Rough Calculations for Pumping a Deep Well
Rough Calculations for Pumping a Deep Well
(OP)
So I have been thrown a question about pumping an underground water supply which is a little outside of my comfort zone. A friend of a friend has a piece of land with a sizable underground water supply. A 36 inch diameter cased well and 24 inch monitoring well have both been drilled and the well will be pulling from around a thousand feet deep. If I wanted a rough estimate on the cost in energy to pump a certain amount of water from the well what kind of specifics would I need assuming I was using a typical pump for such an application. And what type of pumps are generally used for pulling water from such a deep well. Thanks in advance.
Tim
Tim





RE: Rough Calculations for Pumping a Deep Well
Hu_ft = required user_head_ft = required_system_pressure_psig * 2.31
Total_pump_head Ht = Hw + Hu
Pump discharge pressure_psig = Ht / 2.31
The required hydraulic power is,
Power_ftlbs_per_sec = Ht * Q_gpm /7.4805/60
Q_gpm = flowrate in gallons per minute
HorsePower = Power_ftlbs_per_sec /550
Power_input_to_pump (Hp)= HorsePower/Pump_Efficiency
For rough estimate use a pump efficiency of 0.65 or have a look at a manufacturer's catalogue.
Electrical Power required is,
Power_input_to_motor (kW) = 0.746 * Power_input_to_pump / motor_efficiency
Say 0.9 for motor efficiency.
multiply your power input to motor by the cost per kWh x the running time.
Use a submersible pump, typical fig here, http:
Goulds Pumps residential water supply website,
http://www.goulds.com/master.asp?ID=3#2
Grundflo also makes many different water well supply pumps.
University of Nebraska irrigation website,
http:/
Let us know if you need mo info.
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Rough Calculations for Pumping a Deep Well
RE: Rough Calculations for Pumping a Deep Well
Head will be the vertical height from the expected pumping drawdown level to the highest point of your discharge pipe work plus all friction losses in the rising maim and delivery pipe work.
For interest - what is the flow rate you require and what
A thousand foor deep well doesn't give any indication as to what the standing water level is and what the pumping level is - without this information you are guessing
RE: Rough Calculations for Pumping a Deep Well
For interest- what is the flow rate you require and what is the anticipated head?
RE: Rough Calculations for Pumping a Deep Well
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Rough Calculations for Pumping a Deep Well
As far as pumps go, a 4" diameter pump is the standard for a residential application and there are many manufacturers. Goulds, Berkley, sta-rite, Grundfos, Mcdonald, just to name a few. Please provide more info on you pumping conditions and available power supply and I will be happy to help you find a pump that will fit.
RE: Rough Calculations for Pumping a Deep Well
Based on the sizes of the casings quoted, I'd guess this is a large irrigation well.
RE: Rough Calculations for Pumping a Deep Well