<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=utf-8">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:"Segoe UI Emoji";}
@font-face
{font-family:"Segoe UI";
panose-1:2 11 5 2 4 2 4 2 2 3;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
span.StylE-mailovZprvy20
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:70.85pt 70.85pt 70.85pt 70.85pt;}
div.WordSection1
{page:WordSection1;}
/* List Definitions */
@list l0
{mso-list-id:775564555;
mso-list-template-ids:-2128690338;}
@list l0:level1
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level2
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:1.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level3
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:1.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level4
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:2.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level5
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:2.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level6
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:3.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level7
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:3.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level8
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:4.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level9
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:4.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l1
{mso-list-id:887961017;
mso-list-template-ids:-2007586090;}
@list l1:level1
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l1:level2
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:1.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l1:level3
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:1.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l1:level4
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:2.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l1:level5
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:2.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l1:level6
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:3.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l1:level7
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:3.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l1:level8
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:4.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l1:level9
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:4.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l2
{mso-list-id:1498959018;
mso-list-template-ids:-1786871942;}
@list l2:level1
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l2:level2
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:1.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l2:level3
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:1.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l2:level4
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:2.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l2:level5
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:2.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l2:level6
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:3.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l2:level7
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:3.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l2:level8
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:4.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l2:level9
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:4.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l3
{mso-list-id:1583484250;
mso-list-template-ids:-269309474;}
@list l3:level1
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l3:level2
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:1.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l3:level3
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:1.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l3:level4
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:2.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l3:level5
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:2.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l3:level6
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:3.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l3:level7
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:3.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l3:level8
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:4.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l3:level9
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:4.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
ol
{margin-bottom:0in;}
ul
{margin-bottom:0in;}
--></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-US" link="#0563C1" vlink="#954F72">
<div class="WordSection1">
<p class="MsoNormal">Hust<span lang="CS">ý :-) Tohle mě nenapadlo, díky.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="CS"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="CS">Aleš Procháska<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span lang="CS">From:</span></b><span lang="CS"> Hw-list <hw-list-bounces@list.hw.cz>
<b>On Behalf Of </b>konference@vojtek.biz<br>
<b>Sent:</b> Tuesday, 18 April, 2023 12:51<br>
<b>To:</b> 'HW-news' <hw-list@list.hw.cz><br>
<b>Subject:</b> RE: přenos tepla proudícím vzduchem<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Je to hnus jdu na pracák – tohle mi dal chat GPT<o:p></o:p></p>
<p class="MsoNormal">Okoknuto běžným okem to dává smyls <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<div style="border:solid #D9D9E3 1.0pt;padding:0in 0in 0in 0in">
<p class="MsoNormal" style="margin-bottom:15.0pt;background:#444654"><span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif;color:#D1D5DB">Pro výpočet teploty T2 vzduchu v trubce lze použít vztah pro výpočet tepelného přenosu v konvekci:<o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:15.0pt;margin-right:0in;margin-bottom:15.0pt;margin-left:0in;background:#444654">
<span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif;color:#D1D5DB">Q = h * A * (T1 - To)<o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:15.0pt;margin-right:0in;margin-bottom:15.0pt;margin-left:0in;background:#444654">
<span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif;color:#D1D5DB">kde:<o:p></o:p></span></p>
</div>
<div style="border:solid #D9D9E3 1.0pt;padding:0in 0in 0in 5.0pt">
<ul style="margin-top:0in" type="disc">
<li class="MsoNormal" style="color:#D1D5DB;mso-list:l0 level1 lfo3;background:#444654">
<span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif">Q je teplo přenesené konvekcí v joulech (J)<o:p></o:p></span></li><li class="MsoNormal" style="color:#D1D5DB;mso-list:l0 level1 lfo3;background:#444654">
<span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif">h je koeficient přestupu tepla konvekcí, v watt na metr čtvereční na kelvin (W/(m2*K))<o:p></o:p></span></li><li class="MsoNormal" style="color:#D1D5DB;mso-list:l0 level1 lfo3;background:#444654">
<span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif">A je plocha povrchu trubky, kterou proudí vzduch, v metrech čtverečních (m2)<o:p></o:p></span></li><li class="MsoNormal" style="color:#D1D5DB;mso-list:l0 level1 lfo3;background:#444654">
<span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif">T1 je teplota vzduchu v trubce, v kelvinech (K)<o:p></o:p></span></li><li class="MsoNormal" style="color:#D1D5DB;mso-list:l0 level1 lfo3;background:#444654">
<span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif">To je teplota okolního prostředí, v kelvinech (K)<o:p></o:p></span></li></ul>
</div>
<div style="border:solid #D9D9E3 1.0pt;padding:0in 0in 0in 0in">
<p class="MsoNormal" style="mso-margin-top-alt:15.0pt;margin-right:0in;margin-bottom:15.0pt;margin-left:0in;background:#444654">
<span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif;color:#D1D5DB">Pro výpočet koeficientu přestupu tepla konvekcí lze použít například Nusseltovu rovnici, která je závislá na rychlosti proudění vzduchu, průměru trubky a dalších parametrech.<o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:15.0pt;margin-right:0in;margin-bottom:15.0pt;margin-left:0in;background:#444654">
<span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif;color:#D1D5DB">Poté lze použít rovnici pro změnu teploty vzduchu v trubce, kterou jsem uváděl v předchozí odpovědi, aby se vypočetla teplota T2.<o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:15.0pt;margin-right:0in;margin-bottom:15.0pt;margin-left:0in;background:#444654">
<span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif;color:#D1D5DB">ΔT = Q / (m * c_p)<o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:15.0pt;margin-right:0in;margin-bottom:15.0pt;margin-left:0in;background:#444654">
<span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif;color:#D1D5DB">T2 = T1 - ΔT<o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:15.0pt;margin-right:0in;margin-bottom:15.0pt;margin-left:0in;background:#444654">
<span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif;color:#D1D5DB">kde:<o:p></o:p></span></p>
</div>
<div style="border:solid #D9D9E3 1.0pt;padding:0in 0in 0in 5.0pt">
<ul style="margin-top:0in" type="disc">
<li class="MsoNormal" style="color:#D1D5DB;mso-list:l3 level1 lfo6;background:#444654">
<span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif">ΔT je změna teploty vzduchu v trubce, v kelvinech (K)<o:p></o:p></span></li><li class="MsoNormal" style="color:#D1D5DB;mso-list:l3 level1 lfo6;background:#444654">
<span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif">m je hmotnost vzduchu, který prochází trubkou, v kilogramech (kg)<o:p></o:p></span></li><li class="MsoNormal" style="color:#D1D5DB;mso-list:l3 level1 lfo6;background:#444654">
<span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif">c_p je tepelná kapacita vzduchu při konstantním tlaku, v joulech na kilogram na kelvin (J/(kg*K))<o:p></o:p></span></li></ul>
</div>
<div style="border:solid #D9D9E3 1.0pt;padding:0in 0in 0in 0in">
<p class="MsoNormal" style="margin-top:15.0pt;background:#444654"><span style="font-size:12.0pt;font-family:"Segoe UI",sans-serif;color:#D1D5DB">Pro výpočet h a ΔT je třeba znát rychlost proudění vzduchu v trubce, průměr trubky, hmotnost vzduchu a tepelnou
kapacitu vzduchu při konstantním tlaku.<o:p></o:p></span></p>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b>From:</b> Hw-list <<a href="mailto:hw-list-bounces@list.hw.cz">hw-list-bounces@list.hw.cz</a>>
<b>On Behalf Of </b>Aleš Procháska<br>
<b>Sent:</b> Monday, April 17, 2023 6:38 PM<br>
<b>To:</b> HW-news <<a href="mailto:hw-list@list.hw.cz">hw-list@list.hw.cz</a>><br>
<b>Subject:</b> OT: přenos tepla proudícím vzduchem<o:p></o:p></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<p class="MsoNormal" style="background:white"><span style="font-size:12.0pt;color:black">Nemáte prosím někdo po ruce vzoreček či odkaz jak vypočítat o kolik tepla odebere (resp. o kolik se ohřeje) vzduch proudící trubkou o určitém průměru, délce a teplotě?
Povedlo se mi sice najít různé návody na výpočet tepelných výměníků a chladičů, ale je tam tolik parametrů a jdou tak obecné, že nemaje zkušeností, nevypočítal bych tím vůbec nic
</span><span style="font-size:12.0pt;font-family:"Segoe UI Emoji",sans-serif;color:black">🙂</span><span style="font-size:12.0pt;color:black"><o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal" style="background:white"><span style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
</div>
<div>
<p class="MsoNormal" style="background:white"><span style="font-size:12.0pt;color:black">díky<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal" style="background:white"><span style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
</div>
<div>
<p class="MsoNormal" style="background:white"><span style="font-size:12.0pt;color:black">Aleš Procháska<o:p></o:p></span></p>
</div>
</div>
</body>
</html>