{"id":45453,"date":"2019-10-18T06:08:24","date_gmt":"2019-10-18T05:08:24","guid":{"rendered":"https:\/\/www.thermal-engineering.org\/quest-ce-que-la-chaleur-en-thermodynamique-definition\/"},"modified":"2020-02-25T10:32:21","modified_gmt":"2020-02-25T09:32:21","slug":"quest-ce-que-la-chaleur-en-thermodynamique-definition","status":"publish","type":"post","link":"https:\/\/www.thermal-engineering.org\/fr\/quest-ce-que-la-chaleur-en-thermodynamique-definition\/","title":{"rendered":"Qu&#8217;est-ce que la chaleur en thermodynamique &#8211; D\u00e9finition"},"content":{"rendered":"<div class=\"su-quote su-quote-style-default\">\n<div class=\"su-quote-inner su-clearfix\">La chaleur est la quantit\u00e9 d&#8217;\u00e9nergie qui circule spontan\u00e9ment d&#8217;un corps \u00e0 un autre en raison de leur diff\u00e9rence de temp\u00e9rature.\u00a0La chaleur est une forme d&#8217;\u00e9nergie, mais c&#8217;est une \u00e9nergie en transit.\u00a0G\u00e9nie thermique<\/div>\n<\/div>\n<div class=\"su-divider su-divider-style-dotted\"><\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<h2>Chaleur en thermodynamique<\/h2>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Zeroth-Law-of-Thermodynamics-heat.png\"><img loading=\"lazy\" class=\"alignright size-medium wp-image-16452 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Zeroth-Law-of-Thermodynamics-heat-300x158.png\" alt=\"loi de z\u00e9roth de thermodynamique-chaleur\" width=\"300\" height=\"158\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Zeroth-Law-of-Thermodynamics-heat-300x158.png\" \/><\/a>Alors que\u00a0<strong>l&#8217;\u00e9nergie interne<\/strong>\u00a0fait r\u00e9f\u00e9rence \u00e0 l&#8217;\u00e9nergie totale de toutes les mol\u00e9cules de l&#8217;objet, la\u00a0<strong>chaleur<\/strong>\u00a0est la quantit\u00e9 d&#8217;\u00e9nergie\u00a0<strong>qui circule<\/strong>\u00a0spontan\u00e9ment d&#8217;un corps \u00e0 un autre en raison de leur diff\u00e9rence de temp\u00e9rature.\u00a0<strong>La chaleur<\/strong>\u00a0est une forme d&#8217;\u00e9nergie, mais c&#8217;est une\u00a0<strong>\u00e9nergie en transit<\/strong>\u00a0.\u00a0La chaleur n&#8217;est pas la propri\u00e9t\u00e9 d&#8217;un syst\u00e8me.\u00a0Cependant, le transfert d&#8217;\u00e9nergie sous forme de chaleur se produit au niveau mol\u00e9culaire \u00e0 la suite d&#8217;une\u00a0<strong>diff\u00e9rence de temp\u00e9rature<\/strong>\u00a0.<\/p>\n<p>Consid\u00e9rons un\u00a0<strong>bloc de m\u00e9tal<\/strong>\u00a0\u00e0 haute temp\u00e9rature, constitu\u00e9 d&#8217;atomes oscillant intens\u00e9ment autour de leurs positions moyennes.\u00a0<strong>\u00c0 basse temp\u00e9rature<\/strong>\u00a0, les atomes continuent \u00e0 osciller, mais avec\u00a0<strong>moins d&#8217;intensit\u00e9<\/strong>\u00a0.\u00a0Si un bloc de m\u00e9tal plus chaud est mis en contact avec un bloc plus froid, les atomes qui oscillent intens\u00e9ment au bord du bloc plus chaud d\u00e9gagent son \u00e9nergie cin\u00e9tique aux atomes les moins oscillants situ\u00e9s au bord du bloc froid.\u00a0Dans ce cas, il y a\u00a0<strong>transfert d&#8217;\u00e9nergie<\/strong>\u00a0entre ces deux blocs et la\u00a0<strong>chaleur circule<\/strong>\u00a0du bloc le plus chaud au bloc le plus froid par ces vibrations al\u00e9atoires.<\/p>\n<p>En g\u00e9n\u00e9ral, lorsque deux objets sont mis en\u00a0<strong>contact thermique<\/strong>\u00a0, de la\u00a0<strong>chaleur circule<\/strong>\u00a0entre eux\u00a0<strong>jusqu&#8217;\u00e0 ce<\/strong>\u00a0qu&#8217;ils\u00a0<strong>s&#8217;\u00e9quilibrent<\/strong>\u00a0.\u00a0Lorsqu&#8217;il\u00a0existe\u00a0une\u00a0<strong>diff\u00e9rence de temp\u00e9rature<\/strong>\u00a0, la chaleur circule spontan\u00e9ment\u00a0<strong>du syst\u00e8me le plus chaud vers le syst\u00e8me le plus froid<\/strong>\u00a0.\u00a0Le transfert de chaleur se fait par\u00a0<strong>conduction<\/strong>\u00a0ou par\u00a0<strong>rayonnement thermique<\/strong>\u00a0.\u00a0Lorsque le\u00a0<strong>flux de chaleur cesse<\/strong>\u00a0, on dit qu&#8217;ils sont \u00e0 la\u00a0<strong>m\u00eame temp\u00e9rature<\/strong>\u00a0.\u00a0On dit alors qu&#8217;ils sont en\u00a0<a title=\"\u00c9quilibre thermique\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/thermodynamic-properties\/what-is-temperature-physics\/thermal-equilibrium\/\"><strong>\u00e9quilibre thermique<\/strong><\/a>\u00a0.<\/p>\n<p>Comme pour le travail, la quantit\u00e9 de chaleur transf\u00e9r\u00e9e\u00a0<strong>d\u00e9pend du chemin<\/strong>\u00a0et non pas simplement des conditions initiales et finales du syst\u00e8me.\u00a0Il existe en fait de nombreuses mani\u00e8res de prendre le gaz de l\u2019\u00e9tat i \u00e0 l\u2019\u00e9tat f.<\/p>\n<p>En outre, comme pour le travail, il est important de faire la distinction entre la\u00a0<strong>chaleur ajout\u00e9e<\/strong>\u00a0\u00e0 un syst\u00e8me provenant de son environnement et la\u00a0<strong>chaleur \u00e9vacu\u00e9e<\/strong>\u00a0d&#8217;un syst\u00e8me vers son environnement.\u00a0Q est positif pour la chaleur ajout\u00e9e au syst\u00e8me. Par cons\u00e9quent, si la chaleur quitte le syst\u00e8me, Q est n\u00e9gatif.\u00a0\u00c9tant donn\u00e9 que W dans l&#8217;\u00e9quation correspond au travail effectu\u00e9 par le syst\u00e8me, si ce travail est effectu\u00e9 sur le syst\u00e8me, W sera n\u00e9gatif et E\u00a0<sub>int<\/sub>\u00a0augmentera.<\/p>\n<p>Le symbole\u00a0<strong>q<\/strong>\u00a0est parfois utilis\u00e9 pour indiquer la chaleur ajout\u00e9e ou retir\u00e9e d&#8217;un syst\u00e8me\u00a0<strong>par unit\u00e9 de masse<\/strong>\u00a0.\u00a0Il est \u00e9gal \u00e0 la chaleur totale (Q) ajout\u00e9e ou \u00e9limin\u00e9e divis\u00e9e par la masse (m).<\/p>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<h2>Capacit\u00e9 thermique<\/h2>\n<p><strong><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/specific-heat-capacities-substances.png\"><img loading=\"lazy\" class=\"alignright size-full wp-image-16879 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/specific-heat-capacities-substances.png\" alt=\"Tableau des capacit\u00e9s thermiques sp\u00e9cifiques\" width=\"301\" height=\"454\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/specific-heat-capacities-substances.png\" \/><\/a>Diff\u00e9rentes substances<\/strong>\u00a0sont affect\u00e9es \u00e0\u00a0<strong>diff\u00e9rentes magnitudes<\/strong>\u00a0par l&#8217;\u00a0<strong>ajout de chaleur<\/strong>\u00a0.\u00a0Lorsqu&#8217;une quantit\u00e9 donn\u00e9e de chaleur est ajout\u00e9e \u00e0 diff\u00e9rentes substances, leurs temp\u00e9ratures augmentent de mani\u00e8re diff\u00e9rente.\u00a0Cette\u00a0<strong>constante de proportionnalit\u00e9<\/strong>\u00a0entre la\u00a0<strong>chaleur Q<\/strong>\u00a0absorb\u00e9e ou perdue par l&#8217;objet et le\u00a0<strong>changement de temp\u00e9rature T<\/strong>\u00a0r\u00e9sultant\u00a0de l&#8217;objet est appel\u00e9e\u00a0<strong>capacit\u00e9 calorifique C<\/strong>\u00a0d&#8217;un objet.<\/p>\n<p><em><strong>C = Q \/ \u0394T<\/strong><\/em><\/p>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<p><strong><span>La capacit\u00e9 calorifique<\/span><\/strong><span>\u00a0est une\u00a0<\/span><a title=\"Propri\u00e9t\u00e9s \u00e9tendues et intensives\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/extensive-and-intensive-properties\/\"><span>propri\u00e9t\u00e9 \u00e9tendue<\/span><\/a><span>\u00a0de la mati\u00e8re, ce qui signifie qu&#8217;elle est proportionnelle \u00e0 la taille du syst\u00e8me.\u00a0<\/span><strong><span>La capacit\u00e9 calorifique C<\/span><\/strong><span>\u00a0a l&#8217;unit\u00e9 d&#8217;\u00e9nergie par degr\u00e9 ou d&#8217;\u00e9nergie par kelvin.\u00a0Lorsqu&#8217;elle exprime le m\u00eame ph\u00e9nom\u00e8ne qu&#8217;une\u00a0<\/span><a title=\"Propri\u00e9t\u00e9s \u00e9tendues et intensives\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/extensive-and-intensive-properties\/\"><span>propri\u00e9t\u00e9 intensive<\/span><\/a><span>\u00a0, la\u00a0<\/span><strong><span>capacit\u00e9 thermique<\/span><\/strong><span>\u00a0est divis\u00e9e par la quantit\u00e9 de substance, de masse ou de volume, donc la quantit\u00e9 est ind\u00e9pendante de la taille ou de l&#8217;\u00e9tendue de l&#8217;\u00e9chantillon.<\/span><\/p>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<h2><span>La capacit\u00e9 thermique sp\u00e9cifique<\/span><\/h2>\n<p><span>La\u00a0<\/span><strong><span>capacit\u00e9 thermique<\/span><\/strong><span>\u00a0d&#8217;une substance par unit\u00e9 de masse est appel\u00e9e\u00a0<\/span><strong><span>capacit\u00e9 thermique sp\u00e9cifique (c\u00a0<\/span><sub><span>p<\/span><\/sub><span>\u00a0)<\/span><\/strong><span>\u00a0de la substance.\u00a0L&#8217;indice p indique que la capacit\u00e9 thermique et\u00a0<\/span><strong><span>la capacit\u00e9 thermique sp\u00e9cifique<\/span><\/strong><span>\u00a0s&#8217;appliquent lorsque la chaleur est ajout\u00e9e ou retir\u00e9e\u00a0<\/span><strong><span>\u00e0 pression constante<\/span><\/strong><span>\u00a0.<\/span><\/p>\n<p><strong><em><span>c\u00a0<\/span><sub><span>p<\/span><\/sub><span>\u00a0= Q \/ m\u0394T<\/span><\/em><\/strong><\/p>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<h2><span>La capacit\u00e9 thermique sp\u00e9cifique<\/span><\/h2>\n<p><span>Dans le\u00a0<\/span><a title=\"Loi du gaz parfait\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/ideal-gas-law\/\"><span>mod\u00e8le de gaz parfait<\/span><\/a><span>\u00a0, les\u00a0<\/span><strong><span>propri\u00e9t\u00e9s intensives\u00a0<\/span><em><span>c\u00a0<\/span><sub><span>v<\/span><\/sub><\/em><\/strong><span>\u00a0et\u00a0<\/span><em><strong><span>c\u00a0<\/span><sub><span>p<\/span><\/sub><\/strong><\/em><span>\u00a0sont d\u00e9finies pour les substances compressibles pures et simples comme des d\u00e9riv\u00e9es partielles de l&#8217;\u00a0<\/span><strong><span>\u00e9nergie interne\u00a0<\/span><em><span>u (T, v)<\/span><\/em><\/strong><span>\u00a0et de l&#8217;\u00a0<\/span><strong><span>enthalpie\u00a0<\/span><em><span>h (T, p)<\/span><\/em><\/strong><span>\u00a0, respectivement:<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Specific-Heat-at-Constant-Volume-and-Constant-Pressure.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-16806 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Specific-Heat-at-Constant-Volume-and-Constant-Pressure.png\" alt=\"Chaleur sp\u00e9cifique \u00e0 volume et pression constants\" width=\"106\" height=\"138\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Specific-Heat-at-Constant-Volume-and-Constant-Pressure.png\" \/><\/a><\/p>\n<p><span>o\u00f9 les indices\u00a0<\/span><strong><span>v<\/span><\/strong><span>\u00a0et\u00a0<\/span><strong><span>p<\/span><\/strong><span>\u00a0d\u00e9signent les variables maintenues fixes pendant la diff\u00e9renciation.\u00a0Les propri\u00e9t\u00e9s\u00a0<\/span><strong><span>c\u00a0<\/span><sub><span>v<\/span><\/sub>\u00a0<\/strong><span>et\u00a0<\/span><strong><span>c\u00a0<\/span><sub><span>p<\/span><\/sub><\/strong><span>\u00a0sont appel\u00e9es\u00a0<\/span><strong><span>chaleurs sp\u00e9cifiques<\/span><\/strong><span>\u00a0(ou\u00a0<\/span><strong><span>capacit\u00e9s calorifiques<\/span><\/strong><span>\u00a0) car dans certaines conditions particuli\u00e8res, elles relient le changement de temp\u00e9rature d&#8217;un syst\u00e8me \u00e0 la quantit\u00e9 d&#8217;\u00e9nergie ajout\u00e9e par transfert de chaleur.\u00a0Les unit\u00e9s SI sont\u00a0<\/span><strong><span>J \/ kg K<\/span><\/strong><span>\u00a0ou\u00a0<\/span><strong><span>J \/ mole K<\/span><\/strong><span>\u00a0.\u00a0Deux chaleurs sp\u00e9cifiques sont d\u00e9finies pour les gaz, une pour\u00a0<\/span><strong><span>un volume constant (c\u00a0<\/span><sub><span>v<\/span><\/sub><span>\u00a0)<\/span><\/strong><span>\u00a0et une pour\u00a0<\/span><strong><span>une pression constante (c\u00a0<\/span><sub><span>p<\/span><\/sub><span>\u00a0)<\/span><\/strong><span>\u00a0.<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Molar-specific-heats-ideal-gas.png\"><img loading=\"lazy\" class=\"alignright size-full wp-image-16807 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Molar-specific-heats-ideal-gas.png\" alt=\"Chaleur sp\u00e9cifique aux molaires - gaz parfait\" width=\"353\" height=\"251\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Molar-specific-heats-ideal-gas.png\" \/><\/a><span>Selon la\u00a0<\/span><strong><span>premi\u00e8re loi de la thermodynamique<\/span><\/strong><span>\u00a0, pour un proc\u00e9d\u00e9 \u00e0 volume constant avec un gaz parfait monatomique, la chaleur sp\u00e9cifique molaire sera:<\/span><\/p>\n<p><strong><em><span>C\u00a0<\/span><sub><span>v<\/span><\/sub><span>\u00a0= 3 \/ 2R = 12,5 J \/ mol K<\/span><\/em><\/strong><\/p>\n<p><span>car<\/span><\/p>\n<p><strong><em><span>U = 3 \/ 2nRT<\/span><\/em><\/strong><\/p>\n<p><span>On peut d\u00e9duire que la\u00a0<\/span><strong><span>chaleur sp\u00e9cifique molaire<\/span><\/strong><span>\u00a0\u00e0 pression constante est:<\/span><\/p>\n<p><em><strong><span>C\u00a0<\/span><sub><span>p<\/span><\/sub><span>\u00a0= C\u00a0<\/span><sub><span>v<\/span><\/sub><span>\u00a0+ R = 5 \/ 2R = 20,8 J \/ mol K<\/span><\/strong><\/em><\/p>\n<p><span>Ce\u00a0<\/span><strong><em><span>C\u00a0<\/span><sub><span>p<\/span><\/sub><\/em><\/strong><span>\u00a0est sup\u00e9rieur \u00e0 la chaleur sp\u00e9cifique molaire \u00e0 volume constant\u00a0<\/span><strong><em><span>C\u00a0<\/span><sub><span>v<\/span><\/sub><\/em><\/strong><span>\u00a0, car il faut d\u00e9sormais fournir de l&#8217;\u00e9nergie\u00a0<\/span><strong><span>non seulement<\/span><\/strong><span>\u00a0pour\u00a0<\/span><strong><span>\u00e9lever la temp\u00e9rature<\/span><\/strong><span>\u00a0du gaz mais aussi pour que le\u00a0<\/span><strong><span>gaz fonctionne<\/span><\/strong><span>\u00a0car dans ce cas le volume change.<\/span><\/p>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<h2><span>La chaleur latente de vaporisation<\/span><\/h2>\n<figure id=\"attachment_16677\" class=\"wp-caption alignright\" aria-describedby=\"caption-attachment-16677\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Specific-Enthalpy-Water-and-Steam-min.png\"><img loading=\"lazy\" class=\"size-medium wp-image-16677 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Specific-Enthalpy-Water-and-Steam-min-242x300.png\" alt=\"Chaleur latente de vaporisation - eau \u00e0 0,1 MPa, 3 MPa, 16 MPa\" width=\"242\" height=\"300\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Specific-Enthalpy-Water-and-Steam-min-242x300.png\" \/><\/a><figcaption id=\"caption-attachment-16677\" class=\"wp-caption-text\"><span>La chaleur de vaporisation diminue avec l&#8217;augmentation de la pression, tandis que le point d&#8217;\u00e9bullition augmente.\u00a0Elle dispara\u00eet compl\u00e8tement \u00e0 un certain point appel\u00e9 le point critique.<\/span><\/figcaption><\/figure>\n<p><span>En g\u00e9n\u00e9ral, lorsqu&#8217;un mat\u00e9riau\u00a0<\/span><strong><span>change de phase<\/span><\/strong><span>\u00a0du solide au liquide, ou du liquide au gaz, une certaine quantit\u00e9 d&#8217;\u00e9nergie est impliqu\u00e9e dans ce changement de phase.\u00a0En cas de changement de phase liquide en gaz, cette quantit\u00e9 d&#8217;\u00e9nergie est connue sous le nom d&#8217;\u00a0<\/span><a title=\"Enthalpie de vaporisation\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/thermodynamics\/what-is-energy-physics\/what-is-enthalpy\/enthalpy-of-vaporization\/\"><strong><span>enthalpie de vaporisation<\/span><\/strong><\/a><span>\u00a0, (symbole \u2206H\u00a0<\/span><sub><span>vap<\/span><\/sub><span>\u00a0; unit\u00e9: J) \u00e9galement connue sous le nom de\u00a0<\/span><strong><span>chaleur (latente) de vaporisation<\/span><\/strong><span>\u00a0ou chaleur d&#8217;\u00e9vaporation.\u00a0La chaleur latente est la quantit\u00e9 de chaleur ajout\u00e9e ou retir\u00e9e d&#8217;une substance pour produire un changement de phase.\u00a0Cette \u00e9nergie d\u00e9compose les forces d&#8217;attraction intermol\u00e9culaires, et doit \u00e9galement fournir l&#8217;\u00e9nergie n\u00e9cessaire \u00e0 l&#8217;expansion du gaz (le\u00a0<\/span><strong><span>travail p\u0394V<\/span><\/strong><span>).\u00a0Lorsque de la chaleur latente est ajout\u00e9e, aucun changement de temp\u00e9rature ne se produit.\u00a0L&#8217;enthalpie de vaporisation est fonction de la pression \u00e0 laquelle cette transformation a lieu.<\/span><\/p>\n<p><span>Chaleur latente de vaporisation &#8211; eau \u00e0 0,1 MPa (pression atmosph\u00e9rique)<\/span><\/p>\n<p><strong><span>h\u00a0<\/span><sub><span>lg<\/span><\/sub><span>\u00a0= 2257 kJ \/ kg<\/span><\/strong><\/p>\n<p><span>Chaleur latente de vaporisation &#8211; eau \u00e0 3 MPa (pression \u00e0 l&#8217;int\u00e9rieur d&#8217;un g\u00e9n\u00e9rateur de vapeur)<\/span><\/p>\n<p><strong><span>h\u00a0<\/span><sub><span>lg<\/span><\/sub><span>\u00a0= 1795 kJ \/ kg<\/span><\/strong><\/p>\n<p><span>Chaleur latente de vaporisation &#8211; eau \u00e0 16 MPa (pression \u00e0 l&#8217;int\u00e9rieur d&#8217;un\u00a0<\/span><a title=\"Pressuriseur\" href=\"https:\/\/www.nuclear-power.com\/pressurizer\/\"><span>pressuriseur<\/span><\/a><span>\u00a0)<\/span><\/p>\n<p><strong><span>h\u00a0<\/span><sub><span>lg<\/span><\/sub><span>\u00a0= 931 kJ \/ kg<\/span><\/strong><\/p>\n<p><span>La\u00a0<\/span><strong><span>chaleur de vaporisation<\/span><\/strong><span>\u00a0diminue avec l&#8217;augmentation de la pression, tandis que le\u00a0<\/span><a title=\"Saturation - point d'\u00e9bullition\" href=\"https:\/\/www.thermal-engineering.org\/fr\/quest-ce-que-la-saturation-point-debullition-definition\/\"><span>point d&#8217;\u00e9bullition<\/span><\/a><span>\u00a0augmente.\u00a0Elle dispara\u00eet compl\u00e8tement \u00e0 un certain point appel\u00e9 le\u00a0<\/span><a title=\"Point critique de l'eau\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/materials-nuclear-engineering\/properties-of-water\/critical-point-of-water\/\"><span>point critique<\/span><\/a><span>\u00a0.\u00a0Au-dessus du point critique, les phases liquide et vapeur sont indiscernables et la substance est appel\u00e9e\u00a0<\/span><a title=\"Fluide supercritique - Eau supercritique\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/materials-nuclear-engineering\/properties-steam-what-is-steam\/supercritical-fluid-supercritical-water\/\"><span>fluide supercritique<\/span><\/a><span>\u00a0.<\/span><\/p>\n<p><span>La chaleur de vaporisation est la chaleur n\u00e9cessaire pour vaporiser compl\u00e8tement une unit\u00e9 de\u00a0<\/span><a title=\"Liquide satur\u00e9 et sous-refroidi\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/materials-nuclear-engineering\/properties-steam-what-is-steam\/saturated-and-subcooled-liquid\/\"><span>liquide satur\u00e9<\/span><\/a><span>\u00a0(ou condenser une unit\u00e9 de masse de vapeur satur\u00e9e) et elle est \u00e9gale \u00e0\u00a0<\/span><strong><span>h\u00a0<\/span><sub><span>lg<\/span><\/sub><span>\u00a0= h\u00a0<\/span><sub><span>g<\/span><\/sub><span>\u00a0&#8211; h\u00a0<\/span><sub><span>l<\/span><\/sub><\/strong><span>\u00a0.<\/span><\/p>\n<p><span>La chaleur n\u00e9cessaire pour faire fondre (ou geler) une masse unitaire \u00e0 la substance \u00e0 pression constante est la chaleur de fusion et est \u00e9gale \u00e0\u00a0<\/span><strong><span>h\u00a0<\/span><sub><span>sl<\/span><\/sub><span>\u00a0= h\u00a0<\/span><sub><span>l<\/span><\/sub><span>\u00a0&#8211; h\u00a0<\/span><sub><span>s<\/span><\/sub><\/strong><span>\u00a0, o\u00f9 h\u00a0<\/span><sub><span>s<\/span><\/sub><span>\u00a0est l&#8217;enthalpie du solide satur\u00e9 et h\u00a0<\/span><sub><span>l<\/span><\/sub><span>\u00a0est l&#8217;enthalpie du liquide satur\u00e9.<\/span><\/p>\n<figure id=\"attachment_16676\" class=\"wp-caption aligncenter\" aria-describedby=\"caption-attachment-16676\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Phease-Changes-Heat-of-Vaporization-Water-min.png\"><img loading=\"lazy\" class=\"size-large wp-image-16676 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Phease-Changes-Heat-of-Vaporization-Water-min-1024x454.png\" alt=\"Changements de phase - enthalpie de vaporisation\" width=\"669\" height=\"297\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Phease-Changes-Heat-of-Vaporization-Water-min-1024x454.png\" \/><\/a><figcaption id=\"caption-attachment-16676\" class=\"wp-caption-text\"><span>Chaleur latente de vaporisation &#8211; eau \u00e0 0,1 MPa.\u00a0Partie dominante de la chaleur absorb\u00e9e.<\/span><\/figcaption><\/figure>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<p>&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;.<\/p>\n<p>Cet article est bas\u00e9 sur la traduction automatique de l&#8217;article original en anglais. Pour plus d&#8217;informations, voir l&#8217;article en anglais. Pouvez vous nous aider Si vous souhaitez corriger la traduction, envoyez-la \u00e0 l&#8217;adresse: translations@nuclear-power.com ou remplissez le formulaire de traduction en ligne. Nous appr\u00e9cions votre aide, nous mettrons \u00e0 jour la traduction le plus rapidement possible. Merci<\/p>\n","protected":false},"excerpt":{"rendered":"<p>La chaleur est la quantit\u00e9 d&#8217;\u00e9nergie qui circule spontan\u00e9ment d&#8217;un corps \u00e0 un autre en raison de leur diff\u00e9rence de temp\u00e9rature.\u00a0La chaleur est une forme d&#8217;\u00e9nergie, mais c&#8217;est une \u00e9nergie en transit.\u00a0G\u00e9nie thermique Chaleur en thermodynamique Alors que\u00a0l&#8217;\u00e9nergie interne\u00a0fait r\u00e9f\u00e9rence \u00e0 l&#8217;\u00e9nergie totale de toutes les mol\u00e9cules de l&#8217;objet, la\u00a0chaleur\u00a0est la quantit\u00e9 d&#8217;\u00e9nergie\u00a0qui circule\u00a0spontan\u00e9ment d&#8217;un &#8230; <a title=\"Qu&#8217;est-ce que la chaleur en thermodynamique &#8211; D\u00e9finition\" class=\"read-more\" href=\"https:\/\/www.thermal-engineering.org\/fr\/quest-ce-que-la-chaleur-en-thermodynamique-definition\/\" aria-label=\"En savoir plus sur Qu&#8217;est-ce que la chaleur en thermodynamique &#8211; D\u00e9finition\">Lire la suite<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[8],"tags":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v15.4 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Qu&#039;est-ce que la chaleur en thermodynamique - D\u00e9finition<\/title>\n<meta name=\"description\" content=\"La chaleur est la quantit\u00e9 d&#039;\u00e9nergie qui circule spontan\u00e9ment d&#039;un corps \u00e0 un autre en raison de la diff\u00e9rence de temp\u00e9rature. La chaleur est une forme d&#039;\u00e9nergie, mais c&#039;est une \u00e9nergie en transit. G\u00e9nie thermique\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.thermal-engineering.org\/fr\/quest-ce-que-la-chaleur-en-thermodynamique-definition\/\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Qu&#039;est-ce que la chaleur en thermodynamique - D\u00e9finition\" \/>\n<meta property=\"og:description\" content=\"La chaleur est la quantit\u00e9 d&#039;\u00e9nergie qui circule spontan\u00e9ment d&#039;un corps \u00e0 un autre en raison de la diff\u00e9rence de temp\u00e9rature. La chaleur est une forme d&#039;\u00e9nergie, mais c&#039;est une \u00e9nergie en transit. G\u00e9nie thermique\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.thermal-engineering.org\/fr\/quest-ce-que-la-chaleur-en-thermodynamique-definition\/\" \/>\n<meta property=\"og:site_name\" content=\"Thermal Engineering\" \/>\n<meta property=\"article:published_time\" content=\"2019-10-18T05:08:24+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2020-02-25T09:32:21+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Zeroth-Law-of-Thermodynamics-heat-300x158.png\" \/>\n<meta name=\"twitter:card\" content=\"summary\" \/>\n<meta name=\"twitter:label1\" content=\"\u00c9crit par\">\n\t<meta name=\"twitter:data1\" content=\"Nick Connor\">\n\t<meta name=\"twitter:label2\" content=\"Dur\u00e9e de lecture est.\">\n\t<meta name=\"twitter:data2\" content=\"6 minutes\">\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.thermal-engineering.org\/fr\/#website\",\"url\":\"https:\/\/www.thermal-engineering.org\/fr\/\",\"name\":\"Thermal Engineering\",\"description\":\"\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":\"https:\/\/www.thermal-engineering.org\/fr\/?s={search_term_string}\",\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"fr-FR\"},{\"@type\":\"ImageObject\",\"@id\":\"https:\/\/www.thermal-engineering.org\/fr\/quest-ce-que-la-chaleur-en-thermodynamique-definition\/#primaryimage\",\"inLanguage\":\"fr-FR\",\"url\":\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Zeroth-Law-of-Thermodynamics-heat-300x158.png\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.thermal-engineering.org\/fr\/quest-ce-que-la-chaleur-en-thermodynamique-definition\/#webpage\",\"url\":\"https:\/\/www.thermal-engineering.org\/fr\/quest-ce-que-la-chaleur-en-thermodynamique-definition\/\",\"name\":\"Qu'est-ce que la chaleur en thermodynamique - D\\u00e9finition\",\"isPartOf\":{\"@id\":\"https:\/\/www.thermal-engineering.org\/fr\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.thermal-engineering.org\/fr\/quest-ce-que-la-chaleur-en-thermodynamique-definition\/#primaryimage\"},\"datePublished\":\"2019-10-18T05:08:24+00:00\",\"dateModified\":\"2020-02-25T09:32:21+00:00\",\"author\":{\"@id\":\"https:\/\/www.thermal-engineering.org\/fr\/#\/schema\/person\/e8c544db9afedaec8574d6464f9398bb\"},\"description\":\"La chaleur est la quantit\\u00e9 d'\\u00e9nergie qui circule spontan\\u00e9ment d'un corps \\u00e0 un autre en raison de la diff\\u00e9rence de temp\\u00e9rature. La chaleur est une forme d'\\u00e9nergie, mais c'est une \\u00e9nergie en transit. G\\u00e9nie thermique\",\"inLanguage\":\"fr-FR\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.thermal-engineering.org\/fr\/quest-ce-que-la-chaleur-en-thermodynamique-definition\/\"]}]},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.thermal-engineering.org\/fr\/#\/schema\/person\/e8c544db9afedaec8574d6464f9398bb\",\"name\":\"Nick Connor\",\"image\":{\"@type\":\"ImageObject\",\"@id\":\"https:\/\/www.thermal-engineering.org\/fr\/#personlogo\",\"inLanguage\":\"fr-FR\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/84c0dec310b44b65da29dc9df6925239?s=96&d=mm&r=g\",\"caption\":\"Nick Connor\"}}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","_links":{"self":[{"href":"https:\/\/www.thermal-engineering.org\/fr\/wp-json\/wp\/v2\/posts\/45453"}],"collection":[{"href":"https:\/\/www.thermal-engineering.org\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.thermal-engineering.org\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.thermal-engineering.org\/fr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.thermal-engineering.org\/fr\/wp-json\/wp\/v2\/comments?post=45453"}],"version-history":[{"count":0,"href":"https:\/\/www.thermal-engineering.org\/fr\/wp-json\/wp\/v2\/posts\/45453\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.thermal-engineering.org\/fr\/wp-json\/wp\/v2\/media?parent=45453"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.thermal-engineering.org\/fr\/wp-json\/wp\/v2\/categories?post=45453"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.thermal-engineering.org\/fr\/wp-json\/wp\/v2\/tags?post=45453"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}