Awesome. Does holding the pressure after shutdown prove the carb float valve and check valves are working perfectly? For how long does it hold it?
checking fuel pressure - mechanical pump - a question
- Thread starter deQuincey
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That is a good question. This installation is perfect for testing leak down. Is there a spec for the time constant? (I need this on my bavaria as the fuel drains back into the fuel tank after an undetermied, but short, time.)
The important take away from this thread is that in addition to his thumbs, we now have seen DeQ's toes.
.2 bar = 2.9 psi which is what I run on my 3x webers, too much pressure can blow past needle valves. A check valve would solve any concerns regarding draining back to tank.
.2 bar = 2.9 psi which is what I run on my 3x webers, too much pressure can blow past needle valves. A check valve would solve any concerns regarding draining back to tank.
I should have asked a more precise question:
If I replace the house pressure regulator with an alternator and drop from 80 psi on a 1.5 inch pipe that the city provides to 40 psi after the alternator, how much electricity will I generate in the normal course of water usage (watering the lawn, cooking, drinking, flushing, washing machine, and showers which would be about 10 minutes a day for one of the five residents...).
i do not have an answer to how much time does the setup hold the pressure, but i can tell that less than 6 hours, this will be empiric too, we might be able to tell the exact time if someone volunteers to sit in my engine for a while and checks it continuosly
by the way, my setup includes an anti-return valve, that is put just before the pump, see the second pic, the tiny black thing in the fuel line
by the way, my setup includes an anti-return valve, that is put just before the pump, see the second pic, the tiny black thing in the fuel line
Honolulu
Well-Known Member
Arde: since your question remains... The juice your sprinkler alternator will generate will depend on the rate of flow through whatever line it is connected to, and the efficiency of the alternator in converting that flow to power.
It's an interesting potential use of your local water purveyor. I live near the bottom end of the local pressure range and my house pressure outside the PRV is 155 psi; in the house it's likely about 40 psi. The pressure differential won't do any work nor generate power until there's flow.
The answer is that for me in Honolulu, no flow I could possibly use would generate enough kW to offset the cost of water, which includes a rather larger surcharge for the sewer system. That's what solar PV and solar hot water are for. Unhelpfully, the local power utility is about to be bought out by NextEra, a mainland-based power operator that has a very poor record with regard to homeowner power generation.
I am just hoping that Tesla or someone will develop a battery system that will pencil out for homeowners. So far this has not happened, but if it did, I could power the house and charge the i3 from the roof... and use the i3 and battery storage at night?
It's an interesting potential use of your local water purveyor. I live near the bottom end of the local pressure range and my house pressure outside the PRV is 155 psi; in the house it's likely about 40 psi. The pressure differential won't do any work nor generate power until there's flow.
The answer is that for me in Honolulu, no flow I could possibly use would generate enough kW to offset the cost of water, which includes a rather larger surcharge for the sewer system. That's what solar PV and solar hot water are for. Unhelpfully, the local power utility is about to be bought out by NextEra, a mainland-based power operator that has a very poor record with regard to homeowner power generation.
I am just hoping that Tesla or someone will develop a battery system that will pencil out for homeowners. So far this has not happened, but if it did, I could power the house and charge the i3 from the roof... and use the i3 and battery storage at night?
Sorry for the delay. As noted, you need to know both pressure drop and volumetric flow rate to calculate Power. My calculation was as follows:
P [kW] = 5.446e-3[kW*hr/ccf/psi]*B[psi]*C[ccf/hr]
B is the pressure drop in psi.
C is the flow rate in ccf/hr (1ccf = 110 cubic feet).
From the equation above, the unit energy per ccf is just given by,
E [kW*hr/ccf] = 5.446e-3[kW*hr/ccf/psi]*B[psi]
But, if you note that our water rate in the SJWC district is $3.5634/ccf, you can quickly figure out how much it costs to power with water.
Arde, I originally used 100-psi for our operating pressure, so my first figure was low. If you only use 40-psi of the available pressure drop, it'll cost you $16/kW*hr, but your sprinklers will make all the way to your peonies.
Obviously, I have some time on my hands. I am in China. This thread has be my sole recreational connection to the western world for the last 10-days. Hence, my dramatic increase in e9 post rate. BTW, no e9 sightings.
P [kW] = 5.446e-3[kW*hr/ccf/psi]*B[psi]*C[ccf/hr]
B is the pressure drop in psi.
C is the flow rate in ccf/hr (1ccf = 110 cubic feet).
From the equation above, the unit energy per ccf is just given by,
E [kW*hr/ccf] = 5.446e-3[kW*hr/ccf/psi]*B[psi]
But, if you note that our water rate in the SJWC district is $3.5634/ccf, you can quickly figure out how much it costs to power with water.
Arde, I originally used 100-psi for our operating pressure, so my first figure was low. If you only use 40-psi of the available pressure drop, it'll cost you $16/kW*hr, but your sprinklers will make all the way to your peonies.
Obviously, I have some time on my hands. I am in China. This thread has be my sole recreational connection to the western world for the last 10-days. Hence, my dramatic increase in e9 post rate. BTW, no e9 sightings.
Thanks David. My point was that for the volume of water that I need to consume anyways the energy cost is free. Today I use the large pressure drop for the pleasure of the shower massaging my back, but I could generate electricity instead of a strong shower. With electric cars creating the largest distributed battery storage in history time shifting of generation to consumption should not be a problem. And if water pressure uses gravity for distribution you can always generate some electricity even during power outages.
I would not change my shower habits. The 2nd law of thermodynamics guarantees that you will not get back as much energy as pleasure you give up. What do you think of a peltier based trickle charger that uses the heat produced by my compost bin to keep the coupe and bav batteries topped off?
is it me or this thread is going down the slippery slopeeeeeee....
I apologize, it is not just you! I do have two relevant questions.
1. Have you checked your leak-down with the new gauge installation?
2. Where did you source your check valve?
1. Have you checked your leak-down with the new gauge installation?
2. Where did you source your check valve?
1- i beg your pardon, i do not fully understand your question, i think i dont have a leak down, the presuure gauge is a sort of check for future failure in the fuel feeding of the carbs, now it works well, and i can see how it behaves, so if there is a problem in the future i will be able to tell going through some simple checks
2- that particular check valve i bought it from walloth, i do not know if it is still in their catalog, if it is not the case, recently i bought an aluminium one from the same guys that sell the pressure gauge kit, if you are interested i can check the invoice to tell their name and contact details (i also bought from them a nice vacuum pulse dampner that i use in the distributor advance hose)
2. Thanks for the info. I will check with W&N.
1. Leak down: When you turn off the engine, how much time elaspes before the pressure gauge reads zero?
1. Leak down: When you turn off the engine, how much time elaspes before the pressure gauge reads zero?
DeQ, what is that around your oil filler cap?
i do not really know how much time it holds the pressure, i have some data,
at least it holds the pressure for 45 minutes
six hours later reads zero
when between one and the other happens, i do not know yet
hi steve, i answered this before,
it is a fire proof fiber necklace to absorb tiny oil leak from the cap itself, read it carefully, from the cap construction, not from the seal that is obviously new and fresh
DQ, thank you for those data points! I am sure that my BAV is leaking down much faster than that. Installation of the check valve should certainly help.
another check gauge
i have included another checking point,
this gasoline pressure gauge is working well
it keeps on 0,20 bar all the time
now i added a pressure gauge to check coolant pressure, i know the wáter reservoir cap is lock at 1 bar, but how much pressure is usually in the circuit ?
answer is:
0,28 bar is my coolant pressure, this one increases a bit when rpms go up, i have been able to read 0,35 almost 0,4 bar
today i took advantage of a nice and fresh morning to woke up at 7 a.m. and drive to a nice place, and found town centre open to traffic,...;-)
i have included another checking point,
this gasoline pressure gauge is working well
it keeps on 0,20 bar all the time
now i added a pressure gauge to check coolant pressure, i know the wáter reservoir cap is lock at 1 bar, but how much pressure is usually in the circuit ?
answer is:
0,28 bar is my coolant pressure, this one increases a bit when rpms go up, i have been able to read 0,35 almost 0,4 bar
today i took advantage of a nice and fresh morning to woke up at 7 a.m. and drive to a nice place, and found town centre open to traffic,...;-)
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