[Stoves] Stove testing with and beyond the WBT
Dean Still
deankstill at gmail.com
Sun Apr 7 01:14:07 CDT 2013
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, <rongretlarson at comcast.net> 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" <deankstill at gmail.com>
> *To: *"Discussion of biomass cooking stoves" <
> stoves at lists.bioenergylists.org>
> *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, <rongretlarson at comcast.net> 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" <rchiang at cleancookstoves.org>
>> *To: *"Crispin Pemberton-Pigott" <crispinpigott at gmail.com>, "Paul
>> Anderson" <psanders at ilstu.edu>, "Discussion of biomass cooking stoves" <
>> stoves at lists.bioenergylists.org>
>> *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:crispinpigott at gmail.com]
>> *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: psanders at ilstu.edu Skype: paultlud Phone: +1-309-452-7072
>>
>> Website: www.drtlud.com
>>
>>
>>
>>
>>
>>
>> ------------------------------
>>
>>
>> Please consider the environment before printing this email.
>>
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>
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