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Testing of IC Engines:
- Engine
Performance Parameters:
- Brake
Power (BP):
Power available at the crankshaft.
- Indicated
Power (IP):
Total power developed in the combustion chamber.
- Friction
Power:
Difference between indicated and brake power.
- Thermal
Efficiency:
Ratio of work output to heat input.
- Volumetric
Efficiency:
Ratio of the volume of charge taken in during the suction stroke to the
swept volume of the piston.
- Specific
Fuel Consumption: Fuel consumption rate per unit power output.
- Dynamometers:
- Instruments
used for measuring power output of an engine. Types include:
- Prony Brake Dynamometer
- Rope Brake Dynamometer
- Eddy Current Dynamometer
- Hydraulic Dynamometer
- Morse
Test: Used to
find out the indicated power of multi-cylinder engines.
- Heat
Balance Test:
Distribution of heat input among useful work, cooling water, exhaust
gases, and other losses.
- Retardation
Test: Used to
determine frictional power.
- Fuel
& Air Intake Measurement: For determining the actual amount of intake and
calculating the air-fuel ratio.
Emission Control:
- Pollutants
from IC Engines:
- Carbon
monoxide (CO)
- Hydrocarbons
(HC)
- Oxides
of Nitrogen (NOx)
- Particulate
Matter (for diesel engines)
- Carbon
Dioxide (CO2):
Not a pollutant in the traditional sense, but a greenhouse gas.
- Emission
Control Techniques:
- Catalytic
Converters:
Devices that facilitate chemical reactions to convert harmful emissions
into less harmful substances.
- Three-way catalysts: Convert CO, HC, and NOx.
- Diesel oxidation catalysts: Convert CO and HC in diesel engines.
- Exhaust
Gas Recirculation (EGR): Recirculates a portion of exhaust gases back into the
engine combustion chamber to reduce NOx emissions.
- Diesel
Particulate Filters: Capture and store particulate matter from diesel exhaust.
- Lean
NOx Traps and Selective Catalytic Reduction (SCR): For NOx reduction in diesel
engines.
- Evaporative
Emission Control Systems: Capture fuel vapors from the fuel tank and charcoal
canister.
- Alternative
Fuels:
- Using
fuels like ethanol, biodiesel, and compressed natural gas (CNG) can
reduce certain emissions compared to traditional gasoline or diesel.
- Engine
Modifications:
- Adjusting
the air-fuel ratio, ignition timing, and compression ratio can help
control emissions.
- After-treatment
Systems:
- Technologies
applied after the combustion process to treat and reduce emissions.
- Engine
Management Systems: Advanced systems that can adjust engine parameters in real-time
for optimal performance and reduced emissions.
- Euro
and Bharat Stage Emission Standards: These are regulatory frameworks that set limits on
permissible emission levels for various pollutants from automobiles.
Understanding and controlling emissions from IC engines are
essential due to the environmental and health impacts of these pollutants. As
regulations become stricter, innovations in engine design, after-treatment
technologies, and alternative fuels become increasingly critical.