Conversion from mg/m3 to mg/kWh

http://www.longman.co.uk/gcsechemistry/worksheets/pdfs/worksheet8.pdf explains all.

CH₄ = 16g/mol

C₂H₆ = 30g/mol

C₃H₈ = 44g/mol

C₄H₁₀ = 58g/mol

Then use the conversion 1kWh = 3.6 x 10⁶ Joules.

First off all thank you,

But as you know these are correct for complete combustion.

for example i measured 20 ppm CO = 20 x 1.25 mg/m3 = ? mg/kWh

One could do an engineering approximation by proportioning the CO₂ to unburnt materials to give an estimate of the energy needed to produce the flue gases present.

Try it, and see what happens?

Could you elaborate on this for a novice to the topic - the equation you give suggests knowing the relation of m³ gas output in relation to boiler KWh rating. Is there a distinction between combusted and non -combusted products output etc . The situation is clearly more complicated than I can appreciate at present , but it may be worth the time to explain it in more detail (ie does it amount to knowing volumetric gas output etc ). Some questions can find answers if explained in terms that the uninitiated are familiar with - it may be familiar or straightforward to yourself , but the more people that can comprehend the problem the better chance there is of a useful reply. I'm sure the description makes perfect sense to somebody in the trade , but if an answer is not forethcoming , I think you need to broaden the terms.

do u solve your problem

because I have same problem :(

I would suggest that your easiest approach would be to use the rated value of the burner for your Kw figure. In my part of the world our regulations simply work on PPM. Assuming your burner is working at a reasonable level of excess air it all comes down to the same thing. PPM is simply a percentage of flue gas. The flue gas volume is directly related to the output of the burner.

20PPM is a quite respectable CO figure so unless you have to present actual figures in mg/kwh I would not be too concerned. If that's high fire I would say your burner is running well.

My measurements ;

excess air = 1.2 CO2 = 10 % vol CO = 21 ppm SO2 = 2 ppm O2 = 4.2 % vol

Burner Heat İnput Qn = 1450 kW Test Gas = CH4

1 ppm No2 = 2.05 mg/m3

8.9ppm No2 = 18.245 mg/m3

Natural Gas E = 9.45 kWh/m3

A gas boiler uses 11.4 m3/hr of gas (from boiler manufacturer)

(18.245 mg/m3 x 11.4 m3/hr) / 9.45 kWh/m3 = 22 mg/kWh

Susan