[Stoves] Fuel qualities as the limiting factor, and getting rid of WBT (Was: Frank on helium surrogate)

Sat Jan 28 06:24:14 CST 2017

Dear Frank

I must protest that the WBT is not ‘just a test procedure’. Please everyone, get with the program (definitions).

A protocol is a way of testing, which includes two things: A test apparatus set up to a certain specification (quality) and a set of calculations that are performance on the result.

What you do during the experiment  is separate from what you measure and how you calculate. You can pick any test sequence of using or not using a lid, lighting, ramping up and down and so on.

A test may have a ‘standard duty cycle’ or ‘stove operation sequence’ of steps, as the WBT does, but that set of steps is not the test protocol nor the calculations.

The WBT has multiple failures on all counts:

  *   It is a poorly conceived experiment that makes numerous conceptual errors about what to measure and what metrics will mean when reported
  *   It contains multiple mathematical errors which are propagated through subsequent calculations, including larger variability in the output than the inputs – a clear indicator that there is something fundamentally wrong with it
  *   It has a fixed and largely irrelevant sequence of steps which while intended to replicate a cooking task, do not.

In rural Laos, (the Lao Republic) a WBT was being conducted in the presence of a group of village women. After a time observing the test they started giggling to each other, bursting out laughing occasionally. Asked what was so funny, they said, “No one cooks like that!”

It does not take an anthropologist to tell you that these women, seeing a single episode, know that whatever the rating of the stove will be, it will not be relevant to them or their choice in stove product.

Regards
Crispin

Nikhil,

What's the line: "by God, I think s/he's got it (right!) or as we old civil right/anti-war/pro environment & women ACTIVISTS used to say with much gusto: " RIGHT ON MAN, RIGHT ON!".

In memory,
Cecil

Sent from my BlackBerry 10 smartphone.
From: Traveller
Sent: Saturday, January 28, 2017 12:33 AM
To: Frank Shields
Reply To: miata98 at gmail.com<mailto:miata98 at gmail.com>
Cc: Discussion of biomass cooking stoves; Cecil Cook; Xavier Brandao
Subject: Re: Fuel qualities as the limiting factor, and getting rid of WBT (Was: Frank on helium surrogate)

Frank:

Pray tell, why is that a critical feature - starting with the fuel and ending with a completed cooking task?

I never saw mere heating water as a major "cooking task", nor the relevance of various measurements of combustion efficiency, heat transfer efficiency,control efficiency, all measured in reference to particular fuel and particular pot.

This is a decades old obsession of bean-counters of thermodynamic efficiency, fuel consumption, trees saved, etc. that has a partial but not a controlling place in design of usable cookstoves for specific uses in specific contexts of cooking and markets for fuels.

Now WBT is extended to CO and PM2.5 hourly emission rates, no matter that the rather baseless WHO IAQ Guideline is in terms of annual average exposure.

I submit WBT has no valid purpose. I am not technically qualified to address whether any other test is any better, just that if performance metrics are not relevant to the cook, no matter of lab fanaticism will get the biomass stove movement anywhere.

Time to question purported science. If it doesn't serve the needs, it is deficient. We didn't  use thermodynamicists alone to design furniture, did we? And furniture is a bigger business than biomass stoves.

I go back to my very post back in June or July -- what is the service standard and what is the objective of standard setting? Nobody has yet dared to propose an answer.

Nikhil

(India +91) 909 995 2080

On Fri, Jan 27, 2017 at 11:33 PM, Frank Shields <franke at cruzio.com<mailto:franke at cruzio.com>> wrote:
The water test must NOT ‘Go’. It is just a test procedure that needs modification FOR THE PURPOSE of what we want to interpret the results. It is the only test I have seen where we start with the FUEL and end with a completed COOKING TASK. Starting with the fuel and ending with a completed task is a MUST.

Thanks

Frank

On Jan 27, 2017, at 9:33 AM, Traveller <miata98 at gmail.com<mailto:miata98 at gmail.com>> wrote:

Frank:

Thank you. This comports well with my understanding of coal combustion in industrial/power generation use and also childhood experience with woody fuels and charcoal.

Specifying lab tests with "oak", "spruce" etc. is intellectual imperialism. WBT must go from IWA.

Nikhil

---------
(India +91) 909 995 2080

On Fri, Jan 27, 2017 at 3:26 PM, Frank Shields <franke at cruzio.com<mailto:franke at cruzio.com>> wrote:

You ask:

I have two reasons to ask:

a) the importance of fuel chemistry (instead of some pre-specified wood, having a range of locally used biomass or new processed biomass) at various stages of combustion; and, On Jan 27, 2017, at 1:21 AM, Traveller <miata98 at gmail.com<mailto:miata98 at gmail.com>> wrote:
Others will know more; but the chemistry of the biomass (carbon particle density, packing carbon density, void space, fixed and volatile fractions, moisture, ash  etc.) is much more important to know than ‘oak’ or ‘spruce’. I believe its the preparation of the gases before entering the secondary thats most important and thinking we might be able to make adjustments if we can learn the mix that burned hot and clean. I’m thinking the helium surrogate thats bled in with the primary air at a very controlled and constant rate will be very useful when monitoring the gases entering the secondary. I’m sure someone must have tried this. Perhaps Tom Reed or Jim Jetter?

Thanks

Frank

Thanks

Frank
Frank Shields
Gabilan Laboratory
Keith Day Company, Inc.
1091 Madison Lane
Salinas, CA  93907
(831) 246-0417<tel:(831)%20246-0417> cell
(831) 771-0126<tel:(831)%20771-0126> office
fShields at keithdaycompany.com<mailto:fShields at keithdaycompany.com>

franke at cruzio.com<mailto:franke at cruzio.com>

Thanks

Frank
Frank Shields
Gabilan Laboratory
Keith Day Company, Inc.
1091 Madison Lane
Salinas, CA  93907
(831) 246-0417<tel:(831)%20246-0417> cell
(831) 771-0126<tel:(831)%20771-0126> office
fShields at keithdaycompany.com<mailto:fShields at keithdaycompany.com>

franke at cruzio.com<mailto:franke at cruzio.com>

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