Internal Combustion Engine - CHAPTER 9
Locate converter close to engine
does heat it as quickly as possible after the engine is started
Thermal battery
energy from a thermal storage system
Atmospheric nitrogen
exists as a stable diatomic molecule at low temperatures.
Quenching
in terms of combustion refers to extinguishing a flame
Oil
is a high molecular weight hydrocarbon compound that does not burn as readily as gasoline
Cyanuric acid
is a low-cost solid material that sublimes in the exhaust flow.
Two stroke oil
is a special type of motor oil intended for use in crankcase compression two stroke engines.
Catalyst
is a substance that accelerates a chemical reaction by lowering the needed for it to proceed
NOx
is a very undesirable emission
TEL
is also known as Tetraethyl lead
Ammonia
is an undesirable emission
Exhaust gas recycle
is done by ducting some of the exhaust flow back into the intake system.
Photochemical smog
is form when HC emission get into the atmosphere and react with atmospheric gases.
Maximum Carbon Monoxide
is generated when an engine runs rich
Ground-level ozone
is harmful to lungs and other biological tissue.
Monoatomic Oxygen
is highly reactive and initiates a number of different reactions.
Catalytic converter
is the most effective after treatment system for reducing engine emission
Durability
is the serious limitation using zeolite molecular sieves method
Crevice volume
is the space between the Cylinder wall and the piston
Valve Seat
is the surface against which an intake or an exhaust valve rests during the portion of the engine operating cycle when that valve is closed
Valve
is usually a flat disk of metal with a long rod
Blowby gas
is very high in hydrocarbon
Vanous method
it is used when soot build up becomes excessive and regeneration is needed
ppm
means " parts per million"
Engine Misfire
means that car's engine skip over one of the process of its combustion cycle.
TRUE
modern high compression engines could not use low octane fuel.
1990s
more fuel efficient engines we developed so the average automobile consume less than half the fuel used in 1970s
incomplete combustion
occur when there is not enough oxygen to allow the fuel to react completely.
Over 90%
of carbon particles originally generated within an engine are thus consumed and never get exhausted.
10%-50%
of the lead exhausted out with the other combustions products.
Lead
one of the major pollutant was phase out as a fuel additive in 1980s
3%
percentage of fuel in the chamber can be forced into the crevice volume
Platinum
promote exidation of CO and HC
Palladium
promote oxidation of CO and specially HC
Sulfur
promote the conversion of SOz to SO3
Rhodium
promote the reaction of NOx
Emissions
rate of a given pollutant from a given source.
Hydrocarbon emissions
result from the presence of unburned fuel in the exhaust of an engine
Dual fuel engines
run on a combination of gasoline and methanol (0-85%)
EMS
stands for engine management system
EGR
stands for exhaust gas recycle.
2500 - 3500K
temperature range that can exist in an engine
Modern two-stroke cycle engine
that uses fuel injection have cooler exhaust because of their high efficiency and lean operation.
PCV (positive crankcase ventilation) system
the first effort at controlling pollution from automobiles
Pressure
the formation of NOx depends on ____.
Increase gasoline octane number
the used of Tetraethyl lead
Phosphorus
these come from impurities in the air and small amounts in some fuel blends and lubricating oil.
Cold start-ups
when an engine is started after not being operated for several hours
Engine start and warm up
where Hydrocarbon emissions are greatest
The simplest way to reduce NOx emissions is to hold the combustion chamber temperature down.
The simplest way to reduce NOx emissions is to hold the combustion chamber temperature down.
Soluble Organic Fraction
This absorbed portion of the soot particles
20%
This accounted for up to ____ of total emission because of the crankcase breather tube being vented out to the atmosphere
valve overlap
both the exhaust and intake valves are open
Nitrogen
can also be found in fuel blends
NH3
chemical formula of ammonia
Unleaded gasoline
contains 150 - 600 ppm sulfur by weight
Diesel Fuels
contains up to 5000 ppm sulfur by weight
0.15gm/liter
- the leaded gasoline contains about ______ of lead in the fuel
A very rich mixture there is not enough oxygen to react with all the carbon, resulting in high levels of HC in the exhaust products
A very rich mixture there is not enough oxygen to react with all the carbon, resulting in high levels of HC in the exhaust products
1940s
Air pollution was First recognized as a problem in Los Angeles, California
Ammonia injection systems are not practical in automobiles or on other smaller engines
Ammonia injection systems are not practical in automobiles or on other smaller engines
Respiratory Irritant
Any substance which can cause inflammation or other adverse reactions in the respiratory system.
CO also known as carbon monoxide
CO also known as carbon monoxide
Chemical reaction preheating uses the heat liberated from an exothermic chemical reaction
Chemical reaction preheating uses the heat liberated from an exothermic chemical reaction
Very low CO emission
Cl engines that operate overall lean generally have ______.
1960s
Emission Standard were beginning to be enforced California
Exhaust gases leaving the combustion chamber of an SI engine contain up to 6000 ppm(parts per million) of hydrocarbon component, the equivalent of 1 - 1.5% of the fuel.
Exhaust gases leaving the combustion chamber of an SI engine contain up to 6000 ppm(parts per million) of hydrocarbon component, the equivalent of 1 - 1.5% of the fuel.
2000 ppm
Exhaust gases of an engine can have up to _____ of oxides of nitrogen
HC also known as hydrocarbon
HC also known as hydrocarbon
Spark plug
HC emissions can be reduced if a second ________ is added to an engine combustion chamber
Unlead Fuel
Harder metals and added surface treatments are used for engines designed to use ______________.
1980s
Lead was phased out in the _______.
Lean burn engines uses stratified charge
Lean burn engines uses stratified charge
Under Load
Maximum density of particulate emissions occurs when the engine is ____ at WOT.
NOx also know as nitric oxide
NOx also know as nitric oxide
Nitrogen
NOx is created mostly from ___ in the air
No EGR is used at idle and very little at low speeds.
No EGR is used at idle and very little at low speeds.
No EGR is used during WOT, when maximum power is desired.
No EGR is used during WOT, when maximum power is desired.
Reactive
Other gases that are stable at low temperatures but become ___ and contribute to the formation of NOx at high temperatures include water vapor and oxygen
Ozone
Released NOx reacts in the atmosphere to form ____ and one is of the major causes of photochemical smog.
Higher exhaust temperature can be caused by
Stoichiometric Air - Fuel Combustion High Engine Speed Retarded Spark Low expansion Ratio
Flow rate of EGR
The ____ is controlled by the EMS.
30%
The amount of EGR flow can be as high as ____ of the total intake.
The farther the sparkplug is from the ring gap , the greater the HC in the exhaust
The farther the sparkplug is from the ring gap , the greater the HC in the exhaust
95%
____ NOx reduction has been achieved using cyanuric acid.
Carbon Monoxide
a colorless, odorless, poisonous gas, is generated in an engine
Flame heating
a flame is initiated in the burner using fuel air pumped from external sources
Crankcase breather tube
a major source of HC emissions that was vented out to the atmosphere at old automobiles.
Solid carbon soot
a problem unique to CI engines when using EGR.
Superinsulation
accelrate the temperature rise to steady-state condition
Electric heating
allows much quicker heating by means of thermal conduction
Chemical Radicals
an atom, molecule, or ion that has an unpaired valence electron
Soot particles
are clusters of solid carbon spheres
Carbon spheres
are generated in the combustion chamber in the fuel-rich zones
Thermal Converter
are high temperature chambers through which the exhaust gas flows
Zeolite molecular sieves
are materials that absorb selected molecular compounds and catalyze chemical reactions.
Thermal Converter
as a means of lowering emissions
1%
as much as ____ of fuel was vented to the atmosphere through the crankcase breather in some automobiles.
TRUE
at high temperatures the sulfur combines with hydrogen to form Hydrogen Sulfide and in oxygen to form Sulfur Dioxide
Photochemical Smog
becomes a major problem in many large cities in the whole world