AB POWER ENGINEERING

CONCEPT

International System of Units

What is the meaning of SI as a unit of measurement

10

How many times greater is the power of carabao over a man?

100 to 150 watts (0.13 hp – 0.2 hp)

An adult human under good physical condition can typically develop a sustained power output around ____

0.126 hp/ha

Human power contribution

0.7 hp to 1.3

Draft animals can actually produce power at a rate of ____

15 – 20%

External Combustion Engine is a type of engine that burns fuel outside the engine cylinder. What is the approximate thermal efficiency for this engine?

External Combustion Engines

In this type of engine the fuel is burnt outside the engine cylinder

boiler

in a device called ____ to produce hot gas or steam, which is used in the engine cylinder to develop the mechanical work

Internal Combustion Engines

the burning or combustion of the fuel takes place inside the engine cylinder and the resulting explosion causes an instantaneous application of pressure to a piston

40%

The thermal efficiency of ICE is approximately ____

ELECTRIC MOTOR

Electricity supplies power for lighting buildings, for heating and for operating water pumps and refrigeration equipment

50-99

energy conversion efficiency of electric motor

25

energy conversion efficiency of gasoline engine

40

energy conversion efficiency of diesel engine

AC motor

operates using an alternating current power source. In agriculture, these motors are commonly used for operations such as water pumping, ventilation, and conveying. They are well-suited for applications where constant speed is required

DC motor

operates using a direct current power source.

Universal motor

These are small series motors up to 3.73 kW rating which are commonly designed to operate on either direct current or alternating current

Shunt-wound motor

A type of DC motor, in which the field winding is connected in parallel with the armature, constant speed application

Series-wound motor

A type of DC motor, in which the field winding is connected in series with the armature, high starting torque

Compound-wound motor

A type of DC motor, which has a series-field and shunt-field winding, speed-torque characteristics may be adjusted

Synchronous

A type of AC motor capable of raising the power factor of systems having large induction motor loads

Wound-rotor

A type of AC motor, wherein secondary windings are wound with discrete conductors with the same number of poles as the primary winding on the stator

Squirrel-cage

A type of AC motor wherein the rotor or secondary winding consists merely of 28 identical copper or cast-aluminum bars solidly connected to conducting end wings on each end

power output

referred to by its motor rating, which is typically expressed in horsepower (HP) or kilowatts (kW),

Locked-Rotor Torque

motor torque at zero speed or the maximum torque available to start the load

Pull-up Torque

lowest value of the torque produced by the motor between zero and full load

Full-load Torque

torque necessary to produce the motor's rated power at rated speed

Breakdown Torque

maximum torque a motor can carry without an abrupt drop in speed that make the motor stall or stop

Acceleration Torque

torque available for acceleration

ampacity

current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its temperature rating

disconnecting means

device, or group of devices, or other means by which the electric motor can be disconnected from the power supply

enclosure

case or housing which prevents the operator from accidental contact with energized parts and protect the motor from physical damage

frame designation

standardized motor mounting and shaft dimensions as established by National Electric Manufacturers Association (NEMA) or International Electrotechnical Commission (IEC)

rotor

rotating part of electric motor which is typically constructed of a laminated steel core containing current-carrying copper wires

stator

stationary part of electric motor consisting of copper windings which is placed in a laminated iron core

2-7x of the full-load current

During starting of the motor, the magnitude of the current is expected to be _____

Temperature Rating; 20,000hrs

The temperature capability of each insulation class is defined as being the maximum temperature at which the insulation classes can be operated to yield an average life of ____

Duty Rating

This refers to how frequently the motor is started and for how long it will run each time it is started

Continuous duty

type of service in which the motor is operated at or near full load for more than 60 minutes at a time. This is the common situation for many motors.

Intermittent duty

the load is only for 10, 20, or 30 minutes at a time with a rest or cooling period between operations

Service Factor

Indicates the maximum load that can be successfully carried by the motor if it is to operate continuously and remain within a safe temperature range

Motor Nameplate

normally located on all produced electric motors.

Generator

Generates power for farmstead such as lighting, driving motor, heating, etc.

Motor

Provides power for various stationary farmstead equipment

Engine

Provides power for both stationary and mobile agricultural machines and equipment

Turbine

Supplies energy to propel high-speed equipment used to drive small generators and milling machines

Boiler

Provides steam for power generation and for various food processing operation

Solar Collector

Supplies energy for drying, space heating, and others

Solar Cell

Provides power for lighting, water pumping, etc

Peltier Chip

Runs small fan, cooling, etc

Furnace

Burns fuel to produce heat for drying grains, kiln firing, tobacco curing, and others

Gasifier

Produces heat for various applications and for powering gasoline and/or diesel engines

Biogas Digester

Produces heat for cooking and for fueling ICEs

Piston

to receive gas pressure and transmit the thrust to the connecting rod. It is the prime mover in the engine, to give tight seal to the cylinder through bore and slide freely inside of cylinder

Crank Shaft

It converts the reciprocating motion of the piston into rotary motion of crankshaft

Fuel Injector

electronically controlled device that sprays fuel directly into the intake manifold or combustion chamber, usually used in compression ignition engine.

Spark Plug

to deliver the high –voltage electric current from the ignition system into the combustion chamber to ignite the compressed air fuel mixture

Crankcase

main body of the engine, serves as the lubricating system too and sometime it is called oil sump

Oil Pan/Oil Sump

Located at the bottom of the crankcase where engine oil is contained to lubricate the engine

Dip Stick

is used in measuring the level of lubricating oil in the engine

Cylinder Block

The main body of IC engine, and the part in which the intake of fuel, compression of fuel and burning of fuel take place, guide the piston

Cylinder Head

to seal the cylinder block and not to permit entry and exit of gases on cover head valve engine

Manifold

to supply the air fuel mixture and collects the exhaust gases equally form all cylinder

Connecting Rod

connects the piston to crankshaft and transmits the motion and thrust of piston to crankshaft. It converts the reciprocating motion of the piston into rotary motion of crankshaft

Engine Bearing

used to support the moving parts, to reduce friction between these moving parts

Flywheel

an energy storage device of the engine to keep it at uniform speed when the crankshaft is not receiving power from the piston

Engine Governor

a device that automatically regulates and maintains the engine's speed within specified limits despite variations in load, Its primary function is to control the amount of fuel supplied to the engine

Valve

Use to control the inlet (air and fuel) and exhaust of internal combustion engine.

Carburetors

A mechanical device that mixes air and fuel by relying on air pressure to pull fuel into the engine

Piston Rings

retain compression, reduce cylinder wall contact thereby reduce friction losses and wea

Camshaft

used in IC engine to control the opening and closing of valves at proper timing

Shaft

Machine element that transmit torque and power

Key

used to fasten shaft, pulleys and gear hubs together

Bearing

reduce friction and allow for smoother rotation

Spline

series of axial keys machined into a shaft with corresponding grooved machined into the bore of the mating part

Bore

size of the opening of the cylinder almost equal to the the diameter of the piston plus the rings

Stroke

distance traveled by a piston from the TDC to the BDC

Top Dead Center

the uppermost position of the piston during the compression and exhaust stroke

Bottom Dead Center

the lowest most position of the piston during the intake and power stroke

Piston Displacement

volume displaced by the piston in one stroke

Clearance volume

volume in the combustion chamber when the piston is at the TDC position

Cylinder Volume

sum of piston displacement and clearance volume

Compression Ratio

ratio of the cylinder volume to the clearance volume

Mean Effective Pressure

average amount of pressure generated during the power stroke of the piston

Intake Stroke

fuel and air or air alone is suck in the combustion chamber as the piston moves in downward direction

Compression Stroke

fuel and air or air is compressed by the piston as it moves in upward direction

Power Stroke

fuel and air is ignited to produce power at the downward movement of the piston and transmitted it into the crankshaft of the engine

Exhaust Stroke

burn fuel and gases is discharged from the combustion chamber

Misfiring

means one or more cylinders fail to properly ignite and burn the air–fuel mixture during the combustion cycle

Backfiring

combustion that occurs outside the cylinder, in the intake or exhaust system, rather than inside the combustion chamber

Intake backfire

(popback): Flame travels backward through the intake manifold, often heard as a cough or bang at the carburetor/throttle body

Exhaust backfire

(afterfire): Unburned fuel exits the cylinder and ignites in the hot exhaust manifold, catalytic converter, or muffler, causing pops from the tailpipe

Detonation

an abnormal combustion event inside the cylinder where part of the air–fuel mixture (the “end-gas”) auto-ignites explosively after the spark plug has already initiated normal combustion

Knocking

essentially the audible and mechanical manifestation of detonation; the terms are often used interchangeably

Knock

the sound and vibration caused by detonation’s pressure waves forcing engine parts to vibrate

Spark-Ignition Engine

uses a spark to ignite fuel

Compression-Ignition Engine

Uses high compression to raise the temperature of the air in a chamber and ignites the injected fuel without spark

14-22 to 1

compression ratio of CI

5-8 to 1

compression ratio of SI

30-36%

thermal eff of CI