Peter Daysh Davey Water Heater Query

[Duncan]

OK, I have some first results from my sonic boiler (SBSJ1) set up, as shown in photo previously.

I will show my method for determining Pinput and Poutput and the results, and invite comments on both.

I have a CEN-TECH P3 "Kill-a-watt" meter that displays KW-H to 0.01 accuracy. I ran this P3 meter with a load until it just turned on the display to 0.05 KWH. Next I ran my SBSJ1 device until it reached boiling (which stirs the water), stopped registering the time elapsed with a stop-watch, 62 seconds. I quickly measured Temperatures inside the inner bell and between the inner and outer bells using an infrared temp probe.

I let the sbsj1 cool (to 98F) and ran a second time with the same measurements, and this time the P3 turned to 0.06 KWH, so I stopped the run there to take measurements, 31s. The total elapsed time was 62+31 = 93 s.

By using the P3 JUST AS the reading turns to a higher value, increasing by 0.01KWH, I believe the accuracy is quite good, probably within 10% with this method.

Consider a 100W bulb for 1 hour = 0.1 KWH. Thus, 0.01 KWH in 1/10th hour = 6 minutes = 360 s.
Here in my experiment we have 0.01 KWH in 93 seconds, so the power is more than 100W, and I calculate:
Pin = 360s/93s X 100W = 387W.

Next, to calculate the output power, first I calculate the heat-energy Q calorimetrically, using the Temp-rise in the water.
Q = Cg X m X (Tfinal - Tinitial).

For the first run of 62 s, Tfinal - Tinitial = 147Fahr - 83F = 64F = 36Celsius temp rise.
For the second run of 31 s, Tfinal - Tinitial = 145F - 98F = 47F = 26Celsius temp rise.


Here, Q = 4.18 [J/g-C] X 125g X 36C = 18810 J for the first run, and
Q = 4.18 [J/g-C] X 125g X 26C = 14120 J for the second run.
Total heat measured, Qtotal = 32930 J in 93 s, so
Pout = Q/total-time = 32930J/93s = 354W.

Which is less than Pinput.

Finally, I calculate the efficiency n = Pout/Pin = 354W/387W = 0.91. Not surprising -- NO tuning attempted for this base-line run.


Any comments on the method or the results?
Thanks,
Steve

Specific Heat
anyway using your test run you have basically taken
(62s + 31s) = 93s to raise 125g of water (36 + 26) = 62Deg C
if this were to be done with 100% efficiency if would take
4.186 x 125 x 62 = 32441.5 Joules = 32441.5 watt/seconds
32441.5/1000 = 32.44 Kw/seconds 32.44/60 = 0.540 KW/ Min 0.540/60 = 0.0090 KW/hr
note prof this is the very best efficiency possible given the mathematical specific heat exchange of water. however you claim to have achieved this temperature rise using only 0.01 Kw/H .. this would give you an efficiency of
0.009Kw/h/0.01kw/h x100% = 90 % now thats a bit more like ... think I'll have to go back to adding school!! in fact Ive also rounded off here and there so your 91% seems on the button

[RAMSET]

Keep you in our thoughts and prayers

Michael
Scary thing to have happen!! very controllable too...stay well and please keep us posted !!
Thank you for your contributions here and elsewhere.
Chet

[PhysicsProf]

Sorry all, have just noticed the mistake I have made in the above post, IT IS NOW CORRECTED. It should read that the mains 120/240v side is the low vltage control side.

My excuse is that I have not been too well in the last few weeks, I am going into hospital on monday for scans etc "hope they do not hit the erase button" as it seems I have had a small stroke which caused me to see double for a few days.

Mike

We're pulling for you, Mike! Hope it goes well Monday. I've appreciated your posts.

[Michael John Nunnerley]

mistake made

Sorry all, have just noticed the mistake I have made in the above post, IT IS NOW CORRECTED. It should read that the mains 120/240v side is the low vltage control side.

My excuse is that I have not been too well in the last few weeks, I am going into hospital on monday for scans etc "hope they do not hit the erase button" as it seems I have had a small stroke which caused me to see double for a few days.

Mike

[evolvingape]

I stand corrected!

Hi Cherryman,

I had not accounted for maximum VA rating of such a relatively large load, thankyou for the correction, and thankyou everyone for proposing the solution. It was a relevant comment in passing as I was not on that page for that reason

I cannot say too much now as I am double checking my calculations but wait a little while and you can read about what I am working on at Environmentally Friendly Engines & Green Solutions | Sea Bird Adventure soon, it will be my first article published on that site (assuming editorial approval of course).

In the meantime if you want to do some essential background reading check these links out, you are going to need to understand this system information in the future anyway, unless your happy with a kettle being the limit of the boilers potential:

Heat capacity - Wikipedia, the free encyclopedia

Latent heat - Wikipedia, the free encyclopedia

Properties of Saturated Steam - SI Units

Use of enthalpies to calculate energy needed and / or recovered

Steam Tables Online

Rob

[Slovenia]

Thanks!!

Thanks Mike for sharing here!!

Try this

[ATTACH]9983[/ATTACH]

Two transformers of 120 or 240V to 12v, the 12v side is the low voltage control side, the diodes should be to handle the voltage and current.
The low voltage DC can be a 9v battery such as PP3

Mike

[Michael John Nunnerley]

Try this

Try this



Two transformers of 120 or 240V to 12v, the high voltage side is the low voltage control side, the diodes should be to handle the voltage and current.
The low voltage DC can be a 9v battery such as PP3

Mike

[Duncan]

cherryman your link showing error

[Duncan]

Duncan
So we have a learning tool [the boiler ]

I have recently wanted to ask Eric what he thinks about this ?

A Gift IMO!!

THx
Chet

[Cherryman]

There are designs designed for stage lighting, regularly 2Kw.
They can be bought from Ebay very cheaply, usually six at
a time. You need to give them a low voltage (probably from
0 - 12v),m and the socket, usually round pin 15amp then goes from
0 - 220volt, with the ability to handle 2Kw. Search for "Strand
dimmer racks".

Paul-R

Tnx Paul, I will look around .

How about this?

Vermogensregelaar 110-240 V~, 4000 VA - Vermogensregelaar-bouwpakketten - Conrad Electronic

[PhysicsProf]

OK, I have some first results from my sonic boiler (SBSJ1) set up, as shown in photo previously.

I will show my method for determining Pinput and Poutput and the results, and invite comments on both.

I have a CEN-TECH P3 "Kill-a-watt" meter that displays KW-H to 0.01 accuracy. I ran this P3 meter with a load until it just turned on the display to 0.05 KWH. Next I ran my SBSJ1 device until it reached boiling (which stirs the water), stopped registering the time elapsed with a stop-watch, 62 seconds. I quickly measured Temperatures inside the inner bell and between the inner and outer bells using an infrared temp probe.

I let the sbsj1 cool (to 98F) and ran a second time with the same measurements, and this time the P3 turned to 0.06 KWH, so I stopped the run there to take measurements, 31s. The total elapsed time was 62+31 = 93 s.

By using the P3 JUST AS the reading turns to a higher value, increasing by 0.01KWH, I believe the accuracy is quite good, probably within 10% with this method.

Consider a 100W bulb for 1 hour = 0.1 KWH. Thus, 0.01 KWH in 1/10th hour = 6 minutes = 360 s.
Here in my experiment we have 0.01 KWH in 93 seconds, so the power is more than 100W, and I calculate:
Pin = 360s/93s X 100W = 387W.

Next, to calculate the output power, first I calculate the heat-energy Q calorimetrically, using the Temp-rise in the water.
Q = Cg X m X (Tfinal - Tinitial).

For the first run of 62 s, Tfinal - Tinitial = 147Fahr - 83F = 64F = 36Celsius temp rise.
For the second run of 31 s, Tfinal - Tinitial = 145F - 98F = 47F = 26Celsius temp rise.


Here, Q = 4.18 [J/g-C] X 125g X 36C = 18810 J for the first run, and
Q = 4.18 [J/g-C] X 125g X 26C = 14120 J for the second run.
Total heat measured, Qtotal = 32930 J in 93 s, so
Pout = Q/total-time = 32930J/93s = 354W.

Which is less than Pinput.

Finally, I calculate the efficiency n = Pout/Pin = 354W/387W = 0.91. Not surprising -- NO tuning attempted for this base-line run.


Any comments on the method or the results?
Thanks,
Steve

[wrtner]

Hey Rob, I tried that yesterday! Great minds think alike

Anyway, I suspected it at forehand already, but tried anyway... Got a good 2 seconds .. Before it died.

Most dimmers go to are not capable of handling the wattage. I got a 300 W dimmer, and smoked it in 2 seconds. You need a dimmer capable of dimming your peak wattage. ( my setup <3000 )

So good plan, but find a powerful dimmer.

There are designs designed for stage lighting, regularly 2Kw.
They can be bought from Ebay very cheaply, usually six at
a time. You need to give them a low voltage (probably from
0 - 12v),m and the socket, usually round pin 15amp then goes from
0 - 220volt, with the ability to handle 2Kw. Search for "Strand
dimmer racks".

Paul-R

[Cherryman]

Hi everyone,

There is an additional option for experimentation with electrode boilers:

Pulse-width modulation - Wikipedia, the free encyclopedia

"Light dimmers for home use employ a specific type of PWM control. Home-use light dimmers typically include electronic circuitry which suppresses current flow during defined portions of each cycle of the AC line voltage. Adjusting the brightness of light emitted by a light source is then merely a matter of setting at what voltage (or phase) in the AC halfcycle the dimmer begins to provide electrical current to the light source (e.g. by using an electronic switch such as a triac). In this case the PWM duty cycle is the ratio of the conduction time to the duration of the half AC cycle defined by the frequency of the AC line voltage (50 Hz or 60 Hz depending on the country)."

So it should be possible using a simple, commonly available home-use light dimmer switch to pulse current at variable rates through the water. Water being a polar molecule will attempt to align itself to the electromagnetic field supplied by the AC and therefore in theory it should cause either rotation or linear vibration of the molecular bonds at a rate defined by the frequency. The frequency will remain fixed but you will have some control over when current flows within the AC half cycle and at what pressure voltage. The duty cycle of the current pulses will become a user defined variable with a duty cycle <100%.

Please apologise to your wives for me for the now inevitable stripping of light switch dimmers from your households walls

Rob

Hey Rob, I tried that yesterday! Great minds think alike

Anyway, I suspected it at forehand already, but tried anyway... Got a good 2 seconds .. Before it died.

Most dimmers go to are not capable of handling the wattage. I got a 300 W dimmer, and smoked it in 2 seconds. You need a dimmer capable of dimming your peak wattage. ( my setup <3000 )

So good plan, but find a powerful dimmer.

[evolvingape]

Current Pulse Pressure Waves

Hi everyone,

There is an additional option for experimentation with electrode boilers:

Pulse-width modulation - Wikipedia, the free encyclopedia

"Light dimmers for home use employ a specific type of PWM control. Home-use light dimmers typically include electronic circuitry which suppresses current flow during defined portions of each cycle of the AC line voltage. Adjusting the brightness of light emitted by a light source is then merely a matter of setting at what voltage (or phase) in the AC halfcycle the dimmer begins to provide electrical current to the light source (e.g. by using an electronic switch such as a triac). In this case the PWM duty cycle is the ratio of the conduction time to the duration of the half AC cycle defined by the frequency of the AC line voltage (50 Hz or 60 Hz depending on the country)."

So it should be possible using a simple, commonly available home-use light dimmer switch to pulse current at variable rates through the water. Water being a polar molecule will attempt to align itself to the electromagnetic field supplied by the AC and therefore in theory it should cause either rotation or linear vibration of the molecular bonds at a rate defined by the frequency. The frequency will remain fixed but you will have some control over when current flows within the AC half cycle and at what pressure voltage. The duty cycle of the current pulses will become a user defined variable with a duty cycle <100%.

Please apologise to your wives for me for the now inevitable stripping of light switch dimmers from your households walls

Rob

[kenssurplus]

Hi All,

I have several stainless steel "containers" cut and their acoustic resonances mapped, but looking back through the thread, oh back as far as page 37 or so,
there seems to be conflicting info about the frequencies that we are supposed to tune the cap or ring to. One post says 60,120,240,480 hz for USA and another says 300 hz for USA. I am ready to start removing metal to raise the freq. but I would like to know the lastest and most up to date correct info.
Anyone have that?