{"id":47803,"date":"2019-11-06T10:32:39","date_gmt":"2019-11-06T09:32:39","guid":{"rendered":"https:\/\/www.thermal-engineering.org\/o-que-e-o-ciclo-de-compressao-de-vapor-ciclo-de-refrigeracao-definicao\/"},"modified":"2020-01-25T09:20:45","modified_gmt":"2020-01-25T08:20:45","slug":"o-que-e-o-ciclo-de-compressao-de-vapor-ciclo-de-refrigeracao-definicao","status":"publish","type":"post","link":"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-ciclo-de-compressao-de-vapor-ciclo-de-refrigeracao-definicao\/","title":{"rendered":"O que \u00e9 o ciclo de compress\u00e3o de vapor &#8211; Ciclo de refrigera\u00e7\u00e3o &#8211; Defini\u00e7\u00e3o"},"content":{"rendered":"<div class=\"su-quote su-quote-style-default\">\n<div class=\"su-quote-inner su-clearfix\">O sistema t\u00edpico de compress\u00e3o de vapor consiste em quatro componentes: Compressor, Condensador, V\u00e1lvula de expans\u00e3o, Evaporador.\u00a0Ciclo de compress\u00e3o de vapor &#8211; Ciclo de refrigera\u00e7\u00e3o.\u00a0Engenharia T\u00e9rmica<\/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>Ciclo de compress\u00e3o de vapor &#8211; Ciclo de refrigera\u00e7\u00e3o<\/h2>\n<figure id=\"attachment_18076\" class=\"wp-caption alignright\" aria-describedby=\"caption-attachment-18076\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/vapor-compression-cycle-heat-pump.png\"><img loading=\"lazy\" class=\"size-medium wp-image-18076 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/vapor-compression-cycle-heat-pump-282x300.png\" alt=\"Ciclo de compress\u00e3o de vapor - Ciclo termodin\u00e2mico de bombas de calor.\" width=\"282\" height=\"300\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/vapor-compression-cycle-heat-pump-282x300.png\" \/><\/a><figcaption id=\"caption-attachment-18076\" class=\"wp-caption-text\">Ciclo de compress\u00e3o de vapor &#8211; Ciclo termodin\u00e2mico de bombas de calor.<\/figcaption><\/figure>\n<p>A\u00a0<strong>compress\u00e3o de vapor<\/strong>\u00a0usa um fluido refrigerante l\u00edquido circulante como meio (geralmente\u00a0<strong>R134a<\/strong>\u00a0) que absorve e remove o calor do espa\u00e7o a ser resfriado e subsequentemente rejeita esse calor em outro local.\u00a0A figura mostra um sistema t\u00edpico\u00a0<strong>de compress\u00e3o de vapor de<\/strong>\u00a0est\u00e1gio \u00fanico\u00a0.\u00a0O sistema t\u00edpico de compress\u00e3o de vapor consiste em quatro componentes:<\/p>\n<ul>\n<li><strong>Compressor<\/strong><\/li>\n<li><strong>Condensador<\/strong><\/li>\n<li><strong>V\u00e1lvula de expans\u00e3o<\/strong>\u00a0(tamb\u00e9m chamada de v\u00e1lvula do acelerador)<\/li>\n<li><strong>Evaporador<\/strong><\/li>\n<\/ul>\n<p>Em um ciclo ideal de compress\u00e3o de vapor, o sistema que executa o ciclo passa por uma s\u00e9rie de quatro processos: um processo isentr\u00f3pico (adiab\u00e1tico revers\u00edvel), um processo de estrangulamento alternado com dois processos isob\u00e1ricos:<\/p>\n<ul>\n<li><a title=\"Processo isentr\u00f3pico\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-processo-isentropico-definicao\/\"><strong>Compress\u00e3o isentr\u00f3pica<\/strong><\/a>\u00a0(compress\u00e3o no compressor de pist\u00e3o) &#8211; Um refrigerante em circula\u00e7\u00e3o, como o R134a, entra no compressor como vapor de baixa press\u00e3o, ou um pouco abaixo da temperatura no interior do refrigerador.\u00a0O meio gasoso \u00e9 comprimido adiabaticamente do estado 1 ao estado 2 pelo compressor de pist\u00e3o (ou por bombas centr\u00edfugas) a uma press\u00e3o e temperatura relativamente altas.\u00a0O ambiente trabalha com o g\u00e1s, aumentando sua energia interna (temperatura) e comprimindo-o (aumentando sua press\u00e3o).\u00a0Por outro lado, a entropia permanece inalterada.\u00a0O trabalho necess\u00e1rio para o compressor \u00e9 dado por<strong>\u00a0W\u00a0<\/strong><strong><sub>C<\/sub><\/strong><strong>\u00a0= H\u00a0<\/strong><strong><sub>2<\/sub><\/strong><strong>\u00a0&#8211; H\u00a0<\/strong><strong><sub>1<\/sub><\/strong><strong>\u00a0.<\/strong><\/li>\n<li><strong><a title=\"Processo isob\u00e1rico\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-processo-isobarico-definicao\/\">Rejei\u00e7\u00e3o de calor isob\u00e1rica<\/a>\u00a0(em um condensador)<\/strong>\u00a0&#8211; O vapor superaquecido viaja sob press\u00e3o atrav\u00e9s de bobinas ou tubos que comp\u00f5em o condensador.\u00a0Nesta fase, o refrigerante passa pelo condensador, onde o refrigerante condensa e h\u00e1 transfer\u00eancia de calor do refrigerante para o ambiente mais frio.\u00a0O calor rejeitado l\u00edquida \u00e9 dada por<strong>\u00a0Q\u00a0<\/strong><strong><sub>re<\/sub><\/strong><strong>\u00a0= H\u00a0<\/strong><strong><sub>3<\/sub><\/strong><strong>\u00a0&#8211; H\u00a0<\/strong><strong><sub>2<\/sub><\/strong><strong>\u00a0.\u00a0<\/strong>Quando o refrigerante sai do condensador, ele ainda est\u00e1 sob press\u00e3o, mas agora est\u00e1 apenas ligeiramente acima da temperatura ambiente.<\/li>\n<li><a title=\"Processo de estrangulamento - processo isent\u00e1lpico\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-processo-de-estrangulamento-processo-isentalpico-definicao\/\"><strong>Processo isent\u00e1lico<\/strong><\/a>\u00a0(expans\u00e3o em uma v\u00e1lvula de expans\u00e3o) &#8211; O refrigerante no estado 3 entra na v\u00e1lvula de expans\u00e3o e se expande para a press\u00e3o do evaporador.\u00a0Esse processo geralmente \u00e9 modelado como um processo de limita\u00e7\u00e3o para o qual a entalpia permanece constante.\u00a0<strong>H\u00a0<\/strong><strong><sub>4<\/sub><\/strong><strong>\u00a0= H\u00a0<\/strong><strong><sub>3<\/sub><\/strong><strong>\u00a0.\u00a0<\/strong>A diminui\u00e7\u00e3o repentina da press\u00e3o resulta na evapora\u00e7\u00e3o do flash do tipo explosivo de uma por\u00e7\u00e3o (normalmente cerca de metade) do l\u00edquido.\u00a0O calor latente absorvido por essa evapora\u00e7\u00e3o \u00e9 extra\u00eddo principalmente do refrigerante l\u00edquido ainda adjacente, um fen\u00f4meno conhecido como<em>\u00a0auto-refrigera\u00e7\u00e3o<\/em>\u00a0.<\/li>\n<li><a title=\"Processo isob\u00e1rico\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-processo-isobarico-definicao\/\"><strong>Adi\u00e7\u00e3o de calor isob\u00e1rico<\/strong><\/a>\u00a0(<strong>\u00a0em um evaporador<\/strong>\u00a0) &#8211; O refrigerante frio e parcialmente vaporizado continua atrav\u00e9s das bobinas ou tubos da unidade do evaporador.\u00a0Nesta fase (entre o estado 4 e o estado 1), h\u00e1 uma transfer\u00eancia de calor de press\u00e3o constante para o meio l\u00edquido a partir de uma fonte externa, uma vez que a c\u00e2mara est\u00e1 aberta para fluir para dentro e para fora.\u00a0\u00c0 medida que o refrigerante passa pelo evaporador, a transfer\u00eancia de calor do espa\u00e7o refrigerado resulta na vaporiza\u00e7\u00e3o do refrigerante.\u00a0O calor l\u00edquido adicionado \u00e9 dado por<strong>\u00a0Q\u00a0<\/strong><strong><sub>add<\/sub><\/strong><strong>\u00a0= H\u00a0<\/strong><strong><sub>1<\/sub><\/strong><strong>\u00a0&#8211; H\u00a0<\/strong><strong><sub>4<\/sub><\/strong><\/li>\n<\/ul>\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><span>Durante um ciclo de compress\u00e3o de vapor, o trabalho \u00e9 feito no fluido pelas bombas entre os estados 1 e 2 (\u00a0<\/span><strong><span>compress\u00e3o isentr\u00f3pica<\/span><\/strong><span>\u00a0).\u00a0N\u00e3o h\u00e1 trabalho realizado pelo fluido, pois entre os est\u00e1gios 3 e 4 o processo \u00e9 isent\u00e1lico.\u00a0O fluido de trabalho em um ciclo de compress\u00e3o de vapor segue um circuito fechado e \u00e9 reutilizado constantemente.<\/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\"><\/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<h2><span>Coeficiente de desempenho &#8211; Bomba de calor, Geladeira, Ar condicionado<\/span><\/h2>\n<p><span>Em, a geral\u00a0<\/span><a title=\"Efici\u00eancia t\u00e9rmica\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-eficiencia-termica-definicao\/\"><strong><span>efici\u00eancia t\u00e9rmica<\/span><\/strong><\/a><span>\u00a0,\u00a0<\/span><strong><em><span>\u03b7\u00a0<\/span><\/em><\/strong><strong><em><sub><span>th<\/span><\/sub><\/em><\/strong><span>\u00a0, de qualquer\u00a0<\/span><a title=\"Motores t\u00e9rmicos\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-heat-engine-definicao\/\"><span>motor de calor<\/span><\/a><span>\u00a0como a raz\u00e3o entre o\u00a0<\/span><a href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-trabalho-em-termodinamica-definicao\/\"><span>trabalho<\/span><\/a><span>\u00a0que faz,\u00a0<\/span><strong><span>W<\/span><\/strong><span>\u00a0, para o\u00a0<\/span><a href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-calor-na-fisica-calor-definicao\/\"><span>calor<\/span><\/a><span>\u00a0de entrada a uma temperatura elevada, Q\u00a0<\/span><sub><span>H<\/span><\/sub><span>\u00a0.<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/thermal-efficiency-formula-1.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-16945 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/thermal-efficiency-formula-1.png\" alt=\"f\u00f3rmula de efici\u00eancia t\u00e9rmica - 1\" width=\"125\" height=\"82\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/thermal-efficiency-formula-1.png\" \/><\/a><\/p>\n<p><span>A\u00a0<\/span><strong><span>efici\u00eancia t\u00e9rmica<\/span><\/strong><span>\u00a0,\u00a0<\/span><strong><em><span>\u03b7\u00a0<\/span><\/em><\/strong><strong><em><sub><span>th<\/span><\/sub><\/em><\/strong><span>\u00a0, representa a fra\u00e7\u00e3o de\u00a0<\/span><strong><span>calor<\/span><\/strong><span>\u00a0,\u00a0<\/span><strong><span>Q\u00a0<\/span><\/strong><strong><sub><span>H<\/span><\/sub><\/strong><span>\u00a0, que \u00e9 convertida\u00a0<\/span><strong><span>em trabalho<\/span><\/strong><span>\u00a0.<\/span><\/p>\n<figure id=\"attachment_18074\" class=\"wp-caption alignright\" aria-describedby=\"caption-attachment-18074\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Heat-Pump-Heating-and-Air-Conditioning.png\"><img loading=\"lazy\" class=\"size-medium wp-image-18074 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Heat-Pump-Heating-and-Air-Conditioning-267x300.png\" alt=\"Bomba de calor - aquecimento e ar condicionado\" width=\"267\" height=\"300\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Heat-Pump-Heating-and-Air-Conditioning-267x300.png\" \/><\/a><figcaption id=\"caption-attachment-18074\" class=\"wp-caption-text\"><span>Bomba de calor, Geladeira, Ar condicionado &#8211; princ\u00edpio b\u00e1sico de opera\u00e7\u00e3o<\/span><\/figcaption><\/figure>\n<p><span>Mas em\u00a0<\/span><strong><span>bombas de calor<\/span><\/strong><span>\u00a0e\u00a0<\/span><strong><span>geladeiras<\/span><\/strong><span>\u00a0, o trabalho n\u00e3o \u00e9 uma sa\u00edda.\u00a0Para uma refrigera\u00e7\u00e3o ou bombas de calor, a efici\u00eancia t\u00e9rmica indica at\u00e9 que ponto a energia adicionada pelo trabalho \u00e9 convertida na produ\u00e7\u00e3o l\u00edquida de calor.\u00a0Do ponto de vista econ\u00f4mico, o\u00a0<\/span><strong><span>melhor ciclo de refrigera\u00e7\u00e3o<\/span><\/strong><span>\u00a0\u00e9 aquele que\u00a0<\/span><strong><span>remove a maior quantidade de calor<\/span><\/strong><span>\u00a0do interior da geladeira (reservat\u00f3rio frio) para o menor gasto de trabalho mec\u00e2nico ou energia el\u00e9trica.\u00a0A propor\u00e7\u00e3o relevante \u00e9, portanto, quanto maior essa propor\u00e7\u00e3o, melhor a geladeira.\u00a0Chamamos essa raz\u00e3o de\u00a0<\/span><strong><span>coeficiente de desempenho<\/span><\/strong><span>\u00a0, indicado pela\u00a0<\/span><strong><span>COP<\/span><\/strong><span>\u00a0.<\/span><\/p>\n<p><span>O\u00a0<\/span><strong><span>coeficiente de desempenho<\/span><\/strong><span>\u00a0, \u00a0\u00a0<\/span><strong><span>COP,<\/span><\/strong><span>\u00a0tamb\u00e9m \u00e9 definido para bombas de calor, mas neste momento seguimos o calor l\u00edquido adicionado ao reservat\u00f3rio quente.\u00a0O\u00a0<\/span><strong><span>COP<\/span><\/strong><span>\u00a0geralmente excede 1, especialmente em bombas de calor, porque, em vez de apenas converter o trabalho em calor, ele\u00a0<\/span><strong><span>bombeia calor adicional<\/span><\/strong><span>\u00a0de uma fonte de calor para onde o calor \u00e9 necess\u00e1rio.<\/span><\/p>\n<p><span>Em geral, o\u00a0<\/span><strong><span>COP<\/span><\/strong><span>\u00a0\u00e9 altamente dependente das condi\u00e7\u00f5es operacionais, especialmente a temperatura absoluta e a temperatura relativa entre o dissipador de calor e o sistema.<\/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>Coeficiente de desempenho &#8211; Geladeira, Ar condicionado<\/span><\/h2>\n<p><span>O\u00a0<\/span><strong><span>coeficiente de desempenho<\/span><\/strong><span>\u00a0,\u00a0<\/span><strong><span>COP<\/span><\/strong><span>\u00a0, de um\u00a0<\/span><strong><span>refrigerador<\/span><\/strong><span>\u00a0\u00e9 definido como o calor removido do reservat\u00f3rio frio Q\u00a0<\/span><sub><span>frio<\/span><\/sub><span>\u00a0(ou seja, dentro de um refrigerador) dividido pelo trabalho W realizado para remover o calor (ou seja, o trabalho realizado pelo compressor).<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/COP-coefficient-of-performance-equation.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-18070 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/COP-coefficient-of-performance-equation.png\" alt=\"COP - coeficiente de desempenho - equa\u00e7\u00e3o\" width=\"162\" height=\"83\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/COP-coefficient-of-performance-equation.png\" \/><\/a><\/p>\n<p><span>Como pode ser visto, quanto melhor (mais eficiente) for a geladeira, mais calor\u00a0<\/span><strong><span>Q\u00a0<\/span><sub><span>frio<\/span><\/sub><\/strong><span>\u00a0pode ser removido do interior da geladeira por uma determinada quantidade de trabalho.\u00a0Como a\u00a0<\/span><a title=\"Primeira Lei da Termodin\u00e2mica\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-a-primeira-lei-da-termodinamica-definicao\/\"><span>primeira lei da termodin\u00e2mica<\/span><\/a><span>\u00a0deve ser v\u00e1lida tamb\u00e9m neste caso (Q\u00a0<\/span><sub><span>frio<\/span><\/sub><span>\u00a0+ W = Q\u00a0<\/span><sub><span>quente<\/span><\/sub><span>\u00a0), podemos reescrever a equa\u00e7\u00e3o acima:<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/COP-coefficient-of-performance-equation2.png\"><img loading=\"lazy\" class=\"aligncenter size-medium wp-image-18071 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/COP-coefficient-of-performance-equation2-300x81.png\" alt=\"COP - coeficiente de desempenho - equa\u00e7\u00e3o2\" width=\"300\" height=\"81\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/COP-coefficient-of-performance-equation2-300x81.png\" \/><\/a><\/p>\n<p><span>Para um refrigerador ideal (sem perdas e irreversibilidades), pode-se derivar que:<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/COP-coefficient-of-performance-equation3.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-18072 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/COP-coefficient-of-performance-equation3.png\" alt=\"COP - coeficiente de desempenho - equa\u00e7\u00e3o3\" width=\"235\" height=\"91\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/COP-coefficient-of-performance-equation3.png\" \/><\/a><\/p>\n<p><span>Essas f\u00f3rmulas s\u00e3o aplicadas tamb\u00e9m a um\u00a0<\/span><strong><span>ar condicionado<\/span><\/strong><span>\u00a0, que funciona muito como uma geladeira.<\/span><\/p>\n<p><span>Por outro lado, o COP para aquecimento e resfriamento \u00e9 diferente.<\/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>Coeficiente de desempenho &#8211; Bomba de calor<\/span><\/h2>\n<p><span>Para aquecimento, o\u00a0<\/span><strong><span>COP<\/span><\/strong><span>\u00a0\u00e9 a propor\u00e7\u00e3o do calor adicionado ao sistema (reservat\u00f3rio quente).\u00a0Usando a primeira lei da termodin\u00e2mica, defina COP tamb\u00e9m como o calor removido do reservat\u00f3rio frio, mais o trabalho de entrada no trabalho de entrada.<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/coefficient-of-performance-heat-pump-equation.png\"><img loading=\"lazy\" class=\"aligncenter size-medium wp-image-18073 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/coefficient-of-performance-heat-pump-equation-300x66.png\" alt=\"coeficiente de desempenho - bomba de calor - equa\u00e7\u00e3o\" width=\"300\" height=\"66\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/coefficient-of-performance-heat-pump-equation-300x66.png\" \/><\/a><\/p>\n<p><span>Para uma bomba de calor ideal (sem perdas e irreversibilidades), pode-se derivar que:<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/coefficient-of-performance-heat-pump-equation2.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-18069 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/coefficient-of-performance-heat-pump-equation2.png\" alt=\"coeficiente de desempenho - bomba de calor - equa\u00e7\u00e3o2\" width=\"266\" height=\"77\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/coefficient-of-performance-heat-pump-equation2.png\" \/><\/a><\/p>\n<p><span>Observe que essas equa\u00e7\u00f5es devem usar uma\u00a0<\/span><strong><span>escala de temperatura absoluta<\/span><\/strong><span>\u00a0(T\u00a0<\/span><sub><span>frio<\/span><\/sub><span>\u00a0, T\u00a0<\/span><sub><span>quente<\/span><\/sub><span>\u00a0) e \u00e9 apenas uma\u00a0<\/span><strong><span>efici\u00eancia m\u00e1xima te\u00f3rica<\/span><\/strong><span>\u00a0.\u00a0De acordo com a f\u00f3rmula acima, o COP m\u00e1ximo ating\u00edvel para T\u00a0<\/span><sub><span>quente<\/span><\/sub><span>\u00a0= 35 \u00b0 C (308 K) e T\u00a0<\/span><sub><span>frio<\/span><\/sub><span>\u00a0= 0 \u00b0 C (273 K) seria 8,8.\u00a0Mas, na realidade, os melhores sistemas est\u00e3o em torno de 4,5.<\/span><\/p>\n<p><span>Como pode ser visto, o COP de um sistema de bomba de calor pode ser melhorado reduzindo a\u00a0<\/span><strong><span>diferen\u00e7a de temperatura<\/span><\/strong><span>\u00a0(T\u00a0<\/span><sub><span>quente<\/span><\/sub><span>\u00a0&#8211; T\u00a0<\/span><sub><span>frio<\/span><\/sub><span>\u00a0).\u00a0Portanto, reduzir a temperatura de sa\u00edda (T\u00a0<\/span><sub><span>quente<\/span><\/sub><span>\u00a0) \u00e9 muito eficiente, mas requer transfer\u00eancia de calor muito eficiente do sistema de bomba de calor para o ambiente (por exemplo, uso de piso encanado).\u00a0Um aumento na temperatura de entrada (T\u00a0<\/span><sub><span>frio<\/span><\/sub><span>\u00a0) significa, por exemplo, uma fonte de calor no solo superdimensionada.<\/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>Exemplo &#8211; Bomba de Calor &#8211; Aquecimento e Ar Condicionado<\/span><\/h2>\n<p><span>Uma\u00a0<\/span><strong><span>bomba de calor revers\u00edvel<\/span><\/strong><span>\u00a0possui um coeficiente de desempenho,\u00a0<\/span><strong><span>COP = 3,0<\/span><\/strong><span>\u00a0, quando operada no\u00a0<\/span><strong><span>modo de aquecimento<\/span><\/strong><span>\u00a0.\u00a0Seu compressor consome\u00a0<\/span><strong><span>1500 W<\/span><\/strong><span>\u00a0de energia el\u00e9trica.<\/span><\/p>\n<ol>\n<li><span>Calcule a quantidade de calor (\u00a0<\/span><strong><span>Q\u00a0<\/span><\/strong><strong><sub><span>quente<\/span><\/sub><\/strong><span>\u00a0) a bomba de calor pode adicionar a um quarto?<\/span><\/li>\n<li><span>Se a\u00a0<\/span><strong><span>bomba de calor<\/span><\/strong><span>\u00a0fosse colocada no\u00a0<\/span><strong><span>modo de resfriamento<\/span><\/strong><span>\u00a0(por exemplo, para atuar como um ar-condicionado no ver\u00e3o), qual seria a expectativa do seu\u00a0<\/span><strong><span>coeficiente de desempenho<\/span><\/strong><span>\u00a0?\u00a0Suponha que tudo o mais permane\u00e7a o mesmo e negligencie todas as outras perdas.<\/span><\/li>\n<\/ol>\n<p><span>Solu\u00e7\u00e3o:<\/span><\/p>\n<p><span>No\u00a0<\/span><strong><span>COP<\/span><\/strong><span>\u00a0, que \u00e9 definido como:<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/coefficient-of-performance-heat-pump-equation.png\"><img loading=\"lazy\" class=\"aligncenter size-medium wp-image-18073 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/coefficient-of-performance-heat-pump-equation-300x66.png\" alt=\"coeficiente de desempenho - bomba de calor - equa\u00e7\u00e3o\" width=\"300\" height=\"66\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/coefficient-of-performance-heat-pump-equation-300x66.png\" \/><\/a><\/p>\n<p><span>a quantidade de calor que a bomba de calor pode adicionar a uma sala \u00e9 igual a:<\/span><\/p>\n<p><strong><span>Q\u00a0<\/span><\/strong><strong><sub><span>quente<\/span><\/sub><\/strong><span>\u00a0=\u00a0<\/span><sub><span>aquecimento de<\/span><\/sub><span>\u00a0COP\u00a0x W = 3 x 1500 =\u00a0<\/span><strong><span>4500 W ou 4500 J \/ s<\/span><\/strong><\/p>\n<p><span>No caso do\u00a0<\/span><strong><span>modo de resfriamento<\/span><\/strong><span>\u00a0, a bomba de calor (ar-condicionado) com\u00a0motor de\u00a0<\/span><strong><span>1500 W<\/span><\/strong><span>\u00a0pode retirar o calor\u00a0<\/span><strong><span>Q de\u00a0<\/span><sub><span>frio<\/span><\/sub><\/strong><span>\u00a0de dentro da casa e despejar Q\u00a0<\/span><sub><span>quente<\/span><\/sub><span>\u00a0= 4500 W no exterior quente.\u00a0Usando a primeira lei da termodin\u00e2mica, que declara:<\/span><\/p>\n<p><strong><span>Q\u00a0<\/span><sub><span>frio<\/span><\/sub><span>\u00a0+ W = Q\u00a0<\/span><\/strong><sub><strong><span>quente<\/span><\/strong><span>\u00a0,<\/span><\/sub><\/p>\n<p><span>obt\u00e9m-se o calor,\u00a0<\/span><strong><span>Q\u00a0<\/span><sub><span>frio<\/span><\/sub><span>\u00a0= 3000 W<\/span><\/strong><span>\u00a0.\u00a0A partir da defini\u00e7\u00e3o:\u00a0<\/span><strong><span>COP\u00a0<\/span><sub><span>cooling<\/span><\/sub><\/strong><span>\u00a0= 3000\/1500 =\u00a0<\/span><strong><span>2<\/span><\/strong><span>\u00a0.<\/span><\/p>\n<p><span>Observe que, neste exemplo, temos muitas suposi\u00e7\u00f5es.\u00a0Por exemplo, assumimos que a diferen\u00e7a de temperatura (T\u00a0<\/span><sub><span>quente<\/span><\/sub><span>\u00a0&#8211; T\u00a0<\/span><sub><span>fria<\/span><\/sub><span>\u00a0) \u00e9 a mesma para os dois modos.\u00a0Mas trocamos reservat\u00f3rios, sem nenhum impacto na COP.\u00a0\u00c9 apenas um exemplo ilustrativo.<\/span><\/p>\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>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":"<p>O sistema t\u00edpico de compress\u00e3o de vapor consiste em quatro componentes: Compressor, Condensador, V\u00e1lvula de expans\u00e3o, Evaporador.\u00a0Ciclo de compress\u00e3o de vapor &#8211; Ciclo de refrigera\u00e7\u00e3o.\u00a0Engenharia T\u00e9rmica Ciclo de compress\u00e3o de vapor &#8211; Ciclo de refrigera\u00e7\u00e3o Ciclo de compress\u00e3o de vapor &#8211; Ciclo termodin\u00e2mico de bombas de calor. A\u00a0compress\u00e3o de vapor\u00a0usa um fluido refrigerante l\u00edquido circulante &#8230; <a title=\"O que \u00e9 o ciclo de compress\u00e3o de vapor &#8211; Ciclo de refrigera\u00e7\u00e3o &#8211; Defini\u00e7\u00e3o\" class=\"read-more\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-o-ciclo-de-compressao-de-vapor-ciclo-de-refrigeracao-definicao\/\" aria-label=\"More on O que \u00e9 o ciclo de compress\u00e3o de vapor &#8211; Ciclo de refrigera\u00e7\u00e3o &#8211; Defini\u00e7\u00e3o\">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":"<!-- This site is optimized with the Yoast SEO plugin v15.4 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>O que \u00e9 o ciclo de compress\u00e3o de vapor - Ciclo de refrigera\u00e7\u00e3o - Defini\u00e7\u00e3o<\/title>\n<meta name=\"description\" content=\"O sistema t\u00edpico de compress\u00e3o de vapor consiste em quatro componentes: Compressor, Condensador, V\u00e1lvula de expans\u00e3o, Evaporador. 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