Energy Density and Conversion.
Patrick, Sun Jan 22 2017, 01:57AMI need help these units of energy, power and time have my brain all upside down.
If I have 300ml of methanol which is 0.0364 M joules per Liter, (and assuming 100% efficiency) for how many seconds can I get 300 watts ?
starting here, 1 L / 0.3 L = 3.3 then,
0.0364 MJ / 3.3 = 0.011 MJ available in the 300ml.
next 0.011 MJ = 11,000 J.
And 11,000 J / 300 W = 36 seconds is totally wrong.
This dimensional analysis is driving me nuts. Its right in front of me too, i just know it. theres a time value missing i think.
Re: Energy Density and Conversion.
Plasma, Sun Jan 22 2017, 03:23AM
Patrick
Are you sure 0.036MJ/kg is correct, most fuels seem to be around 1-20MJ/kg.
I tried looking on engineering toolbox website but they didn't have methanol.
Plasma, Sun Jan 22 2017, 03:23AM
Patrick
Are you sure 0.036MJ/kg is correct, most fuels seem to be around 1-20MJ/kg.
I tried looking on engineering toolbox website but they didn't have methanol.
Re: Energy Density and Conversion.
Bjørn, Sun Jan 22 2017, 03:24AM
I got the same result, your value for energy content of your methanol looks to be completely wrong, unless it is diluted to the extreme.
Bjørn, Sun Jan 22 2017, 03:24AM
I got the same result, your value for energy content of your methanol looks to be completely wrong, unless it is diluted to the extreme.
Re: Energy Density and Conversion.
Patrick, Sun Jan 22 2017, 03:31AM
the great all knowing wiki doesnt lie. bow to its greatness. submit to its power.
mmmm apparently if i use the wrong numbers i get the wrong answer. Methane and Methanol perhaps are different chemicals.
Patrick, Sun Jan 22 2017, 03:31AM
the great all knowing wiki doesnt lie. bow to its greatness. submit to its power.
mmmm apparently if i use the wrong numbers i get the wrong answer. Methane and Methanol perhaps are different chemicals.
Re: Energy Density and Conversion.
Bjørn, Sun Jan 22 2017, 03:39AM
You used the value for methane instead of for methanol.
Bjørn, Sun Jan 22 2017, 03:39AM
You used the value for methane instead of for methanol.
Re: Energy Density and Conversion.
Patrick, Sun Jan 22 2017, 03:41AM
i just realized that !
Patrick, Sun Jan 22 2017, 03:41AM
i just realized that !
Re: Energy Density and Conversion.
Patrick, Mon Jan 23 2017, 04:14AM
Ok lets try this with a clear mind.
15.6 MJ / 3.3 = 5.2 MJ available in 300mL
5.2 MJ / 300 W = 17333 / 3600 sec/Hr = 4.8 hours.
4.8 Hr x 0.25 (%) = 1.2 hours.
this seems right ? I think.
Patrick, Mon Jan 23 2017, 04:14AM
Ok lets try this with a clear mind.
15.6 MJ / 3.3 = 5.2 MJ available in 300mL
5.2 MJ / 300 W = 17333 / 3600 sec/Hr = 4.8 hours.
4.8 Hr x 0.25 (%) = 1.2 hours.
this seems right ? I think.
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