plumber Posted October 10, 2009 Report Share Posted October 10, 2009 With the advent of low flow devices and mandated water conservation, there is surplus energy at your water meter that you are paying for anyway. I'd really like to hear some input on the following. This would only apply to those who have metered/unmetered water supplies for which they pay for. Not private well systems. I read about the slotted disc turbine earlier... I wonder if a variation would be applicable in this use. Those with paid for water pressures of 40 psi or more could easily "peel" incoming pressure with a in- line turbine that allows for a pressurized flow through. Partial generating through gearing or port / slot configuration. This sealed turbine would then transfer this peeled energy to one of many options. Compressed air comes to mind as a storage option or generated electricity to batteries or back to the grid. This would in fact produce and store energy any time water is used. Assuming typical plumbing and a 2.4 gpm average on water saving plumbing fixtures, volume would not be an issue. Choose your comfort level when picking things like shower heads and faucets. These days, 30 psi and a properly sized water system is actually functional. So those with good pressure, say 50 psi and up could easily peel 20 plus psi every time they use water. This is nothing to sneeze at. Plumbing code puts min. domestic water pressure at 25 psi. U.P.C. Local water purveyors often insist on pressure reducing valves after 75-85 psi. Lota folks out there with high end water pressure. What think ye all? I know it;s not global, but hey, it is conservation. plumber. Quote Link to comment Share on other sites More sharing options...
C1ay Posted October 10, 2009 Report Share Posted October 10, 2009 To accomplish what? Water meters don't measure the amount of pressure you use, only the volume. If you're going to peel some volume off to do work like turning a turbine you're going to pay for it the same as if it came out your faucet. Quote Link to comment Share on other sites More sharing options...
Turtle Posted October 10, 2009 Report Share Posted October 10, 2009 first, a note on water pressure in municipal water supply systems. this pressure is a result of hydraulic head and typically , if not exclusively, it is developed by using water towers. the reason is that if pumps provided the pressure, a large demand by users could outstrip the pumps capacity which would stop all flow or reduce every user's pressure as well as damage/destroy the pumps by running them dry. likewise if a pump provided the pressure and no users were using, then the pump would continue to increase pressure and damage/rupture/destroy either the delivery pipes or the pump itself. peeling off the small amount you suggest given the cross-section of typical delivery lines at the users' site would provide so little power as to be virtually useless for doing any appreciable work. :) :) Quote Link to comment Share on other sites More sharing options...
Moontanman Posted October 10, 2009 Report Share Posted October 10, 2009 Are you talking about using the energy from the water you already use in your house? Can you figure how much energy you would get from the average house at say 50psi by the number of gallons a day used? Quote Link to comment Share on other sites More sharing options...
plumber Posted October 10, 2009 Author Report Share Posted October 10, 2009 Are you talking about using the energy from the water you already use in your house? Can you figure how much energy you would get from the average house at say 50psi by the number of gallons a day used? To Moontanman, cheers! You got it. clay did not. Turtle read my post again. You too clay. Quote Link to comment Share on other sites More sharing options...
Turtle Posted October 10, 2009 Report Share Posted October 10, 2009 ... Turtle read my post again. ... i don't need to. the equations you need to get at what moonman brought up are in the link i gave. :) Quote Link to comment Share on other sites More sharing options...
plumber Posted October 10, 2009 Author Report Share Posted October 10, 2009 Hi MOONTENMAN, I have to keep my replies short...puter eats em. Yes siree, it is a valid conservation of energy you are already paying for... kind of like buying different light bulbs or keeping doors shut. I dont think you'd be going "offgrid" anytime soon, but it's alot funner to contemplate then buying fluorescent bulbs. Cross connection and contamination are non issue. If viewed as a new type of PR valve (pressure reducing valve), only a in line spring check would be needed up stream. Not to protect the municipal water supply, but to make the valve work. I gotta go, take care .plumber. Quote Link to comment Share on other sites More sharing options...
plumber Posted October 10, 2009 Author Report Share Posted October 10, 2009 first, a note on water pressure in municipal water supply systems. Hey turtle, I really apologize, I read the first three sentences of your reply and quit. Because I don't need to know what I already know, and so many responses in these forums are not problem solving or innovative...as in accepted quality control principles and brain storming. The last part of your post does apply. I was inspired by this use: Whole house distillation units that only use power to heat the water. The condenser uses incoming cold water coiled above the unit to condense, But no booster pump to restore the water to working pressure! I think that is awesome. Incoming pressure is spent into a fly wheel or some sort of storage...this is the part that was not disclosed in a way I could grasp...hence my though direction in this forum. Anyway, these units depressurize incoming water in prep for distillation and store that energy in some fashion. it is then reintroduced in a second tank that is gravity fed and separated by a check valve. I am assuming the second tank provides volume during demand cycles. So, diminishing returns aside, this "pump" rotor, ( I suspect a turbine) is an enclosed proprietary device. That is what I am intrigued about. plumber Quote Link to comment Share on other sites More sharing options...
Turtle Posted October 10, 2009 Report Share Posted October 10, 2009 Hey turtle, I really apologize, I read the first three sentences of your reply and quit. Because I don't need to know what I already know, ... no problem. assume nothing about what i don't know by what i don't say & i'll do you the same courtesy. give me some time to consider your additions. :naughty: :D Quote Link to comment Share on other sites More sharing options...
C1ay Posted October 10, 2009 Report Share Posted October 10, 2009 To Moontanman, cheers! You got it. clay did not. Turtle read my post again. You too clay. I get it just fine. If you understood the physics and the math you would too but the fact that you've even made the suggestion in the first place shows that you do not. The bottom line is that you will pay the same for the energy coming into the house via your water supply no matter how you use it so there is nothing to gain. Quote Link to comment Share on other sites More sharing options...
plumber Posted October 11, 2009 Author Report Share Posted October 11, 2009 come on clay, you are being too smart and too fast... the original post already said you are paying for it any way...please read it again. Excess pressure not volume is already being used in similar applications. Very simple hot head. Quote Link to comment Share on other sites More sharing options...
Turtle Posted October 11, 2009 Report Share Posted October 11, 2009 Hey turtle, ... I was inspired by this use: Whole house distillation units that only use power to heat the water. The condenser uses incoming cold water coiled above the unit to condense, But no booster pump to restore the water to working pressure! I think that is awesome. Incoming pressure is spent into a fly wheel or some sort of storage...this is the part that was not disclosed in a way I could grasp...hence my though direction in this forum. Anyway, these units depressurize incoming water in prep for distillation and store that energy in some fashion. it is then reintroduced in a second tank that is gravity fed and separated by a check valve. I am assuming the second tank provides volume during demand cycles. So, diminishing returns aside, this "pump" rotor, ( I suspect a turbine) is an enclosed proprietary device. That is what I am intrigued about. plumber i did some searching for "whole house distillation unit" and some variations on that theme, but mostly found either adverts or industrial installations. nothing yet like you describe though. :) where did you run across this? do you have a link or other resource i can examine? Quote Link to comment Share on other sites More sharing options...
C1ay Posted October 12, 2009 Report Share Posted October 12, 2009 Very simple hot head. That won't get you far around here Do the work and support your proposition or find another forum. If you want to debate then debate, scientifically. If you just want to insult, goodbye. Let's see if I can help you understand this since I have been a hydraulic engineer for over 30 years now... Static pressure in a pipe conveys no energy at all. No matter if you have 20 PSI or a 1000 PSI waiting at your faucet there is no transfer of energy until you open the faucet and allow flow. Consequently there is no bill from the water company until you open the faucet and allow flow because nothing has transferred to you. Once you do open a faucet then there is a movement of energy through the system. This energy can be calculated by taking the flow in GPM times the gauge pressure (PSIG) and dividing by the constant 1714 to obtain the energy in horsepower, assuming 100% efficiency...i.e,[math]HP = \frac{GPM * PSI}{1714}[/math]. It is quite frequently a convenience to convert horsepower to watts since each horsepower of energy is 746 watts. Now, let's say, for the sake of discussion, that you have 50 PSIG at the faucet and you want to draw water at 1 gallon per minute. You may just have to barely open the valve at that pressure to create a small orifice that provides a sufficient passage at 50 PSIG to allow 1 gallon per minute to pass through the valve. It should be simple to see at this point that cutting the available pressure in half to 25 PSIG is going to require you to open the valve to about twice the amount to get the same 1 gallon per minute. Cutting the pressure in half will cut the transferred energy in half though as expected. Run the numbers in the energy equation above to see for yourself. Now, what can you do to reduce the pressure at the valve. You can add another valve in parallel with the first that allows 1 gallon a minute to go elsewhere, like an accumulator, and the energy could be stored as you propose but the flow through the water meter is now 2 GPM at 50 PSIG, the sum of the outlets, and you are now paying for twice as much water in order to use 25 pounds of the available pressure to store energy for alternative use. You can use the equation above to determine how much energy you could store per gallon. Another alternative would be to use a motorized flow divider to peel of flow and reduce pressure. A 50:50 divider would accomplish the same thing as above though and would still cost you twice as much in water to get the same usage at your faucet as you had before modifying anything. Now, if you want to extract energy from your water system for storage or work that energy, as a combination of flow and pressure, must pass through the meter. If you peel any off at all it becomes additive to your water usage and increases your bill. There is not some amount now that you are being charged for that is being wasted. Pressure alone, all by it's lonesome, does nothing and you are not charged for the pressure coming into your house, only the flow you use regardless of the pressure. You cannot tap the pressure by itself and get any yield from it, you must have flow and any flow you have is an increase, plain and simple. Quote Link to comment Share on other sites More sharing options...
Donk Posted October 12, 2009 Report Share Posted October 12, 2009 I recall that some years ago somebody in the UK was talking about producing a motor to run on mains pressure. In those days water metering wasn't common - only the largest users had metered supplies. The water company quickly squashed the idea. Mains pressure didn't come free - they were using power to run the pumps that provided the pressure. Anyone using such a device on an unmetered supply would be prosecuted for power theft. I didn't find anything about the incident online, but small water-powered generators were commonly available 100 years ago.Water Engines Quote Link to comment Share on other sites More sharing options...
chilehed Posted October 17, 2009 Report Share Posted October 17, 2009 ...So those with good pressure, say 50 psi and up could easily peel 20 plus psi every time they use water. This is nothing to sneeze at. Plumbing code puts min. domestic water pressure at 25 psi. U.P.C. Local water purveyors often insist on pressure reducing valves after 75-85 psi. Lota folks out there with high end water pressure. What think ye all? I know it;s not global, but hey, it is conservation. plumber.Assuming a flow rate of 10 gpm and a line pressure of 60 psi, the max hydraulic energy available would be 240 watts if you just dumped the water onto the ground next to the meter. Figuring in efficiency losses and the fact that you'd want to have some pressure left at the shower head in the upstairs bathroom, you might be able to power a 60 watt bulb. Compare the costs of the installation with the savings in untility bills, and I suspect you'll decide it's not worth doing. Quote Link to comment Share on other sites More sharing options...
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