Dear Ron, Most of the time a TLUD/char making stove can boil the water and then simmer using the initial load of fuel so there's no interruption of the normal function. I try to design batch loaded stoves to boil and simmer anyway so cooks are happy. More like a gas stove.
I don't have trouble testing TLUDs and batch loaded stoves. As you saw in Jim Jetter's last paper, the TLUD outscored fan stoves with especially high thermal efficiency (over 50%). TLUDs/char making stoves can score very well (super low CO, CO2, PM and very high thermal efficiency) when tuned which is reality for these stoves. Paul Anderson and I had a nice chat today about Stove Camp, etc. We agreed that initially we like to look at the emissions of CO, CO2, PM in a TLUD or other super clean stove in real time on the computer screen while tuning the stove to burn as cleanly as possible, like adjusting the carburetor in a motor. I do that first and then do the longer boiling and simmering test once the stove is working well. Please try to come to Stove Camp this year, if possible. I think you'll really like having quantified results and I'll bring you, and everyone, coffee and donuts in the morning. All Best, Dean On Sat, Apr 6, 2013 at 8:44 PM, <[email protected]> wrote: > Dean, list, cc Ranyee > > 1. Thanks for the response. Most of your response below is fine, but > my problem with the presently stated GACC (probably other) procedures is in > your two lines below that read: * > * > *"Figure out how much energy was used to boil the water* > *Do the same for simmering water."* > > I believe this means interrupting a test part way through, then > reassembling and finishing a test. For most 3-stone or standard stoves > there is little problem with this, but for a TLUD or other char-making > stove, it is impossible to reassemble the char and biomass in the initial > configuration. I believe Jim Jetter realizes this and doesn't test such > char-making stoves in this prescribed manner. But will other testers > understand proper procedures for char-making stoves, when the approach > doesn't encourage the differences in stove types ? > > 2. Char-making stoves appears at the GACC site ( > http://www.cleancookstoves.org/our-work/the-solutions/cookstove-technology.html) > this way > *Advanced Biomass Cookstoves** * > > *There are two primary types of advanced biomass stoves that can achieve > high levels of performance, forced air stoves and gasifier stoves, both of > which can run on processed or raw biomass.* > * * > > *Forced air stoves have a fan powered, for example, by a battery, an > external source of electricity, or a thermoelectric device that captures > heat from the stove and converts it to electricity. This fan blows high > velocity, low volume jets of air into the combustion chamber, which when > optimized results in much more complete combustion of the fuel. In some > cases these stoves appear to be more robust to variations in how users > cook, as well.* > > * > * > * Gasifier stoves force the gases and smoke that result from incomplete > combustion of fuels such as biomass back into the cookstove's flame, where > the heat of the flame then continues to combust the particles in the smoke > until almost complete combustion has occurred, resulting in very few if any > emissions. Typical gasifier stoves are known as Top Lit Updraft (TLUD) > stoves because some fuel is lit on top of the stove, forcing combustible > products to pass through the flame front before being emitted into the > air. In a gasifier stove with a fan, the jets of air create superior > mixing of flame, gas, and smoke and can be extremely clean. However, > testing needs to confirm how robust these stoves are in field conditions.*" > > > * *a. The problem is that nowhere in this excerpt or elsewhere on > this page does the char-production concept appear - only char being used as > a fuel. > > b. Except for one sentence, this above makes it sound as though fans > and "gasifiers" are mutually exclusive categories. The concept of power > level control-ability through air supply is missing. > > c. Also, the word "pyrolysis" is missing. Gasification is a > different technical subject and approach than pyrolysis. I am afraid this > demonstrates a failure of the GACC process-to-date to properly understand > and handle char-making stoves (with important carbon negative implications > that also are entirely missing at this site). Putting char in the ground > is not a stove concept, but it is a reason for taking care with reporting > on the efficiency of converting biomass to char - whch now nowhere appears > explicitly as an efficiency. This efficiency should be given in terms of > both energy (joules) and carbon (and/or CO2) > > d. I am not faulting anyone who set this up. It is just that the > GACC system and website needs to undergo a review by those who place high > priority on carbon negativity and forest preservation. As near as I can > tell the measurement procedures ave involved no-one with a primary interest > in char making. I have started a new process based on a GACC committee > that has looked at charcoal-using stoves. I would love to include you, > Ranyee and anyone wanting to be involved.. > > e. The forest preservation issue is intimately tied in with *illegal > * char production - a topic I similarly find missing at the GACC site. > I'd rather see char placed in the ground, but when I first started working > on this topic in the early 1990's and first discussed this in 1995 on an > early Tom Miles site, I was thinking *only* of forest preservation. I > was most motivated by the enormous waste and devastation associated with > char use in Sudan. The rural char-making problem has only gotten worse - > and I don't see GACC taking this problem on in the discussions of > charcoal-using stoves. > > 3. This is to answer your last questions below: > *"What more do you want done? * > *Add the climate change effect of burying the char?* > *Etc?* > *We could try it at Stove Camp?"* > > *RWL3:** a. *No, the climate side of biochar is probably not the best > way to employ your (excellent) skills at Aprovecho and Stove camp. There > are hundreds (thousands?) of tests going on with soil scientists - and > these tests take time and a lot of soil experience. But you probably can > help GACC by developing tests that better characterize the numerous > positive features of char-making stoves. For instance, my reading of stove > user literature says that time spent tending a fire is very important - and > I don't see that as part of any present GACC test procedures. A simple > start-stop stopwatch cumulative accounting of the tender's time would be a > valuable additional data point - without doing anything new. This > could/should be compared to a test where one could only tend the fire every > 6, 8, 10 (?) minutes. > > b. I'd like to see you do some tests on a concept I have for a > char-making stove where fuel can be added. (This can be done with the > World Stove Lucia, sometimes called a TLOD). This can be open source and I > would be glad to talk about this with anyone - but I haven't tried it and > it may not work. Your generating a range of approaches (augers?) for this > claimed drawback of TLUDs would be very helpful. > > c. I'd like to see more efforts at continual monitoring of weight of > any/every stove during a test run. Balance beams? > > d. I'd like to see an experimental approach developed that optimally > compared stoves with inherently different optimum operating parameters. > That is, one could have a fine stove that didn't do well with boiling 5 > liters of water, but was perfect (meaning low cost?) for 1 liter (or some > other non-standard amount). How should tests with different pots and water > combinations be compared (if they can)? > > e. I have seen little (nothing?) on the optimum gap for escaping gases > below a cookpot. And I saw wide variations at the GACC stove demos. > Receving Aprovecho guidance on this will be of help to all stovers. > > f. Same then for getting an optimum skirt. I think you have some > skirt formulae, but I'll bet this needs more work. > > g. I'd like to see more on ways to better couple flame energy into > the pot - ala the work of Dale Andreatti > > h. Some experimental testing of the analytical modeling work nearing > completion by Nordica. > > Again - thanks for your response and offer to help with char-making > stoves and stove testing. > > Ron > (who just watched his alma mater (Michigan) make it (barely) to the > national basketball finals - so the above is probably in need of > considerable editing) > > ------------------------------ > *From: *"Dean Still" <[email protected]> > *To: *"Discussion of biomass cooking stoves" < > [email protected]> > *Sent: *Friday, April 5, 2013 5:05:29 PM > *Subject: *Re: [Stoves] Stove testing with and beyond the WBT > > Hi Ron, > > When we test TLUDs that make charcoal the protocol is pretty much the same > as for non char making stoves. Most any stove makes some char. Some TLUDs > just make more, right? > > Put biomass fuel in TLUD > You know the energy content and moisture content > (Use the bomb calorimeter if needed) > Boil the water > Separate the unburned wood from the char > Weigh both > Use the bomb calorimeter to see how much energy is in the char > Figure out how much energy was used to boil the water > Do the same for simmering water. > The hood tells us how much CO2, CO, PM was made to boil and simmer the > water with that stove. > > What more do you want done? > Add the climate change effect of burying the char? > Etc? > We could try it at Stove Camp? > > Best, > > Dean > > > On Fri, Apr 5, 2013 at 2:42 PM, <[email protected]> wrote: > >> Ranyee, list, Crispin, and Paul >> >> Thanks for your "test" response below, on behalf of GACC. >> >> I am not very worried about fixing what Crispin has identified for the >> vast majority of existing stoves. I am sure he is raising valid concerns >> but they are not mine (nor I think Paul's). The earlier messages in this >> thread do not seem to be related at all to the new brand of (superior??) >> stoves that make char. >> >> The present standards were developed when no-one was even aware of the >> potential of char-making stoves. The present set of measurements for >> char-makng stoves are akin to judging the quality of oranges using rules >> set up for apples. Therefore, I strongly urge getting a separate group >> together with only char-making and carbon negative climate interests to >> assist in any revision to the present standards. The fact that about half >> of the stoves being demonstrated in Phnom Penh two weeks ago are being >> given testing tasks and rankings that are ill-suited for their design >> should be of serious concern to GACC. >> >> I thought you and the entire GACC staff put on a marvelous conference >> in a wonderful location. >> >> Ron >> ------------------------------ >> *From: *"Ranyee Chiang" <[email protected]> >> *To: *"Crispin Pemberton-Pigott" <[email protected]>, "Paul >> Anderson" <[email protected]>, "Discussion of biomass cooking stoves" < >> [email protected]> >> *Sent: *Friday, April 5, 2013 1:52:37 PM >> *Subject: *Re: [Stoves] Stove testing with and beyond the WBT >> >> Paul, Dean, Crispin, et al. - >> >> >> >> We’re looking forward to seeing the detailed proposed protocol. For all >> protocol development, we at the Alliance have been emphasizing the need for >> review by broad stakeholders – regional testing centers, manufacturers, >> investors, and consumer representatives as much as possible, so we hope >> that the review process can continue with this effort. At one point >> Crispin had questioned whether this process leads to independent review. I >> think independence is a tricky concept, because it’s unclear who the >> independence would be from. But I think a better way to achieve the broad >> goal is to have inclusive and public review (if you have enough voices, the >> result is somewhat independent from everyone). I think the issues to >> especially focus on will be ones that impact the various stakeholders - >> testing feasibility, resources needed (time, financial, equipment), clarity >> for communicating results, etc. >> >> >> >> As Dean mentioned, we are focused on how to integrate field >> considerations into best practices for testing and standards. We had much >> discussion at the Forum (notes are currently being polished), and it will >> continue. It will be important to work out how we fit the different >> protocols together, when which protocol is used, based on context, >> resources, goals. How would newly developed procedures supplement, >> partially replace, replace existing protocols? Of course, this is also >> related to the goal for harmonization as raised in the IWA. >> >> >> >> Paul also raised the issue of recalculating older test results so they >> can be comparable or harmonized. I think another issue to consider is how >> much have technologies changed and are the older test results still >> applicable. We are also planning discussions to map out a strategy for >> integrating future testing results and data together, especially to >> communicate stove performance (IWA Tiers) that has been independently >> evaluated. Part of the discussion should be around what is the minimal set >> of data that the testing centers need to share to facilitate collaboration >> and harmonization among the different centers. >> >> >> >> Best regards, >> >> Ranyee >> >> >> >> >> >> *From:* Crispin Pemberton-Pigott [mailto:[email protected]] >> *Sent:* Thursday, April 04, 2013 9:41 PM >> *To:* 'Paul Anderson'; 'Discussion of biomass cooking stoves' >> *Cc:* Ranyee Chiang >> *Subject:* RE: Stove testing with and beyond the WBT >> >> >> >> Dear Paul and Everyone >> >> >> >> Thanks for devoting so much time to considering the tasks ahead and the >> alternative paths forward. As you know from your travels we face a huge >> variety of testing requirements in the field. It is my hope that we can >> create an agreed scientific platform on which to perform a wide variety of >> culturally relevant tests that provide normalised results. The Toolbox is a >> collection of mathematical and cultural tools for measuring performance >> over a wide range of conditions in diverse cultures. >> >> >> >> I am particularly thankful to Cecil Cook for the efforts contributed to >> developing the social science tools about which we will hear a lot more in >> the coming months. The cultural appropriateness of stoves is often >> considered only after a technology has been ‘invented’. Being relevant is a >> major consideration to marketing campaigns. Sustainability is strongly >> desired and being sustainable means being simultaneously an improvement and >> desirable from cultural, economic and environmental points of view. It is >> by definition a Triple Bottom Line adventure. >> >> >> >> We will share as much as we can as and when contributors add to the >> Toolbox. Although it is an inadequate description due to the fact it is >> brief, I have attached a Powerpoint presentation giving some of the >> motivating factors for creating the Stove Testing Toolbox and what can be >> expected from it. >> >> >> >> Very briefly it intends to provide each tool with the purpose, the >> metrics, the definitions and the presentation of results for conducting a >> single testing element of any performance evaluation. While this is >> implicit in many tests, this divides each task conceptually into discrete >> segments and creates validated processes that normalises data in order to >> permit a wide range of tests to give comparable results. It does not >> specify any tasks, it specifies how a task *of that type* should be done >> to get a relevant and correct output. >> >> >> >> This is widely done in the fields of assessing engineering performance >> and medical research into diseases and treatments. >> >> >> >> Regards >> >> Crispin >> >> >> >> >> >> Dear Stovers, >> >> Since the GACC Forum in Cambodia, the topic of stove testing "problems >> and opportunities" have led me to some thoughts to share, along with some >> examples. In the document I wrote: >> >> I believe that a collection and combination of various tests will SERVE >> MUCH BETTER the needs of the cookstove communities than will the >> overreliance on the “standard WBT”, even when that WBT has eventually been >> corrected for errors in calculation, and formally reviewed openly. >> >> >> The attached document is for all to read and share with others, and it >> will be placed on the www.drtlud.com and could be at the Stoves >> website if Tom and Erin think it is worthy. >> >> Paul >> >> Paul S. Anderson, PhD aka "Dr TLUD" >> >> Email: [email protected] Skype: paultlud Phone: +1-309-452-7072 >> >> Website: www.drtlud.com >> >> >> >> >> >> >> ------------------------------ >> >> >> Please consider the environment before printing this email. >> >> _______________________________________________ >> 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://stoves.bioenergylists.org/ >> >> >> _______________________________________________ >> 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://stoves.bioenergylists.org/ >> >> >> > > _______________________________________________ > 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://stoves.bioenergylists.org/ > >
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