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Anglicky v odbornch pedmtech"Support of teaching technical subjects in EnglishTutorial: Physics

Topic: Turbosupercharger

Prepared by : RNDr. Ondej Jebek

Projekt Anglicky v odbornch pedmtech, CZ.1.07/1.3.09/04.0002je spolufinancovn Evropskm socilnm fondem a sttnm rozpotem esk republiky.

Turbosupercharger

General information:Type of pump used to gas pumpingDeveloped for air craft engines lack of air in high altitudeUsed mainly at combustion engines increasing efficiencyAdvantages and disadvantages:Main advantage is increased efficiency at minimal weight increaseMain disadvantage is increase of compression ratio and susceptibility to self-ignition

Turbosupercharger

Turbosupercharger is driven by exhaust gasesSupercharger blasts and pushes air inside cylinderExhaust and supercharger turbines are fit on the same shaftTurbosuperchargers efficiency is about 80%Turbosupercharger of engine 1.2 TSI works in range of 1500 revolutions/min. - 3500 rev./min.For increasing of revolutions range, there is variable blades geometry of turbosuperchargers one by oneTurbosupercharger principle

Turbosupercharger coolingTurbosupercharger is cooled by engine oilFor sufficient turbosupercharger cooling , it is important to provide continuous circuit of engine oilIt is important to let turbosuperchargers cool for 2 minutes before stopping the car

Compressed air coolingCompressed air heats up on the way to valve This problem eliminates Intercooler

Cooling

Turbosupercharger rotates very quickly 10 000 to 300 000 rev./minSuch quick revolutions could be the problem for common ball bearings which could explodeThat is why there are used fluid bearings in which are moving parts separated and they are cooled by thin cover of engine oilEGR valve protects turbosuperchargers damage when braking by engineExcessive air is blown back to suction

Turbosupercharger construction

Intake air must be cleanExhaust gases must be without stationary partsAfter driving at high power output, engine must go for 2 minutes before switching off at idling and it enables turbosupercharger coolingIf it does not happen and engine is switched off, oil stops circulating and it remains in turbosupercharger where this oil can be burnedOverburnt oil can choke its supply and it can cause turbosupercharger damageTurbosupercharger reliability

It is the moment between depressing of gas pedal and beginning of engine reactionTime between increasing of flammable mixture inside the cylinder and pressure increase on turbosupercharger bladesUnpleasant especially for co-driverTurboeffect preventionSome producers prefer 2 smaller turbosuperchargers to one big turbosupercharger (each works in different speed range)At some petrol engines, there are advantages of mechanical compressor and turbosupercharger as well Small compressor works only at low revolutions, at higher revolutions turbosupercharger takes over Turboeffect

Explain the meaning of EGR valve

Activity I

Describe the meaning of turbosupercharger and focus on its advantage and disadvantageActivity II

JAN, Zdenk; DNSK, Bronislav ; UPERA, Ji . Automobily 1. Brno: Avid, 2004. 211 s.JAN, Zdenk; DNSK, Bronislav ; UPERA, Ji . Automobily 2. Brno: Avid, 2004. 120 s.JAN, Zdenk; DNSK, Bronislav ; UPERA, Ji . Automobily 3. Brno: Avid, 2004. 220 s.JAN, Zdenk; DNSK, Bronislav ; UPERA, Ji . Automobily 4. Brno: Avid, 2004. 350 s.

Translation:www.seznam.czwww.slovnik.czJANATA, Petr. Handy slovnk technick anglicko-esk a esko-anglick. Plze: Nakladatelstv Fraus, 2000. ISBN 80-7238-075-3Lingea LEXIKON 5, Technick slovnk anglicko-esk a esko-anglick. 2010.

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