단열과 가역 단열 과정의 차이점은 무엇입니까?


대답 1:

가역 및 단열 공정을 단열 가역 공정이라고합니다. 단열 공정은 열 전달이없는 열역학적 공정입니다. 용어 "지방족"은 문자 그대로 통과 불가능하거나 불 침투성을 의미한다.

단열 시스템은 단열 시스템이므로 공정 중에 열을 방출하거나 방출하지 않습니다. 가역적 프로세스는 전달 된 열의 양이 시스템 엔트로피 변화에 정비례하는 프로세스이다. 엔트로피 변화가 없기 때문에 전달되는 열은 0입니다. 따라서이 프로세스는 단열 가역 프로세스입니다. 이러한 프로세스를 등방성 프로세스라고도합니다.

열전달과 관련된 과정을 당뇨병 과정이라고합니다. 또한 되돌릴 수없는 단열 과정은 등 엔탈피 과정입니다. 이 프로세스는 작업을 추출하지 않습니다. 단열 가역 프로세스에서 dQ = TdS = 0입니다. 즉 엔트로피의 변화는 0입니다. 단열 불가역 과정에서 dQ = 0은 TdS (TdS> 0)와 같지 않습니다. 엔트로피 변화는 0보다 큽니다.


대답 2:
  • Inirreversibleprocessmoreworkhastobegivenorlessworkwouldbeobtainedcomparetoreversibleprocessbecauseofirreversibilities(suchasfriction,rapidexpansionofgasetc.).Reversibleandirreversibleprocessesareidentifiedbyatermwhichisknownasentropygeneration(Sgen).Entropygeneration([math]Sgen)[/math]istheentropygeneratedwithinthesystemboundarybecauseofirreversibilities.In irreversible process more work has to be given or less work would be obtained compare to reversible process because of irreversibilities (such as friction, rapid expansion of gas etc.).Reversible and irreversible processes are identified by a term which is known as entropy generation (S_{gen}). Entropy generation ([math]S_{gen})[/math] is the entropy generated within the system boundary because of irreversibilities.

폐쇄 시스템에 대한 엔트로피 균형 방정식-

ΔSsystem=ΔQT+Sgen(1)\Delta S_{system} = \displaystyle \frac{\Delta Q}{T} + S_{gen} \ldots (1)

따라서 폐쇄 시스템의 엔트로피는 열 전달 및 엔트로피 생성에 의해 변경 될 수 있습니다.

ΔQT=Entropychangedbyheattransfer\frac{\Delta Q}{T} = Entropy changed by heat transfer

Sgen=EntropygenerationinsidetheboundaryofthesystemS_{gen} = Entropy generation inside the boundary of the system

  • Soforanadiabaticsystem,ΔQ=0and1sttermineq(1)vanishes.Therefore,So for an adiabatic system, \Delta Q = 0 and 1st term in eq(1) vanishes. Therefore,

ΔSsystem=Sgen\Delta S_{system} = S_{gen}

AndforanyirreversibleprocessSgen>0.ThenAnd for any irreversible process S_{gen} \gt 0. Then-

단열 돌이킬 수없는 과정-

ΔSsystem>0\Delta S_{system} \gt 0

  • Butforreversibleadiabaticsystem,1sttermaswellas2ndtermvanish.Becauseforreversibleprocess(slowandfrictionlessprocess)Sgen=0andBut for reversible adiabatic system, 1st term as well as 2nd term vanish. Because for reversible process (slow and friction less process ) S_{gen} = 0 and

ΔSsystem=0(2)\Delta S_{system} = 0 \ldots (2)

Accordingtoeq(2)entropychangeiszeroinreversibleadiabaticprocesssoitisknownasIsentropicprocess.Butreverseisnottruei.eisentropicprocessisnotareversibleadiabaticprocess.Becauseentropygeneration(inirreversibleprocess)canbecompensatedbyentropyreductionduetoheattransferfromthesystem(ΔQ<0).According to eq(2) entropy change is zero in reversible adiabatic process so it is known as “Isentropic” process. But reverse is not true i.e isentropic process is not a reversible adiabatic process. Because entropy generation (in irreversible process) can be compensated by entropy reduction due to heat transfer from the system (\Delta Q < 0).

따라서 단열 과정이 가역적이라면 등 엔트로피 과정이 될 것입니다.


대답 3:
  • Inirreversibleprocessmoreworkhastobegivenorlessworkwouldbeobtainedcomparetoreversibleprocessbecauseofirreversibilities(suchasfriction,rapidexpansionofgasetc.).Reversibleandirreversibleprocessesareidentifiedbyatermwhichisknownasentropygeneration(Sgen).Entropygeneration([math]Sgen)[/math]istheentropygeneratedwithinthesystemboundarybecauseofirreversibilities.In irreversible process more work has to be given or less work would be obtained compare to reversible process because of irreversibilities (such as friction, rapid expansion of gas etc.).Reversible and irreversible processes are identified by a term which is known as entropy generation (S_{gen}). Entropy generation ([math]S_{gen})[/math] is the entropy generated within the system boundary because of irreversibilities.

폐쇄 시스템에 대한 엔트로피 균형 방정식-

ΔSsystem=ΔQT+Sgen(1)\Delta S_{system} = \displaystyle \frac{\Delta Q}{T} + S_{gen} \ldots (1)

따라서 폐쇄 시스템의 엔트로피는 열 전달 및 엔트로피 생성에 의해 변경 될 수 있습니다.

ΔQT=Entropychangedbyheattransfer\frac{\Delta Q}{T} = Entropy changed by heat transfer

Sgen=EntropygenerationinsidetheboundaryofthesystemS_{gen} = Entropy generation inside the boundary of the system

  • Soforanadiabaticsystem,ΔQ=0and1sttermineq(1)vanishes.Therefore,So for an adiabatic system, \Delta Q = 0 and 1st term in eq(1) vanishes. Therefore,

ΔSsystem=Sgen\Delta S_{system} = S_{gen}

AndforanyirreversibleprocessSgen>0.ThenAnd for any irreversible process S_{gen} \gt 0. Then-

단열 돌이킬 수없는 과정-

ΔSsystem>0\Delta S_{system} \gt 0

  • Butforreversibleadiabaticsystem,1sttermaswellas2ndtermvanish.Becauseforreversibleprocess(slowandfrictionlessprocess)Sgen=0andBut for reversible adiabatic system, 1st term as well as 2nd term vanish. Because for reversible process (slow and friction less process ) S_{gen} = 0 and

ΔSsystem=0(2)\Delta S_{system} = 0 \ldots (2)

Accordingtoeq(2)entropychangeiszeroinreversibleadiabaticprocesssoitisknownasIsentropicprocess.Butreverseisnottruei.eisentropicprocessisnotareversibleadiabaticprocess.Becauseentropygeneration(inirreversibleprocess)canbecompensatedbyentropyreductionduetoheattransferfromthesystem(ΔQ<0).According to eq(2) entropy change is zero in reversible adiabatic process so it is known as “Isentropic” process. But reverse is not true i.e isentropic process is not a reversible adiabatic process. Because entropy generation (in irreversible process) can be compensated by entropy reduction due to heat transfer from the system (\Delta Q < 0).

따라서 단열 과정이 가역적이라면 등 엔트로피 과정이 될 것입니다.