Internal combustion engine-Seminarski rad-Engleski jezik 2-Saobracajni fakultet
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Internal combustion engine-Seminarski rad-Engleski jezik 2-Saobracajni fakultet

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Seminarski rad, saobracajni fakultet, engleski jezik 2, FACULTY OF TRANSPORT AND ENGINEERING, SEMINAR PAPER, Internal combustion engine, Internal combustion mechanics, Motor s unutarnjnjim izgaranjem,kompresija, Mehanika...
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Internal combustion engine

FACULTY OF TRANSPORT AND ENGINEERING

SEMINAR PAPER

Internal combustion engine

Zvonimir Bužanić mentor: 1192 010 413 / FPZ viši predavač Cestovni smjer, VII. stupanj Katja Bošković - Gazdović

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1. Internal combustion engine

A colorized automobile engine

The internal combustion engine is a heat engine in which the burning of a fuel occurs in a confined space called a combustion chamber. This exothermic reaction of a fuel with an oxidizer creates gases of high temperature and pressure, which are permitted to expand. The defining feature of an internal combustion engine is that useful work is performed by the expanding hot gases acting directly to cause movement, for example by acting on pistons, rotors, or even by pressing on and moving the entire engine itself. This contrasts with external combustion engines such as steam engines which use the combustion process to heat a separate working fluid, typically water or steam, which then in turn does work, for example by pressing on a steam actuated piston. The term Internal Combustion Engine (ICE) is most often used to refer specifically to reciprocating engines, Wankel engines and similar designs in which combustion is intermittent. However, continuous combustion engines, such as Jet engines, most rockets and many gas turbines are also very much internal combustion engines.

Four-stroke cycle (or Otto cycle)

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2. History Non-compression

Leonardo da Vinci, in 1509, and Christiaan Huygens, in 1673, described constant pressure engines. (Leonardo's description may not imply that the idea was original with him or that it was actually constructed.)

Early internal-combustion engines were used to power farm equipment. English inventor Sir Samuel Morland used gunpowder to drive water pumps in the 17th century. In 1794, Robert Street built a compression-less engine whose principle of operation would dominate for nearly a century.

The first internal combustion engine to be applied industrially was patented by Samuel Brown in 1823. It was based on what Hardenberg calls the "Leonardo cycle," which, as this name implies, was already out of date at that time. Just as today, early major funding, in an area where standards had not yet been established, went to the best showmen sooner than to the best workers. The Italians Eugenio Barsanti and Felice Matteucci patented the first working, efficient internal combustion engine in 1854 in London (pt. Num. 1072) but did not get into production with it. It was similar in concept to the successful Otto Langen indirect engine, but not so well worked out in detail. In 1860, Jean Joseph Etienne Lenoir (1822 - 1900) produced a gas-fired internal combustion engine not dissimilar in appearance to a steam beam engine. This closely resembled a horizontal double acting steam engine, with cylinders, pistons, connecting-rods and fly wheel in which the gas essentially took the place of the steam. This was the first internal combustion engine to be produced in numbers. The American Samuel Morey received a patent on April 1, 1826 for a "Gas Or Vapor Engine". His first (1862) engine with compression having shocked itself apart, Nikolaus Otto designed an indirect acting free piston compression-less engine whose greater efficiency won the support of Langen and then most of the market, which at that time, was mostly for small stationary engines fueled by lighting gas. In 1870 in Vienna Siegfried Marcus put the first mobile gasoline engine on a handcart.

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Compression

The most significant distinction between modern internal combustion engines and the early designs is the use of compression and in particular of in-cylinder compression. The thermodynamic theory of idealized heat engines was established by Sadi Carnot in France in 1824. This scientifically established the need for compression to increase the difference between the upper and lower working temperatures, but it is not clear that engine designers were aware of this before compression was already commonly used. In fact it may have misled designers who attempted to emulate the Carnot cycle in ways that were not useful. The first recorded suggestion of in-cylinder compression was a patent granted to William Barnet (English) in 1838. He apparently did not realize its advantages, but his cycle would have been a great advance if sufficiently developed. Nikolaus Otto working with Gottlieb Daimler and Wilhelm Maybach in the 1870s developed a practical four-stroke cycle (Otto cycle) engine. The German courts, however, did not hold his patent to cover all in-cylinder compression engines or even the four stroke cycle, and after this decision in-cylinder compression became universal.

Karl Benz

Karl Benz, working independently, was granted a patent In 1879 for his internal combustion engine, a reliable two-stroke gas engine, based on Nikolaus Otto's design of the four-stroke engine. Later Benz designed and built his own four- stroke engine that was used in his automobiles, which became the first automobiles in production. In 1896, Karl Benz invented the boxer engine, also known as, the horizontally opposed engine, in which the corresponding pistons reach top dead centre simultaneously, thus balancing each other with respect to momentum.

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Applications

Internal combustion engines are most commonly used for mobile propulsion systems. In mobile scenarios internal combustion is advantageous, since it can provide high power to weight ratios together with excellent fuel energy-density. These engines have appeared in almost all automobiles, motorbikes, many boats, and in a wide variety of aircraft and locomotives. Where very high power is required, such as jet aircraft, helicopters and large ships, they appear mostly in the form of gas turbines. They are also used for electric generators and by industry. For low power mobile and many non-mobile applications an electric motor is a competitive alternative. In the future, electric motors may also become competitive for most mobile applications. However, the high cost, weight, and poor energy density of lead-acid batteries and even NiMH batteries and lack of affordable on board electric generators such as fuel cells has largely restricted their use to specialist applications. However recent battery advancements in lightweight Li-ion and Li-poly chemistries are bringing safety, power density, lifespan, and cost to within acceptable or even desirable levels. For example recently battery electric vehicles began to demonstrated 300 miles of range on Lithium, now improved power makes them appealing for plug-in hybrid electric vehicles whose electric range is less critical having internal combustion for unlimited range.

3. Internal combustion mechanics The potato cannon uses the basic principle behind any reciprocating internal combustion engine: If you put a tiny amount of high-energy fuel (like gasoline) in a small, enclosed space and ignite it, an incredible amount of energy is released in the form of expanding gas. You can use that energy to propel a potato 500 feet. In this case, the energy is translated into potato motion. You can also use it for more interesting purposes. For example, if you can create a cycle that allows you to set off explosions like this hundreds of times per minute, and if you can harness that energy in a useful way, what you have is the core of a car engine! Almost all cars currently use what is called a four-stroke combustion cycle to convert gasoline into motion. The four-stroke approach is also known as the Otto cycle, in honor of Nikolaus Otto, who invented it in 1867. The four strokes are: Intake stroke, Compression stroke, Combustion stroke, Exhaust stroke.

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4. Operation All internal combustion engines depend on the exothermic chemical process of combustion: the reaction of a fuel, typically with air, although other oxidisers such as nitrous oxide may be employed. The most common fuels in use today are made up of hydrocarbons and are derived from petroleum. These include the fuels known as diesel, gasoline and liquified petroleum gas. Most internal combustion engines designed for gasoline can run on natural gas or liquified petroleum gases without modifications except for the fuel delivery components. Liquid and gaseous biofuels, such as Ethanol can also be used. Some can run on Hydrogen, however this can be dangerous. Hydrogen burns with a colorless flame, and modifications to the cylinder block, cylinder head, and head gasket are required to seal in the flame front. All internal combustion engines must have a means of ignition to promote combustion. Most engines use either an electrical or a compression heating ignition system. Electrical ignition systems generally rely on a lead-acid battery and an induction coil to provide a high voltage electrical spark to ignite the air- fuel mix in the engine's cylinders. This battery can be recharged during operation using an alternator driven by the engine. Compression heating ignition systems, such as diesel engines and HCCI engines, rely on the heat created in the air by compression in the engine's cylinders to ignite the fuel. Once successfully ignited and burnt, the combustion products, hot gases, have more available energy than the original compressed fuel/air mixture (which had higher chemical energy). The available energy is manifested as high temperature and pressure which can be translated into work by the engine. In a reciprocating engine, the high pressure product gases inside the cylinders drive the engine's pistons. Once the available energy has been removed the remaining hot gases are vented (often by opening a valve or exposing the exhaust outlet) and this allows the piston to return to its previous position (Top Dead Center - TDC). The piston can then proceed to the next phase of its cycle, which varies between engines. Any heat not translated into work is a waste product and is removed from the engine either by an air or liquid cooling system.

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1. Motor s unutarnjnjim izgaranjem

Obojani automobilski motor

Motor s unutarnjnjim izgaranjem je vrući motor u kojem se izgaranje goriva dešava u ograničenom prostoru zvanom komora za izgaranje. Ova egzotermička reakcija goriva sa oksidantom stvara plinove visoke temperature i tlaka, kojima je dozvoljeno da se šire. Definicija vrijednosti motora s unutarnjnjim izgaranjem prikazuje da koristan posao izvršen širenjem vrućih plinova djeluje direktno na pokretanje, na primjer na pokretne klipove, rotore, ili čak na pritiskivanje i micanje samog motora. Suprotnost sa motorima sa vanjskim izgaranjem kao što su parni strojevi koji koriste proces izgaranja da zagriju posebnu tekućinu poput vode ili pare. Koji tada naizmjence vrše rad, na primjer pritiščući paru na pokrenuti klip. Izraz motor s unutarnjnjim sagorijevanjem (MUS) se često koristi kao poveznica sa izmjenjivim motorima, Wankel motorima i sličnim dizajnima u kojim je izgaranje u prekidima. Svejedno, motori sa neprekidnim izgaranjem, poput mlaznih motora, većine raketa i mnogih motornih turbina su zapravo motori s unutarnjnjim izgaranjem.

Četvero-taktni ciklus (tj. Otto ciklus)

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2. Povijest Bez kompresije

Leonardo da Vinci, 1509, i Christiaan Huygens, 1673, opisali su motore sa konstantnim pritiskom. (Leonardov opis možda neće prikazati da je to njegova originalna ideja ili da je zapravo konstruiran.)

Rani motori s unutarnjnjim izgaranjem su se koristili za napajanje opreme na farmama. Engleski izumitelj Sir Samuel Morland koristio je barut za pokretanje vodenih pumpi u 17-tom stoljeću. 1794, Robert Street je konstruirao motor bez kompresije na čijem principu rada je dominirao gotovo stoljeće.

Prvi motor s unutarnjnjim izgaranjem koji je bio proizveden industrijski je patentirao Samuel Brown 1823. Bio je baziran na, kako ga je Hardenberg zvao "Leonardovom periodu," koji, kako mu ime govori, je već bio neupotrebljiv u to vrijeme. Također i danas, rano financiranje, u područjima gdje još nisu utvrđeni standardi, odlazi prije najboljim menađerima nego najboljim radnicima. Talijani Eugenio Barsanti i Felice Matteucci patentirali su prvi efikasni motor s unutarnjnjim izgaranjem koji radi 1854 u Londonu (patent broj 1072) no nisu došli do proizvodnje. Bio je sličan konceptu uspješnome Otto Langen indirektnom motoru, ali nije bio toliko detaljno dorađen. 1860, Jean Joseph Etienne Lenoir (1822 - 1900) napravio je benzinom paljeni motor sa unutrašnjim izgaranjem koji izgledom nije bio različitiji od parnog motora. To odgovara dvostrukom horizontalnom motoru na paru, sa cilindrima, klipovima, spojnim šipkama i zamašnjacima u kojima je benzin zamjenio paru. To je bio prvi motor sa unutrašnjim izgaranjem koji je bio proizveden u većim brojevima. Amerikanac Samuel Morey dobio je patent 01.04.1826. za "Benzinski ili parni motor ". Njegov prvi (1862) motor sa kompresijom se sam raspao, Nikolaus Otto dizajnirao je indirektno djelujući slobodni klip sa manjom kompresijom motora čija je efikasnost dobila podršku Langena i većine tržišta, koji u to vrijeme, je bio uglavnom za male nepokretne motore pokretane benzinom. 1870 u Vienni Siegfried Marcus je napravio prvi mobilni motor pokretan ručno.

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Kompresija

Najveća razlika između modernih motora s unutarnjnjim izgaranjem i prvih motora je korištenje kompresije i posebno kompresije u cilindru. Termodinamičku teoriju idealnih vrućih motora je napravio Sadi Carnot u Francuskoj 1824. Taj znanstveni podatak zahtjevao potrebu da se poveća razlika kompresije između gornje i donje radne temperature, ali nije bilo jasno da li su inžinjeri svjesni toga prije nego je kompresija opće prihvaćena. Zapravo, dizajnere koji su pokušali emulirati Carnotov ciklus to je vodilo u krivom smjeru te na taj način nije bilo dobro iskorišteno. Prvi zabilježeni patent baziran na kompresiji cilindra je William Barnet (Engleska) 1838. On očito nije shvatio prednosti, no njegov ciklus bi bio odličan da je bio dovoljno izgrađen. Nikolaus Otto radeći sa Gottlieb Daimlerom i Wilhelm Maybachom 1870 izgradili su praktični 4-erotaktni (Otto ciklus) motor. Njemački sudovi, ipak, nisu smatrali da patent pokriva sve motore sa kompresijom unutar cilindra niti 4- ero taktni ciklus, te nakon ove odluke kompresija unutar cilindra je postala univerzalna.

Karl Benz

Karl Benz, radeći samostalno, je dobio patent 1879 za njegov motor sa unutrašnjim izgaranjem, pozdanim dvotaktnim benzinskim motorom, baziranim na Nikolaus Ottoovom dizajnu četverotaktnog motora. Kasnije Benz je dizajnirao i sagradio svoj vlastiti četverotaktni motor koji se koristio u automobilima, koji su postali prvi automobili u proizvodnji. 1896, Karl Benz je inventirao 'bokser' motor, također znan kao, horizontalno izgrađeni motor, u kojem su odgovarajući klipovi doticali centar simultano, te balansirali jedan drugog u pravom momentu.

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Primjena

Motori s unutarnjnjim izgaranjem se najčešće korišteni za sisteme za kretanje. U pokretnim scenarijima motori s unutarnjnjim izgaranjem su u prednosti, jer mogu dati veliku snagu u odnosu na masu zajedno sa odličnom zbijenošću energije goriva. Takvi motori se pojavljuju u gotovo svim automobilima, motociklima, brodovima i u raznim varijantama aviona i lokomotiva. Tamo gdje je potrebna velika snaga, kao što su mlažnjaci, helikopteri i veliki brodovi koriste se turbine. Također se koriste i za električne generatore i industriju. Za manje snage i mnoge ne mobilne primjene, električni motor je konkurentna alternativa. U budućnosti, električni motori bi mogli postati konkurentni za većinu mobilnih motora. Svejedno, veliki trošak, težina i slaba snaga baterija, pa čak i NiMH baterija i nedostatak jeftinih električnih generatora kao što su gorive ćelije vrlo ograničavaju njihovu upotrebu samo na specijalne slučajeve. Ipak novija otkrića sa laganom Li-ion i Li-poly kemijom donose sigurnost, veću kolićinu energije, dulji vijek trajanja, te trošak koji je prihvatljiv ili čak i poželjan. Na primjer nedavno su prikazani električni motori koji prelaze 300 milja sa baterijama baziranim na Litiju, koji se sada sa poboljšanom snagom ugrađuju u hibridna električna vozila čije mogućnosti prelaska određene udaljenosti su manje važne zbog dodatnog motra s unutarnjnjim izgaranjem koji pruža neograničenu udaljenost.

3. Mehanika unutarnjeg izgaranja Top za rajčice koristi bazični princip svakog povratno nastupnog motora s unutarnjnjim izgaranjem: Ako stavite malu količinu visoko kvalitetnog goriva (poput benzina) u mali zatvoreni prostor i zapalite ga, velika količina energije je otpuštena u obliku širećeg plina. Tu energiju možete iskoristiti da lansirate rajčicu 150 metara. U tom slučaju, energija je translatirana u kretanje rajčice. Moguće je koristiti energiju u mnogo korisnije namjene. Na primjer, ako možete napraviti ciklus koji dozvoljava da napravite stotinu eksplozija u minuti, i ako možete upregnuti tu energiju u korisnom smislu, tada imate osnovu automobilskog motora! Gotovo svi automobili trenutno koriste četverotaktni ciklus sagorijevanja da pretvore benzin u kretanje. Četverotaktni motor je također poznat i kao Otto ciklus, u čast Nikolaus Ottou, koji ga je izumio 1867. Četri takta su: dovod, kompresija, sagorijevanje, ispuh.

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4. Rad motora Svi motori s unutarnjnjim izgaranjem ovise o egzotermičkom kemijskom procesu sagorijevanja: rakcijom goriva, tipično sa zrakom, iako i drugi oksidi poput nitro oksida mogu biti dodani. Najćešće korištena goriva u upotrebi su nastala iz hidrokarbonata i dobivena iz petroleja. To uključuje goriva poput dizela, benzina i tekućeg petroleja. Većina motora s unutarnjnjim izgaranjem na benzin su dizajnirani tako da se mogu pokretati i na prirodni plin ili na tekući petrolej bez modifikacija osim o dovodu komponenata goriva. Tekuća i plinovita biogoriva, poput Etanola mogu biti korištena. Neki mogu raditi i na Hidrogen, no ipak to može biti opasno. Hidrogen gori bezbojnim plamenom, a modifikacije na bloku cilindra, glavi cilindra i glavi brtvila su potrebne da bi zatvorile plamen. Svi motori s unutarnjnjim izgaranjem moraju imati paljenje da bi došlo do sagorijevanja. Većina motora koristi električni ili kompresijsko toplinski sistem za paljenje. Električni sustavi za paljenje ovise o bateriji punjenoj kiselinom i indukcijskom svitku kako bi proizveli veliku iskru koja pali mješavinu goriva i zraka u cilindrima motora. Ta se baterija može puniti dok ju se koristi sa alternatorom, kojim upravlja motor. Sistem paljenja zagrijavanjem kompresije, poput dizel motora i HCCI motora, oslanja se na toplinu stvorenu u zraku kompresije unutar motora cilindra da zapali gorivo. Jednom uspješno zapaljeni i sagoreni, zapaljivi produkti, vrući plinovi, imaju više energije nego izvorno kompresirana mješavina zraka i goriva (koja je imala veću kemijsku energiju). Dostupna energija je manifestirana kao vruća temperatura i pritisak koji može biti prebačen u rad motora. U izmjeničnom motoru, visoki pritisak proizvodi plinove unutar cilindra koji tjeraju klipove motora. Jednom kad je dostupna energija iskorištena preostali vrući plinovi se izbacuju (često otvaranjem klipa ili izlaganjem prema ispuhu) i to omogućuje klipovima da se vrate u početnu poziciju (sami vrh centra - TDC). Klipovi tada mogu produžiti na slijedeći stupanj svog ciklusa, koji varira između motora. Bilo kakva toplina koja nije prebačena u rad je uzaludan produkt i izbačen je iz motora ili putem zraka ili tekućeg sistema za hlađenje.

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internal combustion engine motor s unutarnjim izgaranjem confined ograničen piston klip resemble nalik na distinction razlika four stroke engine četverotaktni motor propulsion krenuti naprijed, pokretanje acid kiselina conecting rod klipnjača, spojna šipka reciprocating povratno-nastupni reciprocating rod radilica enclosed zatvoren, oklopljen harness upregnuti, oklop core jezgra, srž cylinder block cilindrični blok cylinder head glava motora gasket brtvilo coil opruga ignition paljenje cycle ciklus liquid cooling system vodeno hlađenje

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