<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style><![endif]--><style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0mm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.MsoPlainText, li.MsoPlainText, div.MsoPlainText
{mso-style-priority:99;
mso-style-link:"Plain Text Char";
margin:0mm;
margin-bottom:.0001pt;
font-size:10.5pt;
font-family:Consolas;}
p.MsoAcetate, li.MsoAcetate, div.MsoAcetate
{mso-style-priority:99;
mso-style-link:"Balloon Text Char";
margin:0mm;
margin-bottom:.0001pt;
font-size:8.0pt;
font-family:"Tahoma","sans-serif";}
p.MsoNoSpacing, li.MsoNoSpacing, div.MsoNoSpacing
{mso-style-priority:1;
margin-top:5.0pt;
margin-right:0mm;
margin-bottom:5.0pt;
margin-left:0mm;
mso-add-space:auto;
font-size:11.0pt;
font-family:"Arial","sans-serif";
color:#1F497D;}
p.MsoNoSpacingCxSpFirst, li.MsoNoSpacingCxSpFirst, div.MsoNoSpacingCxSpFirst
{mso-style-priority:1;
mso-style-type:export-only;
margin-top:5.0pt;
margin-right:0mm;
margin-bottom:0mm;
margin-left:0mm;
margin-bottom:.0001pt;
mso-add-space:auto;
font-size:11.0pt;
font-family:"Arial","sans-serif";
color:#1F497D;}
p.MsoNoSpacingCxSpMiddle, li.MsoNoSpacingCxSpMiddle, div.MsoNoSpacingCxSpMiddle
{mso-style-priority:1;
mso-style-type:export-only;
margin:0mm;
margin-bottom:.0001pt;
mso-add-space:auto;
font-size:11.0pt;
font-family:"Arial","sans-serif";
color:#1F497D;}
p.MsoNoSpacingCxSpLast, li.MsoNoSpacingCxSpLast, div.MsoNoSpacingCxSpLast
{mso-style-priority:1;
mso-style-type:export-only;
margin-top:0mm;
margin-right:0mm;
margin-bottom:5.0pt;
margin-left:0mm;
mso-add-space:auto;
font-size:11.0pt;
font-family:"Arial","sans-serif";
color:#1F497D;}
span.PlainTextChar
{mso-style-name:"Plain Text Char";
mso-style-priority:99;
mso-style-link:"Plain Text";
font-family:Consolas;}
span.BalloonTextChar
{mso-style-name:"Balloon Text Char";
mso-style-priority:99;
mso-style-link:"Balloon Text";
font-family:"Tahoma","sans-serif";
mso-fareast-language:EN-CA;}
span.EmailStyle22
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Dear Marc<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Your post was a ‘keeper’. Thanks so much. You are doing very good work with nearly nothing backing you. <o:p></o:p></span></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>“</span>What I think is responsible is that the particular chemical structure of rice hull (high ash, a silica skeleton) acts as a brake on the "char reactions" …”<o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I suspect it is worth looking at the ash and char content to see if there is not a mistake being made relative to the application of the Siegert constants. That will affect the final number and are rooted in the chemical composition of the fuel, which has of course changed.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I believe we will one day be able to compensate for this in real time by using a sum of the gases emitted. So far, just feeling for a way in the almost-dark. Thanks for identifying the discrepancy and let’s keep looking for the reason. You can at least guess Siegert constants for the char based on a guess at its chemical composition and report the difference it makes in the final calculation. If it is greater than your measurement errors we have something significant to talk about.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I have been having a very interesting time in Java talking to people using stoves for ‘industrial’ purposes. We are going to have to redefine what ‘domestic’ stoves are! Rice hull is a widely available fuel and I have yet to see a decent burner for them locally save a photo of an exact knock-off of Roger Samson’s Mayon Turbo Stove.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Here, in reply, is a simple test result for thermal efficiency on something made locally. It shows how the thermal efficiency varies systematically with power giving a policy manager valuable information about how it performs in different circumstances. This was for one pot size only (large). Different pots (and woks) yield different profiles and efficiencies at the same power.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><img width=472 height=217 id="Picture_x0020_1" src="cid:image003.jpg@01CDAFB8.F04F6230"><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The trend line is for both water heating and boiling.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><img width=473 height=179 id="Picture_x0020_4" src="cid:image006.jpg@01CDAFB8.F04F6230"><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The instantaneous efficiency values are provided for entertainment purposes and are jumping around due to the (im)precision of the scale. The overall efficiency of 23.0% is based on the overall mass measurement which is quite precise (1 part in 450) so it meets (that part of) the IWA precision requirement for Tier performance claims. The two charts are extracted from the same set of data.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I wondered if the thermal efficiency was related to the water temperature but have not corrected these thermal efficiency numbers for the power level at the time. Here it is anyway:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><img width=472 height=283 id="Picture_x0020_6" src="cid:image007.jpg@01CDAFB8.F04F6230"><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The trend is for the heating portion only. It is too shaky to make a claim, I want to see the power-corrected plot.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Regards<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Crispin<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p></div></div></body></html>