[Stoves] TLUD stoves and tests

[Kirk H.]

Crispin,
Thank you for your response.  There are several points where I think there was some miscommunication between us.
Dear Xavier and Kirk

The TLUD is a type of combustion, not a stove product. There are good ones and bad ones. I have tested more of the latter than the former. Burning from the top down doesn't guarantee great performance.  Some evidence from the field shows acceptance of the TLUD stoves, others show a poor fit with the local culture. Beware over-claiming.
I called it the TLUD type stove.  A TLUD type stove would of course use the TLUD type of combustion.  We agree on this.
I have been working on TLUD type stoves for 5 years, and I agree with you that there can be both good and poorly performing TLUDs.  
I did not make any statements about acceptance, so there is no over-claiming here.  
For this reason, it would be helpful to mention that there are other types of combustion that are very clean, when properly constructed and operated, matched to suitable fuels. These days, there is no measurable difference in performance between a very good TLUD and a very good crossdraft stove. I am sure there are equally good downdraft stoves. Depending on the application, they each have different strengths. 
For what reason?  There were three different topics In the first paragraph.
I agree with you that there are other types of combustion that are clean, each with its own strengths.  This is why wrote “TLUDs are among the most capable types of wood cooking stoves”.  This statement does not exclude other types of stoves.  We agree here.
As for the CSI test, it is in two parts: a protocol for the development of a 'Technical Test', (TT) and a method for conducting a TT and processing the data. Lab manuals documenting this as a Standard Operating Procedure (SOP) also include a standardized method for recording, naming and archiving data so it can be checked by an external auditor.  
I am looking forward to testing my stoves, cooking vessels, and the interface between (pot stand, pot skirt, pot lid, Wonder-wok (a sunken pot type wok base which exhausts into a chimney which we made at the last Aprovecho stove camp and which won the Cat Pee award)) with this test.
A contextual ‎test naturally uses appropriate pots and fuels. One should not get nor give the impression that it suggests certain or particular pots. Such things are defined by the community of interest. 
Xavier said this and I thought it was a good thing.   We agree here.
It is not a Controlled Cooking Test. It is a carefully controlled lab test that replicates a pattern of operating the stove crafted to replicate the average use patterns, or a test sequence crafted to require the stove to cover the whole range of power and pot accommodation required in a community, or to cover a portion of that range. It is rare that a stove can 'do everything' a family needs. Stoves are developed for particular markets and functions. 
Sounds good.  We agree here.
In its technically simplest form, it is a pot-swapping test, like the Indian National Standard. More technically sophisticated labs like CAU and Jakarta use a heat exchanger in the pot to control the water temperature while quantifying the heat gained. It is reasonably accurate, typically ±2200 Joules. 
Still sounding good.
A major potential is crafted into the protocol which is the inclusion, in future, of the Decombustion Theory that estimates the ultimate analysis of the fuel 'just burned' and it's moisture and energy content. At present there is no other test method which can do this.  ‎The intention is to provide a far more accurate estimate of the energy available from the fuel while it burns inhomogeneously, in real time. This method, when fully implemented, will significantly change the rated thermal performance of solid fuel burning stoves (because they tend not to burn their fuels homogeneously).
OK.  Take your word for it.
‎There is always something new...
I know!  Isn’t it great!  The field of TLUD type stoves was wide open for inventing new things, so I stepped in.  I love it!  We agree yet again!
Regards 
Crispin 

Kirk H.


Sent from Mail for Windows 10

From: Crispin Pemberton-Pigott
Sent: Monday, July 23, 2018 9:43 PM
Subject: Re: [Stoves] TLUD stoves and tests

Dear Xavier and Kirk

The TLUD is a type of combustion, not a stove product. There are good ones and bad ones. I have tested more of the latter than the former. Burning from the top down doesn't guarantee great performance.  Some evidence from the field shows acceptance of the TLUD stoves, others show a poor fit with the local culture. Beware over-claiming.

For this reason, it would be helpful to mention that there are other types of combustion that are very clean, when properly constructed and operated, matched to suitable fuels. These days, there is no measurable difference in performance between a very good TLUD and a very good crossdraft stove. I am sure there are equally good downdraft stoves. Depending on the application, they each have different strengths. 

As for the CSI test, it is in two parts: a protocol for the development of a 'Technical Test', (TT) and a method for conducting a TT and processing the data. Lab manuals documenting this as a Standard Operating Procedure (SOP) also include a standardized method for recording, naming and archiving data so it can be checked by an external auditor.  

A contextual ‎test naturally uses appropriate pots and fuels. One should not get nor give the impression that it suggests certain or particular pots. Such things are defined by the community of interest. 

It is not a Controlled Cooking Test. It is a carefully controlled lab test that replicates a pattern of operating the stove crafted to replicate the average use patterns, or a test sequence crafted to require the stove to cover the whole range of power and pot accommodation required in a community, or to cover a portion of that range. It is rare that a stove can 'do everything' a family needs. Stoves are developed for particular markets and functions. 

In its technically simplest form, it is a pot-swapping test, like the Indian National Standard. More technically sophisticated labs like CAU and Jakarta use a heat exchanger in the pot to control the water temperature while quantifying the heat gained. It is reasonably accurate, typically ±2200 Joules. 

A major potential is crafted into the protocol which is the inclusion, in future, of the Decombustion Theory that estimates the ultimate analysis of the fuel 'just burned' and it's moisture and energy content. At present there is no other test method which can do this.  ‎The intention is to provide a far more accurate estimate of the energy available from the fuel while it burns inhomogeneously, in real time. This method, when fully implemented, will significantly change the rated thermal performance of solid fuel burning stoves (because they tend not to burn their fuels homogeneously).

‎There is always something new...

Regards 
Crispin 


Xavier
 
The primary point I am making is that the TLUD stove is an excellent type of stove.  A well designed TLUD type stove will do well, whatever test it is given.  A lesser performing type stove will accordingly do less well, whatever test it is given.  Dr. Anderson is doing good work in his promotion of this type of stove.  
 
The CSI test can test many different cooking vessels.  This is good!  Is there a lab on the west coast of the USA where I/we can have cooking vessels tested with this test?  This would be a lab with quality equipment and well trained personal, not back yard equipment.
 
“Both disliked and liked tests” you replaced with “You mean unreliable and reliable”.  No, I meant disliked and liked tests.  Unreliable and reliable are judgmental, and I chose disliked and liked  because they are not judgmental.  I said what I meant.
 
Very little progress has been made.  I assume that you are not saying that we should give up.  
 
TLUDs are among the most capable types of wood cooking stoves, providing steady heat for whatever cooking vessel is used.  They are deserving of consideration.  Because they do not require continuous attention while in use, they could make a welcome addition for many busy cooks.
 
Kirk H.
 
 
Sent from Mail for Windows 10
 
From: Xavier Brandao
Sent: Tuesday, July 17, 2018 9:04 AM
To: 'Discussion of biomass cooking stoves'
Subject: Re: [Stoves] TLUD stoves and tests
 
Dear Kirk,
 
We could also call « arguing »: « sound scientific discussion ».
Researchers are arguing about climate change, Artifical Intelligence, the size of the universe … All that is necessary, I believe.
 
The « WBT argument » that has been going on « for years » is more like Crispin hammering the fact that the WBT is not reliable, with little to no reaction, and Ron strongly defending the WBT because of the tiers and denominator equation.
Lately, all the evidence against the WBT has been compiled, discussed, and has not been refuted.
We also talked about alternative protocols at length.
 
“I had a choice and I chose to work on the TLUD.”
Very good. We are many different people, we can all work on many different things, and share our findings.
 
None of the above discussions prevented anyone to work on the stove they like. Instead they gave them full information and warning about the situation with tests.
I spend very little of my time talking about the WBT, I’m busy with other things.
 
“If you were working on tests that could be used for all cooking vessels instead of just a pot of water I might abide with you”
The CSI does that, normally. It is contextual. Crispin might be able to give more clarifications here. Kirk, have you tried this protocol?
 
I believe the new standard allows different cooking vessels as well?
 
“both disliked and liked tests”
You mean unreliable and reliable.
 
Indeed, now is the time to move forward. We want to move forward. We want to drive, drive, drive, fast. But it’s good that we checked first if the car was safe or if it was heading in the right direction.
 
The ProPublica article sums it up well: only little progress has been achieved by the cookstove sector, after decades of hard work.
The cause for that certainly wasn’t overthinking, was it?
 
Best,

Xavier
 
 
 
De : Stoves [mailto:stoves-bounces at lists.bioenergylists.org] De la part de Kirk H.
Envoyé : mardi 17 juillet 2018 03:46
À : Discussion of biomass cooking stoves
Objet : [Stoves] TLUD stoves and tests
 
Xavier,
 
The main idea in my response on 7-13 was that well designed TLUDs are excellent stoves, capable of suppling steady, efficient, and low particulate heat for cooking purposes.  As far as arguing over tests is concerned, some have indeed been arguing for years.  This was/is over the portion of the WBT which measures the efficiency of getting heat into a pot of water, which to me is very limited.  I had a choice and I chose to work on the TLUD.  
 
The next part of my statement is important:   “This especially for tests which have more to do with the cooking vessel than with the stove itself.”  If you were working on tests that could be used for all cooking vessels instead of just a pot of water I might abide with you, but not for a test the results of which are of no value for anything but the test pot of water.  Do we have a test for stir frying in a wok?  Nope.  Only a pot of water.  Yet woks are extensively used for cooking.  And it doesn’t even matter if we use a wood stove.  The cooking vessel tests would get the same results over a natural gas burner as long as all the variables like skirt, lid, and pot stand are held the same.  These tests have to do with the cooking vessel not the capabilities of the stove.  
 
I can abide with the WBT or WHT as long as it is made clear that the disputed portion includes only the efficiency of getting heat into a pot of water, but says nothing about other much used cooking vessels, such as putting soup in the pot instead of water, or woks, griddles, ovens, etc.  Also I note that these cooking vessel tests can use any heat source, like natural gas or electrical, and except for a limited relationship to fire power, do not measure the qualities of the stove itself.  Measurements concerning the stove are taken by the sensors and filters.
 
Both the disliked and liked tests have a very limited scope.  How about looking into some more versatile tests that are not limited to a pot of water.  How would we test the efficiency of getting the heat into a wok being used for stir frying?  Perhaps we could use an infrared thermometer to measure the temperature of the food and end the test when it all reaches a temperature that kills bacteria.  How about testing the stove and the cooking vessel separately, so each has its own values?  That would give the consumer a much better preview of both, and more knowledge to pick and choose.
 
TLUDs are very capable stoves, effectively heating whatever cooking vessel under which they are placed.
 
Kirk H.
 
 
Sent from Mail for Windows 10
 
 



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20180724/70ae2780/attachment.html>