Carnot Cycle da Reversed Carnot Cycle

Carnot Cycle

Na Carnot cycle wani tsarin kimiyya na da tarihi mai kyau a cikin gida. Yana yi lissafin energy na da shi a matsayin heat zuwa abubuwan da za su iya amfani da su a yankin reversible-adiabatic (isotropic) da wasu manyan abubuwa.

Efficiency na engine na Carnot shine wahid ya zama haske na ratio daga temperature na hot thermal reservoir zuwa temperature na cold reservoir. Na Carnot cycle shine mafi girma na efficiency benchmark wanda akwai wani cycle ko engine zai iya samun ta.

Aka yi aiki a kan fluid na aiki a karamin lokacin farko na cycle da kuma aka yi aiki a kan fluid na aiki a karamin lokacin biyu na cycle. Farin bayan biyu shine net work done.

Za a iya sauti efficiency na cycle tare da amfani da processes na da aiki kadan da ke aiki da adawa masu reversible. A cikin rayuwar, babu zan iya samun cycles na reversible saboda irreversibility na aiki da ke aiki waɗannan processes ba zan iya zama.

Refrigerators da heat engines na da suka yi aiki a kan reversible cycles suna nuna models don kula heat engines da refrigerators na da suka yi aiki a kan harkar. A cikin development na cycle na da suka yi aiki, reversible cycle ya faru cewa starting point da aka yi karfin a cikin haka don tabbatar da abin da suka bukata.

Na Carnot cycle an sanar da four reversible processes (2 nos. reversible- isothermal and 2 nos. reversible-adiabatic processes) shine haka:

An nuna na Carnot Cycle a cikin misalina na piston:
STEP 1 – 2
(Reversible Isothermal Expansion, Th = Constant)

TH shine temperature na gas na farko da kuma temperature na reservoir, an yi aiki a kan cylinder head.

Temperature na gas yana zama lafiya lokacin da gas yana zama kadan da kuma an yi amfani da infinitesimal-heat (dT) don zama constant a kan reservoir zuwa gas.
Adadin heat da aka faɗa a kan process zuwa gas shine Qh

STEP 2 – 3
(Reversible adiabatic expansion temperature drop from TH to TL)

System an zama adiabatic lokacin da an badalce reservoir ta heat da insulation. A cikin wannan process, temperature na gas yana zama lafiya zuwa Tl daga Th.

Wannan process yana nufin reversible kuma adiabatic (note that engineering thermodynamics take da definition na musamman don systems da processes).

STEP 3 – 4
(Reversible Isothermal Compression, Tl = constant)

A cikin stage-3, an badalce insulation na cylinder head da sink ta heat a temperature Tl. Lokacin da external force ya zama inwards don yi aiki a kan gas, temperature na gas yana zama ci.

Amma temperature na gas an yi amfani da rejection ta heat zuwa sink. Adadin heat da aka reject a cikin process shine Ql.
STEP 4 – 1
(Reversible adiabatic compression temperature increases from Tl to Th)

Sink ta energy an badalce insulation da kuma temperature na gas yana zama ci daga Tl zuwa Th a cikin process na compression.

Net Work Done

Aiki da aka yi a kan gas a cikin process na expansion shine area na da ta a cikin curve 1-2-3.
Aiki da aka yi a kan gas a cikin process na compression shine area na da ta a cikin curve 3-4-1

Saboda haka, net work done shine area na da ta a cikin path 1-2-3-4-1.

Importance of the Carnot Cycle

Heat engine efficiency depends on the maximum and minimum temperature of the cycle:
Carnot states that the efficiency of the heat engine is independent of the type of fluid and only depends upon the maximum and minimum temperatures during the cycle.

Thus the efficiency of the heat engine is higher when operates on super-heated steam temperature.
Carnot Cycle and Second law of thermodynamics:

Carnot cycle clearly demonstrated the fact that the heat is absorbed from the high-temperature source called reservoir and the heat is rejected to sink. This fact becomes the basis for the second law of thermodynamics. But external work is required in order to move the heat in the reverse direction.

Reversed Carnot Cycle

Carnot cycle is a reversible cycle, and it becomes the Carnot refrigeration cycle when the process reversed. The direction of heat and work interactions are totally reversed, thus
Thus,

• Heat absorbed from low-temperature-reservoir is Ql

• Heat rejected to a high-temperature-reservoir is Qh

• Work done is Wnet-in

Reversed Carnot cycle is the same as that of the conventional Carnot Cycle except for the direction of the processes.

History of Carnot Cycle

Na Carnot cycle ana kiranta "N. L. Sadi Carnot" wanda ya gina shi a shekarar 1824. Sadi Carnot ana kiran da shi a matsayin founder na thermodynamics saboda discovery na heat da work relationship. Carnot shine daya daga cikin mafi girman da suka fahimta cewa heat shine works a form na different.

Statement: Respect the original, good articles worth sharing, if there is infringement please contact delete.