<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><snip><br class=""><div><blockquote type="cite" class=""><div class="">On Jan 12, 2017, at 9:27 PM, Crispin Pemberton-Pigott <<a href="mailto:crispinpigott@outlook.com" class="">crispinpigott@outlook.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div style="font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: initial; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); width: 1003px; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif, sans-serif; color: rgb(31, 73, 125);" class=""><span style="font-family: 'Slate Pro';" class="">3. On an ENERGY basis (not fuel basis), only the actual released energy in the biomass (after subtracting the energy that is still in the charcoal) should be used to calculate the heat transfer efficiency of the stove."</span></div><div style="font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: initial; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); width: 1003px; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif, sans-serif; color: rgb(31, 73, 125);" class=""><span style="font-family: 'Slate Pro';" class=""><br class=""></span></div><div style="font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: initial; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); width: 1003px; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif, sans-serif; color: rgb(31, 73, 125);" class=""><span style="font-family: 'Slate Pro';" class="">The heat transfer efficiency of a stove is an internal phenomenon. It is the percentage of the heat available in the gas passing the pot that makes it into the pot. To make the calculation one has to consider the energy released from the fuel, not the energy available from the fuel. That means CO, for example, and free hydrogen (H2) must be deducted from the heat available from missing (burned) fuel. It also means trying to discover the amount of energy remaining in all the fuel not burned. It is difficult to extinguish immediately on completion of the test. An error is involved. </span></div></div></blockquote></div><div class=""><br class=""></div><div class=""><snip></div><div class="">The problem has been is estimating the energy left in the after mass made of wood, char, water, ash. This can’t be easily done. We need a sharp, reproducible value easily obtained from different labs. This has been the problem. </div><div class=""><br class=""></div><div class="">The purpose for the testing is comparison of stoves. And it would be nice if we could use the value to transfer to what will happen with biomass found in the wild. </div><div class=""><br class=""></div><div class="">Using the energy in the volatiles previously determined in the pipe is such a way. Making sure the fire goes to completeness by prodding and pocking the fuel to keep it going as long as possible until the water temperature drops, say 5 degrees(?) is easily reproduced. </div><div class=""><br class=""></div><div class="">Now we have a sharp starting point (light a match) and a sharp ending point (temperature drop) and an exact total volatile energy moving past the pot as determined previously from the pipe on that fuel. If a stove is designed such it uses energy from the char being volatilized to CO and that to CO2 at the pot and not included in the total energy - that just calculates out as a better stove. </div><div class=""><br class=""></div><div class="">Moisture should not be calculated into the method. If we are comparing stoves we use oven dry fuel. If we are seeing what happens with wild fuel moisture is one of the variables that may improve or lessen the results. We want to know.</div><div class=""><br class=""></div><div class="">Biggest hangup is that we are stuck on the definition of ‘heat transfer efficiency’ as pertains to the Engineering books. That does not apply here because, like so many things, the natural environment too variable to accommodate engineering books. We start with a clean sheet of paper and just think about what we are trying to determine. We develop a new dictionary. </div><div class=""><br class=""></div><div class=""><br class=""></div><br class=""><div class="">
<div class="">Thanks</div><div class=""><br class=""></div><div class="">Frank</div><div class="">Frank Shields</div><div class="">Gabilan Laboratory</div><div class="">Keith Day Company, Inc.</div><div class="">1091 Madison Lane</div><div class="">Salinas, CA 93907</div><div class="">(831) 246-0417 cell</div><div class="">(831) 771-0126 office</div><div class=""><a href="mailto:fShields@keithdaycompany.com" class="">fShields@keithdaycompany.com</a></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><a href="mailto:franke@cruzio.com" class="">franke@cruzio.com</a></div><div class=""><br class=""></div><br class="Apple-interchange-newline">
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