[Stoves] Irrelevant lab testing - for what purpose?

Thu Jun 1 19:13:13 CDT 2017

Dear Stovers, 

None of the tests mean anything useful for the real World for several reasons. We need to have a common measure that can be taken across all biomass fuels (processed like pellets and lumber and wild). This common measure needs to be reproducible with consistent results and easy for all labs to get the same values. This common measure is oven dried biomass ground up and sampled and total energy determined. Then placed into a TGA filled with nitrogen and determine the weight loss when heated to 550c. Then add oxygen and determine the ash. You get three measurements to use:
1) Total energy 
2) total energy in the carbon of the fixed char
3) calculated total energy of the volatiles heating the secondary

We do not use hydrogen. Unless we measure it. Placing it at 6% means nothing and could later give problems if down the road we have a low or high hydrogen content that affects a fire. That from mixing char into briquettes or having biomass with lots of resins. Should we want to see how that low - high value of hydrogen effects the combustion we run into problems when all the data has been given the value of 6%.  

We do not consider moisture in the calculations because of the many variables and uncertainties if offers. We report moisture in the test results package. But we can always go back to oven dry the fuel and get the dry weight basis results. This is common procedure on COMPARING using dry weight and OPERATIONS using wet as-Received basis. 

Then at the back end we complete a task. Boiling water is an excellent task because it represents many cooking tasks. We need a task to represent grilling and frying. It needs to use a common typical food and we need to establish on measuring a sharp end point (task completed).

Air quality means nothing. Nobody cares about air quality. We are cooking food with what we have available. We can look at air quality from the different devices and see which ones are doing the best - but that is only secondary to getting the task completed.  

The biomass used is not called corn cobs and pellets and oak and pine. We need to have a continuum of measures on some type of spider graph to classify the fuel. We can give a ‘visual’ of corncob along with location on the spider graph classification system. 

The above will result in:
Top number
1) total energy going to the pot
2) total char that can be produced
3) Total energy in the char that can be produced
Bottom number
1) per time it takes to cook
2) per char that was produced
3) per energy in the char used elsewhere

Added tests on the raw biomass we can determine fuel used, trees cut etc. 

NOTHING WILL GET DONE UNTIL WE DO THE ABOVE! 

 We do the above then make adjustments on the 6-Box system to optimize the system. Air quality is just one of the parameters we use when optimizing. 

We have a lot of work to do….

Regards

Frank

> On Jun 1, 2017, at 1:43 PM, Crispin Pemberton-Pigott <crispinpigott at outlook.com> wrote:
> 
> "'Five of the stoves presented here were also tested at the US EPA, with results agreeing within 20% or better on all fuel and emissions measures,...'"
> 
> Hang on, how does this validate the results for the 50 tests?
> 
> If they both used the same stoves and protocol, the result is as defective as the protocol. WBT3.0, which was not peer reviewed just as the Aprovecho-modified ‎v3.1 wasn't, doesn't give a meaningful fuel consumption value (because of the char energy deduction error. For emissions, that is a crap-shoot because the uncertainty of the Aprovecho-made PM test equipment is at least 50%.
> 
> As Fabio Riva meticulously pointed out (in his peer reviewed journal article), the combination of the WBT and a PEMS hood was not able to definitely place more than 75% of 'improved stoves' above 0% improvement even at a confidence interval of 0%. And that is before trying to assign some absolute value for the performance, just 'is it better at all?'
> 
> What does "within 20%" mean if the uncertainty is 50%?
> 
> WBT3.0 doesn't even correctly report the mass of water boiled and the conceptually erroneous fuel consumption formula is what was 'corrected' in v3.1 so how can it rate performance?
> 
> Unless the EPA used the same defective calculations, there is no way they could get a comparable result. If I gave the same stoves to the Brookhaven National Lab and asked them to report the performance, they could provide an answer that could serve as a baseline against which the quality of the Aprovecho testing could be ‎evaluated. 
> 
> Crispin 
> 
> 
> 
> +++++++++
> 
> To continue in my criticism of WBT and energy efficiency as a performance metric.... 
> 
> I discovered a paper by Aprovecho folks - Nordica MacCarty, Dean Still and Damon Ogle, "Fuel use and emissions performance of fifty cooking stoves in the laboratory and related benchmarks of performance <http://www.sciencedirect.com/science/article/pii/S0973082610000311> Energy for Sustainable Development, Volume 14, Issue 3, September 2010, Pages 161–171. http://dx.doi.org/10.1016/j.esd.2010.06.002 <http://dx.doi.org/10.1016/j.esd.2010.06.002>.
> 
> .. The authors claim in the Abstract: 
> 
> Performance of 50 different stove designs was investigated using the 2003 University of California-Berkeley (UCB) revised Water Boiling Test (WBT) Version 3.0 to compare the fuel use, carbon monoxide (CO) and particulate matter (PM) emissions produced. While these laboratory tests do not necessarily predict field performance for actual cooking, the elimination of variables such as fuel, tending, and moisture content, helps to isolate and compare the technical properties of stove design.
> 
> It stretches credulity that stove designs are tested on the basis of excluding fuel, tending, and moisture content. 
> 
> This is engineering madness. Standard fuel, standard pots, standard water.  No cook, just the theologians of thermodynamics.  I am surprised Tom Miles thinks I am crazy to call that the dominant paradigm of stovers needs to be shaken from the root to the skies. What there is to protect will stay, but WBT not only must go, all past results of WBT must be dumped as "technical error". 
> 
> It has been a technical terror. 
> 
> I can understand Aprovecho engineers' vested interests in a certain kind of "stoves ideology" but I wonder if they realize just how laughable they are to the world with statements like 
> 
> "From this data, it was possible to recommend benchmarks of improved cookstove performance. " and that 
> 
> 'Five of the stoves presented here were also tested at the US EPA, with results agreeing within 20% or better on all fuel and emissions measures, suggesting standard evaluation at various locations is possible.
> 
> Probably doesn't matter. So long as EPA and Approvecho results coincide, their interests and ideological agenda will also coincide. All in the name of fact-free, cook-free science of cookstoves. 
> 
> Boil blood, not water. This whole storm of "standards" is a nightmare or a pleasant dream, take your pick. Emission rates and efficiency ratios have little to do with usefulness of a cookstove. 
> 
> Nikhil
> 
> 
> 
> ------------------------------------------------------------------------
> Nikhil Desai
> (India +91) 909 995 2080 <tel:+91%2090999%2052080>
> Skype: nikhildesai888
> 
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Thanks

Frank
Frank Shields
Gabilan Laboratory
Keith Day Company, Inc.
1091 Madison Lane
Salinas, CA  93907
(831) 246-0417 cell
(831) 771-0126 office
fShields at keithdaycompany.com

franke at cruzio.com

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