Cau 1: Neu thanh phan c ban cua phng trnh bao toan dong, c che truyen van

nao thng mang tnh noi troi trong qua trnh truyen khoi, truyen nhiet?

Tr li:

* Cac thanh phan c ban cua phng trnh bao toan dong

- Dong khoi lng: dm/ d ma trng hp rieng la dong cau t dNi/d ng

qua trnh chuyen khoi va chuyen hoa hoc.

-Dong nang lng dW/d ma trng hp rieng la dong nhiet dH/d ng vi

qua trnh chuyen nang lng ( chuyen nhiet).

- Dong ong lng: d(mv)/d ng vi qua trnh chuyen ong lng con goi

la qua trnh thuy ong)

* C che truyen van thng mang tnh noi troi:

- Truyen khoi: khuech tan (thanh phan truyen van thanh phan dan), nh

luat Fick

- Truyen nhiet: he so dan nhiet nh luat Fourier

- Truyen ong lng: nh luat Newton

Thanh phan noi troi:

He so cap khoi khong la ham trang thai.

He so cap nhiet ( dien tch truyen nhiet)

He so truyen khoi

Cau 2: Goi ten 3 qua trnh phan tach bang nhiet, cac qua trnh ong lc phan t co

or khong co cac chat them vao? Hay neu s khac biet c ban gia chung?

Cau 3:Cac kieu dan pha nao trong qua trnh truyen khoi, trong moi trng lu chat

ma anh ch biet?

Cau 4: Neu nguyen ly nhan qua ap dung trong qua trnh truyen van?

Cau 5: Khai niem dong? The nao la qua trnh on nh? The nao la qua trnh bat on

nh? The nao la qua trnh can bang?

* Khai niem dong: Dong J la s bien oi theo thi gian cua ai lng tuan

theo nh luat bao toan

d

dJ

Cac ai lng tuan theo lbt chnh la cac ai lng anh gia cac thuoc tnh cua vat

chat nh khoi lng m (hoac so mol cau t i: Ni), nang lng W va ong lng mv

* Cac qua trnh:

- Qua trnh on nh:

- Qua trnh bat on nh:

-Qua trnh can bang: khi van toc qua trnh trong he bang 0, ta noi he trang

thai can bang

Cau 6: Neu kha nang tao dien tch tiep xuc pha trong qua trnh truyen khoi gia 2

pha long kh?

Cau 7:Anh ch hieu the nao ve hien tng Dien tch tiep xuc pha trong qua trnh

truyen van.

Cau 8: Neu 4 loai n v o lng vat chat e bieu dien ong lc qua trnh trong qua

trnh truyen khoi

Cau 9: Bieu dien cac cong thc quy oi gia phan khoi lng va phan mol

Cau 10:Bieu dien 3 che o dong khac tren mam cua 1 thap mam van, vi s truyen

van long va kh. (hap thu)

Cau 11: Anh ch hieu the nao khuech tan tng ng va 1 chieu. Hay bieu dien 2

hien tng truyen van nay?

Cau 12: trang thai on nh hay cho biet nh luat nao xac nh qua trnh khuech

tan tng ng va khuech tan 1 chieu.

Cau 13: S khuech tan va ong lc gi vai tro g trong qua trnh tnh toan thiet b

truyen khoi, truyen nhiet?

Cau 14: Truyen van va truyen nhiet xuyen tng va truyen khoi xuyen pha co g

giong nhau va khac nhau?

Cau 15:Viet phng trnh bieu dien truyen khoi oi lu, he so cap khoi va cac n v

nong o khac cua ong lc qua trnh?

Cau 16: Da tren c s nao ta co s tng t truyen nhiet va truyen khoi? Hay bieu

dien s lien quan gia cap nhiet va cap khoi? Neu he so dan nhiet at va he so

khuech tan co cung o ln (Khac thanh phan khoi lng)

Cau 17: S tng t cac nh luat truyen nhiet, truyen khoi truyen ong lng cua

dong cap va dong dan?

Cau 18: Bieu dien phng trnh bao toan dong cua Damkoehler? Giai thch cac

thanh phan trong o? Bieu dien trong trng hp ac biet truyen nhiet va truyen

khoi? Cac dang bao toan dong khac ma anh ch quen thuoc?

(nh luat Fick, Fourier, NaviStock, Bernouli.)

Tra li:

nh luat bao toan dong Damkoehler: Tong bien oi cua cac thanh phan cua

dong = 0, hoac la vat chat 1 dong trong he thong khong mat i ma ch chuyen t thanh

phan dong nay sang thanh phan dong khac.

(Bien oi: dong oi lu + dong dan + dong cap + nguon + tai cho =0)

Bieu thc toan hoc tong quat tng ng:

div(v) div( grad ) + + G + / =0

Phng trnh co 3 thanh phan mo ta cau truc va hai thanh phan mo ta ong hoc. Khi phan

tch cau truc chung ta ch can quan tam ti 3 thanh phan mo ta cau truc. P113

Bieu thc toan hoc cho dong khoi lng: 2.21 a

div (v)- div(D grad ) + + G +/ =0

Bieu thc toan hoc cho dong cau t: 2.21b

div (Civ)- div(Di grad i) + iCi+ i.r +Ci/ =0

Bieu thc toan hoc cho dong nhiet 2.21c

div (CpTv)- div(a grad(CpT)) + /(Cp) ((CpT)+ i.rH +((CpT)/ =0

Bieu thc toan hoc dong ong lng: 2.21d Navier Stock

div (vov)- div( grad(v)) + / * (v)+ grad + (v)/=0

Cau 19:Neu dang cau truc cac cong thc ban thc nghiem e xac nh he so cap cho

qua trnh truyen nhiet, khoi, da tren c s nao e thiet lap chung?

Cau 20: Y ngha vat ly cua cac chuoi so ong dang : Smith, We, Le, Nussen, Pr, Re,

Sh,

Chuan so Re: bieu th moi quan he gia lc quan tnh va lc ma sat

Chuan so Reynods:

WddWRe

22Re

ndndK

Chuan so Froude: bieu th moi quan he gia lc quan tnh va lc trong trng

Chuan so Froude: gd

WFr

2

g

dnFrK

2

Chuan so Euler: th moi quan he gia lc ay va lc quan tnh

Chuan so Euler: 2W

pEu

Chuan so Fourier: truyen van nhiet khong on nh theo thi gian

Chuan so Fourier: 2a

Fo

Chuan so Peclet: ac trng cho mc o xao tron trong qua trnh truyen van vat

chat

Chuan so Peclet: ScD

WdPe Re

Chuan so Nusselt: bieu th moi quan he gia truyen nhiet bang oi lu nhiet va

truyen van bang dan nhiet

Chuan so Nussel:

dNu

Chuan so Weibe ac trng cho anh hng sc cang be mat

Chuan so Weibe:

dWWe

2

32dnWeK

Chuan so archimede: the hien dong chay co lan lon hat ran

Chuan so Arshimed: 2

3

2

2

3

2

2

23

2

2Re

dggdgd

FrAr

Chuan so Galiler: Fr

dgGa

2

2

32 Re

Chuan so Homokhron: d

WHo

Chuan so Cong suat: 53dn

NK

Chuan so Lagrang:

WW

p

W

pEuLa

2Re

Chuan so Lyashenco:

2

2

2

3

0

3

ReRe

Fr

g

W

ArLy

Chuan so Newton: 2mW

F

mW

FNe

Chuan so Damkeler:

K

IW

lD

W

kDDa

Chuan so Diakonov: n

KDi

Chuan so Phan bo: n

VK rU

Chuan so Prandl:

PCPr

Chuan so Biot:

1

2

Bi

Chuan so Sherwood: D

dSh

Chuan so Schmid: DD

vSc

Chuan so Stanton: WCPe

NuSt

p

Chuan so Levis: DCD

aLe

p

Cau 21: Co cac che o dong nao tren thap mam van? Giai thch c che hnh thanh.

Phng trnh van toc khuech tan

nh luat Fick: Mt lng cht rt nh dq khuch tan qua b mt trong thi gian dt va

vi mt chenh lch nng o gradC th:

dq = - D. . GradC. dt

Cac nh luat truyen van: truyen van vat chat, nang lng, xung lng xay ra do chenh

lech the truyen van tc la do chenh lech khoi lng, nang lng, xung lng trong mot

n v the tch.

The truyen van trong truyen van vat chat la khoi lng rieng hay nong o

The truyen van trong truyen van nang lng la enthanpy rieng Cp.pro.t

The truyen van trong truyen van xung lng la ong lng n v the tch wpro

a nhiu l (Sieve Trays) a chp (Bubble-Cap Trays) a ng khi (Chimmey Trays) a van (valve Trays)

S phn b dn chy qua van nh hng rt ln n s tip xc pha v cht lng cc phn on.

T l hon lu tng, s mm gim nhng ng knh thp tng

- Gi V: th tch ca h

- Phng trnh vn tc khuch tn: