a. Energy
With our energy to work. In pumping energy required to lift water with a certain flow. Water energy is supplied by a pump that moves by human power or motors using solar energy, wind or fuel. Energy is usually measured in Watt-hours or watt-hour (Wh or Wjam). Because the value of 1 Wh is very small, the unit normally used is the kilowatt-hour (kWh) where 1 kWh = 1,000 Wh.
Some general overview of the value of the energy used for a specific job are:
- A farmer works in a rice field using the energy of about 0.2 to 0.3 kWh per day
- The fan on the table using 0.3 kWh of energy every hour
- Air conditioning uses about 1 kWh of energy every hour
Note that the time period is always given when explaining the amount of energy required. Eg farmers requires 0.2 kWh of energy every day to work, the energy is supplied from the food eaten each day. In irrigation the amount of energy needed is determined in units of time daily, monthly or seasonal. A crucial aspect of energy is that energy can be converted from one form of energy into other forms.
Humans and animals to convert food into useful energy to move a muscle. In a system of pumps driven by diesel engines, the energy is converted several times before it is used to pump water. Chemical energy contained by diesel fuel is burned in a diesel engine to produce mechanical energy. This energy is entered into the pump through the rotary shaft (drive shaft) and finally into the water.
“The calculation of the required pump energy.”
The amount of energy required to pump water depends on the volume of water pumped and head required is calculated by the formula:
Example
600 m3 of water pumped daily into a water tank which is located 10 m above ground level. Calculate how much energy is required?
Using the above equation, the energy of water = (600 x 10) / 365 = 16.4 kWh per day.
b. Power or Power (Power)
The term force or power is often confusing in the context of the energy terms. The term is related but different meanings. Energy is the capacity to do a job, while the power is the rate at which energy is used. Force or power is the rate of energy use is usually measured in kilowatts (kW). The power needed to pump water is called hydropower defined by the equation:
Other commonly used unit for power is the horsepower (HP) with a conversion of 1 HP = 0.74 kW or 1 kW = 1.35 HP.
Example:
In the example above has been calculated that the energy required every day to lift up to 600 m3 of water up to 10 m is 16.4 kWh. How hydroelectric necessary? To calculate the water power of water takes energy needed for pumping:
- If pumping continuously for 24 hours per day, then the Air Force (kW) is 16.4 / 24 = 0.68 kW = 0.92 HP
- If the pump is only working 12 hours / day, then hydropower = 16.4 / 12 = 1.37 kW = 1.85 HP
- If pumping only 6 hours / day, then hydropower = 16.4 / 6 = 2.73 kW = 3.68 HP.
Note:
The energy required is the same for all three cases. But energy depends on the rate of energy use. The number of workers needed is greater if energy use shorter time. Another way compute power and energy is to use pumped water discharge (of the volume of water pumped).
Water Power (kW) = 9,81x Debit (m / sec) x Head (m)
Furthermore, the water energy can be calculated from water power by multiplying the operating time,
Energy Water = Water Power (kW) x Operational time (hours)