sources and measurement of farm power Flashcards
(48 cards)
Types of Farm Work
Tractive Work and Stationary Work
Work requiring pulling or drawing efforts
Tractive Work
Work accomplished by means of belt, gears, electric motors, etc.
Stationary Work
Sources of Farm Work
Domestic Animals, Wind Power, Water Power, Electric Power, Internal Combustion Engines (ICEs), Solar Energy, Biomass Energy, and Human Power
Source of farm power that uses horses, mules, cows and other animals of the sort
Domestic Animals
Source of farm power limited for farm use, cannot be controlled and seldom available
Wind Power
Source of farm power solely for stationary works and electric generation
Water Power
Source of farm power used extensively for supplying heat, light and heating.
Electric Power
Source of farm power most dominant for tractive work applications
Internal Combustion Engines (ICEs)
Unlimited source of farm power and is most common used for lighting and heating; often converted into electricity
Solar Energy
Source of farm power that is a substitute for fossil fuels
Biomass Energy
Source of farm power that utilizes power of man
Human Power
Power range of farm animals
0.7 to 1.3 hp
Power Formula
Force * Speed
Reasons for use of domestic animals
> small farm
rolling topography
crops not suitable for mech
lack of fuel due to cost
high initial cost of equipment
plenty low cost labor supply
Wind Power Formula (in hp)
0.00000525D^2W^3
*where D is the max diameter of the wheel in ft
W is the wind velocity in mph
Classifications of Windmills
According to shaft orientation, According to blade material, According to shaft speed
Wind Power Formula (theoretical)
0.5ρA*V
where ρ is air density always equal to 1.25 kg/m^3
A is the area of the rotor in m^2
V is the wind speed in m/s
Water Power Formula (in kW)
(Q*H)/102
where Q is the volume of water flowing per minute in cms
H is the head or vertical drop of water in m
Reason of theoretical 60 to 80% water power
> hydraulic losses in conduit and turbines
mechanical losses in bearings and transmissions
electrical losses in generators
Types of water generating devices
Hydraulic rotating prime movers, hydraulic rams, and hydraulic air compressors
Formula for Electric Power (W)
Voltage (V)*Current(amp)
Advantages of electric motor
> simple and compact
light in weight
limited maintenance
starts easily and readily
operated quietly
smooth & uniform power
uniform & variable loads
ICE Formula
PLANn/76*60
where P is the indicated mep in kg/cm^2
L is the piston stroke in m
A is the piston area in cm^2
N is the number of power strokes per minute
n is the number of cylinders
