??(leakage)?????

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??(leakage)?????

1. ????? ????,????,????(vapor-liquid two phase)??
2. ????? ??vessel??,??(equipment)??,??(pipeline)??
3. ??????? ???????(complete rupture),???????
4. ????? ??????,?????
5. ????? ??????,????,?????
6. ??????? ?????(fluid momentum)??,????????

2
???????? ???????? ????/?????
??????????????????,????????????????,????????,?????
?????,?????????????????????????????????
??????????,?????????????????????????????????
?????????????????????????????,???.????????????????
???????.?????????????????????????
????????,????????,????????????,???????????????
???.?????????????????????,???????????????????,?.??
????????,????????,????? ?????????????,?????????
???????????????,???????????,?????????????????,????
???????????????????????????,?????,????????????????
?? (97.4.1)
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???????

• ???????????
• ????,???????,??????
• ?????????????????,???????
• ??????????????(turbulent momentum jet),
  ???????????????(plume) ????????????(liquid
  jet),????????????(stream)
• ???(seriousness) ????????
• ??????(emergency response)????

5
????????

• ???? ???????? ??????? ?????????
  ??????????????
• ???? ????????,???????? ????????????,????????????
  ??
• ?????? ????????,???????????,??????
  ???????????????????

6
????(various possibilities)?????
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(No Transcript)
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(No Transcript)
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Source Models

• ?????????????(??)???
• flow of liquid through a hole
• flow of liquids through a hole in a tank
• flow of liquids through pipes
• flow of vapor through holes
• flow of vapor through pipes
• flashing liquids
• liquid pool evaporation or boiling
• ? ?????????,???????,???????????

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??(??)??(leakage rate)

• ???????????,??????,?? ????? (?????????adiabatic
  process) ? ???????? (flash equilibrium)
• ?? ?????????????,????????????????????????,
  ambient temperature?
• ??????,????,????????,???????

12
??????

• ?????????? (sonic flow), ?????????? (subsonic
  flow)
• ????? r crit (P/Pa) crit (?1)/2 ?/(?-1)
  ??? Cp/Cv P?????(???)???
• ??????,?????? 1.4 ? ??r crit 1.9,
  ??????????,?Pa 1 bar then P 1.9
  bar???,????????,??????????

13
??????????
? Gv Cd A P ?/ao (kg/sec) Cd discharge
coefficient (????Re??,??0.6 1.0?) A ????? P
????? ao ???? (?RT/M) 1/2 ????? ?
2?2/(?-1) (P/Pa) 2/? 1 (P/Pa) (?-1)/?
1/2 ????? ? ? (2/(?1)) (?1)/2(?-1)
(?????????????) ????????choked flow
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????
Ex. ????200 psig, 80oF, ?????0.1 inch dia.,
???????? Ans. ????1.4 ? r crit 1.9 ? ?? P/Pa
214.7/14.7 14.6 gt 1.9 ? ???????? ? ????? ?
? (2/(?1)) (?1)/2(?-1) 0.81 ? then Gv Cd A
P?/ao (??Cd??1.0) 3.79 x 10-2 lbm/sec ??
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??????????

• ????? GL Cd A ? 2 (p pa)/? 2 g h ½
• ??p, pa ????????????? Cd??discharge coefficient
  h ??????????
• ???????,(p-pa)p (gauge)??????
• ??????,???(p-pa)????????????

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???????????????

• GL ? u A ??????????
• m ? At hL ???????????,hL????????,At ???????
• Then dm/dt - GL ? ??hL ???
• dhL/dt - Cd A/At 2 (p-pa)/? g hL ½
• ??,??????GL 0 ??????
• t At/A (1/Cd g) 2 (p pa)/? g hLo ½

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????????

• ????????,??????,?????????
• ????????,??Bernoulli equation (mechanical energy
  balance equation)
• ?P/? ?u2/2 g ?z F -Ws/m
• F frictional loss ??????,??????,??????????,????
  ?? f(Re)
• ???????,????friction factor ? ??????? u ? ??Re ?
  ?????f ? ????u ??????
• ???? ? u A

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????????????

• ??????????,???????????????,?????????????,????????,
  ????,??????????
• ? ?????????,???????

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??????????

• ????????,???? ? ?? fire ball
• ????????,???????,???? ? ??flash fire ?????
  unconfined vapor cloud explosion
• ??????(???),????? ? ????jet flame
• ?????(??),??????????? ? ???????
• ??????,?????????? ? ??pool fire