turbochargers & superchargers chapter 7. forced induction 4 ways to increase compression...
TRANSCRIPT
TURBOCHARGERS & SUPERCHARGERS
CHAPTER 7
FORCED INDUCTION
• 4 WAYS TO INCREASE COMPRESSION– SUPERCHARGING– TURBOCHARGING– CHEMICAL– ENGINE
MODIFICATION
TURBOCHARGERS
• COMPRESSES AIR GOING INTO COMBUSTION CHAMBER
• DEPENDS ON RAPID EXPANSION OF EXHAUST GASES LEAVING COMBUSTION CHAMBER
• TURBO LAG IS A CHARACTERISTIC
TURBOCHARGER PARTS
• TURBINE• SHAFT• COMPRESSOR• WASTEGATE• ACTUATOR• CENTER HOUSING
– CONTAINS COOLING SECTION
222C
VANE WHEELS
TURN AT 100,000 RPM
TURBO CYCLE
• EXHAUST GAS FORCES TURBINE TO ROTATE• COMPRESSOR FORCES (PACKS) CREATING A
DENSE AIR-FUEL MIXTURE• CREATES A POSITVE PRESSURE (BOOST)
223C
BOOST PRESSURE CONTROL
• WASTEGATE DIAPHRAGM
• CONTROLS BOOST PRESSURE
• MECHANICAL OR ELECTRONICALLY CONTROLS WASTEGATE OPERATION
224C
TURBOCHARGER COOLING
• EXHAUST FLOW PAST TURBINE WHEEL CAUSES HIGH TEMPS
• WATER COOLING• OIL COOLING• OIL SEALS • MUST LET TURBO
COOL DOWN ON SHUTOFF
HEAVY DUTY APPLICATION
• SAME PRINCIPLE AS SMALLER ONES
• BOOST PRESSURE SLIGHTLY HIGHER
• COOLING A LOT MORE IMPORTANT
• DIESEL TRUCK, LOCOMOTIVE, HEAVY EQUIPMENT
POWER OUTPUT COMPARISON
ROTARY RACING ENGINE
MAINTENANCE / PROBLEMS
• LACK OF OIL• DIRTY OIL• MECHANICAL DAMAGE OF VANE
WHEELS• WASTEGATE CONTROL PROBLEMS• OIL CAKING
DIAGNOSIS
• OIL LEAKS, HOSES, LINKAGES• BLUE SMOKE• EXCESSIVE NOISE• EXHAUST LEAKS• TEST BOOST PRESSURE• TURBO R & R REQUIRES PRE-
LUBING
PAGE 302 LAB
SUPERCHARGERSSUPERCHARGERS
SUPERCHARGER OPERATION
• BELT OR GEAR DRIVEN• ROTORS ACT LIKE A PUMP AND
COMPRESS AIR (PAGE 310 LAB)• SUPERCHARGER SPEED IS LIMITED BY
ENGINE SPEED -TURNS A LOT SLOWER• SOMETIMES USED WITH INTERCOOLER
TO COOL AIR• BYPASS BUTTERFLY VALVE 230 LAB
BLOWN ENGINE
• MORE RELIABLE THAN A TURBO
• MUST RECEIVE PROPER LUBRICATION
• IMPROVED THROTTLE RESPONSE OVER A TURBO