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Thit kMBA in lc
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Mba in lc l mt b phn rt quan trng trong h thng in . Vic
ti in nng i xa t nh my in n h tiu th trong cc h thng incn phi c rt nhiu ln tng gim in p . Do tng cng sut t cacc Mba ln hn nhiu ln so vi cng sut my pht . Tuy hiu sut caMba thng rt ln ( 98-99% ) Nhng do s lng Mba nhiu nn tng tnhao trong h thng rt ng k v th vn t ra trong thit k Mba vn lgim tn hao nht l tn hao khng ti trong Mba .
Khuynh hng pht trin ca ngnh ch to Mba in lc hin nayltng c gii hn v cng sut , vin p , ngoi ra cn m rng thangcng sut ca Mba thnh nhiu dy p ng mt cch rng ri vi nhucu s dng v vn hnh Mba . lm c iu trong thit k , ch toMba ta phi khng ngng ci tin , tm ra nhng vt liu mi tt hn , thayi kt cu mch t hp l , tng trnh cng ngh...
Qua bn n mn hc ny gip em hiu v lm quen vi cng victhit k Mba ni ring v my in ni chung . Mc d rt c gng trongqu trnh thit k nhng chc chn khng trnh khi nhng sai st , emmong cc thy , c cng cc bn ng gp nhng kin xy dng .
Em xin chn thnh cm n .
H ni . Ngy 10.10.2001
Sinh vin
Phn I : Tnh ton cc kch thc ch yu
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1.1 Cc i lng in cbn ca Mba1.1.1 Cng sut mi pha ca mba:
S f =m
S=
3
400=133,33 (KVA)
1.1.2 Cng sut mi tr: S= tS
= 3
400
=133,33 (KVA)
1.1.3 Dng in dy nh mc:
-Pha CA:2
3
.2
3
10
U
SI dm= = )(6,6
10.35.3
10.4003
3
A=
-Pha HA:1
3
1.3
10.
U
SI dm= = )(36,577
10.4,0.3
10.4003
3
A=
1.1.4 Dng in pha nh mc:-Pha CA: u Y 6,622 ==IIf (A)
-Pha HA: u Y If1=I1= 577,36 (A)1.1.5 in p pha:
C CA v HA u Y:.3
22
UUf = = )(26,20207
3
10.35 3V=
)(94,2303
400
3
11 V
UUf ===
1.1.6 Cc thnh phn in p ngn mch:
Thnh phn tc dng: (%)15,1400.10
4600.1010..
10...100..3
3
====
dm
n
f
f
f
nf
rS
PImIm
UrIu
Thnh phn phn khng: %866,415,15 2222 === rnx uuu
1.1.7 in p thca cc dy qun:Pha CA: 852 =thU (KV)
Pha HA: 51 =thU (KV) ( Bng 2)1.2 Chn cc s liu xut pht v thit k sb li thp:1.2.1 Li st :
Chn li st kiu tr , dy qun cun thnh hnh tr nn tit din ngang catr st c dng bc thang i xng ni tip vi hnh trn ng knh d
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d
d
01
Theo bng 4 vi cc tm l tn c p chn s bc l 6Vt liu li st : dng tn silic m hiu 3404 c chiu dy : 0,35 mm-Bng8
p tr ta dng nm g sut gia ng giy Baklit vi tr hay vi cun dy hp
p gng ta dng x p vi bu lng xit ra ngoi gngX p gng trn v di c lin kt vi nhau bng nhng bulng thng
ng chy dc ca s li st gia hai cun dy. gia x p vi gng phi ltm cacton cch in h thng x st khng to thnh mch t kn .1.2.2 Chn tn silic v cng tcm trong trChn tn silic cn lnh m hiu 3404 c chiu dy 0,35mmta chn BT=1,6T
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1.2.3 Cc h s v sut tn hao, sut tho trong tr v gng.1/ H s dy: Tra Bng 10 : k = 0,922/ H s chm kn Bng 4: kc=0,8843/ H s li dng li thp: kld=kc.k = 0,884.0,92=0,8134/ H s tng cng tit din gng: ( Bng 6) k
g=T
g:T
t=1,015
T cm trong gng BG=BT/kg=1,6/1,015=1,5765/ H s quy i t trng tn: kR=0,956/ T cm khe hkhng kh gia tr v gng:
ghp cho 2/TKK BB = = )(131,12
6,1T=
7/ Sut tn hao thp (Bng 45 ) Trong tr pT= 1,295(W/kg)Trong gng p G =1,251(W/kg)
8/ Sut t ho ( Bng50) Trong tr q T=1,775 (W/Kg)
Trong gng q G =1,675(W/Kg)1.2.4 Chn cch in : ( Bng 18,19)1. Cch in gia tr v dy qun HA: a01= 15 (mm)2. Cch in gia dy qun HA v CA: a12=27 (mm)3.cch in gia dy qun CA v CA: a22=30 (mm)4. cch in gia dy qun CA n gng : l02=75 (mm)5.b dy ng cch in CA v HA : 12=5 (mm)6.Tm chn gi cc pha : 22=3 (mm)7.u tha ng cch in: l2=50 (mm)
8. Chiu rng quy i t trng tn: aR=a12+1/3(a1+a2)trong 24 '21 10.
3
=+
Skaa
(Bng 12) k=0,59
019,010.33,133.59,03
2421 ==+
aa
aR=0,027+0,019=0,047(m)
1.3 Xc nh kch thc ch yu ca MBA:MBA cn thit k l loi my 3pha 3 tr kiu phng dy qun ng tm (H.4)
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l
a2
d21
d
lo
a01
a1 c
a22
c
Cc kch thc ch yu ca MBA l:- ng knh tr st: d- Chiu cao dy qun: l- ng knh trung bnh gia hai dy qun: d121.3.1 Tnh h s kch thc cbn :H s biu din quan h gia ng knh trung bnh d12 vi chiu cao dyqun l.
l
d12. =
chi ph ch to MBA l nh nht, mt khc vn m bo cc ch tiu k thutta cn phi tm c gi tr ti u .
Cng sut trn mt tr : S
=U.IThnh phn phn khng ca in p ngn mch :
(%)10..
.......9,7 412 =lu
kadwIfU
v
rRx
(%)10..
......9,7 4=v
rRx
u
kawIfU
Trong :. I, w: l dng in v s vng cun dy CA hoc HA. f =50Hz tn s li in
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.kr=0,95 h s Rogovski
.aR=0,047 m chiu rng quy i t trng tn
.uv=4,44.f.BT.TT in p trn mt vng dy
.TT=kld2/4 Tit din tr
rR
xldT
rR
vxv
kaf
ukdBf
kawf
uuwuS
...9,7
10...4
...44,4
.....9,7
10.10....
22
34'
==
Rt ra:22
'
...
...507,0
ldTx
rR
kBuf
kaSd
=
Trong biu thc trn ch c thay i trong mt phm vi rng quyt nh ti sthay i ng knh d
t A= 176,0813,0.6,1.866,4.50
95,0.047,0.33,133507,0
...
.'.507,0 4
224
22==
ldTx
rR
kBuf
kaS
tm c ti u, trc ht ta xc nh trng lng tc dng ca MBAa. Trng lng tc dng ca li st: Li st gm hai phn tr v gng
Trng lng st ca tr :
+=+= 0
120 .2
...
4
..).2.(.. l
dk
dtllTtG FeldFeTT
Trong : +S tr tc dng : t=3+T trng st )/(7650 3mKgFe= +ng knh trung bnh gia 2 dy qun : d 12 =a.dH s : a=1,4 (Bng13)
+Khong cch gia cun dy v gng : l 0 = 0,075 (m)
d =A.X ; d12=a.A.X ; =X4 ; 22
1 .XAX
AGT += (2-42)
Trong : ldkAaA ...10.663,534
1 =
0
24
2 ...10.605,3 lkAA ld=
Thay s : )(401,351813,0.176,0.4,1.10.663,5 341 KgA == )(09.68075,0.813,0.176,0.10.605,3 242 KgA ==
Trng lng st gng: cho n gin ta gi thit gng c tit din ch nht :
))1.((.4...2))1.((...2
2eCtkdkeCtTkG FeldGFeTGG +=+=
Trong : +Khong cch gia hai tr : C= 2221212 .2 aaad +++ +Chiu dy cun CA: a 2 =b.d/2+Tr s b (Bng 14) : b = 0,32+Khong cch cch in : a12= 0,027(m) ; a22= 0,03(m)+d =a.A.X
+H s tng cng gng : k=1.015Thay vo : 22
3
1 .. XBXBGG += (2-48) vi:
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).(...10.40,2
).(...10.40,2
2212
24
2
34
1
aaAkkB
ebaAkkB
ldG
ldG
+=
++=
Thay s : )(977,229)41,032,04,1.(176,0.813,0.015,1.10.40,2 34 KgB =++= )(968,34)03,0027,0.(176,0.813,0.015,1.10.40,2 242 KgB =+=
Trng lng tc dng ca li st MBA :3
1
2
22
1 .).( XBXBAX
AGGG GTFe +++=+=
b. Trng lng dy qun ng :
2.
.
=
K
PkG
nf
dq (2-53)
Trong : .K l hng s ph thuc in trsut ca dyqun : KCu =2,4.10-12
+mt dng in :12.
...746.0
dS
uPk vnf=
+kf: h s tnh n tn hao ph trong dy qun, trong vch.Chn kf=0,94 (Bng 15)
Thay d12=a.A.X, uv=4,447.BT.TT ; TT= ldkd
4
. 2vo ( 2-53) :
2
1
X
CGdq = .
Trong :222
2'
1..... AUfBkk
SaKC
rTldf
dq=
Vi tn s f=50Hz :
222
2
1AUBkk
SakC
rTldf
dq= vi dy ng : Kdq=2,46.10-2
( )kgC 39,340176,0.15,1.6,1.813,0.94,0
4,1.40010.46,2
222
22
1 ==
Khi tnh c trng lng cch in ca dy qun v phn dy qun tng thmdng iu chnh in p cun CA th trng lng ton b dy qun phinhn thm h s k=1,06Gi thnh vt liu td: dqdqgTFetd GkCGGCC ..++=
Trong CFe v Cdq tng ng l gi 1kg st lm li v 1kg kim loi ng lmdy qun kn cc chi ph v ch to li st v dy qun cng nh cc ph
liu khng dng c . Thng biu din gi thnh theo n v quy c vicch chn gi thnh 1kg st lm n v.
( )X
CkK
X
AXABXB
C
CC dqFe
Fe
td
td
112
22
3
1
' ... ++++== (2-59)
Trong : 84,1==Fe
dq
dqFeC
CK (Bng 16)
o hm CT 2-59 v cho trit tiu: 0'
=dX
dCtd xc nh tr s X tng ng
vi gi thnh vt liu tc dng cc tiu t phng trnh:
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045 =+ DCXBXX (2-60)
924,106,1.84,1.977,229.3
39,340.2..
3
2
509,0977,229.3
401,3513
320,0977,229
)09,68968,34(.
3
2.
3
2
1
1
1
1
1
22
===
===
=+
=+
=
kKB
CD
BAC
B
ABB
dqFe
Thayvo (2-60): X5+ 0,320.X
4- 0,509.X- 1,924=0
Gii phng trnh trn bng phng php d ta c : X=1,21Tng ng vi tr s 068,24 == X
So snh vi phm vi tr s cho trong Bng 17 [ ]4,2;8,1 chn c cn phi cn c vo nhng tham s k thut ca mba thit
k:1. Tn hao khng ti: ).('0 ggttf GpGpkP +=
Trong : + pt ; pg sut tn hao trong tr v gng (bng 45)Pt = 1,295 (w/kg) ; pg=1,251(w/kg)
+ kf : h s ph, (Bng 43) ; k
f=1,25
Gt,Gg;theo biu thc (2-42) v (2-48)2. Thnh phn phn khng ca dng in khng ti
(%)1010.
10.3
2
S
Q
S
Qiox ==
Vi Q l cng sut t ho, gn ng tnh bi cng thc :)('' QQQkQ fcf ++=
Trong :+ ''fk : h s kn s phc hi t tnh khng hon ton khi li l tn ly
2,1k''f = +Qc : cng sut tn hao chung ca tr v gng:
Qc=qt.Gt+ qg.Gg (VA) (2-64)
qt ;qg l sut tn hao ca tr v gng: Bng 50 qt=1,775 (VA/kg)
qg=1,675 (VA/kg)+Qf: cng sut t ho phi vi gcQf= 40 qt.G0 =(VA) 40 .1,775. G0 =71. G0
G0 l trng lng ca mt gc3334334
0 74,21.176,0.813,0.015,1.10.486,0...10.486,0 XXXAkkG ldg ===
+ Q : cng sut t ho nhng khe hkhng kh ni gia cc l thp
tTqQ .2,3 = (VA) =3,2 .4000 Tt (2-67)
+ q : sut t ho khe h: bng 50Tit din tc dng ca ca tr : Tt = 223 0198,0785,0 XXAkld =
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Trong tnh ton sb c th coi gn ng dng in khng ti i0=i0x3. Mt dng in trong dy qun:
dqdqdqdq
nf
GGGGK
Pk 110.219,42
10.75,1433
.10.4,2
4600.93,0
.
612
12
.====
Trong : +2
1
XCGdq =
+K=2,4.10-12
+kf=0,93
i vi MBA du 610.5,4Cu (A/m2)
4. Lc chc :Lc hng knh tc dng ln mt trong hai dy qun :
)(.
..10.2610...).(628,0
'2262
max Naf
SukkiF
R
xnrr
==
38,51)1(5
100.41,1)1(
100.41,1 5/15,1./. =+=+= ee
uk XR uu
n
n
)(10.712,194047,0.50
33,133.5.38,5110.26 3
22 NFr ==
ng sut ko tc dng ln tit din si dy dn :3.
...2XM
T
Frr ==
Trong :
206,0176,0.4,1
4600
.95,0.93,0.38,51.10.244,0.....10.244,0
66
===
Aa
P
kkkM
n
rfnCu iu kin : 2/(60 mMN Lp bng cc i lng :
1,2 1,8 2,4 3,0 3,64X 1,047 1,158 1,245 1,316 1,377
XXA /401,351/1 = 335,63 303,46 282,252 267,022 255,19322
2 .09,68. XXA = 74,64 91,300 105,54 117,922 129,112
21T X.AX/AG + 410,27 394,27 387,79 384,79 384,30033
1 .977.229. XXB = 263,952 357,117 443,805 524,145 600,46322
2 .968,34. XXB = 38,332 48,89 54,201 60,561 66,3042
2
3
1G X.BX.BG + 302,284 406,007 498,006 584,706 666,767GTFe GGG + 712,554 800,277 885,796 969,496 1051,067
TTt G.295,1G.p = 531,299 510,580 502,188 498,303 487,670GGG G.251,1G.p = 378,157 507,915 623,01 731,467 834,126
G.pG.p(25,1P GGTt0 += 1136,82 1273,119 1406,498 1537,213 1652,245
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TTT G.775,1G.q = 728,23 699,83 688,33 683,002 682,133GGG G.675,1G.p = 506,326 680,062 834,160 979,383 1116,832
GGTTC G.qG.qQ + 1234,556 1379,892 1522,49 1662,385 1798,9543
0 .74,21 XG = 24,952 33,759 41,953 49,548 56,762
0f G.71Q = 1771,592 2396,889 2978.663 3517,908 4030,1022.0198,0 XTT = 0,022 0,0266 0,0307 0,0343 0,0375
TTQ .12800= 281,6 340,48 391,68 439,04 480
)QQQ(2,1Q fc
3287,748 4117,261 4892,833 5619,333 6309,056
)S.10/(Qi x0 = 0,822 1,03 1.23 1,40 1,582
1dq X/CG = 310,488 253,812 219,587 196,529 179,503dqdqdqFe G.95,1G.k.k =
605,452 494,933 428,195 382,232 350,03
dqdqFeFe
'
td G.k.kGC +
1318,006 1295,21 1313,991 1351,728 1401,97
dqG/1.10.219,426= 2,4.10
6 2,65.106 2,85.106 3,012.106 3,15.106
3
r X.123,0 0,141 0,191 0,237 0,280 0,321
XXAd .176,0. == 0,151 0,167 0,179 0,190 0,198d.4,1d.ad12 = 0,211 0,234 0,251 0,266 0,277/d.l 12 0,552 0,408 0,329 0,279 0,242
+Vi gii hn P0=920 W 6,2 +Vi gii hn i0=1,5% [ ]6,3;2,1 +Tr s =2,068 ng vi CtdminTa chn gi tr =2,068 tho mn tt c cc tiu chun t ra.
1.3 Cc kch thc ch yu :1/ ng knh tr st :
)(211,0068,2.176,0 44 mAd ===
Chn ng knh tiu chun gn nht : dm=0,22Tnh li tr sm :
44,2176,0
22,044
=
=
=
A
ddmdm
2/ ng knh trung bnh ca rnh du gia hai dy qun :
1210112 .2.2 aaadd dm +++= (2-77)
+ )(021,0019,0.1,13
. 2111 maa
ka ==+
= ; Trong : k1=1.1 v 019,03
21 =+ aa
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+ a01=1,5 cm
+ a12=2,7 cmcmd 9,317,21,2.25,1.22212 =+++=
3/ Chiu cao dy qun :
cmd
ldm
0516,4144,2
9,31..12 ===
Tit din thun st ca tr :
)(038,04
22,0..813,0
4
..
4
...
222
md
kd
kkT dmlddm
cdT ====
in p mt vng dy : )(5,13038,0.6,1.50.44,4...44,4 VTBfu TTv ===
Phn II. Tnh ton dy qun.
2.1 Tnh dy qun HA.1. S vng dy mt pha ca dy qun HA: W1 =
v
t
U
U1
Trong +Ut1 l in p trn mt tr ca dy HA:Ut1 = Uf1 = 230,94 (V)
+Uv = 13,5 (V) - in p mt vng dy.
W1 =5,13
94,230=17,1 18(vng)
Tnh li in p mt vng dy
Uv =18
94,230= 12,83 (V)
Cng t cm thc trong tr st l :
Bt =t
v
Tf
U
..44,4=
038,0.50.44,4
83,12= 1,5208 (T)
2. Mt dng in trung bnh.
Sb tnh theo cng thc: tb = 0,746.kg.12
.
Sd
UP vn 104
( A/m2)
tb = 0,746 . 0,93 .318,0.400
83,12.4600.10
4= 2,689 .10
6( A/m
2)
3. Tit din vng dy sb:
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T '1 =tb
tI
1 =
tb
fI
1 =610.689,2
844,360= 134,216.10
-6(m
2) = 134,216 (mm
2)
Chn kt cu dy qun, da theo Bng 38:
Vi S = 250 KVA ; It = 360,844 (A) ; U1 = 0,4 ( KV)
T '1 = 134,261 (mm2)
Chn kt cu dy qun hnh xon mch n dy dn bt. ( H.5) . Vi u iml bn ccao, cch in bom, lm lnh tt.
hv
Hnh 5.
4. Chiu cao sb mi vng dy:
hv1 =
4W
l
1
1
+
- hr1
Trong : + hr1 l kch thc hng trc ca rnh du gia cc bnh dy: Bng54a: Ly hr1 = 4(mm)
+ l1: Chiu cao dq HA: l1 = 39,634cm = 0,39634 (m)
+ W1 = 36 (vng)
hv1 =436
39634,0
+- 0,004 = 0,006m = 6 (mm)
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hv1 < 0,0165m ( 16,5mm) do dng dy qun hnh xon mch n.
5. Cn cvo hv1 v T '1 chn dy dn theo Bng 21:
- Chn s si chp song song l : mv1 = 6
- Tit din si dy : 23,4(mm2)
- Kch thc dy dn: b.6,6.2,4
2,6.8,3; 23,4
6. Tit din mi vng dy:
T1 = n.v1. Td1 . 10-6
= 6 . 23,4 . 10-6
= 140,4 . 10-6
(m2)
7. Mt dng in thc:
1 =1
1
T
I=
610.4,140
844,360
= 2,57 . 106
( A/m2) = 2,57 (MA/m
2)
8. Chiu cao dy qun:Dy dn hnh xon mch n hon v ba ch, gia cc bnh dy u c rnh
du
l1 = b . 10-3
. (W1 + 4 ) + k. hr1 ( W1 + 3 ) . 10-3
l1 = 6,6. 10-3 ( 36 + 4 ) + 0,95 . 4 ( 36 + 3 ) 10 -3 = 0,412 (m)
Trong : + b = 6,6(mm)
+ W1 = 36 (vng)
+ hhr= 4 (mm)
+ k = 0,95: h s kn s co ngt ca tm m sau khi p cht cun dy.
9. B dy ca dy qun:
hv
hr
hv
a
a1
b
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a1 =n
n 1v a . 10-3
=1
6. 4,2 . 10
-3=25,2.10
-3= 0,0252 (m)
Vi dy qun hnh xon mch n : n =1.
10. ng knh trong ca dy qun HA:
D '1 = d + 2a01 = 0,17 + 2. 0,004 = 0,178 (m)
11. ng knh ngoi ca dy qun:
D "1 = D'
1 + 2a1 = 0,178 + 2. 0,0252 = 0,228 (m)
12. B mt lm lnh ca dy qun:
M1 = 2.t .k .. (D '1 + a1 ) ( a1 + b
. 10-3
) .W1 (m2
)
+ k : H s kn b mt dy qun b tm dm che khut ly k = 0,75
+ t : S tr tc dng : t =3
M1 = 2.3.0,75.3,142 ( 0,178 + 0,0252) ( 0,0252 + 6,6 .10-3) = 0,091 (m2)
13. Trng lng ng dy qun HA:
Gcu1 =t . 2
. "1
'
1DD
W1 .T1cu = 28 t . 2
. "1
'
1DD
W1 .T1 . 103
=28 . 3.2
228,0178,0 +.36.140,4.10
-6.10
3= 86,188(Kg)
2.2 Tnh dy qun CA.
1. Chn siu khin in p: on dy iu chnh nm lp ngoicng, mi nc iu chnh c b tr thnh hai nhm trn di dy qun ni tip
vi nhau v phn bu trn ton chiu cao dy qun. (H.7 ) . Ch rng hainhm ca on dy iu chnh phi qun cng chiu vi dy qun chnh.
%Um p (V) u dy
+5 36750 A X1
+2,5 35875 A X2
0 35000 A X3
-2,5 34425 A X4
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-5 33250 A X5
X1
X2
X3
X4X5
A
2. S vng dy ca cun CA ng vi p m :
W2 = W1.1
2
f
f
U
U= 36 .
940,230
10.207,20 3= 3149,961 3150 (vng )
3. S vng dy ca mt cp iu chnh p:
Wc = 0,025. W2m = 0,025 . 3150 = 78,75 79 (vng )
4. S vng dy tng ng cc u phn p:
+ Cp [+5%Um]: 36750 (V) : W2 = W2m = 3150 + 2.79 = 3308(vng)
+ Cp [+2,5%Um]: 35875(V) : W2 = W2m + Wc = 3150 + 79 = 3229 (vng)
+ Cp Um: 35000(V) : W2 = W2m = 3150
+ Cp [-2,5%Um]:34425(V)
W2 = W2m - Wc = 3150 2 . 79 = 2992(vng)
5. Mt dng in sb:
2 = 2tb - 1 = 2 . 2,689 . 106
- 2,577 . 106
= 2,808 . 106
(A/m2)
6. Tit din dy dn sb:
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T '2 = 62
2
10
I=
66 10.10.808,2
124,4
= 1,469(mm2)
7. Chn kiu dy qun:
Theo bng 38: Vi S =250 (KVA) ; It2 = 4,124(A) ; U2 = 35(KV)
+ T '2 = 1,469(mm2)
Chn kt cu dy qun kiu: hnh ng nhiu lp dy dn trn. u im: Cngngh ch to n gin , nhc: Tn nhit km, bn ckhng cao.
8. Chn dy dn:Bng 20: Chn dy b 1 .8,1
4,1. 1,54
9. Tit din ton phn ca mi vng dy:
T2 = nv2.Td2.10-6
= 1,54.10-6
(m2)
10. Mt dng in thc:
2 =2
2
T
I=
610.54,1
124,4
= 2,678.10-6
(A/m2) = 2,678 (MA/m
2)
11. S vng dy trong mt lp: W12 = '22
3
2
.
10.
dn
l
v - 1 = 8,1.1
10.412,0 3
- 1 =
228(vng)
Trong ly l2 = l1 = 0,412(m)
12. S lp ca dy qun: n12 =12
2
W
W=
288
3150= 14 (lp)
13. in p lm vic gia hai lp k nhau:
U12 = 2W12. Uv = 2. 228 . 6,415 = 2925,240(V)
14. Chiu dy cch in gia cc lp:
Bng 26: + S lp giy cp: 4 lp
+ Chiu dy mt lp giy cp: 0,12(mm)
Chiu dy cch in gia cc lp: 12 = 4. 0,12 = 0,48mm
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15. Phn phi s vng dy trong cc lp, chia t lp:
+ Do s lp ca dy qun c lm trn thnh s nguyn n12 = 14 (lp) nn svng dy trong mi lp khng ng bng w12 ( 228 vng).
Ta phn phi 12 lp trong c s vng dy l W12 = 228vng cn 2 lp ngoicng c s vng dy t hn:
w12 = ( 3150 -12. 228 )/2 = 207(vng)
+ tng iu kin lm mt, phn dy qun CA thnh hai t lp gia hai t crnh du dc trc a22
T lp trong : C s lp n =5 lp
T lp ngoi: C s lp m = n12 - n = 14 - 5 = 9 (lp)Kch thc rnh dy: Bng 54 : a22 = 5(mm)
16. Chiu dy dy qun CA:
a2 = [ ][ ]'2212'
2 )1()1()( amnmnd ++++ .10-3
Trong : + d'
2 = 1,8 mm , m = 9 , n =5
+ 12 = 4. 0,12 = 0,48 (mm) , a'
22 = 5(mm)
a2 = [ ][ ]310.5)19()15(48,0)95(8,1 ++++ = 36.10
-3(m)
Vi in p 35 KV ta b tr thm mn chn tnh in bng kim loi dy 0,5mm( ni in vi dy qun cao p) lp trong cng ca cun CA. Mn chn ccch in hai pha bng cch in lp nn chiu dy cun CA s l:
a2 = ( )[ ] )(10.5,3710.48,0.25,03610.2(333
1
'
2 ma c =++=++
+ c = 0,5mm
+ 1 = 12 = 0,48(mm)
y ch l kch thc hnh hc cun dy, cn khi tnh s tn th ly gi tra2 = 36. 10
-3(m) v lc coi rnh du c tng ln:
a '12 = ( a12 + c + 21). 10-3
= ( 27 + 0,5 + 2. 0,48) 10+-3= 28,5. 10
-3(m)
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17. ng knh trong ca dy qun CA :
)(282,010.27.2228,010..2 33121"
2' maDD =+=+=
18. ng knh ngoi ca dy qun CA :
)(357,010.5,37.2282,0.2 322'
2" maDD =+=+=
19. Khong cch gia hai tr cnh nhau:
)(377,010.20357,010. 33222" maDC =+=+=
20..B mt lm lnh ca dy qun :
)(275,3412,0).357,0282.0.(.88,0..3.5,1)..(...5,1 222"
2'
2 mlDDktM =+=+=
Trong k= 0,88 : h s tnh n b mt lm lnh b cc chi tit cch in chekhut
21.Trng lng ng ca dy qun CA:
)(191,13010.10.54,1.3150.2
357,0282,0.3.2810...
2..28 36322
2"
2'
2 KgTwDD
tG dmCu =+
=+
=
Hai cun dy Iu chnh c trng lng :
)(51,6191,130.05,0.05,0 2/ KgGG Cucd ===
Phn III: Tnh ton ngn mch
3.1. Tn hao ngn mch:
Tn hao ngn mch ca Mba hai dy qun l tn hao khi ngn mch mt dyqun cn dy qun kia t vo iu p ngn mch Un cho dng in trong chai dy qun u bng nh mc .
3.1.1. Tn hao chnh: L tn hao ng trong dy qun:
Pcu = I2.R =
T
lT 622 10.... = 2 (T.l)..10-6
Pcu = 2(T.l.d).
d
, 10
-6= 2,4m 10
-12. 2. Gcu (4-3)
Trong : + : Mt dng in (A/m2)
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+ 1= 2,570. 10
6(A/m
2)
+2 = 2,678 . 106(A/m
2)
+ T tit din dy ng: (m2)
+ l chiu di dy dn (m)
+ d: T trng dy dn d = 8900kg/m3+ : in trsut ca dy dn 750C
= 0,02135 m
+ Gcu : Trng lng ng dy qun:
+ Dy qun HA: Gcu = 86,188(kg)
Pcu = 2,4 . 10-12
. 2,572. 10
12. 86,188 1366,231(W)
- Dy qun CA: Gcu2 = 130, 191 (kg)
Pcu2 = 2,4 . 10-12
. 2,6782
.1012
.130,191
= 2240,855(W)
Vy tn hao ng:
Pcu= Pcu1 + Pcu2 = 1366,231 + 2240,855 = 3607,086 (W)
3.1.2. Tn hao ph trong dy qun:
Tn hao ph thng c ghp vo tn hao chnh bng cch thm h s kfvotn hao chnh:
Pcu + Pf= Pcu. kf.
Trong kf ph thuc vo kch thc hnh hc ca dy dn v s sp xp cady dn trong tn tht tn.
- Trong dy qun HA:
+ S thnh dn song song vi t thng tn: m = 36
kf1 = 1 + 0,095 . 108
.2a4.n2
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Trong : + =l
mb.kr=
412,0
95,0.36.10.1,6 3= 0,506
+ b = 6,1(mm)
+ a = 3,7(mm)
kf1 = 1 + 0,95.108 ( 0,506)2 . ( 3,7)4. 10-12 . 62 = 1,0164
Trong dy qun CA.
kf2 = 1 + 0,044. 1082.d4.n2
Vi : n = 14
d = 1,3(mm)
m = 288 =l
md..kr =
412,0
95,0.288.10.3,1 3= 0,683
kf2 = 1 + 0,44. 108(0,683)2 . 1,32.10-12.142 = 1,001
Dy qun HA l dy qun hnh xon c s si ghp song song l 6 do cnc tn hao ph gy nn bi dng in phn b khng u gia cc dy ghpsong song v hon v khng hon ton.
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a
b
1 2 3 4 5 6
mm
nn
kfhv1 = 1 + 0,53 . 10
-2
.
2
( cu
f
)
2
.a
4
(n
4
20n
2
+ 64)
kfhv1 = 1 + 0,53. 10-2
(0,506)2.
2
02135,0
50
. 3,7
4.10
-12(6
4 20. 6
2+ 64)
kfhv1 = 1,001
3.1.3. Tn hao chnh trong dy dn ra:
Pr = 2,4. 10-12.2.Gr
1. i vi dy qun HA:
- Chiu di dy dn ra HA: lr1 = 7,5l = 7,5. 0412 = 3, 090(m)
- Trng lng ng dy dn ra HA:Gr1 = lr1.Tr1. = 3,09 . 140,4. 10
-6. 8900 = 3,861(kg)
- Tn hao trong dy dn ra HA:
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Pr1 = 2,4 . 10-12
. 2,572. 10
-12. 3,861 = 61,206(W)
2. i vi dy qun CA:
- Chiu di dy dn ra CA
lr2 = 7,5.l = 7,5. 0,412 = 3,090 (m)
- Trng lng ng dy dn ra CA:
Gr2 = lr2.Tr2. cu = 3,09 . 1,54.10-6
. 8900 = 0,042(kg)
- Tn hao trong dy dn ra CA:
Pr2 = 2,4 . 10-12
. ( 2,678)2
. 1012
. 1,042 = 0,729 (W)
3.1.4. Tn hao trong vch thng v cc chi tit kim loi khc:
Do mt phn t thng tin khp mch qua vch thng du, cc x p gng, ccbulng...., nn pht sinh tn hao trong cc b phn ny.
Pt = 10.k.s
Trong h s k tra theo bng 40a: k = 0,015
Pt = 10 . 0,015 . 250 = 37,5 (W)
3.1.5. Nhvy ta c tn hao ngn mch ca mba l:
Pn = Pcukf1 + Pcu2kf2 + Pr1 + Pr2 + Pt
Pn = Pcu1 ( kf1 + kfhv1 1 ) + Pcu2kf2 + Pr1 + Pr2 + Pt = 1366,231( 1,0164 + 1,001
1) + +2240,855. 1,001 + 61,206 + 0,729 + 37,5 = 3732,534
(W)
So snh vi s liu cho :3700
534,3732.100 = 100,879%
Nu k c dy qun iu chnh ( khi 100,05Um)
Pn = 3732,534 + 0,05 ( 2240,855.1,001) = 3844,689(W)
3.2. Xc nh in p ngn mch:
3.2.1. Thnh phn in p ngn mch tc dng.
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Unr=dm
nr
U
U.100 =
dm
dmn
U
Ir ..100 =
mIU
mIr
dmdm
dmn
.
.
.
.100=1000.S
Pn 100
Unr=S
Pn
.10=
250.10
534,3732= 1,439 (%)
3.2.2. Tnh thnh phn in p ngn mch phn khng:
unx =dm
dmn
U
IX.100 =
2
..'...9,7
v
rr
U
kasf .10
1%
Trong : + =l
d12
+d12 = d m + 2a01 + 2a1 + a12 = 0,17 + 2.0,004 + 2.0,0252 + 0,027 = 0,255 (m)
+ = 3,142 .412,0
255,0= 1,944
+ar= a12 + 1/3(a1 + a2) = 0,027 + 1/3 ( 0,0252 + 37,5 . 10-3) = 0,048(m)
+kr= 1 - ( 1 e1/6
)
+ =412,0.142,3
0375,00252,0027,0
.
2112 ++=++
l
aaa
= 0,069
+kr= 1 0,069 ( 1 e-1/0,069
) = 0,931
Unx = 2415,6
931,0.048,0.944,1.333,83.50.9,7. 10
-1= 6,949%
3.2.3. in p ngn mch ton phn:
Un =22 493,1949,6 + = 7,107%
Sai lch ln hn so vi tiu chun :8,6
8,6107,7 .100 = 4,5%
Nh vy sai s nm trong phm vi 5% t yu cu.
3.3. Lc chc ca dy qun:
Khi mba b s c ngn mch th dng in ngn mch s rt ln, n khngnhng lm tng nhit my m cn gy lc chc ln nguy him i vi dyqun mba.
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3.3.1. Dng in ngn mch cc i.
1.Tr s hiu dng ca dng in ngn mch xc lp:
In =n
dm
U
I100 =
107,7
124,4.100 = 58,027 (A)
2. Tr s cc i ( xung kch) ca dng in ngn mch:
)1(2/.
maxnxnr uu
n eIi+=
)(846,123)1.(2.027,58 949,6/493,1.max Aei =+=
3.3.2. Tnh lc chc khi ngn mch:
Lc chc sinh ra do tc dng ca dng in trong dy qun vi t thng tn.
- Lc hng knh: Do t trng tn dc tc dng vi dng in gy nnFr= Btbimax. W. lv = 0 ,628 (imax.W)
2. kr . 10
-6( 4- 34)
Fr= 0,628. ( 123,846 . 3150)2. 1,944. 0,931. 10
-6= 172978N
Lc Fni vi hai dy qun l trc i nhau ( H.9 ) c tc dng p ( hay nn)dy qun trong v c tc dng trng ( bung) i vi dy qun ngoi.
- Lc chiu trc Ft do t trng tn ngang tc dng vi dng in sinh ra.
Ft = Fr .l2
a r = 172978 .412,0.2
048,0= 10076 (N)
Lc Ft c tc dng nn c hai dy qun theo chiu trc v Ft st gi tr lnnht gia dy qun.
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3.3.3. Tnh ton ng sut ca dy qun:1. ng sut do lc hng knh gy nn:- ng sut nn trong dy qun HA: Do lc nn Fnrgy nnFnr=
2Fn nr1 =
TW
10.F6
nr
=
W.T.2
10.F 6r
=
36.10.4,140.142,3.2
10.1729786
6
= 5,447 (MPa)
- ng sut nn hoc ko trong dy qun CA:
nr2 =3150.10.54,1.142,3.2
10.1729786
6
= 5,675(MPa)
So snh vi gi tr tiu chun: nr 30MPa
100.30
675,5= 18,9% ng sut nn cho php.
2. ng sut do lc chiu trc gy nn:
- Lc chiu trc ch yu l lc nn, n lm hng nhng ming m cchin gia cc vong dy. ( H .10)
a
b
Fn = Ft = 10076
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n =ban
Fn
..
10. 6=
6
6
10.40.2,25.8
10.10076
= 1,25 MPa
Trong : +n : S ming m theo chu vi vng trn dy qun, n=8 (Bng30)
+a, b:kch thc ming m
Chn + B rng tm m b = 40 (mm)
+ B rng tm m a = 25,2(mm)
Phn IV: tnh ton cui cng v h thng mch tv tham skhng ti ca m.b.a
4.1 Tnh ton kch thc li st :1. Ta chn kt cu li thp kiu 3 pha , 3 tr , l thp ghp xen k lm bng
tn cn lnh m hiu 3404 dy 0,35 mm c 4 mi ni nghing 4 gc . p trdng nm g sut gia ng giy baklit vi tr . Gng p bng x p vi bulng sit ra ngoi gng
S bc , chiu dy cc tp l thp v kch thc cc tp l thp tra theo Bng41a : vi d = 0,17 m
Thttp
Tr (mm) Gng ( Trong 1/2 Tt )
1 160 28 160 28 2 145 17 145 17 3 130 10 130 10 4 110 10 110 10 5 85 8 85 16 6 50 8
- S bc thang trong tr nT = 6- S bc thang trong gng nG = 5
- Chiu rng tp l thp gng ngoi cng aG = 85 mm- H s chm kn hnh trn ca bc thang tr kc = 0,927- Din tch tit din ngang cc bc thang ca tr v gng ( Bng 42a )
25,208 cmTbT = 21,214 cmTb =
- Th tch gc mch t : V0 = 2908 cm3
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2. Xc nh tit din tng cc bc thang trong tr :
== 26 5,20810.. cmbaT TTbT 3. Tit din tc dng ca tr st :
bTdT TkT .=
Trong k l h sin y k = 0,92 ( Bng 10 )2
82,1915,208.92,0 cmTT == 4. Tit din tng cc bc thang ca gng :
== 26 2141010.. mmbaT GGbG 5. Chiu dy gng :
( ) mbb TG 162,02.881010172810.3 =+++++==
6. Tit din tc dng ca gng :2972,1961,214.92,0. cmTkT bGdG ===
7. Chiu cao tr st :( )''' 00 llllT ++=
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Trong : l0' v l0'' l khong cch t dy qun n gng trn v gng div bng 0,075 m
mlT 562,0075,0.2412,0 =+=
8. Khong cch gia hai tr cnh nhau : m377,002,0357,010.a''DC 3222 =+=+=
9. Trng lng st ca tr v gng :- Trng lng st 1 gc ca mch t : l phn chung nhau ca tr v gng ,
gii hn bi hai mt trc vung gc nhau6
00 10...= VkG d
Trong : V0 l th tch gc mch t= 7650 ( Kg/m
3) : L t trng thp
`467,207650.10.2908.92,0 60 KgG ==
Trng lng st gng : Gm hai phn :Phn gia hai tr bin :
( ) KgTCtG GG 231,22710.7650.972,196.377,0).13.(2...1.2'4 ===
Phn gng gia cc gc :
KgGG
GG 934,40467,20.2.22
.4'' 00 ====
Trng lng st ton phn ca gng :KgGGG GGG 165,268934,40231,227''' =+=+=
Trng lng st tr : Gm hai phn :
Phn trng vi chiu cao ca s mch t :KglTtG TTT 408,2477650.562,0.10.82,191.3...'
4 ===
Phn tr ni vi gng :KgGaTtG GTT 035,9)467,207650.16,0.10.82,191.(3)10....(''
4
0
3
1 ===
Trong a1G = 160mm Trng lng st tr :
KgGGG TTT 433,256035,9408,247''' =+=+=
Trng lng st ton b ca tr v gng :KgGGG GTFe 608,524165,268433,256 =+=+=
4.2 Tnh ton tn hao khng ti , dng in khng ti v hiu sut mbaKhi cp in p xoay chiu nh mc c tn snh mc vo cun dy scp
v th cp hmch , gi l ch khng ti .1. Tn hao khng ti : Ch yu l tn hao trong l thp silic .
)...(0 GGTTf GpGpkP +=
Trong : sut tn hao pT , pG ph thuc vo t cm BT , BG , m hiu vchiu dy l thp :
TTf
uB
T
VT 506,1
82,191.50.44,4
10.415,6
..44,4
10. 44===
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TT
TBB
G
TTG 467,1
972,196
82,191.506,1. ===
Tit din khe hkhng kh mi ni nghing :
TB
B Tkn 065,12
506,1
2 ===
Tra bng 45 :Vi BT = 1,506 T pT = 1,11 (W/Kg) ; pK= 858,4 (W/m
2)
Vi BG = 1,467 T pG = 1,044 ( W/Kg) ; pK= 810,4 (W/m2)
Vi Bkn = 1,065 T pKN = 398,6 (W/m2)
i vi mch t phng , ni nghing 4 gc , tr gia ni thng , li stkhng t l , tn c sau khi ct v c kh bavia :
ptpepGKKKp
GT
GGTTpppc kkkTnpkGpp
GNGpGpkkP .......
2
).'.(... 0000
+
+++=
Trong :+ N: S lng gc ni ca mch t N = 4+ kp0 = 10,18 l h s kn tn hao phcc gc ni mch t ( Bng 47 )+ kPG = 1 l h s tn hao phgng+ kPT = 1,01 l h s tn hao do tho lp gng trn ( lng dy)+ kPE = 1,02 l h s tn hao do p trai+ kPC = 1,05 l h s kn tn hao do ct dp l tn+ kPB = 1 l h s kn tn hao gp mp hoc kh bavia
+ nK: S khe ni gia cc l thp trong mch t .Thay s :
+
+++= 18,10.467,20.
2
044,111,1)467,20.4231,227.(044,1443,256.11,1.1.05,10P
)(934,813
01,1.02,1.1.)10.972,196.4,810.210.82,191.4,858.110.82,191.2.6,398.4( 444
W=
=+++
Sai lch so vi tiu chun : %74,0100.820
820934,813=
2. Dng in khng ti :
Thnh phn tc dng ca dng in khng ti:
100.100../
./100.% 0
000
S
P
UmS
UmP
I
Ii
f
f
f
RR =
== %326,0
10.250
934,813==
Theo Bng 50 , ta tm c sut t ho :Vi BT = 1,506 T , qT = 1,375 ( VA/Kg) , qKT =17008 (VA/m
2)
Vi BG = 1,467 T , qG = 1,241 (VA/Kg) , qKG = 14884 (VA/m2)
Vi Bkn = 1,065 T , qKN =1975 (VA/m2)
Vi li st kiu tr phng , lm bng thp cn lnh c p tr v gng bng ai, khng c bulng xuyn li :
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++
+++= kkkioir
gt
ggtticibitieig TnqGkkqq
GNGqGqkkkkkQ ....2
).(... .00'
.0
[[ ++= )467,20.4231,227(241,1433,256.375,1.18,1.00,1.01,1.04,1.00,1
] +++++ 82,191.17008.1274,271.1975.4(467,20.745,41.433,1.2
241,1375,1
] 289,382910).972,196.14884.2 4 =+ (VA)
Trong : N=4TK=
2274,27182,191.22 cmTT == vi mi ghp nghing2972,196 cmTT GK == ( Gng )
282,191 cmTT TK == Vi mi ghp thng tr+kib = 1 : H s kn nh hng ca vic ct gt bavia+kic = 1,18 : H s kn nh hng ca vic ct dp l thp+kir= 1,433 : H s kn nh hng do chiu rng l tn cc gc mch t+kig = 1 : H s lm tng cng sut t ho gngkie = 1,04 : H s kn nh hng ca vic p mch tkit = 1,01 : H s kn s tng cng sut t ho do tho lp gng trn
cho dy qun vo trki0 = 41,745 : H s chung ( Bng 53 )Thnh phn phn khng ca dng in khng ti :
%532,1250.10
289,3829
.10% 00 ===
S
Qi x
Dng in khng ti tng :%`566,1326,0532,1% 2220
2
00 =+=+= rx iii
Nh hn so vi dng in khng ti tiu chun.Tr s :
528,5100
532,1.844,3600 ==XI (A)
176,1100
326,0.844,360 ==oRI (A)
615,5100
566,1.844,360
0
==I (A)
3.Hiu sut ca mba khi ti nh mc :
%2.98100.689,3844934,813250000
689,3844934,8131100.1
0
0 =
++
+=
++
+=
ndm
n
PPP
PP
Phn V : Tnh ton nhit
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5.1 Tnh ton nhit ca dy qun :1. Nhit chnh trong lng dy qun hay l st vi mt ngoi ca n:
-Dy qun HA: dy ch nht :cd
q
.0 =
Trong :+ l chiu dy cch in mt phi ca dy dn :m31 10.2,0
=
+ cd : Sut dn nhit ca lp cch in ca dy dnBng 54 : cd = 0,17 (W/m
0C)
+q: Mt dng nhit trn b mt dy qun HA :kp
qfCu.
1 =
Hay 101 10.)'(
....107
+
=
K
fb
abk
kIq
( W/m
2)
Trong :+Wb = 1 s vng dy trong mt bnh dy+k = 0,75 h s che khut b mt lm lnh+ aK= 0,0252 m kch thc hng knh ca dy qun+b
'= 6,6.10
-3
+kf= 1,0164
( )876,44210.
0252,010.6,6.75,0
0164,1.1.844,360.10.57,2.107 103
6
1 =+
=
q W/m2
498,017,0
10.2,0.876,442 301 ==
0 C
- dy qun CA: dy dn trn:tb
2
0
a.P28,0
=
Trong : + a= 0,0375 (m) l chiu dy dy qun+p l tn hao trong mt n v th tch dy qun :
8
'
l
'
22
10.d).d(
d.68,1p
+
= (W/m 3)
+d=1,4.103(m)
+d=1,8.103(m)
+ )m(10.48,0 3l
=
p =1,68 4,57510.10.8,1.10).48,08,1(
10.4,1.10.678,2 833
6.2.122
=+
(W/m3)
+'
1l
l
'
1
tbd..
)d(.
+
+= : dn xut nhit trung bnh
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17,01= (W/m 0 C)
336,010.8,1.17,010.48,0.454,0
10).48,08,1.(17,0.454,033
3
tb=
+
+=
(W/m0C)
C743,6336,0
0375,0.4,575.28,0 02
02 ==
Mt dng nhit trn b mt ca dy qun CA:
915,684275,3
001,1.855,2240
M
k.Pq
2
2f2Cu
2=== (W/m 2 )
2. Nhit chnh gia mt ngoi dy qun i vi du :-Dy qun HA : 6,0
13211d0q.35,0.k.k.k= (6-10b)
Trong : + 0,1k1= khi lm lnh t nhin bng du.
+ 1,1k2 = i vi dy qun trong (HA)+ 85,0k
3 = (Bng 55) khi h 159,02,25/4a/r ==
C666,12876,442.35,0.85,0.1,1.0,1 06,01d0
== -Dy qun CA :
Cqkd06,06,0
220 329,14915,684.285,0. ===
3. Nhit chnh trung bnh ca dy qun i vi du :Dy qun HA: Cddtb
0
100 164,13666,12498,001 ===+=
Dy qun CA: .C824,18329,14743,6.3
2
3
2 02d002dtb0 =+=+=
5.2 Tnh ton nhit ca thng du :1. Chn loi thng :Theo bng 57 ta chn kt cu thng vch phng c ng lm lnh cong.2. Cc kch thc ti thiu bn trong thng
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- Khong cch t dy dn ra ca dy qun CA n dy qun CA :40s
1= (mm) (Bng 31) vi 852 =thU KV, bc cch in 4(mm)
- Khong cch t dy dn ra n vch thng du :42s
2= (mm) (Bng 31) vi 85U
2th= KV ,bc cch in 4 (mm)
-Khong cch t dy dn ra HA n dy qun CA :90s3 = (mm) (Bng 32)
-Khong cch t dy dn ra HA n vch thng25s
4= (mm) (Bng 31)
- ng knh dy dn ra khng bc cch in ca dy qun HA:10d
2= (mm)
- ng knh dy dn ra c bc cch in ca dy qun CA:25d
1
= (mm)
- Khong cch gi dy qun cao p v vch thng :125251090sdss 4235 =++=++= (mm)
- Chiu rng ti thiu ca thng
59,010).102590254240(357,0
10).dssdss(DB
3
3
243121
''
2
=++++++=
++++++=
Ly B =0,6- Chiu di ti thiu ca thng :
3
5
"
2 10.s.2DC.2A
++=
360,110.125.2357,0377,0.2 3 =++= (m)- Chiu cao rut my :
H1=lt+2.hg+n.10=0,562+2.0,16+40.10=0,93 (m)
Trong : + n lchiu dy tm lt di gng di : n=40 mm+chiu cao tr: lt=0,412+2.0,075=0,562 (m)+chiu cao gng hg=0,160 m
- Chiu cao ti thiu t gng trn n np thng : H2Theo bng 58 ly H2= 400 mm= 0,4 m
Khi biu chnh in p t nm ngang gia gng trn v np thng.- Chiu cao thng : H=H1+H2=0,93+0,4=1,33(m)3. Din tch b mt bc x v i lu ca thng du :- Nhit chnh trung bnh cho php ca du i vi khng kh cho dy qun
nng nht CA : C176,41824,1860 0dk
==
- Nhit chnh ca lp du trn so vi khng kh :C50C4,49176,41.2,1.2,1).(2,1 00
dktkdt
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Trong : ly nhit chnh ca du i vi vch thng dt=60C
-Chn s dy ng l mt dy (Bng 60)-Bn knh cong ca cc ng ly R= 0,15(m)
- Chn loi ng trn ng knh 30/27 mm dy 1,5 mm-Khong cch gia hai ng cnh nhau (bc ng) : t=50 mm (Bng 60)-Ly on ng a=50 mm-Khong cch gia hai tm ng :
b = H- (c+e).10-3=1,33 - (60+70).10-3=1,2 (m)
Trong cc khong cch c = 60 mm , e =70 m (Bng 61)
-Chiu di khai trin ca ng :l = b + ( .R-2.R+2.a ).10-3= b +( 1,14.R+2.a ).10-3=1,2 + (1,14.150+2.50 ).10
-3= 1,470 (m)
-sng trong dy : m= 6805,0
6,0.)6,036,1.(2
t
B.)BA(2
o
=+
=+
-B mt bc x ca thng :Mbx=( 2.( A-B )+.B+.( 2.a+2.R+2.td.(n-1) +d ).10
-3).H + 0,5.Mn
Trong b mt bc x ca np thng :
0,5.Mn=0,5.( bn(ln- bn) +.bn2
/4 ) = 0,5.( (B+2.bv).(A-B)+.(B+2.bv)2
/4Trong : bn=B+2.bv l chiu rng np thng
ln=A+2.bv l chiu di np thngbv=0,08 m l chiu rng vnh np thng .
2
2
nm52,0)
4
)16,06,0()6,036,1)(16,06,0.((5,0M.5,0 =
+++=
Mbx=( 2.(1,36-0,6)+.0,6+(2.0,05+2.0,15+0,03)).1,33+0,52=4,756 (m2)
- B mt i lu ca thng : Ml=Mfl.kht+Ml.khTrong : h s hnh dng (Bng 56) kht=1,4.1,15 = 1,61
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kh=1,61
+B mt i lu ca thng phng v np :Mfl=(2.(A-B)+.B).H+0,5.Mn=( 2.(1,36-0,6)+.0,6) ).1,33+0,25 =5 (m
2)
+B mt i lu ca ng :
Ml=Mm.m.l=0,0942.68.1,47=9,42 (m
2
)Ml=5.1,61+9,42.1,61=23,21 (m2)
Trong Mm=0,0942 (m2) l din tch b mt mt mt ng (Bng60)
-B mt i lu ca thng theo tng tn hao :bx25,1
tk
'
dlM.12,1
.5,2
P.05,1M
=
Trong +Tng tn hao :4659689,3844934,813PPP
n0=+=+= (W)
+B mt bc x :
Mbx=(2.(A-B)+.B).H.k=(2.(1,36- 0,6)+.0,6).1,33.1,5=6,8 (m2)Vi k=1,5 (Bng 59) l h s hnh dng thng
226,158,6.12,1176,35.5,2
4659.05,1M
25,1
'
dl== (m2)
Ta thy Ml >Ml
5.3 Tnh ton cui cng nhit chnh ca dy qun v du :1.Nhit chnh ca thng du i vi khng kh :
( ) ( )C7,27
21,23.5,28,6.8,2
689,3844934,81305,1
M.5,2M.8,2
PPk 08,08,0
dlbx
n0
tk
=
+
+=
+
+=
2. Nhit chnh ca du st vch thng so vi thng :6,0
dl
n0
1t.dM
)PP.(k.165,0.k
+=
= 1,421,23
)689,3844934,813.(05,1.165,0.1
6,0
=
+0C
3. Nhit chnh ca thng du so vi khng kh :
8,317,271,4tkdt'dk =+=+= 0C4. Nhit chnh ca lp du trn so vi khng kh :
50388,31.2,1).(tkdtdk
==+= 0C
5. Nhit chnh ca dy qun i vi khng kh :6,508,31824,18'
dkdtb0k0=+=+= < 60 0C
5.4 Trng lng rut my,du v bnh gin du:1. Trng lng rut my :
897)608,524889,222.(2,1GG2,1Gldqr
=+=+= (Kg)
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Trong :+Trng lng dy qun :
889,22251,6191,130188,86GGGGc/d2Cu1Cudq
=++=++= (Kg)
+Trng lng li st : 608,524GGGGTl=+= (Kg)
2. Trng lng du :-Th tch du trong thng : Vd=Vt-Vr=1,461-0,163=1,298 (m)Trong :
+ 461,133,1.4
6,0.6,0.36,1H.
4
B.B.AV
22
t=
+=
+= (m3)
+Th tch rut my :
163,05500
897GV
r
r
r==
= (m3) ; Vi r=5500 (Kg/m
3)
-Trng lng du :( )[ ] [ ] 5854)298,1.(9,0.05,1GVV.9,0.05,1G
dortd=+=+= (Kg)
Trong :Gd: l trng lng du trong h thng lm lnh : 68 ng ,mi ng di 1,47 mtrng lng 1 mt du trong ng l 0,45 (Kg) (Bng 60)3.Bnh dn du :Bnh dn du lm bng thp c chiu dy 2 mm ,c t nm ngang trn np
thng.
Th tch bnh : 13,0298,1.1,0V.1,0Vdgd
=== (m)
-Chiu di bnh : 61,005,0.26,010.a.2Bl 3gd
=+=+ (m)
Ly 6,0lgd= (m)
-ng knh bnh dn du : ml
Vd
gd
gd53,0
6,0.
13,0.4
.
.4===
========================================
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h // b k d 3