Dean - Thanks for the response. See few responses below. ----- Original Message ----- From: "Dean Still" <[email protected]> To: "Discussion of biomass cooking stoves" <[email protected]> Sent: Sunday, April 7, 2013 12:14:07 AM Subject: Re: [Stoves] Stove testing with and beyond the WBT
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. [RWL: That is fine, but I have always thought of a char-maker as having a higher "calling" than as a char-user. (Now mostly or entirely for placing char in the ground - previously to replace illegal char and save forests.) No reason to use char when a char-maker is superior in most regards. So the problem still remains of GACC having a test that accommodates such a stove application .] 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. [RWL: Agreed on all. And I believe the sto ry gets even better when the char is saved. But a fan-type (with fan speed control) char-making stove still might be preferred by many if the turn-down ratio can be much greater. ] 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. [RWL: Nice analogy. Much needed. My list of possible camp activities given below can fit in (emissions and more). 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. [RWL: Thanks for the invite. If I get this new char-making stove idea working [Not a TLUD] I will definitely be there. I think you'll really like having quantified results and I'll bring you, and everyone, coffee and donuts in the morning. [RWL: Hmm.] Ron 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: <blockquote> 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: <blockquote> 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/ </blockquote> _______________________________________________ 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/ </blockquote> _______________________________________________ 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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