TCXDVN Tiu chun xy dng Vit nam

TCXDVN 377: 2006

Bin son ln1

H thng cp kh t trung tm trong nh - Tiu chun thit k

Gas supply - Internal system in domestic- Design standard

H ni 2006

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Li ni u TCXDVN: 377 : 2006 do Vin Khoa hc Cng ngh Xy dng bin son, V Khoa hc Cng ngh trnh duyt, B Xy dng ban hnh theo Quyt nh s: 37/2006/Q-BXD ngy 22 thng 12 nm 2006

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Mc lc Trang

1 Phm vi p dng 7

2 Tiu chun tham chiu 7

3 Thut ng- nh ngha 8

4 Qui nh chung 9

4.1 Yu cu chung 9

4.2 Trch nhim bt buc ca nhng ngi c lin quan 10

4.3 Cc tiu chun phi tun th 10

4.4 Yu cu chung v vt liu ch to ph kin h thng 10

4.5 Yu cu v p sut lm vic ca h thng cp kh t trong nh 10

5 Tnh ton lu lng 10

5.1 Nhu cu s dng kh t 10

5.2 Dung tch cha ca trm cp kh t cho mt h thng trong nh 10

5.3 S lng bn cha cho mt h thng cp kh t trong nh 11

5.4 Lu lng kh t ca h thng 11

6 Mng li ng ng dn trong nh 11

6.1 Yu cu chung 11

6.2 Yu cu v vt liu ch to ng dn 11

6.3 Phng thc ni ng ng dn 12

6.4 Cc chi tit lp xit 12

6.5 Gi chung cho cc loi ng ng dn 12

7 Thit b s dng kh t 13

7.1 Yu cu v khng gian lp t thit b s dng 13

7.2 Yu cu v s lng thit b s dng t trong mt phng 14

8 Trm cp kh ho lng cho mt h thng cp kh t trong nh 14

8.1 Yu cu chung 14

8.2 Yu cu v bn cha kh ho lng 14

8.3 Yu cu v thit b ho hi 15

8.4 Yu cu bo v chng n mn 15

9 Tnh ton mng li cp kh t trung tm trong nh 15

9.1 Yu cu chung 15

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9.2 Yu cu v tn tht p lc 15

9.3 Vn tc chuyn ng ca kh t trong ng ng dn 16

9.4 ng knh trong thit k ca ng dn kh t trong nh 17

10 Thit b o kim v t ng 17

10.1 Yu cu chung 17

10.2 Van an ton 17

10.3 Thit b o kim 17

10.4 Cp chnh xc ca thit b o 17

10.5 H thng t ng iu khin 17

11 Phng chng chy n 17

11.1 Yu cu chung 17

11.2 Tip a v an ton in

11.3 H thng t ng cnh bo 17

12 Ph lc A: Tnh cht vt l ca mt s hydrocacbon. 18

13 Ph lc B: Nhit tr ca cc cht kh nguyn cht. 19

14 Ph lc C: H s hot ng ng thi ca thit b s dng Ksim 20

15 Ph lc D: S lng thit b s dng c th c cp t mt thit b ho hi

kh ho lng cng bc 21

16 Ph lc E: H s nhu cu s dng khng u trong ngy Kg 22

17 Ph lc F: Tnh ton thu lc mng li ng ng cp kh t trung tm

trong nh 23

18 Ph lc G: H s tn tht p lc cc b ca mt s ph kin trong h thng

kh t 29

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Tiu chun xy dng Vit Nam TCXDVN 377: 2006

Bin son ln:1

H thng cp kh t trung tm trong nh Tiu chun thit k Gas supply - Internal system in domestic- Design standard 1. Phm vi p dng

1.1. Tiu chun ny p dng thit k h thng cp kh t trung tm phc v nhu cu sinh hot dn dng trong nh chung c, chung c hn hp nh vn phng,

nh chc nng khc.

1.2. Tiu chun ny khng p dng:

- Cho h thng cp kh t n l c th tch bn cha nh hn 0,45 m3 ;

- Cho h thng cp kh t trong nh cng nghip, xng san, np kh t, kh ho lng

- Cho h thng ng ng dn kh t, kh ho lng ngoi phm vi nh . Ch thch:

Khi thit k h thng cp kh t trong nh , ngoi vic p dng cc qui

nh trong tiu chun ny cn tham kho thm cc qui chun, tiu chun

hin hnh c lin quan.

2. Ti liu vin dn - TCVN 7441: 2004 H thng cung cp kh du m ho lng (LPG) ti ni

tiu th Yu cu thit k, lp t v vn hnh. - tcvn 5066 :1990 ng ng chnh dn kh t, du m, sn phm du m

t ngm di t - Yu cu chung v thit k chng n mn. - TVCN 6486 : 1999. Kh t ho lng (LPG). Tn cha di p sut, v tr,

thit k dung lng v lp t - tcvn 6153 : 1996 Bnh chu p lc yu cu k thut an ton v thit k,

kt cu, ch to. - TCVN 6008 : 1995 Thit b p lc - Mi hn - Yu cu k thut v phng

php kim tra - TCVN 4879 : 1989 (ISO 6309.87) Phng chy, du hiu an ton - TCVN 3255:1986 An ton n, yu cu chung - TCVN 2622 : 1995 Phng chy v cha chy cho nh v cng trnh. - TCVN 4756 89 Qui phm ni t ni khng cc thit b in

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3. Thut ng - nh ngha 3.1 H thng cp kh t trung tm trong nh L h thng mng li ng ng lp t trong nh dn kh t t ngun cung cp

trung tm (t mng li cp kh t chung ngoi nh hay t trm cung cp t ngoi nh) ti cc thit b s dng t ti h gia nh.

H thng cp kh t trung tm trong nh bao gm: Mng li ng ng dn chnh, ng ng, ng nhnh, ng phn phi n cc thit b s dng (bp un, l nng, thit b un nc ), ph kin ng ng nh cc loi van kho, van an ton, thit b o, kim v cc ph kin khc. Khi s dng hi kh t ho lng, ngun cung cp trung tm t ngoi nh cn c th c: Trm cp, bn cha, thit b ho hi v ng ng dn pha ngoi t bn cha vo nh.

3.2 Ph kin ca h thng cp kh t

L tt c nhng chi tit, thit b c t nht mt b phn tip xc trc tip vi kh t v c kt ni thnh b phn ca mng li ng ng dn kh t nh cc loi van, thit b o, kim

3.3 Kh t L thut ng chung gi cc loi hydrocacbon c cng thc ho hc CnH2n+2 th kh

trong iu kin nhit v p sut trong phng (200C v 1 atmotphe). Kh hydrocacbon dng lm nhin liu t trong thit b dn dng thng c thm cht to mi c trng d pht hin khi kh t pht tn trong khng kh do x, h.

3.4 Kh ho lng hay kh du m ho lng (LPG) L thut ng gi loi kh t c khai thc t m du, m kh v sn phm du m. Trong iu kin bnh thng (nhit trong phng v p sut kh quyn) th kh nhng d dng chuyn sang th lng khi b nn cng nhit .

Kh ho lng dng trong dn dng ti Vit Nam hin nay l loi kh ho lng thng mi, thnh phn ch yu l hn hp kh Propan (C3H8) v butan (C4H10).

3.5 Thit b s dng kh t (gi tt l thit b s dng) L thut ng chung ch tt c cc dng thit b dn dng dng t chy kh t nh:

Bp nu, l nng, thit b un nc nng ... 3.6 Thit b ho hi L thit b chuyn dng, dng chuyn i kh ho lng thnh hi cp cho h thng

cp kh t trung tm trong nh. - Thit b ho hi cng bc: S ho hi trong thit b do c cp nhit cng bc

t ngun nhit nhn to (t nng bng ngn la trc tip, hi nc, nc nng, kh nng hay in nng);

- Thit b ho hi t nhin: S ho hi trong thit b xy ra t nhin khng cn ngun nhit nhn to (khng cp nhit cng bc).

3.7 Bn cha kh ho lng L loi bn chuyn dng, c ch to c bit dnh ring tn cha kh ho lng c

dung tch cha ln hn 0,45 m3. 3.8 Bn cha t ni Khi y bn c t bng mt t hoc cao hn v bn khng c bao ph bng t

hoc ct. 3.9 Bn cha t chm Bn c t ngm di t hay c ph hon ton bng t hoc ct c chiu su tnh

t mt t (mt lp t ph) n nh bn khng nh hn 0,2 m v lp t bao ph quanh bn dy hn 6 m.

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3.10 Bn cha na ni na chm Bn t na ni na chm hay t ni nhng c bao ph mt phn bng ct hoc t

c dy lp ph khng qu 0,2m. 3.11 Trm cp kh t Ni t bn cha kh ho lng ngoi nh cung cp hi kh t cho h thng cp trung

tm trong nh v c bao quanh bng hng ro bo v hay tng xy lng. 3.12 Van ngt khn cp Van c c cu ng nhanh bng tay hoc t ng hay kt hp t ng - tay ngt

ngun cung cp kh t trong trng hp khn cp. 3.13 Thit b iu p Thit b lm gim p sut ca kh t trong h thng t p sut cao xung p sut thp

theo yu cu. 3.14 Van iu tit lu lng Van dng lm gim hoc ngt dng cht lng hoc hi khi lu lng dng vt qu

nh mc cho php. 3.15 Van x kh: Van ch dng m cho cc cht kh thot ra khi h thng khi cn thit. 3.16 p sut lm vic

L p sut kh t trong h thng ln nht c php lm vic lu di theo thit k. Ch thch:

p sut kh t trong h thng c hiu l p sut d (phn p sut ln hn p sut kh quyn o bng Manomet).

3.17 p sut nh mc ca thit b p sut cho php lm vic ln nht theo thit k ca nh ch to ghi trong h s k thut

ca thit b. 3.18 H thng thp p L h thng cp kh t c p sut lm vic khng ln hn 0,005 Mpa (0,05 KG/cm2). 3.19 p sut tnh ca mi trng L p sut do ct khng kh trong mi trng to ra, ph thuc vo nhit , gia tc

trng trng v cao ct khng kh . 3.20 Dung tch cha thc L th tch phn rng c th cha nc ca bn cha. 3.21 Dung tch cha cho php L th tch kh ho lng ti a c php cha trong bn v bng 85% dung tch cha

thc ca bn cha. 3.22 Nhu cu s dng kh t trong nh Lng kh t cn thit (kg/h) m bo nng lng nhit phc v vic nu n, sinh

hot dn dng trong nh. i lng ny ph thuc vo s lng ngi (s h gia nh) sng trong nh v mc tiu th nng lng trn u ngi (h gia nh), thng o bng kg/h.

3.23 Lu lng kh t ca h thng L lu lng tnh ton ca h thng ng ng dn trong nh m bo lng kh

t cho cc thit b s dng t trong nh lm vic ng thi, n v o m3/h (m3/s). i lng ny ph thuc rt ln vo s lng, kh nng lm vic ng thi ca cc thit b s dng t trong nh v ph thuc vo nhit , p sut ca dng kh t chuyn ng trong mng ng ng dn.

3.25 H thng tip a san bng th

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L mng li dy tip a i song song v kt ni vi h thng mng li ng dn kh t trong nh hn ch dng in chy qua ng dn kh t khi c s c v in xy ra trong nh m bo khng xy ra chp in gy chy n.

3.26 Ngi thit k L t chc, c nhn c t cch php nhn hnh ngh thit k v c c quan c thm

quyn cho php thit k h thng cp kh t.

4. Qui nh chung

4.1 Yu cu chung Tiu chun ny p dng thit k h thng cp kh t trung tm trong nh . iu

kin lp t mng li ng ng dn, ph kin ng ng, thit b s dng trong mi to nh c th cn tun theo tiu chun ny v cc qui chun, tiu chun thit k khc ca to nh , c bit cc yu cu m bo s dng an ton, phng chng chy n do x, h, khi vn hnh h thng v s dng kh t .

4.2 Trch nhim bt buc ca nhng ngi c lin quan ti thit k h thng cp kh t trung tm trong nh

Ngi thit k phi chu trch nhim trong vic qui nh phng php v vt liu lm kn kht, chn vt liu lm ng dn, cc ph kin ca h thng v v tr lp t cng nh kch thc, chng loi cc dng c o, kim, thit b bo v v cc gii php m bo an ton cho h thng, s dng kh t ph hp vi tiu chun ny. Ngoi ra cn chu trch nhim xem xt v tho thun nhng ngh thay i thit k khi lp t h thng.

4.3 Khi thit k h thng cp kh t trung tm trong nh , ngoi vic phi tun th theo tiu chun ny cn phi tun th theo: - Thit k chng n mn ng ng theo cc iu 3.3; 3.4 v mc 4 trong tiu

chun: Tcvn 5066 : 1990. - Thit k h thng ng ng v thit b ng ng theo iu 4.2.7 trong tiu

chun: TCVN 7441: 2004. - Thit k m bo iu kin phng chng chy n theo TCVN 2622 : 1995, TCVN

6486: 1999, TCVN 1977: 1993 4.4 Tt c cc ph kin ca h thng cp kh t trung tm trong nh , trm cp kh ho

lng nh van an ton, van kho, thit b s dng, dng c o, kim, u cm bin nhit , cm bin nng kh t phi l thit b c thit k, ch to chuyn dng cho kh t, phi ph hp vi tiu chun ny, qui nh ca nh ch to, c quan ng kim , mc ch s dng v cc tiu chun chuyn bit nu c.

4.5 p sut lm vic ca h thng cp kh t trung tm trong nh khng c vt qu 0,003 MPa (0,03 kG/ cm2).

5. Tnh ton lu lng

5.1 Nhu cu s dng kh t trong nh Nhu cu s dng kh t xc nh theo lng tiu th kh ho lng trung bnh ca mt

h gia nh trong thng, kg/h.thng, theo cng thc:

Gn = Gh . Nh . (kg/thng) (1)

Trong :

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- Gn - Nhu cu s dng kh ho lng ca c to nh trong thng, kg/thng;

- Nh- S h s dng kh ho lng trong nh; - Gh Lng tiu th kh ho lng trung bnh ca mt h gia nh trong mt

thng, kg/h, thng.

Ch thch:

Hin nay ti Vit Nam cha c nh mc tiu th kh ho lng cho mt h gia nh nn khi thit k cn nghin cu thng k lng tiu th kh ho lng trung bnh ca mt h gia nh trong mt thng i vi mi loi cng trnh c th qua tnh nhu cu s dng kh ho lng ca c to nh hoc tm thi s dng nh mc 15kg/h. thng l nh mc c thit k ti mt s chung c ca Vit Nam hin nay.

5.2 Dung tch cha ca trm cung cp kh ho lng cho mt h thng trong nh Dung tch cha, kg, cn c ca trm cp xc nh theo cng thc sau:

Gt = Gn (T +t)/ 30 (kg) (2)

Trong :

- T - Khong thi gian gia hai ln nhp kh ho lng vo trm, (ngy); Khong thi gian gia hai ln np khng nn ly nh hn 15 ngy v ln hn 30 ngy (Mt thng np t 01 n 02 ln) ;

- t - Thi gian d phng khi khng nhp kh ho lng kp thi, (ngy). Thi gian d phng nn ly t 5 n 7 ngy.

5.3 S lng bn cha kh ho lng ca mt trm cp kh t S lng bn (N) ca ca mt trm cung cp kh t xc nh theo cng thc:

N = Gt. k/ Vcp (3)

Trong :

- Vcp Dung tch cha cho php ca mt bn cha ph thuc vo cch t bn cha (chm hay ni), o bng m3 ;

- k - Th tch ring ca kh t ho lng p sut lm vic ca bn cha (bar) v nhit trung bnh thng nng nht trong nm (0C).

5.4 Lu lng kh t ca h thng cp kh t trong nh Lu lng kh t, W (m3/h), ca h thng cp kh t trung tm trong nh xc nh

theo cng thc:

itb

m

idt nqKW ..

1=

= (4)

Trong :

- qtb nh mc tiu th kh t ca thit b s dng (m3/h), ly theo h s k thut ca nh ch to hoc theo c tnh k thut ca thit b;

- ni S lng thit b cng loi ; - m - S lng chng loi thit b ; - Km - H s hot ng ng thi ca cc thit b s dng kh t ( tham kho

Ph lc C). 5.5 Cho php xc nh lu lng h thng theo s h gia nh s dng kh t i vi nh

chung c ( tham kho ph lc F)

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6. Mng li ng ng dn trong nh.

6.1 Yu cu chung Mng li ng ng dn kh t trong nh l mng ng ct. Khng thit k mng

ng ng vng, mng c hai ng ng song song cng thc hin mt chc nng.

6.2 Yu cu v vt liu ch to ng dn kh t trong nh ng dn kh t trong nh phi l loi ng tho mn iu kin:

a) ng thp: Phi c tnh hn, rn tt, c dy thnh ng ti thiu 2mm v c gii hn hm lng cc cht ho hc: Ccbon - C 0,25 %, Lu hunh S 0,056 %, Phtpho - P 0,46 %.

b) Cho php s dng ng lm bng vt liu khc lm ng dn kh t trong nh nhng khng thp hn theo tiu chun ca EU, Anh, c th: - Cc ng ng theo tiu chun BS EN 1057; - Gang do theo tiu chun BS 143 v Bs 1256; - Cc loi ng nha (PE) v cc ph kin bng nha theo tiu chun BS 5114

hoc tiu chun BS 7336. c) Cho php s dng ng cao su chuyn dng chu p lc ni cc thit b t

khng c nh nh bp un, thit b un nc nng vo h thng chung. 6.3 Phng thc ni ng ng dn Cc mi ni ng phi hn v cc mi hn ng phi tun th ng theo qui nh trong

TCVN 6008 :1995. Ch cho php ni ren, ni mt bch ti v tr t ph kin h thng nh ni cc loi van, thit b o, kim v thit b s dng kh t.

6.4 Cc chi tit lp xit Thit k cc chi tit lp xit, mt bch ni phi tun th theo iu 5.4 trong tiu chun TCVN 6153 :1996.

6.5 Thit k ng dn kh t i chung vi cc loi ng khc trn mt gi Khi t ng ng dn kh t trn gi chung cng vi cc loi ng ng dn khc

cn t ng ng dn kh t cao hn mt khong cch ln d dng cho vic kim tra, sa cha thay th.

6.6 Khng thit k ng ng dn kh t i trong cc phng c kh nng gy chy, n loi A v B theo TCVN 2622 : 1995, trong vng c kh nng nguy him do n tt c cc loi phng, trong tng hm di trm in, gian my, trong phng c kh nng gy n mn cao (nh tm, khu v sinh..) v khng t ng ng dn xuyn qua knh, hm thng gi

6.7 Cho php thit k ng ng nhnh dn kh t thp p i qua phng nu khng th c gii php khc, khng c t bt k cc loi thit b, ph kin no ca h thng trn on ng i trong phng .

6.8 Khng cho php thit k trc ng ng, ng ng dn chnh i qua phng ng, phng v sinh, phng tm, phng cha rc thi sinh hot.

6.9 Trc ng ng nn t qua phng bp, cu thang, hnh lang hay bn ngoi nh khi iu kin cho php.

6.10 ng ng dn kh t trong nh cn t h, khi khng th t h, cn thit k mng t ng c li y tho, lp d dng; khng gian trong mng phi ln d kim tra v mng phi c thit k c ca thng gi t nhin.

6.11 Khi ng ng trong nh t ngm nn s dng loi ng lm bng thp khng g.

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6.12 Gi ng Trong nh , ng ng dn c t c nh trn tng, sn v di trn bng gi

(gi treo) c khong cch ga cc gi nh sau sau: - Khng qu 2,5 m i vi ng ng dn c ng knh n 25 mm; - Khng qu 3,5 m i vi ng ng dn c ng knh trn 25 mm; - Khng qu 5 m i vi ng ng dn c ng knh trn 50 mm.

6.13 Khi ng ng dn xuyn qua sn, mng nh phi t trong ng lng. Khong cch t mt ngoi ng ng dn ti mt trong ca ng lng phi tho mn iu kin sau: - Khng nh hn 5 mm i vi loi ng dn c ng knh ngoi n 32 mm; - Khng nh hn 10 mm i vi loi ng dn c n > 32 mm. ng lng c th l ng

thp, ng bng cht do. 6.14 ng ng chnh phn phi kh t ti cc trc ng ng trong nh nn thit k treo

bng gi treo di trn tng mt (tng trt) v cch trn nh t 15 mm n 20 mm. 6.15 ng ng dn hi kh ho lng bo ho cn thit k dc khng nh hn 0,003 v

pha thit b tiu th. 6.16 ng ng dn kh t t trm cp bn ngoi vo nh c th t ngm, t ni trn mt

t, t trn cao nhng phi m bo khng b va p c hc di bt k hnh thc no. 6.17 Khi on ng ng dn di trn 50m t trong mi trng c th pht sinh gin n

ng ng theo chiu di, phi thit k c cu b dn n c dng hay hnh ch (Hnh 1).

Khng cho php thit k c cu b gin n kiu ng lng ng.

6.18 Kch thc c cu b, phng php b gin n phi c thit k m bo khi c s gin n khng gy tc hi cho h thng (cong, vnh ng, ph hu ph kin).

6.19 Van kho phi t ti nhng v tr sau: - kho cho mi trc ng ng cung cp kh t cho nh c trn 5 tng; - Trc mi ng h o lu lng (nu khng th kho bng van kho trn ng

nhnh, ng phn phi); - Trc mi thit b tiu th kh t; - Trn nhng on ng nhnh; - Trc mi thit b o kim (nu c).

6.20 Trn ng ng dn kh t vo nh phi c van ngt khn cp t pha ngoi nh (sau thit b ho hi nu h thng s dng hi kh t ho lng) cao khng qu 1,2 m v phi ti v tr d nhn bit v thun li khi thao tc ng, m van.

6.21 Ti im u v cui trc ng ng cn thit k on ng ch c van kho lp thit b kim tra khi cn v phi c van x kh, x cn.

6.22 Ti mi khu vc trong h thng ng dn c th hnh thnh ti kh cc b (ng ct, trn nh h thng) cn thit k t van x kh.

6.23 Yu cu v mu sc lp sn ngoi ca ng dn kh t Ton b h thng cn sn ph ngoi bng lp sn mu vng.

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7. Thit b s dng kh t

7.1 Yu cu v khng gian lp t thit b s dng Phng t bp s dng kh t trong nh cn c ca thot khi, ca s cp khng kh

din tch ti thiu 0,02 m2 nm thp hn ca thot khi. Phng bp cn c chiu sng t nhin v chiu cao phng khng nh hn 2.0m .Th tch phng cn tho mn iu kin sau m bo khng kh cho qu trnh chy t nhin:

- Phng t bp i: 8m3; - Phng t bp ba : 12m3; - Phng t bp bn: 15m3.

Cho php t bp trong phng c chiu cao thp hn 2 m nhng th tch phng phi ln hn 1,25 ln th tch ghi trn v khong trng trc bp un n kt cu c nh i din vi bp khng nh hn 1m.

Khuyn co Khng nn t thit b s dng kh ho lng di tng hm nh chung c, ngay di phng thng tp trung ng ngi.

7.2 Yu cu v s lng thit b s dng t trong mt phng Cho php t ng thi trong mt phng nhiu loi thit b s dng khc nhau (thit b

un nc nng dn dng, bp un) nu m bo theo iu kin nu trong iu 7.1 ca tiu chun ny.

8. Trm cung cp kh ho lng cho mt h thng cp kh t trong nh

8.1 Yu cu chung Khi thit k trm cp kh ho lng cho nh phi tun th nhng qui nh ca tiu

chun TCVN 7441: 2004 v cc yu cu sau:

- Trm cp kh ho lng phi c hng ro, tng bo v c chiu cao khng thp hn 1,6 m lm bng vt liu chng chy. Khong cch t mp bn cha ti hng ro bao quanh khng nh hn 1m;

- Trm cp kh ho lng phi t ti v tr c ng giao thng thun tin cho xe bn, xe cha chy ra, vo trm khi cn;

- Bn cha kh ho lng c th t chm hay t ni trn mt t. Khng cho php t bn cha trong nh c tng bao kn (trong phng). Bn ch to chuyn t chm khng cho php t ni hay na ni na chm;

- Dung tch cha cho php (V) ti a trong mt bn cha: - Khi t chm V 50 m3; - Khi t ni trn mt t V 5 m3. - Bn cha kh ho lng cn t c dc 0,002- 0,003 v hng ca cp kh ho

lng n thit b ho hi; - Bn cha t ni phi c gi v gin thao tc c nh lm bng vt liu chng

chy (xy gch, b tng hay bng thp); - Khong cch t mp bn cha ti cc cng trnh xy dng cn tho mn iu kin

iu 4.1.1.3 ca tiu chun TCVN 7441 : 2004 v iu kin ghi trong bng 2:

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Bng 2 - Khong cch t bn cha ti cng trnh xung quanh

Loi cng trnh Khong cch (m) t mp bn cha

t ni Chn chm di t

Tng dung tch ca trm cha kh ho lng (m3)

n 5 5 10 n 10 1020 2050 50100

100200

Cng trnh cng cng 40 - 15 20 30 40 40

Nh c ca nhn ra trm 20 - 10 15 20 40 40

Khng c ca nhn ra trm 15 - 8 10 15 40 40

Cng trnh cng nghip 15 20 8 10 15 25 35

8.2 Yu cu v bn cha kh ho lng Bn cha kh ho lng c thit k, ch to, trang b cc ph kin km theo v vn

hnh, s dng theo tiu chun TVCN 6153 : 1996, TVCN 6486 : 1999, TVCN 6008 : 1995 v iu 4.2.3 trong tiu chun: TCVN 7441: 2004.

8.3 Yu cu v thit b ho hi Thit k lp t thit b ho hi phi tun th theo iu 4.2.5 trong tiu chun TCVN

7441: 2004 v cc qui nh di y: 8.3.1 Thit b ho hi cng bc ch c s dng khi qu trnh ho hi t nhin khng

cung cp lng kh t theo yu cu hoc khi lng kh t cn cp yu cu c mt hay lu lng khng i theo thi gian.

8.3.2 Thit b ho hi phi c cc ph kin: Thit b khng ch lu lng, p sut, nhit , v thit b bo v khng cho kh t th lng chy vo ng dn pha hi.

8.3.3 Trong thit b ho hi cng bc t bng in tr phi c thit b t ng khng ch nhit , dng in m bo khng c s c chy n do chp, chy in.

8.3.4 Thit b ho hi c th c t h ngoi tri khng cn mi che hay trong phng theo iu kin sau: - Thit b c cng sut ho hi n 200kg/h khng cp nhit trc tip t ngn la,

cho php t trc tip trn nc bn cha hay trong phm vi trm cp kh ho lng cch bn cha ti thiu 1 m.

- Thit b c cng sut ho hi ln hn 200kg/h cn t pha ngoi trm cp kh ho lng v phi cch tng (ro) trm cp ti thiu 10 m v cch nh trn 8 m.

8.3.5 Khi t ngoi tri khng c mi che, thit b ho hi cn c bc cch nhit v t cch nhau ti thiu 1 m nu c nhiu thit b ho hi t cng nhau.

8.3.6 Cng sut thit b ho hi c xc nh theo lu lng h thng . 8.3.7 Cho php thit k t bn cha hi kh ho lng d tr ngay sau thit b ho hi cp

kh t trong gi c nhu cu s dng thp hoc cp b lng kh t trong gi cao im (gi c nhu cu s dng cc i) gim cng sut thit b ho hi.

8.3.8 Bn cha hi iu tit phi c thit k ch to theo tiu chun k thut nh bn cha kh t khc.

8.3.9 S lng thit b ho hi c thit k tu theo nhu cu s dng v chng loi thit b ho hi.

S lng thit b ho hi tnh theo s lng thit b s dng tham kho ph lc D

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8.4 Yu cu v bo v chng n mn 8.4.1 Bn t ni cn c bo v chng dng nhit bc x mt tri chiu trc tip ln bn

(t mi che hay sn mu sng). 8.4.2 Bn t ni phi c bo v chng n mn ca mi trng khng kh nh m, sn

chng r, khi sn chng r phi sn ti thiu hai lp. 8.4.3 Bn t chm cn c bo v chng n mn theo iu 4.2.3.4 trong tiu chun TCVN

7441 : 2004. 8.4.4 Bn t chm, na ni na chm cn bo v chng ngp nc.

9. Tnh ton mng li cp kh t trung tm trong nh

9.1 Yu cu chung Lu lng kh t xc nh theo s lng thit b s dng hay theo nhu cu s dng kh t trong nh v kh nng lm vic khng ng thi ca cc thit b s dng cng nh nhu cu s dng khng u trong ngy. Phi m bo lu lng kh t theo yu cu s dng ln nht (trong gi ca im).

9.2 Xc nh ng knh ng dn ng knh ca ng cp kh t trong nh cn c thit k tn tht p sut trong h thng cho php ln nht v h thng lm vic tin cy, n nh.

1. ng knh trong ca ng dn (dt), cm, c chn s b theo cng thc:

v

td

PW

mt

)273(036238,0

+= (5)

Trong :

- W - Lu lng kh t, m3/h, nhit t0 = 00C v p sut p = 101,32 KPa - t Nhit ca kh t iu kin tnh ton, 0C. - Pm- p sut tuyt i trung bnh ca kh t trong on ng cn tnh. Pm = 0,5.(Pu + Pcui ) (Pa) (6)

- v Vn tc dng kh trong ng ng, m/s. 2. ng knh ng thc ca mng li ng ng dn c chn theo tnh ton thu lc h thng.

(Tnh ton thu lc h thng cp kh t h p tham kho ph lc F).

9.3 Tn tht p sut trong ng ng dn 9.3.1 Tng tn tht p sut ca h thng thp p trong nh (tn tht p sut do ma st theo

chiu di on ng v tn tht p sut cc b) tnh t van ngt khn cp t ngoi nh (sau thit b ho hi) n thit b s dng xa nht v cao nht khng vt qu 60 Pa hay c th tnh theo iu kin m bo p sut ca kh t trong ng trc thit b s dng xa nht v cao nht bng 0,7 p sut nh mc ca thit b s dng.

9.3.2 Tn tht p sut ca mng li ng ng dn kh t trong nh cn tnh thm nh hng ca p sut tnh mi trng khng kh theo cng thc (pa):

p = gh(k - ) (7)

Trong :

- g Gia tc trng trng (g = 9,81m/s2);

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- h Chnh lch cao tuyt i gia im u v im cui ca on ng dn cn tnh, (m);

- k Khi lng ring (mt ) ca khng kh nhit tnh ton, 0C, v p sut 101,32 Kpa, (kg/m3) .

- - Khi lng ring ca kh t nhit tnh ton, 0C, v p sut 101,32 Kpa, (kg/m3).

- p c gi tr dng khi im cui cao hn on u on ng tnh ton v c gi tr m trong iu kin ngc li

9.3.3 Cho php tnh tn tht p sut cc b theo t l phn trm ca tn tht p sut do ma st theo chiu di trong on ng , c th: - on ng chnh n chn trc ng ng : 25 %; - Trn trc ng ng : 20 % - Khi ng ng phn phi di t 1 m n 2 m : 450% - Khi ng ng phn phi di t 3 m n 4 m : 300% - Khi ng ng phn phi di t 5 m n 7 m : 120% - Khi ng ng phn phi di t 8 m n 12 m : 50%

9.3.4 Vn tc chuyn ng ca kh t trong ng ng dn Vn tc chuyn ng ca dng kh t trong ng khng nn vt qu 7 m/s gim n sinh ra do dng kh chuyn ng trong ng.

10. Trang b o kim v t ng

10.1 Yu cu chung - S lng, chng loi v phng php lp t thit b m bo an ton, o, kim, ng

h o p sut tun th theo TCVN 6153 :1996 v TCVN 7441 : 2004.

- Trong trm cha kh ho lng yu cu phi c h thng t ng iu khin lu lng

hi, p sut ca h thng, bn cha v h thng cha chy t ng m bo an ton.

10.2 Van an ton Thit k van an ton tun th theo iu 8.3 trong TCVN 6153 :1996 v TCVN 7441 :

2004 v theo iu kin sau: - Van an ton kiu l xo cn c c cu m van cng bc khi cn thit (khi t

trong h thng h p - p sut lm vic nh mc khng qu 0,005 Mpa cho php khng c c cu m cng bc).

- Van an ton phi m bo bt u lm vic (m ca x) khi p sut trong h thng vt qu 15% p sut lm vic.

- Ming ng x t van an ton, van x kh cn t ngoi nh m bo khng x kh t vo trong nh trong mi iu kin.

10.3 p k Trang b p k tun th theo iu 8.2 trong TCVN 6153 : 1996 10.4 Cp chnh xc ca thit b o

Cp chnh xc ca tt c thit b o, kim khng c nh hn 2,5.

10.5 H thng t ng iu khin - Yu cu phi c h thng t ng iu khin lu lng kh t m bo lng kh t cho h thng v m bo an ton cho thit b ho hi.

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- Cho php s dng h thng t ng iu khin p sut trung tm cho c h thng hay iu khin cc b trn mi thit b ring bit. - iu khin p sut c th bng thit b iu p kiu c kh, in t

11. Phng chng chy n

11.1 Phng chng chy, n Phng chng chy n cho h thng cp kh t trung tm trong nh cn tun th theo iu 9.22 trong TCVN 2622 : 1995.

11.2 Tip a v an ton in Ton b h thng ng ng cp kh t trong nh phi c thit k ni tip a san

bng th cho cc tuyn ng chnh, ng nhnh, ng phn phi 11.3 H thng t ng cnh bo nng cc cht hydrocacbon 11.3.1 Khi iu kin cho php c th thit k h thng t ng cnh bo nng cc cht

hydrocacbon trong khng kh, cc u cm bin cc cht kh c khi lng ring nh hn khi lng ring ca khng kh cng nhit cn t khng vt qu mt trn ca thit b s dng v ti cao ti thiu 20 cm tnh t mt sn nh. V tr t cn chn ni c kh nng tch t kh t nhiu nht.

11.3.2 Cho php s dng h thng t ng cnh bo trung tm gm c h thng t ng cnh bo nng ti trm cp kh ho lng ngoi nh.

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