Remaining mass of water after boiling test. How useful is a water boiling test where you boil away water? It just occurred to me that reducing the volume of water is not the goal of simmering. Simmering should be just before steam escapes the lid or open pot. escaping steam is escaping energy. Boiling away water is not necessary so how should the remaining mass of the water in the pot be counted after a water boiling test when it is actually a waist of energy because of lack of turn down heat control. I know WBT is to test the power of a burner of stove, but how useful is unnecessary power? Just a thought, there is probably a simple answer, Lanny ----- Original Message ----- From: Crispin Pemberton-Pigott To: Stoves Sent: Sunday, April 28, 2013 5:22 PM Subject: Re: [Stoves] Truth in stove reports Re: FW: REQUEST for completesets of raw data of cookstove tests.
Dear Ron The issues with most stove test protocols, but particularly with the WBT's relate to three type of conceptual errors. 1. The mass of water remaining in the pot is used as the amount 'boiled' or 'simmered' and 'specific' performance numbers are incorrect. 2. The consideration of dried, torrefied, charred and ashed materials (i.e. non-new materials) frequently gives misleading performance claims because of the way the energy content and re-useability of the fuels are considered. 3. The formula used in many spreadsheets does not handle fuel moisture correctly - simple math errors that skew different fuel moisture levels differently. There are other issues such as the averaging of ratios and averaging of averages of averages but these are relatively minor in their influence and error. By far the largest difference between 'perceived claims' (what people think they are being told) and the actual meaning of the claimed numbers relates to treating char made by gasifiers as unburned raw fuel. If the TLUD promoters do not get to grips with what is happening a) behind the formulas and b) what is happening behind the scenes with respect to the difference between a 'uses xx g of fuel to perform a WBT' and the fuel needed to do so. The reputation of the stove sector rests on our ability - as a group - to deal with these in a straight forward manner. Regards Crispin From BB9900 ------------------------------------------------------------------------------
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