7/21/2019 Chuong 1-2 on tap
1/12
TRNG I HC BCH KHOA TPHCM
1
1 Pa = 1 N/m2. (Kpa, Mpa)
1 bar = 105N/m2=750mmHg
1 at = 0,981.105N/m2= 1 kgf/cm2= 10 mH2O = 735,5 mmHg.
1 mmH2O = 9,81N/m
2
.
1 mmHg = 133,32 N/m2.
nvopsut
Ap suat tuyet oi (p)
p = pkq+ pd
p = pkq- pck
7/21/2019 Chuong 1-2 on tap
2/12
TRNG I HC BCH KHOA TPHCM
ttdw pdv
wld dpv
dwkt=vdp
k
C
C
v
p
n
1i
iihh CgC
dv > 0W > 0 : hdnnthsinh cng.
dv < 0W < 0 : hnnpthnhncng
dq = Tds= CdtQ > 0 : nulnhitdo hnhnvo.
Q < 0 : nubnthnhtanhit.
C= C = 22,4.C; Cp-Cv=R=8314
Cp-Cv=R
dp < 0Wkt> 0 : hdnnthsinh cngkt.
dp > 0Wkt< 0 : hnnpthnhncngkt
Cng, nhitlng, nhitdung ring
7/21/2019 Chuong 1-2 on tap
3/12
TRNG I HC BCH KHOA TPHCM
3
Miquan hgiathnhphnkhilnggivthnhphnthtchri
1
;i ii n
i i
i
gr
g
;ii ig r
Phntlngcahnhp
1
. ;n
i i
i
r
1
1n
i
ii
g
Thtchringvkhilngringcahnhp
1
ni
i i
gv
1
;n
i i
i
r
.ii i i ii
Rp pg pg r p
R
Phnpsutcaccthnhphn
Thnhphnkhilng:
1
1n
i
i
g
Thnhphnthtch, mol:
;i i
i
V n
r V n 11
n
i
i
r
7/21/2019 Chuong 1-2 on tap
4/12
TRNG I HC BCH KHOA TPHCM
4
Bng s liu gi tr thc nghim
Kh l tng (c)p
, kcal/kmol. (c)v
, kcal/kmol. k
Loi c 1 nguyn t 5 3 1,667
Loi c 2 nguyn t 7 5 1,4
Loi c 3 nguyn t 9 7 1,286
Kh l tng (c)p, kJ/kmol. (c)v, kJ/kmol. k
Loi c 1 nguyn t 20,9 12,6 1,667
Loi c 2 nguyn t 29,3 20,9 1,4
Loi c 3 nguyn t 37,7 29,3 1,286
Nhm1 nguynt: gmcckh nhAr, Ne, He,
Nhm2 nguynt: gmcckh nhO2, N2, H2, CO, Khngkh,
Nhm3 nguynt: gmcckh nhCO2, SO
2, CH
4, C
2H
2, C
2H
4,
BngNDR kmol camtsloichtkh (kcal/kmol.)
BngNDR kmol camtsloichtkh (kJ/kmol.)
7/21/2019 Chuong 1-2 on tap
5/12
TRNG I HC BCH KHOA TPHCM
dq = du + dw; dq = du + pdv
dq = divdp; dq = di + dwkt
2
2
ddq di
V:
du = Cv.dT; di = Cp.dT
Nncc biu thc vit cho L1 c thm cc dng sau
dq = du + pdv = Cv.dT + pdv
dq = divdp = Cp.dTvdp
Cho G kg chtmigii:Q=U+Wtt
Q=I +Wkt
U=GCvT
I=GCpT
nhlutnhitngthnht
Cho 1 kg chtmigii:q=u+Wtt
q=i +Wkt
u=CvT
i=CpT
7/21/2019 Chuong 1-2 on tap
6/12
TRNG I HC BCH KHOA TPHCM
p = const 2 2
1 1
v T
v T
w12= p(v2v1) (J/kg) W12= p(V2V1) (J)
wkt12= 0
Qp= GCp(T2T1) (J) ,U=GCvT
(J/K)2
1
lnpT
S GC
T
w12= 0
Wkt12= V(p1p2), (J)
Qv= U = GCv(T2T1), (J)
(J/K)22 1
1
lnvT
S S S GC
T
v = const 2 2
1 1
p T
p T
7/21/2019 Chuong 1-2 on tap
7/12
TRNG I HC BCH KHOA TPHCM
7
T = const
(J)
2 1
1 2
p v
p v
1 212 12 1 1
2 1
ln lnktp V
W W GRT p V p V
2 1
1 2
ln lnV p
S GR GRV p
QT = W12, (J)
dq = 0, pvk
= const,
p
v
C
k C
2 1
1 2
;
k
p v
p v
11
2 2 1
1 1 2
;
kk
kT p v
T p v
1 1 2 212 1 2 ---1 -1p V p VGRW T T
k k
1 1
1 1 2 1 212
1 1
1 11 1
k k
k kp V p GRT pW
k p k p
Wkt12=k. W12 , S = 0, i=- wkt12
1/
2 1
1 2
;
k
v p
v p
1
11 2
2 1
;kv T
v T
7/21/2019 Chuong 1-2 on tap
8/12
TRNG I HC BCH KHOA TPHCM
Qutrnhabin pvn= const
2 1
1 2
;
n
p v
p v
1
2 1
1 2
;nv p
v p
11 1
2 2 2 1
1 1 1 2
;
nn n
nT p v v
T p v v
1 1
1 1 2 2 1 1 1 1 1 1 1 21 2
2 2 1
1 1 11 1 1 1 1
n n
tt
p V p V p V V GRT V p V T GRW T T
n n n V n V n T
1 21
kt tt
nGRW T T nW
n
Q = GCn (T2T1)
;n p
n v
C Cn
C C
;
p
v
Ck
C
1n v
n kC C
n
2 11
v
n kQ GC T T
n
1
12 1
1 2
;nv T
v T
12 1
1 2
;
n
np T
p T
7/21/2019 Chuong 1-2 on tap
9/12
TRNG I HC BCH KHOA TPHCM
9
Biu din cc qu trnh trn th p - v
7/21/2019 Chuong 1-2 on tap
10/12
TRNG I HC BCH KHOA TPHCM
10
Biu din cc qu trnh trn th T - s
7/21/2019 Chuong 1-2 on tap
11/12
TRNG I HC BCH KHOA TPHCM
V d 1
V d 2
7/21/2019 Chuong 1-2 on tap
12/12
TRNG I HC BCH KHOA TPHCM
V d 3
V d 4
Kho st mththngnhitnghlm vic vichtmigii lkh l
tngA, trngthiban unhitcakhlt1= 600oC. Sau khi cho kh
ginntheo qutrnhonnhitthunnghchntrngthi2 cnhitt2
= 220oC ththypsutkhgim10 lnso viban u. Cngsutsinh ra ca
hthngtrong qutrnhginnW = 1455 kW. ChobitlulngkhiquahthngG = 3,5 kg/s.
Xc nh:
1. S m on nhit ca qu trnh,
2. Gi tr nhit dung ring khi lng ng p Cpv ng tch Cvca kh A.
Cho 2,5 kg khMtan(CH4) ginnngita nhncmtcngthay i
thtchl650 kJ. Trong qutrnhginnninngcakhikhgimimtlngl255 kJ. Xcnhnhitlngtrao ivbinthinnhitca
qutrnh.
Recommended