{"id":48099,"date":"2019-11-08T03:53:46","date_gmt":"2019-11-08T02:53:46","guid":{"rendered":"https:\/\/www.thermal-engineering.org\/o-que-e-o-ciclo-de-carnot-tipos-de-processos-definicao\/"},"modified":"2020-01-27T14:10:40","modified_gmt":"2020-01-27T13:10:40","slug":"o-que-e-o-ciclo-de-carnot-tipos-de-processos-definicao","status":"publish","type":"post","link":"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-ciclo-de-carnot-tipos-de-processos-definicao\/","title":{"rendered":"O que \u00e9 o ciclo de Carnot – Tipos de processos – Defini\u00e7\u00e3o"},"content":{"rendered":"
\n
Ciclo de Carnot – Tipos de processos.\u00a0Em um ciclo de Carnot, o sistema que executa o ciclo passa por uma s\u00e9rie de quatro processos revers\u00edveis internamente.\u00a0Engenharia T\u00e9rmica<\/div>\n<\/div>\n
<\/div>\n
\n
\n
<\/div>\n

Ciclo de Carnot – Processos<\/h2>\n

\"Ciclo<\/a>Em um\u00a0ciclo de Carnot<\/strong>\u00a0, o sistema que executa o ciclo passa por uma s\u00e9rie de\u00a0quatro processos revers\u00edveis internamente<\/strong>\u00a0:\u00a0dois\u00a0processos isentr\u00f3picos<\/a><\/strong>\u00a0(adiab\u00e1ticos revers\u00edveis) alternados com\u00a0dois\u00a0<\/strong>processos isot\u00e9rmicos<\/strong><\/a>\u00a0:<\/p>\n

    \n
  1. compress\u00e3o isentr\u00f3pica<\/strong>\u00a0– O g\u00e1s \u00e9 comprimido adiabaticamente a partir de um estado para o estado 2, onde a temperatura \u00e9\u00a0T\u00a0H<\/sub><\/strong>\u00a0.\u00a0Os arredores trabalham com o g\u00e1s, aumentando sua energia interna e comprimindo-a.\u00a0Por outro lado, a\u00a0entropia<\/strong>\u00a0permanece\u00a0inalterada<\/strong>\u00a0.<\/li>\n
  2. Expans\u00e3o isot\u00e9rmica<\/strong>\u00a0– O sistema \u00e9 colocado em contacto com o reservat\u00f3rio em\u00a0T\u00a0H<\/sub><\/strong>\u00a0.\u00a0O g\u00e1s se expande isot\u00e9rmica enquanto recebe energia Q\u00a0H<\/sub>\u00a0do reservat\u00f3rio quente por transfer\u00eancia de calor.\u00a0A temperatura do g\u00e1s n\u00e3o muda durante o processo.\u00a0O g\u00e1s funciona nos arredores.\u00a0A varia\u00e7\u00e3o total da entropia \u00e9 dada por:\u00a0\u2206S = S\u00a0<\/em><\/strong>1<\/sub><\/em><\/strong>\u00a0– S\u00a0<\/em><\/strong>4<\/sub><\/em><\/strong>\u00a0= Q\u00a0<\/em><\/strong>H<\/sub><\/em><\/strong>\u00a0\/ T\u00a0<\/em><\/strong>H<\/sub><\/em><\/strong><\/li>\n
  3. expans\u00e3o isentr\u00f3pica<\/strong>\u00a0– O g\u00e1s expande-se adiabaticamente de estado 3 para o estado 4, onde a temperatura \u00e9\u00a0T\u00a0C<\/sub><\/strong>\u00a0.\u00a0O g\u00e1s trabalha nos arredores e perde uma quantidade de energia interna igual ao trabalho que sai do sistema.\u00a0Novamente a entropia permanece inalterada.<\/li>\n
  4. compress\u00e3o isot\u00e9rmica<\/strong>\u00a0– O sistema \u00e9 colocado em contacto com o reservat\u00f3rio em\u00a0T\u00a0C<\/sub><\/strong>\u00a0.\u00a0O g\u00e1s \u00e9 comprimido isot\u00e9rmica ao seu estado inicial enquanto descarrega energia Q\u00a0C<\/sub>\u00a0para o reservat\u00f3rio frio por transfer\u00eancia de calor.\u00a0Nesse processo, o ambiente trabalha com o g\u00e1s.\u00a0A varia\u00e7\u00e3o total da entropia \u00e9 dada por:\u00a0\u2206S = S\u00a0<\/em><\/strong>3<\/sub><\/em><\/strong>\u00a0– S\u00a0<\/em><\/strong>2<\/sub><\/em><\/strong>\u00a0= Q\u00a0<\/em><\/strong>C<\/sub><\/em><\/strong>\u00a0\/ T\u00a0<\/em><\/strong>C<\/sub><\/em><\/strong><\/li>\n<\/ol>\n<\/div>\n<\/div>\n

     <\/p>\n

    \n
    \n

    Processo isentr\u00f3pico<\/span><\/h2>\n

    Um\u00a0<\/span>processo isentr\u00f3pico<\/span><\/strong><\/a>\u00a0\u00e9 um\u00a0<\/span>processo termodin\u00e2mico<\/span><\/strong><\/a>\u00a0, no qual a\u00a0<\/span>entropia<\/span><\/strong>\u00a0<\/a>do fluido ou g\u00e1s permanece constante.\u00a0Isso significa que o\u00a0<\/span>processo isentr\u00f3pico<\/span><\/strong>\u00a0\u00e9 um caso especial de um\u00a0<\/span>processo adiab\u00e1tico<\/span><\/strong>\u00a0no qual n\u00e3o h\u00e1 transfer\u00eancia de calor ou mat\u00e9ria.\u00a0\u00c9 um\u00a0<\/span>processo adiab\u00e1tico revers\u00edvel<\/span><\/strong>\u00a0.\u00a0A suposi\u00e7\u00e3o de que n\u00e3o h\u00e1 transfer\u00eancia de calor \u00e9 muito importante, pois podemos usar a aproxima\u00e7\u00e3o adiab\u00e1tica apenas em\u00a0<\/span>processos muito r\u00e1pidos<\/span><\/strong>\u00a0.<\/span><\/p>\n

    Processo isentr\u00f3pico e a primeira lei<\/span><\/strong><\/p>\n

    Para um sistema fechado, podemos escrever a\u00a0<\/span>primeira lei da termodin\u00e2mica em termos de entalpia<\/span><\/a><\/strong>\u00a0:<\/span><\/p>\n

    dH = dQ + Vdp<\/span><\/strong><\/p>\n

    ou<\/span><\/strong><\/p>\n

    dH = TdS + Vdp<\/span><\/strong><\/p>\n

    Processo isentr\u00f3pico (dQ = 0):<\/span><\/strong><\/p>\n

    dH = Vdp \u2192 W = H\u00a0<\/span><\/strong>2<\/span><\/sub><\/strong>\u00a0– H\u00a0<\/span><\/strong>1<\/span><\/sub><\/strong>\u00a0\u00a0\u00a0\u00a0\u00a0\u2192 H\u00a0<\/span><\/strong>2<\/span><\/sub><\/strong>\u00a0– H\u00a0<\/span><\/strong>1<\/span><\/sub><\/strong>\u00a0=\u00a0<\/span>C\u00a0<\/span><\/em><\/strong>P<\/span><\/sub><\/em><\/strong>\u00a0(T\u00a0<\/span><\/em><\/strong>2<\/span><\/sub><\/em><\/strong>\u00a0– T\u00a0<\/span><\/em><\/strong>1<\/span><\/sub><\/em><\/strong>\u00a0) \u00a0\u00a0\u00a0<\/span><\/em><\/strong>\u00a0(para\u00a0<\/span>g\u00e1s ideal<\/span><\/a>\u00a0)<\/span><\/em><\/p>\n

    Processo isentr\u00f3pico do g\u00e1s ideal<\/span><\/strong><\/p>\n

    O\u00a0<\/span>processo isentr\u00f3pico<\/span><\/strong>\u00a0(um caso especial de processo adiab\u00e1tico) pode ser expresso com a\u00a0<\/span>lei dos gases ideais<\/span><\/strong><\/a>\u00a0como:<\/span><\/p>\n

    pV\u00a0<\/span>\u03ba<\/span><\/sup>\u00a0= constante<\/span><\/em><\/strong><\/p>\n

    ou<\/span><\/p>\n

    p\u00a0<\/span>1<\/span><\/sub>\u00a0V\u00a0<\/span>1\u00a0<\/span><\/sub>k<\/span><\/sup>\u00a0= p\u00a0<\/span>2<\/span><\/sub>\u00a0V\u00a0<\/span>2\u00a0<\/span><\/sub>k<\/span><\/sup><\/strong><\/em><\/p>\n

    em que\u00a0<\/span>\u03ba = c\u00a0<\/span>p<\/span><\/sub>\u00a0\/ c\u00a0<\/span>v<\/span><\/sub><\/strong>\u00a0\u00e9 a propor\u00e7\u00e3o de\u00a0aquecimentos espec\u00edficos<\/strong><\/a>\u00a0(ou\u00a0capacidades de calor<\/strong>\u00a0) para o g\u00e1s.\u00a0Um para\u00a0press\u00e3o constante (c\u00a0<\/strong>p<\/sub><\/strong>\u00a0)<\/strong>\u00a0e outro para\u00a0volume constante (c\u00a0<\/strong>v<\/sub><\/strong>\u00a0)<\/strong>\u00a0.\u00a0Observe que essa raz\u00e3o\u00a0\u03ba\u00a0\u00a0<\/strong>= c\u00a0<\/strong>p<\/sub><\/strong>\u00a0\/ c\u00a0<\/strong>v<\/sub><\/strong>\u00a0\u00e9 um fator na determina\u00e7\u00e3o da velocidade do som em um g\u00e1s e em outros processos adiab\u00e1ticos.<\/span><\/p>\n<\/div>\n<\/div>\n

    \n
    \n
    <\/div>\n

    Processo isot\u00e9rmico<\/span><\/h2>\n

    Um\u00a0<\/span>processo isot\u00e9rmico<\/span><\/strong>\u00a0\u00e9 um\u00a0<\/span>processo termodin\u00e2mico<\/span><\/strong><\/a>\u00a0, no qual a\u00a0<\/span>temperatura<\/span><\/strong>\u00a0do sistema\u00a0<\/span>permanece constante<\/span><\/strong>\u00a0(T = const).\u00a0A transfer\u00eancia de calor para dentro ou para fora do sistema geralmente deve ocorrer a uma taxa t\u00e3o lenta, a fim de se ajustar continuamente \u00e0 temperatura do reservat\u00f3rio atrav\u00e9s da troca de calor.\u00a0Em cada um desses estados, o\u00a0<\/span>equil\u00edbrio t\u00e9rmico<\/span><\/strong><\/a>\u00a0\u00e9 mantido.<\/span><\/p>\n

    Processo isot\u00e9rmico e a primeira lei<\/span><\/strong><\/p>\n

    A forma cl\u00e1ssica da\u00a0<\/span>primeira lei da termodin\u00e2mica<\/span><\/a>\u00a0\u00e9 a seguinte equa\u00e7\u00e3o:<\/span><\/p>\n

    dU = dQ – dW<\/span><\/strong><\/p>\n

    Nesta equa\u00e7\u00e3o, dW \u00e9 igual a\u00a0<\/span>dW = pdV<\/span><\/strong>\u00a0e \u00e9 conhecido como\u00a0<\/span>trabalho de fronteira<\/span><\/a>\u00a0.<\/span><\/p>\n

    No\u00a0<\/span>processo isot\u00e9rmico<\/span><\/strong>\u00a0e no\u00a0<\/span>g\u00e1s ideal<\/span><\/strong><\/a>\u00a0, todo o calor adicionado ao sistema ser\u00e1 usado para realizar o trabalho:<\/span><\/p>\n

    Processo isot\u00e9rmico (dU = 0):<\/span><\/strong><\/p>\n

    dU = 0 = Q – W \u2192 W = Q \u00a0\u00a0<\/span>\u00a0\u00a0\u00a0\u00a0<\/em><\/strong>(para g\u00e1s ideal)<\/span><\/em><\/p>\n

    Processo isot\u00e9rmico do g\u00e1s ideal<\/span><\/strong><\/p>\n

    O\u00a0<\/span>processo isot\u00e9rmico\u00a0<\/span><\/strong>\u00a0pode ser expresso com a\u00a0<\/span>lei do g\u00e1s ideal<\/span><\/strong>\u00a0como:<\/span><\/p>\n

    pV = constante<\/span><\/em><\/strong><\/p>\n

    ou<\/span><\/p>\n

    p\u00a0<\/span>1<\/span><\/sub>\u00a0V\u00a0<\/span>1<\/span><\/sub>\u00a0\u00a0= p\u00a0<\/span>2<\/span><\/sub>\u00a0V\u00a0<\/span>2<\/span><\/sub><\/strong><\/em><\/p>\n

    Em um diagrama pV, o processo ocorre ao longo de uma linha (chamada uma isot\u00e9rmica) que tem a equa\u00e7\u00e3o\u00a0<\/span>p = constante \/ V<\/span><\/strong>\u00a0.<\/span><\/p>\n

    Veja tamb\u00e9m:\u00a0<\/span>Lei de Boyle-Mariotte<\/span><\/a><\/p>\n<\/div>\n<\/div>\n

    \n
    \n
    \"Processo<\/a>
    Processo isentr\u00f3pico – principais caracter\u00edsticas<\/span><\/figcaption><\/figure>\n<\/div>\n<\/div>\n
    \n
    \n
    \"Processo<\/a>
    Processo isot\u00e9rmico – principais caracter\u00edsticas
    \n<\/span><\/figcaption><\/figure>\n<\/div>\n<\/div>\n
    <\/div>\n

    ……………………………………………………………………………………………………………………………….<\/p>\n

    Este artigo \u00e9 baseado na tradu\u00e7\u00e3o autom\u00e1tica do artigo original em ingl\u00eas. Para mais informa\u00e7\u00f5es, consulte o artigo em ingl\u00eas. Voc\u00ea pode nos ajudar. Se voc\u00ea deseja corrigir a tradu\u00e7\u00e3o, envie-a para: translations@nuclear-power.com ou preencha o formul\u00e1rio de tradu\u00e7\u00e3o on-line. Agradecemos sua ajuda, atualizaremos a tradu\u00e7\u00e3o o mais r\u00e1pido poss\u00edvel. Obrigado.<\/p>\n","protected":false},"excerpt":{"rendered":"

    Ciclo de Carnot – Tipos de processos.\u00a0Em um ciclo de Carnot, o sistema que executa o ciclo passa por uma s\u00e9rie de quatro processos revers\u00edveis internamente.\u00a0Engenharia T\u00e9rmica Ciclo de Carnot – Processos Em um\u00a0ciclo de Carnot\u00a0, o sistema que executa o ciclo passa por uma s\u00e9rie de\u00a0quatro processos revers\u00edveis internamente\u00a0:\u00a0dois\u00a0processos isentr\u00f3picos\u00a0(adiab\u00e1ticos revers\u00edveis) alternados com\u00a0dois\u00a0processos isot\u00e9rmicos\u00a0: … Ler mais<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[14],"tags":[],"yoast_head":"\nO que \u00e9 o ciclo de Carnot - Tipos de processos - Defini\u00e7\u00e3o<\/title>\n<meta name=\"description\" content=\"Ciclo de Carnot - Tipos de processos. Em um ciclo de Carnot, o sistema que executa o ciclo passa por uma s\u00e9rie de quatro processos revers\u00edveis internamente. Engenharia T\u00e9rmica\" \/>\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\/pt-br\/o-que-e-o-ciclo-de-carnot-tipos-de-processos-definicao\/\" \/>\n<meta property=\"og:locale\" content=\"pt_BR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"O que \u00e9 o ciclo de Carnot - Tipos de processos - Defini\u00e7\u00e3o\" \/>\n<meta property=\"og:description\" content=\"Ciclo de Carnot - Tipos de processos. Em um ciclo de Carnot, o sistema que executa o ciclo passa por uma s\u00e9rie de quatro processos revers\u00edveis internamente. Engenharia T\u00e9rmica\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-ciclo-de-carnot-tipos-de-processos-definicao\/\" \/>\n<meta property=\"og:site_name\" content=\"Thermal Engineering\" \/>\n<meta property=\"article:published_time\" content=\"2019-11-08T02:53:46+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2020-01-27T13:10:40+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Carnot-cycle-Processes-min.png\" \/>\n<meta name=\"twitter:card\" content=\"summary\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\">\n\t<meta name=\"twitter:data1\" content=\"Nick Connor\">\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\">\n\t<meta name=\"twitter:data2\" content=\"3 minutos\">\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\":\"pt-BR\"},{\"@type\":\"ImageObject\",\"@id\":\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-ciclo-de-carnot-tipos-de-processos-definicao\/#primaryimage\",\"inLanguage\":\"pt-BR\",\"url\":\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Carnot-cycle-Processes-min.png\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-ciclo-de-carnot-tipos-de-processos-definicao\/#webpage\",\"url\":\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-ciclo-de-carnot-tipos-de-processos-definicao\/\",\"name\":\"O que \\u00e9 o ciclo de Carnot - Tipos de processos - Defini\\u00e7\\u00e3o\",\"isPartOf\":{\"@id\":\"https:\/\/www.thermal-engineering.org\/fr\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-ciclo-de-carnot-tipos-de-processos-definicao\/#primaryimage\"},\"datePublished\":\"2019-11-08T02:53:46+00:00\",\"dateModified\":\"2020-01-27T13:10:40+00:00\",\"author\":{\"@id\":\"https:\/\/www.thermal-engineering.org\/fr\/#\/schema\/person\/e8c544db9afedaec8574d6464f9398bb\"},\"description\":\"Ciclo de Carnot - Tipos de processos. Em um ciclo de Carnot, o sistema que executa o ciclo passa por uma s\\u00e9rie de quatro processos revers\\u00edveis internamente. Engenharia T\\u00e9rmica\",\"inLanguage\":\"pt-BR\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-ciclo-de-carnot-tipos-de-processos-definicao\/\"]}]},{\"@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\":\"pt-BR\",\"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\/pt-br\/wp-json\/wp\/v2\/posts\/48099"}],"collection":[{"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/comments?post=48099"}],"version-history":[{"count":0,"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/posts\/48099\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/media?parent=48099"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/categories?post=48099"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.thermal-engineering.org\/pt-br\/wp-json\/wp\/v2\/tags?post=48099"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}