Supercharging and Turbocharging

This presentation include the information about the different types of superchargers, advantages & disadvantages of superchargers and turbochargers. One case study of variable geometry turbocharger is included with literature review.

1. SUPERCHARGING AND TURBOCHARGING PANKAJ UDHAV ARVIKAR M.TECH (AUTOMOBILE) 172100015

2. To increase the output of any engine more fuel can be burned and make bigger explosion in every cycle. One way to add power is to build a bigger engine. > But bigger engine, which weigh more and cost more to build and maintain are not always better Another way to add power is to make a normal sized engine more efficient. > This can be accomplish by forcing more air into the combustion chamber. > More air means more fuel can be added and more fuel means a bigger explosion and greater horsepower. This can be done with the help of turbocharger and supercharger

3. A supercharger is an air compressor used for forced induction of an internal combustion engine . The greater mass flow-rate provides more oxygen to support combustion than would be available in a naturally aspirated engine. Supercharger allows more fuel to be burned and more work to be done per cycle, increasing the power output of the engine . Power for the unit can come mechanically by a belt, gear, shaft, or chain connected to the engine's crankshaft . Definition of supercharger

4. To raise the density of the air charge, before it enters the cylinders . To raise engines power output for a given weight and size of the engine . ( for aircraft, marine and automotive engines). To compensate for the loss of power due to altitude . To increase the volumetric efficiency. Purpose of supercharging

5. Air Filter

6. Thermodynamic Cycle Fig. p-v cycle of Naturally aspirated Engine Fig. p-v cycle of Supercharged Engine

7. There are two main types of superchargers defined according to the method of compression Positive displacement (ex. Twin-screw, roots) Dynamic compressors (ex. Centrifugal) The former deliver a fairly constant level of pressure increase at all engine speeds (RPM), whereas the latter deliver increasing pressure with increasing engine speed . Dynamic compressors rely on accelerating the air to high speed and then exchanging that velocity for pressure by diffusing or slowing it down. Types of Supercharger

8. Types of Compressors Centrifugal Axial Flow Vane Twin-screw Roots

9. Limitations of Supercharging A supercharger can consume as much as 20 percent of an engine's total power output . Increase in pressure increases thermal load on engine due to increase in the rate of heat release. Detonation tendency increases in SI engine. Reliability of engine decreases with increase in maximum pressure in the cylinder . Increase the strain on engine and gear train.

10. Turbocharging A turbocharger, or turbo is a centrifugal compressor powered by a turbine that is driven by an engine's exhaust gases . To improve an engine's volumetric efficiency by increasing the intake density. The turbine converts the engine exhaust's potential pressure energy and kinetic velocity energy into rotational power, which is in turn used to drive the compressor.

11. Key Components The turbocharger has three main components A turbine , which is almost always a radial in flow turbine 1. Twin turbo 2. Twin scroll 3. Variable Geometry A compressor , which is almost always a centrifugal compressor The centre housing/hub rotating assembly

12. Benefits Limitations More power compared to the same size naturally aspirated engine. Better thermal efficiency over naturally aspirated engine and super charged engine. Better Fuel Economy by the way of more power and torque from the same sized engine. Better volumetric efficiency . High speed obtained. Better average obtained. Engine weight will increase. If there will be improper maintenance then there will be problem in turbo such as turbo lag. Engine cost will increase.

13. Effect of Variable Geometry Turbocharger (VGT) on Diesel Engine ( ISSN : 2394-9333) LITERATURE REVIEW

14. Drawbacks of Traditional Turbocharger Constant Aspect Ratio(A/R ratio) :- Turbocharger Lag It is also known as Turbocharger Transient Response Time. It is defined as the time taken by the engine to change the power output in response to the throttle change . Depends upon the inertia of the rotating parts and the efficient projection of exhaust gases onto the turbine vanes smallest c.s.a.of intake passage of turbine housing distance from central turbine wheel to centroid of area. A/R ratio =

15. Need for VGT It has a mechanism by which the inlet area can be varied to obtain the required A/R ratio for a given flow rate. By reducing the A/R ratio at low engine speed (when exhaust flow is low), and then gradually increasing, as engine speed increases (when exhaust flow is high ).

16. Case Study In this study applying the VGT turbo and conventional turbo to the high speed direct injection (HSDI) diesel engine and comparing the performance characteristics of the both cases. Vehicle used is international class VI 4700 series delivery truck. The engine simulation used is the V8 DI 7.3 L diesel engine. The specifications of the engine are as follows: T he vehicle and driveline specification as follow:

17. Experimental procedure For comparison study of VGT and conventional turbocharger, engine system is run at the full load . Case A :- Engine is enhanced by VGT Case B :- Engine is attached with Conventional Turbocharger In the both the cases the engine is accelerated between the 0-60 mph . The fuel injection time is kept same for the both cases . At initially the engine is start at the full load with breaks applied and after the 5 seconds breaks are released to achieve the maximum demand up to the 60 mph speed of the vehicle and the engine and vehicle parameters are measured . The parameters measured during each case are engine speed (rpm), vehicle speed (rpm), boost (bar), fuel injected ( g/cycle) and F/A (fuel/air) equivalence ratio Vs. time(s)

18. Test Results

19.   The turbocharger lag can be eliminated by using VG turbocharger because of higher boosting pressure at low speed. There is a cost penalty in choosing a VGT above a conventional turbocharger, but it comes with many performance improvements. The technology discussed can provide improved fuel efficiency, transient response, emissions and torque characteristics . The boost pressure is more at low speed also because of using VG turbochargers. The take off speed of VG turbocharged engine vehicle is faster than conventional turbocharged. VG systems will continue to play an important role in future energy recovery and boosting applications for internal combustion engines . Cost-benefit considerations will dictate many of the choices embedded in the development of such systems. Learnings and Conclusion s

20. Prakash Kumar Sen , Rohit Jaiswal , Shailendra Kumar Bohidar “Performance Analysis of Supercharging Process in SI Engine & CI Engine and Application of Supercharger”, IJARSE, Vol. No.4, ISSN-2319-8354(E ).   Swapnil Desai, Kinchit Agrawal, Kashyap Akbari , Dirgh Patel, Samkit Shah “Review on the Performance Improvement of Two Wheelers Using Modified Supercharger”, IJMTER, DOI:10.21884/IJMTER.2017.4165.JASXX .   Vidit Saxena , Shivpratap Singh Hada , Sourabh Jain “Performance Analysis of Supercharger and Turbocharger Using Ethanol Gasoline Blend” , ICRTESM-16, ISBN: 972-81-932074-4-4 .   Prashant . N. Pakale , S. U. Patel “Performance Analysis of IC Engine Using Supercharger and Turbocharger-A Review”, IJRET, eISSN : 2319-1163, pISSN : 2321-7308 .   Amey Dahad , Prof. A. S. Joglekar “Effect of Variable Geometry Turbocharger (VGT) on Diesel Engine”, IJTRD, Volume 3(2), ISSN: 2394-9333 .   Adam J. Feneley , Apostolos Pesiridis , Amin Mahmoudzadeh Andwari “Variable Geometry Turbocharger Technologies for Exhaust Energy Recovery and Boosting ‐ A Review”, Renewable and Sustainable Energy Reviews 71 (2017) 959–975 .   Jianqin Fu, Qijun Tang, Jingping Liu, Banglin Deng, Jing Yang, Renhua Feng “ A combined air cycle used for IC engine supercharging based on waste heat recovery” , Energy Conversion and Management 87 (2014) 86–95 . References