up with a first patent for an air engine in 1816. The principle of the Stirling Air Engine differs from Cayley's, in which the air is forced through the furnace and exhausted, whereas in Stirling's engine the air works in

10396-478: The outside air is both sufficiently cool and sufficiently dry (depending on the climate) the amount of enthalpy in the air is acceptable and no additional conditioning of it is needed; this portion of the air-side economizer control scheme is called free cooling . Air-side economizers can reduce HVAC energy costs in cold and temperate climates while also potentially improving indoor air quality , but are most often not appropriate in hot and humid climates . With

10509-493: The outside air that replaces it (that is, the ∆T>5 °F) this cooling effect is accomplished more efficiently than the same amount of cooling resulting from a compressor based system. If the outside air is not cold enough to overcome the refrigeration load of the space the compressor system will need to also operate, or the temperature inside the space will rise. Another use of the term occurs in industrial refrigeration, specifically vapor-compression refrigeration . Normally,

10622-669: The performance of the air engines. Robert Stirling's development of the hot air engine was in part motivated by safety. His engine was designed to fail far less catastrophically than the steam engines of the time while obtaining greater efficiency. Though the Stirling engine is rarely used today, its seemingly perpetual motion capability continues to draw the interest of research institutions like Los Alamos National Laboratory and NASA . On 10 July 1819, Stirling married Jane Rankine at Kilmarnock. They had seven children: Rev. Robert Stirling died in Galston, East Ayrshire on 6 June 1878. He

10735-447: The piston rods to seal gaps and minimize the leakage of air from the engine. After developing these improvements, Stirling built two of these heat engines to use at an iron foundry he managed in Dundee. One of these air engines was started in March 1843 where it ran until December 1845 when an air vessel failed. The air vessel failure could be attributed to the metals being unable to withstand

10848-645: The power output of smaller displacement engines that are lighter in weight and more fuel-efficient at normal cruise power.. Similar changes have been applied to smaller Diesel engines, giving them almost the same performance characteristics as gasoline engines. This is especially evident with the popularity of smaller diesel engine-propelled cars in Europe. Diesel engines produce lower hydrocarbon and CO 2 emissions, but greater particulate and NO x pollution, than gasoline engines. Diesel engines are also 40% more fuel efficient than comparable gasoline engines. In

10961-420: The temperature of the liquid before the expansion. The flash gas that is produced in this tank leaves the liquid line and goes to the economizer entrance of the screw compressor. The above systems produce an economizer effect by using compressors, meters, valves and heat exchangers within the refrigeration cycle. In some refrigeration systems the economizer can be an independent refrigeration mechanism. Such

11074-442: The thousands of kilowatts . Electric motors may be classified by the source of electric power, by their internal construction, and by their application. The physical principle of production of mechanical force by the interactions of an electric current and a magnetic field was known as early as 1821. Electric motors of increasing efficiency were constructed throughout the 19th century, but commercial exploitation of electric motors on

11187-526: The village of Methven , Perthshire . A member of the Dublane side of the Stirling family, Robert was born to Patrick and Agnes Stirling. He was one of eight children that Patrick and Agnes shared. His grandfather was Michael Stirling, most famously known for his invention of the threshing machine . Robert's father, Patrick, also spent time experimenting and innovating with industrial agricultural equipment. Though Robert, like his father and grandfather, had

11300-479: The water-side economizer is not a true thermodynamic cycle. Also, instead of passing the cooling tower water through a strainer and then to the cooling coils, which causes fouling , more often a plate-and-frame heat exchanger is inserted between the cooling tower and chilled water loops. Good controls, and valves or dampers, as well as maintenance, are needed to ensure proper operation of the air- and water-side economizers. A common form of refrigeration economizer

11413-439: The work of the foundry in the most satisfactory manner, but has been tested (by a friction brake on a third mover) to the extent of lifting nearly 1,500,000 lbs (approx. 45 HP). This gives a consumption of 2.7 lbs. (approx. 1.22 kg) per horse-power per hour; but when the engine was not fully burdened, the consumption was considerably under 2.5 lbs. (approx. 1.13 kg) per horse-power per hour. This performance

11526-504: The world the hot air engine technology and its enormous advantages over the steam engine. Each of them came with his own specific technology, and although the Stirling engine and the Parkinson & Crossley engines were quite similar, Robert Stirling distinguished himself by inventing the regenerator, the first example of a Regenerative heat exchanger . Parkinson and Crosley introduced the principle of using air of greater density than that of

11639-444: Was appointed as the minister of nearby Galston Parish Church where he continued his ministry until 1878. In July 1819, Robert Stirling married Jane Rankine. Together, they had seven children, five sons and two daughters. Robert Stirling is considered as one of the fathers of hot air engines. Few before him ventured to build air engines, Guillaume Amontons being the first one to build a working hot air engine in 1699. Amontons

11752-458: Was at that time no demand. The Stirling 1816 patent was also about an " Economiser ", the predecessor of the regenerator. In this patent (# 4081) he describes the "economiser" technology and several applications where such technology can be used. Out of them came a new arrangement for a hot air engine. In 1818, one engine was built to pump water from a quarry in Ayrshire, but due to technical issues,

11865-444: Was at the level of the best steam engines whose efficiency was about 10%. After James Stirling, such efficiency was possible only thanks to the use of the economiser (or regenerator). Robert Stirling's best known invention is the heat engine now referred to as the Stirling engine . In 1816 the Stirling brothers applied for a patent in both Scotland and England for a device they invented, a Heat Economiser. The function of this invention

11978-517: Was designed to power the Emma Mærsk , the largest container ship in the world when launched in 2006. This engine has a mass of 2,300 tonnes, and when running at 102 rpm (1.7 Hz) produces over 80 MW, and can use up to 250 tonnes of fuel per day. An engine can be put into a category according to two criteria: the form of energy it accepts in order to create motion, and the type of motion it outputs. Combustion engines are heat engines driven by

12091-403: Was followed in 1807 by George Cayley whose engine was of those in which the fire is enclosed, and fed by air pumped in beneath the grate in sufficient quantity to maintain combustion, while by far the largest portion of the air enters above the fire, to be heated and expanded; the whole, together with the products of combustion, then acts on the piston, and passes through the working cylinder; and

12204-436: Was granted a patent for his design of the first engine with horizontally opposed pistons. His design created an engine in which the corresponding pistons move in horizontal cylinders and reach top dead center simultaneously, thus automatically balancing each other with respect to their individual momentum. Engines of this design are often referred to as “flat” or “boxer” engines due to their shape and low profile. They were used in

12317-463: Was merely a water pump, with the engine being transported to the fire by horses. In modern usage, the term engine typically describes devices, like steam engines and internal combustion engines, that burn or otherwise consume fuel to perform mechanical work by exerting a torque or linear force (usually in the form of thrust ). Devices converting heat energy into motion are commonly referred to simply as engines . Examples of engines which exert

12430-464: Was often treated as a military secret. The word gin , as in cotton gin , is short for engine . Most mechanical devices invented during the Industrial Revolution were described as engines—the steam engine being a notable example. However, the original steam engines, such as those by Thomas Savery , were not mechanical engines but pumps. In this manner, a fire engine in its original form

12543-435: Was previously found capable of raising 700,000 lbs one foot in a minute (approx. 21 HP). Finding this power insufficient for their works, the Dundee Foundry Company erected the second engine, with a cylinder of 16 inches (approx. 40 cm) in diameter, a stroke of 4 feet (approx. 1.20 m), and making 28 strokes in a minute. This engine has now been in continual operation for upwards of two years, and has not only performed

12656-402: Was to store and release heat as air circulated through its mechanisms. This differed from most heat engines which used steam as their method of storing and releasing energy. While in Kilmarnock, he collaborated with another inventor, Thomas Morton, who provided workshop facilities for Stirling's research. By 1818 Stirling had incorporated this Heat Economiser into a piston engine that created

12769-417: Was used to increase the steam-raising efficiency of the boilers of stationary steam engines . It was patented by Edward Green in 1845, and since then has been known as Green's economiser . It consisted of an array of vertical cast iron tubes connected to a tank of water above and below, between which the boiler's exhaust gases passed. This is the reverse arrangement to that usually but not always seen in

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