1.43k likes | 4.89k Views
TURBOCHARGER AND SUPERCHARGER. GUIDE BY MR. PARVIN SHARMA PRESEDENTED BY DAYA SHANKAR GOUR(M.E ).
E N D
TURBOCHARGER AND SUPERCHARGER GUIDE BYMR. PARVIN SHARMA PRESEDENTED BY DAYA SHANKAR GOUR(M.E) JAIPUR INSTITUTE OF ENGINEERING AND MANAGEMENT JAIPUR
INTRODUCTION • The power out put of an engine depends upon the amount of air inducted per unit time and the degree of utilization of this air , and the thermal efficiency of the engine. Indicated engine Power IP=P*L*A*n*K/60000 ……………..(1) Where, IP= indicated power (kW) P=indicated mean effective pressure(N/m2) L=length of stroke A= area of piston n= no of power stroke, for 2-s engine-N and for 4-s engine N/2, N= rpm K= No of cylinders
Three possible methods utilized to increase the air consumption of an engine are as follows • Increasing the piston displacement: This increases the size and weight of the engine, and introduces additional cooling problems. • Running the engine at higher speeds: This results in increased mechanical friction losses and imposes greater inertia stresses on engine parts. • Increasing the density of the charge: This allows a greater mass of the charge to be inducted into the same volume.
DEFINITION The most efficient method of increasing the power of an engine is by supercharging, i.e. increasing the flow of air into the engine to enable more fuel to be burnt. • A Supercharger is run by the mechanical drive, powered by engine power . • A turbocharger uses the otherwise unused energy in the exhaust gases to drive a turbine directly connected by a co-axial shaft to a rotary compressor in the air intake system.
COMPRESSED AIR Air inlet Fig.1 Supercharger
Types Fig. 2 Turbocharger
Need of turbocharger and super charger • For ground installations, it is used to produce a gain in the power out put of the engine. • For aircraft installations, in addition to produce a gain in the power out put at sea-level, it also enables the engine to maintain a higher power out put as altitude is increased.
Working principle of a turbocharger: • A turbocharger is a small radial fan pump driven by the energy of the exhaust gases of an engine. • A turbocharger consists of a turbine and a compressor on a shared shaft. • The turbine converts exhaust to rotational force, which is in turn used to drive the compressor. • The compressor draws in ambient air and pumps it in to the intake manifold at increased pressure, resulting in a greater mass of air entering the cylinders on each intake stroke.
Types of super charger: Based on the use of compressor • Centrifugal type • Roots type • Vane type • Components of turbocharger • Air compressor • Turbine • Intercooler
Selection process of turbocharger • The concept of turbocharger is illustrated in Figure • Compressor air inlet,Point1- p1, T1 • Compressor air out let, point2-p2, T2 • Turbine exhaust gas inlet, point 3-p3,T3 • Turbine exhaust gas outlet- • P4, T4 Illustration of the concept of a turbocharger.
Advantages of supercharger and turbocharger • The more increase the pressure of the intake air above the local atmospheric pressure (boost), the more power the engine produces. Automotive superchargers for street use typically produce a maximum boost pressure between 0.33 to 1.0 bar , providing a proportionate increase in power. • Engines burn air and fuel at an ideal (stoichiometric) ratio of about 14.7:1, which means that if you burn more air, you must also burn more fuel. • This is particularly useful at high altitudes: thinner air has less oxygen, reducing power by around 3% per 1,000 feet above sea level, but a supercharger can compensate for that loss, pressurizing the intake charge to something close to sea level pressure.
Disadvantages of turbocharger and supercharger • Cost and complexity • Detonation • Parasitic losses • Space • Turbo lag
Performance evaluation of the Turbo charged Agricultural Tractor Engine Place: Agricultural Machinery Research Centre, Massey University, Palmerston North, New Zealand in 1990. Tractor- John Deere 3140 No of cylinder-6 Compression ratio- 16.8: 1 Fuel – 10% tallow ester + 90% diesel
Conclusions • Due to low speed of operation and less power in agricultural tractor, turbocharger is used not supercharger for more power generation and to operate it higher altitude. • Turbo-charging a tractor engine is an acceptable method of increasing its performance if carried out within manufacturers’ specifications. • Lower engine operating temperatures result which can be beneficial. • Since the engine lubricating oil is subjected to high temperatures as it passes through the turbocharger the correct oil must be used as specified for turbocharged engines.