<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=""><div class=""><br class=""></div><div class="">Dear Prof. Lloyd and Crispin, Stovers, </div><div class=""><br class=""></div>One thing I have found is getting accurate temperature readings using thermocouples is not easy. You don’t know this until you compare the reading of a couple systems side by side or use a certified thermometer. So I like the idea of temperature change. And I find very interesting its use to determine when maintenance is needed at the mine. Perhaps off topic to expand on this I would like to better understand the process. Fluid (water & chemicals?) pumped down into the mine under high pressure has a temperature reading and the low pressure on the outflow at atmosphere pressure has another? and the resistance due to the pump create heat and high values means maintenance required? something like that?<div class=""><br class=""></div><div class="">Heating water in a pot without stirring will create hot zone at the bottom and especially if there are obstruction in the pot like you have with the coils - is my guess. Super heated water at the bottom. If this is the case you will need a specified size coil for each specified and shape pot. I am thinking a better plan is to have the coil outside the pot submerged in cool recirculating water bath. The long end of the pipe going to the bottom of the cooking pot and the short end placed just below the surface. Water pumped through the coil from the cooling pot and returned will mix in the cooking pot and the system be suitable for any size pot. Calibrate two thermocouples against each other using one pot of hot water then place one at the inflow and the other at the out flow and record debts-T. </div><div class=""><br class=""></div><div class="">Question:</div><div class="">Can you determine the heat getting to the pot by bring the pot of water to a boil them remove the heat source and measure the curve of it cooling? So this is a Blank of heat loss from the pot? so the two values (blank and water temperature) is the heat from the stove that actually gets to the pot? </div><div class=""><br class=""></div><div class="">Question:</div><div class=""><br class=""></div><div class="">Is the 4.186 j/g required to raise the temperature one deg. C the same going from 10c to 11c as it is from 80c to 81c? OR is it just an average of the total range and we need some complex math to determine the actual energy that went into a system going between two specified delta-Ts?</div><div class=""><br class=""></div><div class="">Thanks</div><div class=""><br class=""></div><div class="">Frank</div><div class=""><br class=""></div><div class=""><br class=""><div apple-content-edited="true" class="">
Frank Shields<br class=""><a href="mailto:franke@cruzio.com" class="">franke@cruzio.com</a><br class=""><br class="">
</div>
<br class=""><div><blockquote type="cite" class=""><div class="">On Jun 8, 2015, at 1:25 AM, Philip Lloyd <<a href="mailto:plloyd@mweb.co.za" class="">plloyd@mweb.co.za</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="WordSection1" style="page: WordSection1; font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;"><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">“The delta T in the pipes is not large – maybe 3-7 degrees.” Importantly, delta T is something you can measure really accurately with thermocouples. We used that to determine the efficiency of high-pressure (200 bar) pumps on deep-level mines. The delta T accurate to<span class="Apple-converted-space"> </span></span><span style="color: rgb(31, 73, 125);" class=""> </span><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""><o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">±0.01 deg C between low and high pressure lines was an excellent measure of efficiency and told you precisely when maintenance was necessary.<o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="font-size: 10pt; font-family: Arial, sans-serif; color: rgb(31, 73, 125);" class="">Prof Philip Lloyd</span><span style="color: rgb(31, 73, 125);" class=""><o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="font-size: 10pt; font-family: Arial, sans-serif; color: rgb(31, 73, 125);" class="">Energy Institute</span><span style="color: rgb(31, 73, 125);" class=""><o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="font-size: 10pt; font-family: Arial, sans-serif; color: rgb(31, 73, 125);" class="">Cape Peninsula University of Technology</span><span style="color: rgb(31, 73, 125);" class=""><o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="font-size: 10pt; font-family: Arial, sans-serif; color: rgb(31, 73, 125);" class="">PO Box 652, Cape Town 8000</span><span style="color: rgb(31, 73, 125);" class=""><o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="font-size: 10pt; font-family: Arial, sans-serif; color: rgb(31, 73, 125);" class="">Tel:021 460 4216</span><span style="color: rgb(31, 73, 125);" class=""><o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="font-size: 10pt; font-family: Arial, sans-serif; color: rgb(31, 73, 125);" class="">Fax:021 460 3828</span><span style="color: rgb(31, 73, 125);" class=""><o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="font-size: 10pt; font-family: Arial, sans-serif; color: rgb(31, 73, 125);" class="">Cell: 083 441 5247</span><span style="color: rgb(31, 73, 125);" class=""><o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div class=""><div style="border-style: solid none none; border-top-color: rgb(181, 196, 223); border-top-width: 1pt; padding: 3pt 0cm 0cm;" class=""><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><b class=""><span style="font-size: 10pt; font-family: Tahoma, sans-serif;" class="">From:</span></b><span style="font-size: 10pt; font-family: Tahoma, sans-serif;" class=""><span class="Apple-converted-space"> </span>Stoves [<a href="mailto:stoves-bounces@lists.bioenergylists.org" style="color: purple; text-decoration: underline;" class="">mailto:stoves-bounces@lists.bioenergylists.org</a>]<span class="Apple-converted-space"> </span><b class="">On Behalf Of<span class="Apple-converted-space"> </span></b>Crispin Pemberton-Pigott<br class=""><b class="">Sent:</b><span class="Apple-converted-space"> </span>08 June 2015 12:59<br class=""><b class="">To:</b><span class="Apple-converted-space"> </span>'Discussion of biomass cooking stoves'<br class=""><b class="">Subject:</b><span class="Apple-converted-space"> </span>Re: [Stoves] 'BBM' and the accuracy of RTD's (Way off topic)<o:p class=""></o:p></span></div></div></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><o:p class=""> </o:p></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">Dear Frank<o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">This will give you the idea. The water is circulated through a heat exchanger, not into and out of the pot. That way I can leave the pot to have its local temperature variations and collect heat from a broad area – more representative of the bulk temperature than any single point.<o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">First attempt (pipes a little short)<o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" class=""><image001.jpg></span><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""><o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">Pot on a traditional stove.<o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" class=""><image002.jpg></span><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""><o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" class=""> </span></div><div class=""><div class=""><div class=""><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="color: rgb(31, 73, 125);" class="">></span><span lang="EN-CA" class="">Seems to have several advantages. One being continue mixing of the pot water as the water is returned, no need to decide on a simmer temperature and a boiling temperature (based on elevation)<span class="Apple-converted-space"> </span><span style="color: rgb(31, 73, 125);" class=""><o:p class=""></o:p></span></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">The point is to measure the heat gained by the pot, not to cook anything. A lab test is a simulation. This is a reasonable method of determining the heat gained for as long as you want to run the fire. What we have largely been doing in the past is trying to work out after the fact what the heat flow was. When evaporation Is involved it can get messy, plus no one has been considering the heat lost from the pot.<span class="Apple-converted-space"> </span><o:p class=""></o:p></span></div></div><div class=""><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="color: rgb(31, 73, 125);" class="">></span><span lang="EN-CA" class="">Using K thermocouples? I would think J would be more to measuring the range around boiling. <o:p class=""></o:p></span></div></div><div class=""><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">K is what most people have and they are flexible: can use them in the fire and stack and so on. They are OK for most things.<o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div></div><blockquote style="margin-top: 5pt; margin-bottom: 5pt;" class="" type="cite"><div class=""><div class=""><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; background-color: white;" class=""><span lang="EN-CA" style="font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">>>the flow through the heat exchanger is 35 cc per second. There is five litres of water in the pot. <o:p class=""></o:p></span></div></div><div class=""><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; background-color: white;" class=""><span lang="EN-CA" style="font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div></div></div></blockquote><div class=""><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="color: rgb(31, 73, 125);" class="">></span><span lang="EN-CA" class="">The flow is constant?<span class="Apple-converted-space"> </span><span style="color: rgb(31, 73, 125);" class=""><o:p class=""></o:p></span></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">Surprisingly constant. It is governed by the pressure in the line (or regulator) and temperature. The delta T in the pipes is not large – maybe 3-7 degrees. Obviously it can be tuned. The SEET Lab in Ulaanbaatar has a flow meter on it logged by the computer. It can detect to a precision of a few Watts.<o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="color: rgb(31, 73, 125);" class="">></span><span lang="EN-CA" class="">And the temperature is kept the same in the pot?<span class="Apple-converted-space"> </span><span style="color: rgb(31, 73, 125);" class=""><o:p class=""></o:p></span></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">The water mass and pot temp can vary as you like. I prefer to keep the water temp below 70 so there is no evaporation at all. The Indian test 13152 uses 95 degrees and doesn’t consider evaporation which is a source of experimental error. We set the flow to match the heat gain rate such that it doesn’t rise above 70. Remember that if you consider the losses from the pot to radiation and convection, there is an influence. There is a difference between the heat gained by the pot and the Net heat gained.<span class="Apple-converted-space"> </span><o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="color: rgb(31, 73, 125);" class="">></span><span lang="EN-CA" class="">Its the same 5 liters of water just being circulated? <span style="color: rgb(31, 73, 125);" class=""><o:p class=""></o:p></span></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">No the water is wasted. The inlet is from the wall.<o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="color: rgb(31, 73, 125);" class="">></span><span lang="EN-CA" class="">The only thing left is the change in the energy required to keep the cooling water / heating water in the heat exchanger to maintain the temperature of choice. <span style="color: rgb(31, 73, 125);" class=""><o:p class=""></o:p></span></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">Yes.<span class="Apple-converted-space"> </span><o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">What it does very well (because the pot water temperature change is integrated with the coolant and Delta T) is we can find out the heat gain rate at the full power range of the stove.<span class="Apple-converted-space"> </span><o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">Because the CSI Technical Test operates the stove according to local practise, and that power level is adjusted from time to time depending on the meal choices, we are able to determine the total heat gained for any selected test cycle. That is the ultimate test of the stove: what is the thermal and emissions performance when ‘run that way’?<o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">While the flow rate can be monitored continuously, in fact it doesn’t vary much and there are still things one can do: have the water exit into a large bucket that sits on a scale, log the mass change and watch the flow rate at different temperatures. That provides a correction factor (if needed).<o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">An ultrasonic flow meter is really, and surprisingly, accurate. Because the temperature range is low – 15-30 degrees – the influence of thermal expansions of water is tiny compared with other variations. The water will expand but so does the pipe…<span class="Apple-converted-space"> </span></span><span lang="EN-CA" style="font-size: 11pt; font-family: Wingdings; color: rgb(31, 73, 125);" class="">J</span><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""><o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">The spreadsheet used is the same as that use for heating water in a radiator supply (like the Chinese and Mongolian low pressure boilers). In the short term we will make it able to accommodate 2 pots at the same time to test two-pot stoves.<span class="Apple-converted-space"> </span><o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">I was very surprised at the low Delta T on the low pressure boilers. The inlet and outlet are 4-7 degrees apart if there is a small pump. We also found in January that the pumps are not constant flow which means a flow meter is absolutely required. For the pot heat exchanger connected to the tap there is very little variation.<o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">I will discuss this setup with Julien in July so he can try it independently using his temperature logger. What do you say Julien?<o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">Regards<o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">Crispin<o:p class=""></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span lang="EN-CA" style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class=""> </span></div></div></div></div></div><span style="font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">_______________________________________________</span><br style="font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><span style="font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; 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font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><br style="font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><span style="font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">to UNSUBSCRIBE or Change your List Settings use the web page</span><br style="font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><a href="http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org" style="color: purple; text-decoration: underline; font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org</a><br style="font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><br style="font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><span style="font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">for more Biomass Cooking Stoves, News and Information see our web site:</span><br style="font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><a href="http://stoves.bioenergylists.org/" style="color: purple; text-decoration: underline; font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">http://stoves.bioenergylists.org/</a><br style="font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><br style="font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""></div></blockquote></div><br class=""></div></body></html>