What Is Throttle valve

What Is Throttle valve
A throttle is the mechanism by which fluid flow is managed by constriction or obstruction.

An engine's power can be increased or decreased by the restriction of inlet gases (by the use of a throttle), but usually decreased. The term throttle has come to refer, informally, to any mechanism by which the power or speed of an engine is regulated, such as a car's accelerator pedal. What is often termed a throttle (in an aviation context) is also called a thrust lever, particularly for jet engine powered aircraft. For a steam engine, the steam valve that sets the engine speed/power is often known as a regulator.

1. PRESENTED TO: SIR MUZAMMIL PRESENTED BY: HAFIZ SHAHREYAR RAZA SHAHRUKH WASEEM

2. O v e r vi e w Int r o to Air/Fue l R a tio Com b ustio n T e r m inolog y an d Fundamentals Impo r tance of Air/Fuel R a tio Cont r o l Method s o f Air/Fue l R a ti o Cont r o l P r o s an d Con s o f Ea c h Method

3. T hrottle valve A valve designed to regulate the supply of a fluid (as steam or gas and air) to an engine and operated by a hand wheel , a lever, or automatically by a governor.

4. Combustio n T e rminology Com b ustio n – The rapid o xid a t ion of a fuel, usual l y via th e o x yge n p r esen t i n ai r , r esultin g i n th e r eleas e of energ y (he a t an d light). Com b ustio n i s th e CONT R O LLED r api d o xid a t io n o f a fuel. Explosio n i s th e UNCONT R OLLED r api d o xid a t io n o f a fuel. Stoichiomet r i c R a ti o – T h e perfec t amoun t o f o x ygen and fuel mi x e d du r ing com b ustion su c h th a t nothing is lef t o v e r . Exampl e Reactio n wit h N a tura l Ga s (C H 4 ):  CH 4 + 2O 2 + 8N 2  CO 2 + 2H 2 O + 8N 2 + he a t

5. Combustio n T e rminolog y (cont.) Excess air / lean – Whe n mo r e ai r ( o xygen ) i s p r esent tha n necessa r y t o com b us t th e fuel , r esultin g i n lef t o v er o xygen. Mos t indust r ia l com b ustio n applic a tion s a r e r u n with exces s ai r t o ensu r e th a t the r e i s n o w a ste d fuel. Example : A N a tura l Ga s b u r n e r whi c h r ecei v e s 1 5 pa r t s ai r fo r e v e r y pa r t fue l i s r unnin g wit h 50 % exces s ai r . Thi s b u r n e r ca n b e desc r i be d a s “ r unnin g lean”.  C H 4 + 3O 2 + 12N 2  C O 2 + 2H 2 O + O 2 + 12N 2 + he a t

6. Combustio n T e rminolog y (cont.) Exces s fue l / r ic h – Whe n les s ai r i s p r esen t than necessa r y t o com b us t th e fuel , r esultin g i n un b u r ned fuel. Ce r tai n applic a tion s th a t r equi r e a lon g , luminou s flame o r nee d t o cont r ol th e amoun t o f o x yge n withi n the com b ustio n c h ambe r w oul d h a v e b u r n e r s set-u p t o r un wit h exces s fuel. Sometime s calle d “sub-stoi c h” sinc e it ’ s bel o w the stoi c h iomet r i c air-to-fue l r a ti o .  2CH 4 + 2O 2 + 8N 2  C H 4 + C O 2 + 2H 2 O + 8N 2 + he a t

7. Combustio n F u ndamentals All fuels h a v e a l o w e r and upper flammability limit. Com b ustio n ca n on l y occu r bet w ee n thes e limit s . Whe n c h an g i n g th e fi r i n g r a t e o f a b u r n e r , bot h th e air an d fue l nee d t o tr a v e l togethe r t o st a y bet w ee n these limit s . T ype of Gas LFL UFL S toich N a tura l Ga s (C H 4 ) 5.0% 15.0% (10:1 ) - 9.1% P r opan e Ga s ( C 3 H 8 ) 2.1% 9.5% (25:1 ) - 3.8% Butan e Ga s (C 4 H 10 ) 1.8% 8.4% (32:1 ) - 3.0%

8. Optima l Air/ F ue l rati o cont r o l P r e v ent nuisance shut-d o wns Imp r ope r air/fue l r a ti o ca n caus e th e flam e safeguar d t o lose th e flam e signal Imp r o v e fue l efficien c y Imp r ope r air/fue l r a ti o ca n w a st e fuel Hel p obtain tighte r cont r o l fo r emission s d r i v e n applic a tions Imp r ope r air/fue l r a ti o ca n inc r eas e NO x o r C O p r oduction Hel p obtain bette r temper a tu r e cont r o l Imp r ope r air/fue l r a ti o ca n ma k e cont r ollin g temper a t u r e mo r e difficult

9. Inspira t ors High p r essu r e fuel is deli v e r ed to the inlet of the inspir a tor V e ntu r i tub e design pull s com b ustion ai r into the inspir a tor R a tio cont r o l dict a ted b y the size of the fuel nozzle and an air adjustmen t damper

10. Inspira t or s (cont.) ~4 : 1 T u r nd o wn P r os: L o w Cost, Simple Design, A v aila b l e in ma n y sizes Cons : L o w tu r nd o wn, Minima l c haracte r iz a tion C r itica l Component : Gas Nozzle/Spud

11. C r oss-Connec t e d Rati o R e gula t ors Compose d o f the foll o win g components: Air Cont r o l D e vice (Cont r o l V al v e or VFD) P r opo r tion a tor/R a tio Regul a tor Limiting O r ifice Cont r o l signal sent to the air cont r o l d e vic e , and an impulse line f r om ai r manifold feed s the fue l ’ s r a tio r egul a to r to adjus t the fue l fl o w .

12. C r oss-Connec t e d Rati o R e g s (cont.) ~20: 1 T u r nd o wn P r os: Flexi b le Install a tion , L o w Cost Cons : Minimal c haracte r iz a tion C r itical component: Impulse Line

13. Mechanicall y -Lin k e d Cont r o l V a l v es Ai r V al v e an d Fue l V al v e connecte d vi a me c hanica l linkag e . Common l y foun d in boile r applic a tion s Characte r iza b le fue l v al v e s offe r adjustmen t capabilitie s for the enti r e rang e o f oper a tion. Goo d fo r m ulti-fue l an d oil-fi r ed applic a tion s .

14. Mechanicall y -Lin k e d V a l v e s (cont.) ~40: 1 T u r nd o wn P r os: Higher T u r nd o wn , Mo r e Characte r iz a tion Cons: Higher T o rque Requi r ement s for Cont r o l Moto r s, Less Flexi b le Install a tion C r itica l Component: Linkage a r m bet w een ai r an d fue l v al v es

15. SHAHRUKH WASEEM

16. Elect r o nicall y -Lin k e d Cont r o l V a l v es loc a ted nea r ea c h oth e r . Sometimes r efe r r ed to as “ P arallel P o sitioning” System ’ s cont r o l interface r ecei v e s single cont r o l signal , and cont r o ls m u ltiple actu a to r s (can cont r o l up to 4). Built-in safeties ensu r e th a t actu a to r s tr a v el together to maintain r a ti o . Actu a to r s a r e c haracte r iza b l e , all o win g fo r individual l y defined fl o w cu r v e s . Common l y use d in emission s d r i v e n applic a tion s du e to r e pe a tability o f cont r o l an d l e v el o f c haracte r iz a tion. Flexi b le to instal l since ai r an d fue l v al v e s d o no t nee d to be

17. Elect r o nicall y -Lin k e d V a l v e s (cont.) ~40: 1 T u r nd o wn P r os: Flexi b le Install a tion , G r e a t Cont r o l Resolution Cons: Inc r eased Complexit y an d Cost with Additional Components C r itica l Component: Cont r o l Interface

18. F u ll y Me t ered Mas s Fl o w Cont r o l Ai r an d Fue l fl o w mete r s use d in conjunction with elect r onical l y-lin k ed cont r o l v a l v e s . V al v e position s dete r mine d b y centra l cont r o l interface based on he a t r equi r emen t an d fl o w feedba c k. Common l y use d in emission s d r i v e n applic a tion s du e to r e pe a tability o f cont r o l an d l e v el o f c haracte r iz a tion. Flexi b le to instal l since ai r an d fue l v al v e s d o no t nee d to be loc a ted nea r ea c h oth e r .

19. F u ll y M e t e re d Mas s Fl o w Cont r ol (cont.) ~20: 1 T u r nd o wn P r os: Best A v aila b l e Cont r o l T e c h nolog y , Self- tuning/co r r ecting with fl o w feedba c k Cons : Mo r e expensi ve , Ca n b e sl o w e r to r e spond to ag g r essi v e cont r o l signal s . C r itica l Component: Interface P anel

20. FUNCTION In general terms, the throttle valve must regulate the air or mixture supply for the combustion  engine . Depending on the engine concept, this serves different purposes. In the case of petrol engines, speed and power output are regulated by means of fresh air or mixture dosing. Diesel engines generally do not need a throttle valve. However, in modern diesel cars, throttling the amount of intake air facilitates precision control for  exhaust gas recirculation and stops the engine from shaking when the ignition is switched off .

21. ELECTRONIC THROTTLE ACTUATORS: With electromotive throttle actuators, the position of the throttle valve is regulated mechanically via the accelerator Bowden cable. The throttle valve electronics forward the position of the throttle valve to the  engine control  unit as an electrical signal. This information is compared with other up-to-date data from a variety of engine management sensors. The engine control unit permanently calculates the optimum throttle position for consumption and exhaust gas emissions and sends this information back to the throttle valve as an electrical control signal. The position of the throttle valve is then fine-tuned with the assistance of a servomotor

22. Electronic throttle actuators With electronic throttle actuators, there is no direct connection to the accelerator pedal. The driver's desired load is captured by an electronic accelerator pedal (electromotive throttle actuator). The engine management permanently matches this signal to all other available data from the engine sensors, using the information obtained to calculated the optimum throttle position for the prevailing situation. The electronic throttle actuator is controlled exclusively using the control signal from the engine management and with the assistance of a servomotor

23. Air management valves : If throttle valves are used in diesel engines, they are generally referred to as air management valves. Air management valves can be with or without integrated control electronics. As indicated above, air management valves throttle the intake air in the intake air system of diesel engines via electromotive means in order to achieve precision controlled exhaust gas recirculation and prevent the inconvenient shaking that would otherwise occur when the engine is switched off.

24. Air flap servomotors: Air flap servomotors are electrical actuators with integrated position sensor and optional integrated electronics. They facilitate the continuous adjustment of intake pipe flaps or turbocharger guide vanes, for example, and, by means of more precise control, are able to replace conventional pneumatic drives which are no longer sufficient for the advanced requirements that have to be met.

25. SAFETY The perfect function of the throttle valve is the key to optimum power development of the vehicle in critical situations. As such, the throttle valves make an essential contribution to improved road safety

26. DEPRECIATION Throttle valves are maintenance-free. They are designed to last the entire service life of the vehicle. Poor maintenance (missing oil change intervals, for example) can lead to soiling of the throttle valve and cause deposits to build up, resulting in premature wear or even complete failure. For this reason, compliance with the maintenance intervals prescribed by the vehicle manufacturer is essential.

27. ENVIRONMENTAL PROTECTION Optimum operation of the combustion engine and minimum pollutant emissions rely on precision control of the intake air. Throttle valve modules with integrated electronics enable the intake air quantity to be exactly matched to the prevailing operation conditions independently of the driver's performance requirements. As such they make an important contribution to effective fuel combustion and low pollutant emissions