Interesting comments Crispin. Did no one listen to you in the Hague? On 4/25/12, Crispin Pemberton-Pigott <[email protected]> wrote: > Dear Testing Friends and Appealing to Peter Verhaart for comment (because > you were there!) > > > > I have been looking over the history of stove testing and it is compelling > that the HTP was used for reporting stove performance as early as 1982-3. > There are a number of references to it in > http://www.cookstove.net/others/fuel-economy.html with a number of > citations > from Prasad and Verhaart as well as Piet Visser. > > > > There are some Sankey diagrammes and also inherent heat flows. These are > useful for determining stove performance in a way that allows useful > predictions of field performance to be made based on laboratory tests. > Alex, > See Fig 12 and 13. Is that what you have in mind for system analysis? Is > there software or a function in Excel that can produce that automatically? > It could be built into a stove design tool. > > > > I am attaching some performance curves produced created from a set of more > than 80 tests of three stoves. The relationship between power and pot size > is clearly visible for each stove. If you want to know how it will cook > your > favourite 'burn cycle' you can make a calculation. I am suggesting this is > a > useful extension of the good works done in Eindhoven. > > > > The advantage we have these days is that getting precise emissions > measurement is much easier, as is logging mutiple sets of data in real > time. > The resulting displays are easily generated and optimal conditions > identified quickly. > > > > So my question is how did we go from conducting really good test and stove > analysis with really valuable heterogeneous characterisations in the early > 1980's to a simplistic water boiling test in 2012? It is clear from the > works pouring out of Iowa State for the past 5 years that WBTs are not > helping us much in providing useful information - nothing like what we used > to get before and what we an get now from heterogeneous tests. > > > > So my question to Peter Verhaart is, what do you think about the current > state of affairs? How do we recover from it? > > > > Grant B-T, if you have time, what are we going to do to revive testing to > the point that a programme manager can make an informed choice about stoves > before rolling something out? I am sure you know the systematic error level > in the WBT's is over 30%. > > > > Dr Nate Johnson, you have beat your head against this wall and surely have > some advice to take us forward. The industry is getting stuck even as the > funding available for stove projects grows by the millions. Never has so > much stove money been directed by so little meaningful information on the > performance of the products being promoted. This has to change. In fact it > has to be restored to its former glory using the new tools and > understanding > that has developed in the intervening years. > > > > Interestingly there is a reference at the very end of the article at > http://www.cookstove.net/others/fuel-economy.html to the carbon balance > method of testing. This is the method used at the SeTAR Centre and it is > not > an accident. Most EPA-like methods use a hood (or cabinet) and mass (or > whole)-flow calculations, though EPA does use carbon balance methods for > vehicles. > > > > The issue is precision and accuracy. The systematic errors together with > the experimental errors have to be less than 7% to place a stove securely > on > performance tiers 20% apart. That is basic math. In order to do this in > affordable labs, I suggest that it will require a set of single purpose > tests performed in an HPT manner. The attached chart is one way to provide > that information. > > > > Testing costs a lot. Money is changing hands. There is little point in a > lab providing test results that can be challenged if the stoves turn out > not > to perform in the band claimed. The more complicated and imprecise the > assessment task, the greater the potential for failure to perform. > Reputations are on the line. We have to provide better quality > characterisations of performance (including durability, safety and social > acceptance). > > > > Serious stuff. > > > > Regards to all > > Crispin > > > >
-- Sent from my mobile device David Whitfield V. Executive Director CEDESOL Foundation _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org for more Biomass Cooking Stoves, News and Information see our web site: http://www.bioenergylists.org/
