Post on 04-Dec-2015
description
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
SUPERCHARGERS
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