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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link="#0563C1" vlink="#954F72" style='word-wrap:break-word'><div class=WordSection1><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='mso-element:para-border-div;border:solid #D9D9E3 1.0pt;padding:0cm 0cm 0cm 0cm;background:#444654'><p class=MsoNormal style='margin-bottom:15.0pt;background:#444654;border:none;padding:0cm'><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:0cm;margin-bottom:15.0pt;margin-left:0cm;background:#444654;border:none;padding:0cm'><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:0cm;margin-bottom:15.0pt;margin-left:0cm;background:#444654;border:none;padding:0cm'><span style='font-size:12.0pt;font-family:"Segoe UI",sans-serif;color:#D1D5DB'>kde:<o:p></o:p></span></p></div><div style='mso-element:para-border-div;border:solid #D9D9E3 1.0pt;padding:0cm 0cm 0cm 5.0pt;background:#444654;margin-left:18.0pt;margin-right:0cm'><ul style='margin-top:0cm' type=disc><li class=MsoNormal style='color:#D1D5DB;margin-left:-18.0pt;mso-list:l0 level1 lfo1;background:#444654;border:none;padding:0cm'><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;margin-left:-18.0pt;mso-list:l0 level1 lfo1;background:#444654;border:none;padding:0cm'><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;margin-left:-18.0pt;mso-list:l0 level1 lfo1;background:#444654;border:none;padding:0cm'><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;margin-left:-18.0pt;mso-list:l0 level1 lfo1;background:#444654;border:none;padding:0cm'><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;margin-left:-18.0pt;mso-list:l0 level1 lfo1;background:#444654;border:none;padding:0cm'><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='mso-element:para-border-div;border:solid #D9D9E3 1.0pt;padding:0cm 0cm 0cm 0cm;background:#444654'><p class=MsoNormal style='mso-margin-top-alt:15.0pt;margin-right:0cm;margin-bottom:15.0pt;margin-left:0cm;background:#444654;border:none;padding:0cm'><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:0cm;margin-bottom:15.0pt;margin-left:0cm;background:#444654;border:none;padding:0cm'><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:0cm;margin-bottom:15.0pt;margin-left:0cm;background:#444654;border:none;padding:0cm'><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:0cm;margin-bottom:15.0pt;margin-left:0cm;background:#444654;border:none;padding:0cm'><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:0cm;margin-bottom:15.0pt;margin-left:0cm;background:#444654;border:none;padding:0cm'><span style='font-size:12.0pt;font-family:"Segoe UI",sans-serif;color:#D1D5DB'>kde:<o:p></o:p></span></p></div><div style='mso-element:para-border-div;border:solid #D9D9E3 1.0pt;padding:0cm 0cm 0cm 5.0pt;background:#444654;margin-left:18.0pt;margin-right:0cm'><ul style='margin-top:0cm' type=disc><li class=MsoNormal style='color:#D1D5DB;margin-left:-18.0pt;mso-list:l1 level1 lfo2;background:#444654;border:none;padding:0cm'><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;margin-left:-18.0pt;mso-list:l1 level1 lfo2;background:#444654;border:none;padding:0cm'><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;margin-left:-18.0pt;mso-list:l1 level1 lfo2;background:#444654;border:none;padding:0cm'><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='mso-element:para-border-div;border:solid #D9D9E3 1.0pt;padding:0cm 0cm 0cm 0cm;background:#444654'><p class=MsoNormal style='margin-top:15.0pt;background:#444654;border:none;padding:0cm'><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 0cm 0cm 0cm'><p class=MsoNormal><b>From:</b> Hw-list <hw-list-bounces@list.hw.cz> <b>On Behalf Of </b>Aleš Procháska<br><b>Sent:</b> Monday, April 17, 2023 6:38 PM<br><b>To:</b> HW-news <hw-list@list.hw.cz><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>