Well pump calculation (power, pressure losses ...)

Work concerning plumbing or sanitary water (hot, cold, clean or used). Management, access and use of water at home: drilling, pumping, wells, distribution network, treatment, sanitation, rainwater recovery. Recovery, filtration, depollution, storage processes. Repair of water pumps. Manage, use and save water, desalination and desalination, pollution and water ...
fam
I learn econologic
I learn econologic
posts: 27
Registration: 29/01/10, 09:45

Well pump calculation (power, pressure losses ...)




by fam » 29/09/11, 09:59

Hello

For my isolated site development project, I have finally finished drilling for water (Mandatory in order to obtain a building permit!) And I need help with the calculation of the pump.

Drilling 62m, water height 30m, horizontal distance 25m.

Since I do not have EDF, the idea is to connect the group 1 or 2 times a day to supply the well pump which would fill:

a pressure tank located at the height of the well + 6m (a capacity of 100l seems sufficient to me) (shower and kitchen sink),

plus a tank that I have of 1000 liters placed in height (WC and others)


According to my calculations I would need a pump delivering min 12bars,

for height 4, length 0,3, non-return valves 1,5, filters 0,6, horizontal and tank 5.

For the pipe I intended to use phed in 25 unless there is a real advantage in going bigger.

Can someone confirm this for me?

Thank you in advance.
0 x
"Talking about it is one thing, doing it another.
I made my choice"
Christophe
Moderator
Moderator
posts: 79124
Registration: 10/02/03, 14:06
Location: Greenhouse planet
x 10973




by Christophe » 29/09/11, 10:11

12 bars that seems important to me: especially the 5 bars for 25 m horizontal and balloon?

The linear pressure drops depend on the speed and therefore on the pump power. What flow did you take? Maybe a little too big right?

In short, what is the pressure drop calculation method that you used?

I'm just "inside" right now :)

In any case you will need one (or more) submersible pump at the bottom of the well, but I think you already know that.
0 x
fam
I learn econologic
I learn econologic
posts: 27
Registration: 29/01/10, 09:45

pressure drop calculation




by fam » 29/09/11, 10:28

Hello

Thank you for this quick response, the 5 bars is for the balloon, or 4 +1 to put it under pressure.

At the beginning I thought of working by gravity only. it's a bit tight for the shower. In addition, the advantage of the pressurized balloon is that I can use a (re) gas water heater and place a suitable fitration (depending on what the analysis will reveal).

Otherwise for the calculation of loss 1 per m of immersion depth (40)
3x5 valves, i.e. 15, filtration 6 and 30 meters horizontal 3.
which makes us 40 +15 +6 + 3 = 64/10 = 6,4.

To this must be added the pressure required for the ball (5) and I get 11,4, rounded to 12.

Maybe my calculation is wrong?

cordially
Last edited by fam the 29 / 09 / 11, 10: 36, 1 edited once.
0 x
"Talking about it is one thing, doing it another.

I made my choice"
Christophe
Moderator
Moderator
posts: 79124
Registration: 10/02/03, 14:06
Location: Greenhouse planet
x 10973




by Christophe » 29/09/11, 10:44

Pressurized balloon? I don't know how it works Is it like a bigger suppressor tank?

To increase the pressure, why not use a suppressant beast at 150 €?

Surely that will come back to you cheaper than the balloon + pump?
Ah yes you have no current ... damn.

Wrong I don't know how and where do you get the pressures from? Normally you have to know the speed so the flow you want ...

http://www.thermexcel.com/french/ressourc/pdc_line.htm
http://www.thermexcel.com/french/ressourc/pdc_singu.htm
0 x
Christophe
Moderator
Moderator
posts: 79124
Registration: 10/02/03, 14:06
Location: Greenhouse planet
x 10973




by Christophe » 29/09/11, 21:33

The Thermexel method on linear pressure drops is complex to solve (iteration).

You will find in this message, the .pdf which gives abacuses (valid in low roughness: copper or plastic pipe) usable much faster: https://www.econologie.com/forums/post212918.html#212918
0 x
User avatar
Did67
Moderator
Moderator
posts: 20362
Registration: 20/01/08, 16:34
Location: Alsace
x 8685




by Did67 » 30/09/11, 09:33

No ! No !

Your storage tank will not remain under pressure ... As soon as you collect, the pressure drops.

You must put a recovery pump (booster group) which puts the shower circuit under pressure; not the ball ...

Your balloon, if you want to use a standard balloon not too expensive, it supports 3 bars max ...

So you put your balloon in the air, zero pressure, your immersed "high power" pump pumps into the balloon to fill it and only starts up once per recharge ... Otherwise, a) you go. explode (overload on start-up); b) have a ridiculous yield: each time relaunching the 30 m water column is a considerable "lost" job ...

The overpessor group at the outlet of the balloon will operate in "jerk" mode, as needed. He's studied for him. But you need electricity at this time ...

So it seemed easier to put the ball higher, to have enough pressure for the shower ... A single submerged pump, of sufficient power, used in its place of optimal performance (probably a pump with several stages) ... And use when you want, by garvité. You should be able to have: a) about 10/15 m minimum height; b) a simple circuit to reach the shower to limit the pressure losses; c) a simple water heater, not too sensitive to pressure differences ... The simplest: the shower in a straight line under the ball, and a gas water heater ...
0 x
Christophe
Moderator
Moderator
posts: 79124
Registration: 10/02/03, 14:06
Location: Greenhouse planet
x 10973




by Christophe » 30/09/11, 09:44

Did67 wrote:Your storage tank will not remain under pressure ... As soon as you collect, the pressure drops.

You must put a recovery pump (booster group) which puts the shower circuit under pressure; not the ball ...


Yes it will fall but can remain in the exploitable (=> 1.5 bars) for a good part of the volume (50% :D).

A suppressor does not start as soon as you shoot it!
The problem is that it has no current ...

Apart from the high tank so under pressure I don't see too much solution without mains current ...

Ah if this is what he needs: a small 12V lift pump on solar batteries controlled by the opening of the taps with a "flowmeter switch" (I do not know the exact name) ... Here is a solution which could be essential (without the need for pressurization therefore more expensive initial pumping cost or balloon ...).

Large tank, say 0.5 bar (5m high compared to the pump) : Arrow: 12 V pump : Arrow: water at 3 bars

The more height difference you have between tank and 12V pump, the less energy it will consume.
0 x
User avatar
Did67
Moderator
Moderator
posts: 20362
Registration: 20/01/08, 16:34
Location: Alsace
x 8685




by Did67 » 30/09/11, 14:23

Christophe wrote:
Yes it will fall but can remain in the exploitable (=> 1.5 bars) for a good part of the volume (50%: D) ..


It depends.

If you fill 100% of water, not elastic, the pressure will be at zero as soon as the first liter is withdrawn ... [in this case, moreover, filling is not simple - decompression valve?]

If you fill like a pressure regulating balloon, upside down, in fact, you compress the air which then serves as "pressurization" ... Yes, there you are right ... But the capacity will be reduced ... Must leave at least 1/3 of pressurized air ...
0 x
fam
I learn econologic
I learn econologic
posts: 27
Registration: 29/01/10, 09:45




by fam » 30/09/11, 14:31

Hello

As for the booster tank, the suggestion comes from my well pitcher to whom I had exposed my first idea: Well pump to 1000l buffer tank followed by a 12V booster.
His remarks: purchase of 2 pumps, 2x current and faster battery wear, water stored in quantity so with risk of quality degradation.

With a slightly more powerful pump, and one or more balloons, these disadvantages are eliminated. (Ps I do not buy my material from him ..)

The price of a food-grade water tank (therefore with a bladder) is equivalent to that of the 12V booster. The difference in the price of the well pump is negligible. So I gain in noise, batteries and purer water.

Of course the pressure decreases from the first use, however these tanks are designed for a maximum pressure of 8 bars, so with 5 bars we are largely within the standards. There is therefore a "range" of use.

For good info on the use of booster tanks see http://lokistagnepas.canalblog.com/

A 100 l balloon will give about 40 liters usable under pressure, which seems sufficient for 3/4 people. For 2 years in testing, I find that for a thrifty person 15 liters per day are sufficient:

Morning: coffee, toilet and dishes: 4L
Noon: Meals and dishes 3L
Evening: Shower 5l and meal 3 L.

In my scenario the balloon and the tank are at the highest ie only 2/3 meters above the shower.

If the pressure drops too much I will simply run out of hot water.
Ps there remains the reserve of 1000L in cold water.

Regarding the links for the calculations, thank you I will try to get started but I am far from being an engineer or specialist in fluids or my original request.
It is true that I took the way backwards starting from the required pressure rather than the flow since this is of little interest in my case.

cordially
0 x
"Talking about it is one thing, doing it another.

I made my choice"
User avatar
Macro
Econologue expert
Econologue expert
posts: 6459
Registration: 04/12/08, 14:34
x 1610




by Macro » 30/09/11, 14:33

Personally I would have only one height reservation with gravity flow or slightly pressurized at 1 bar just for that is more than enough to take a shower all it is to have plumbing without elbow with large diameters and good old taps with large opening diameters ...
0 x
The only thing safe in the future. It is that there may chance that it conforms to our expectations ...

 


  • Similar topics
    Replies
    views
    Last message

Go back to “Water management, plumbing and sanitation. Pumping, drilling, filtration, wells, recovery ... "

Who is online ?

Users browsing this forum : No registered users and 143 guests