[Stoves] FW: REQUEST for complete sets of raw data of cookstove tests.

[Kevin]

Dear Paul

(comments below...)
  ----- Original Message ----- 
  From: Paul Anderson 
  To: Discussion of biomass cooking stoves 
  Cc: jetter jim 
  Sent: Tuesday, April 23, 2013 4:11 PM
  Subject: Re: [Stoves] FW: REQUEST for complete sets of raw data of cookstove tests.


  Ron, Crispin, Jim and all,

  One stumbling point is the difference between the words    Fuel    and    Energy.    We cook with fuels.   We cook with energy.   But a piece (1 kg) of wood (fuel) can deliver 16 MJ of energy if burned to ash or it can deliver (example) 11 MJ of energy PLUS charcoal that represents 5 MJ of energy.   

  The piece of wood is totally changed in both cases.   But in the second case, part of that wood has been transformed into charcoal, which is certainly not wood.    Wood consumed is 1 kg.   Energy consumed is 11 MJ (with charcoal left over).   Two very different results to be reported.

  And then there is the case of one kg of agricultural "refuse" that is 16 MJ if consumed totally, or 11 MJ plus charcoal if pyrolyzed, and in NEITHER case was there any consumption of wood.   Where deforestation is an issue, stoves that can use (easily use) agricultural refuse need to be distinguished from the wood burners.  

  # To view the issue differently...
  Two stoves are being compared for "Efficiency". 
  Given facts from Tests:
          STOVE A STOVE B STOVE C STOVE D 
        Nature of Fuel Ag. Waste Ag.Waste Stickwood Stickwood 
        Fuel Energy Supplied, MJ 10 15 10 15 
        Energy to Cooking Pot, MJ 5 5 5 5 
        Energy in Char, MJ 0 5 0 5 
        Stove Efficiency, % 50.00% 33.33% 50.00% 33.33% 


  # So,  we see that for the same cooking task, Stove A and stove C have the best efficiency, both at 50%
  while Stoves B and D also have the same efficiency, both at 33.33%

  # Now it is up to the Customer:
  IF HE WANTS CHAR, he chooses Stove B if he has Ag Waste for fuel, or stove D, if he has stickwood fuel
  IF HE DOES NOT WANT CHAR, he chooses Stove A if he has Ag Waste for fuel, or stove C, if he has stickwood fuel.

  # Thats all the Customer needs to know, in order to make the best choice of stove for his circumstances.

  Even when the stove testing is conducted with wood as the standard fuel, the test RESULTS need to clearly reveal that wood did NOT need to be burned.

  # This is an efficiency test. This is not a test of the merits of using Ag. Waste or Stickwood. The test tests teh stove with whatever fuel is supplied.

  In the movies, "No animals were harmed in the production of this film."
  For SOME cookstoves, "No wood was burned in the cooking of these meals (or the conducting of these tests)."

  # That is an issue above and beyond Stove Efficiency Testing.

  What happens to the charcoal (whether burned or as biochar or otherwise lost) should not be the issue.

  # The "Efficiency Test" is a measure of "efficiency of utilization of fuel by the device being tested." Regardless of the value of the char production, the simple fact is that the char represents non-utilization of the fuel supplied to the device being tested. The fact that the char could be used in another stove, or could be used as Biochar for soil Application is another issue entirely. If we take credit for the fact that the char could be used elsewhere in another system, we could really confuse the issue if we claim such things as :
  " 20% of the supplied energy was lost through the sidewalls of the stove but it heated the kitchen beneficially, so I think the Stove Efficiency should be increased by 20%
  or
  " I am using the stove to heat a small enclosed greenhouse, and I am venting the stack gases inside to use the CO2 by the plants. Since the fuel contained 50% carbon, and it was burned to completion, I claim 100% 'Efficiency of utilization of the fuel."

  # External, or "subsequent usage benefits" are issues outside the scope of "efficiency of use of fuel by the device being tested.
  Best wishes,

  Kevin


  Paul

Paul S. Anderson, PhD  aka "Dr TLUD"
Email:  psanders at ilstu.edu   Skype: paultlud  Phone: +1-309-452-7072
Website:  www.drtlud.comOn 4/22/2013 6:13 PM, rongretlarson at comcast.net wrote:

    Crispin,  Jim,   and List

    See few comments below


----------------------------------------------------------------------------
    From: 
    To: "Discussion of biomass cooking stoves" <stoves at lists.bioenergylists.org>
    Sent: Monday, April 22, 2013 8:47:51 AM
    Subject: Re: [Stoves] FW: REQUEST for complete sets of raw data of        cookstove        tests.


    Dear Jim and Anyone watching



    I won't have time to dig through the messages on this thread that were in limbo. If something is really important to someone, ask again.



    With regard to the char remaining and the wood that has been burned on one end (fuel left over from tests) Harold Annegarn and I have a proposal for how to deal with stoves that can use fuel remaining from a previous burn. In principle, the test should be started with the fuel left over from a previous test. In other words a cooking task that is replicated a number of times in which the fuel left over goes into the stove for the subsequent task provides an opportunity to measure (quite accurately) the raw fuel drawn from the pile.

          [RWL1:    I suggest that any test has to account for stoves being used to BOTH cook AND make char.  I don't sense you will concur with this variation.  Or can you?

        I believe that forcing the reuse of char in many/most char-making stoves will not be the way the char will normally be used - and therefore will give erroneous results.








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