ÀÚµ¿·Î±×ÀÎ
ÄÁÅÙÃ÷ | contents
ÀϹݰԽÃÆÇ
Q&A°Ô½ÃÆÇ
°øÇÐ S/W
½ºÅ͵ð | study
´ÜÀ§È¯»ê
³óµµ°è»ê
ÀϹÝÈ­ÇÐ
È­°øÀϹÝ
È­°ø½Ç¹«

   
  ÅÊÅ©ÀÇ ¿­¼Õ½Ç/¿­À¯ÀÔ °è»ê °ü·Ã ¹®ÀÇ
  ±Û¾´ÀÌ : ·çÇÇ   °íÀ¯ID : bottleway     ³¯Â¥ : 20-09-10 14:23     Á¶È¸ : 4140    
¾È³çÇϼ¼¿ä, ÀÌ°÷À» ÅëÇØ ¸¹Àº°Íµé ¹è¿ì°íÀÖ´Â Ãʺ¸ ¿£Áö´Ï¾îÀÔ´Ï´Ù.
ÀúÀåÅÊÅ©ÀÇ ¿­¼Õ½Ç/¿­À¯ÀÔ·® »êÁ¤À» À§ÇÑ ÆÀ³» ±âÁØÀ» ¼ö¸³ÇÏ´Â ¾÷¹«¸¦ ¼öÇàÇÏ°Ô µÇ¾ú½À´Ï´Ù.
¾÷¹«¼öÇàÀ» À§ÇØ ÆÀ³» Á¸ÀçÇÏ´Â Âü°íÀڷḦ ¹Þ¾ÒÀ¸³ª ¼ö½Ä¾øÀÌ °á°ú°ª¸¸ ÀûÇôÀÖ¾î ÃÑ°ý ¿­Àü´Þ°è¼ö °è»ê ¼ö½Ä ÆľÇÀÌ ¾î·Á¿ö Áú¹®µå¸®°Ô µÇ¾ú½À´Ï´Ù.
ÇØ´ç³»¿ëÀº Àú¿ÂÅÊÅ©ÀÇ ¿­À¯ÀÔ·®À» °è»êÇÑ ³»¿ëÀ̸ç ÁÖ¾îÁø Á¶°Ç°ú °è»ê°á°ú´Â ¾Æ·¡ ÷ºÎÇÑ µ¥ÀÌÅÍ¿Í °°½À´Ï´Ù.
Heat Gain by Shell Qs = Us*A*¡âT ¸¦ ÅëÇØ °è»êÀÌ µÇ´Â°ÍÀ» È®ÀÎÇÒ ¼ö ÀÖÀ¸³ª, ÃÑ°ý¿­Àü´Þ°è¼ö Us°ªÀÇ °Ô»ê¹æ¹ý ÃßÁ¤ÀÌ µÇÁö¾Ê¾Æ ¾î·Á¿òÀ» °Þ°íÀÖ½À´Ï´Ù.
ÁÖ¾îÁø ¿­Àü´Þ°è¼ö´Â Ç¥¸é¿¡¼­ÀÇ ´ë·ù (hc), º¹»ç(hr), ÅÊÅ© ³»ºÎ¿Í ¿ÜºÎ¿¡¼­ÀÇ ¿­Àü´Þ°è¼ö hi¿Í ho, insulation data¸¦ ÅëÇØ È®ÀÎÇÒ ¼ö ÀÖ´Â insulation ÀÚÄÏÀÇ Àüµµµµ Kins¿Í µÎ²²Sins, ±×¸®°í ³»ºÎ À¯Ã¼ÀÇ ¿­Àüµµµµ KfÀÔ´Ï´Ù.
(Á¦°¡ Å×À̺íÀ» º¸°í ÀÌÇØÇÑ ³»¿ëÀÌ À߸øµÇ¾úÀ»°æ¿ì ÁöÀûÇØÁÖ½Ã¸é °¨»çµå¸®°Ú½À´Ï´Ù.)
±Ã±ÝÇÑÁ¡Àº,
1) ÃÑ°ý ¿­Àü´Þ °è¼ö 1/ Us = (1/hc+1/hr+1/hi+1/ho+Sins/Kins) ¼ö½Ä¿¡ ÀÇÇØ °è»êµÈ´Ù°í »ý°¢ÇÏ°í ÇØ´ç ¼öÄ¡µéÀ» ÀÌ¿ëÇÏ¿© °è»êÇÏ¿´À¸³ª ÃÑ°ý¿­Àü´Þ °è¼öÀÇ °ª°ú ´Ù¸¥ °á°ú¸¦ ¾ò°Ô µË´Ï´Ù. ÁÖ¾îÁø ¼öÄ¡µéÀ» ÅëÇØ ÃÑ°ý¿­Àü´Þ °è¼ö¸¦ °è»êÇÑ Á¦ ¹æ¹ýÀÌ ¾î´ÀºÎºÐÀÌ À߸øµÈ°ÍÀÎÁö ±Ã±ÝÇÕ´Ï´Ù.
2) 1)Áú¹®ÀÇ ¼ö½Ä¿¡¼­ ÅÊÅ©ÀÇ º® µÎ²²¿Í ±× Àüµµµµ¸¦ ¼ö½Ä¿¡ ³ÖÁö¾Ê¾Ò´Âµ¥ À̺κÐÀÌ ´©¶ôµÇ¾î ¿Ã¹Ù¸¥ ´äÀ» ¾òÁö¸øÇÑ°ÍÀÎÁö, Á¦°¡ ÁÖ¾îÁøµ¥ÀÌÅ͸¦ Àß È°¿ëÇÏÁö ¸øÇÑ°ÍÀÎÁö ±Ã±ÝÇÕ´Ï´Ù.
3) ÇØ´ç µ¥ÀÌÅÍ¿¡¼­ hc, hr, hi, ho ¸¦ »êÁ¤ÇÏ´Â ±ÔÄ¢À̳ª ¼ö½ÄÀÌ ÃßÁ¤ÀÌ °¡´ÉÇÒ±î¿ä? ÁÖ¾îÁø µ¥ÀÌÅ͸¦ º» »çÀÌÆ®ÀÇ °ú°Å À¯»ç ÁúÀÇ¿¡ ¿Ã·ÁÁֽŠ¼ö½Ä¿¡ Àû¿ë½ÃÄÑ µû¶óº¸¾ÒÀ¸³ª ±× °ªÀÌ ¸¹ÀÌ ´Þ¶ó ¿­Àü´Þ°è¼ö »êÃâ±Ù°Å ÃßÀûÀÌ ½±Áö¾Ê½À´Ï´Ù.

µ¥ÀÌÅÍ´Â ¾Æ·¡¿Í °°À¸¸ç, Áú¹®³»¿ë ÀÌ¿Ü¿¡ Á¦°¡ À߸ø ÀÌÇØÇÏ°íÀְųª ÆľǸøÇÑ ºÎºÐ¿¡´ëÇؼ­ ÁöÀûÇØÁÖ½Ã¸é °¨»çµå¸®°Ú½À´Ï´Ù.

1. Input data
Environment Data & Fluid PropertyTank data
Air temp. (ta)¡¡100.4FDiameter¡¡10.83ft
Wind velocity (V)67.11mi/hrHeignt26.25ft
Gravity accelaration (g)4.18E+08ft/hr2Stored Temp.-13F
¡¡¡¡Pressure14.84psia
Density (r)43.82lb/ft3¡¡¡¡
Thermal conductivity (Kf)0.0739Btu/ft.hr.F¡¡¡¡¡¡¡¡
Specific heat (Cp)0.455Btu/lb.FInsulation data
Viscosity, cp X 2.241.249lb/ft.hrTher.Cond.(Kins) =0.01btu/ft.hr.F
Coff. of Vol. Expansion0.00041/FThickness(Sins) =0.164ft
Emissivity0.8¡¡Resistant (Rins) =15.763ft2.hr.F/Btu
¡¡¡¡¡¡¡¡
Fouling factor =¡¡0.005ft2.hr.F/Btu¡¡¡¡¡¡¡¡
2.0 Heat Gain by Shell
¡¡Coefficient of¡¡¡¡Coefficient of¡¡¡¡
AssumedConvectionRadiationCalculatedAssumedInside filmOutside filmcalculated
tshchrtstwhihotw
98.83.1030.9798.68-126.6344.073-11.94
Total heat transfer coeff. (Us)=0.06186Btu/ft2.hr.F
Area of Tank shell =1138.7ft2*Head Area : 245.6
Heat Gain by Shell. (Qs) =7988Btu/hr

Ambient temperature38¡É
Fluid temperature-25¡É


½ºÅ×Æijë Stefano   20-09-11 01:50
(A1) º¸¿ÂÀÌ µÇ¾î ÀÖ´Â ÅÊÅ©¿¡¼­ÀÇ ¿­¼Õ½ÇÀº ÅÊÅ©³»ºÎÀÇ Convectional Heat Transfer Coefficient(hi), Tank WallÀÇ Thermal Conductivity¿¡ ÀÇÇÑ Àü¿­°è¼ö(k/t), Tank ¿ÜºÎ Àý¿¬ÀçÀÇ Thermal Conductivity¿¡ ÀÇÇÑ Àü¿­°è¼ö( k/t) °ª,  ¹× Tank Insulation Ç¥¸é¿¡¼­ÀÇ Convectional Heat Tansfer Coefficient (ho)¿¡ ÀÇÇØ °áÁ¤µÇ±â ¶§¹®¿¡  ´ÙÀ½ ¼ö½ÄÀ» ¸¸Á·ÇÏ´Â Á¶°Ç¿¡¼­ ¿­¼Õ½ÇÀÌ °è»êµÇ¾î¾ß ÇÕ´Ï´Ù.

Q_loss = U * A * ¥Ät1  = hc  * ¥Ät2  ..................(1)    <-----  ÅÊÅ©³»ºÎ¿¡¼­ Insulation Ç¥¸é±îÁöÀÇ ¿­Àü´Þ ¼ö½Ä 

U = ÅÊÅ©³»ºÎ~º¸¿ÂÀç ¿ÜºÎÇ¥¸é±îÁöÀÇ ¿­Àü´Þ°è¼ö,  ¥Ät1 =³ÃÅ©³»ºÎ~º¸¿ÂÀç ¿ÜºÎÇ¥¸é±îÁöÀÇ ¿ÂµµÂ÷
hc = ÅÊÅ©¿ÜºÎ Ç¥¸é¿¡¼­ÀÇ ´ë·ùÀü¿­°è¼ö,  ¥Ät2 =¿ÜºÎÇ¥¸é~¿ÜºÎ°ø±â¿Âµµ°£ ¿ÂµµÂ÷

1/U =  1/hi + tm/km + t_ins/k_ins ...................(2)    <-----  hi =ÅÊÅ©³»ºÎ ´ë·ùÀü¿­°è¼ö, m = "metal(ÅÊÅ©±Ý¼Ó)", ho=º¸¿ÂÀç


(A2)À§ÀÇ (1)(2)½ÄÀ¸·Î °è»êÇÒ ¼ö ÀÖÀ¸·Á¸é º¸¿ÂÀç Ç¥¸éÀÇ ¿Âµµ¸¦ ¾Ë¾Æ¾ß Çϴµ¥  ÀÌ ¿Âµµ´Â Trial & Error ¹æ¹ýÀ¸·Î ã¾Æ³»¾ß¸¸ ÇÕ´Ï´Ù.    ¶ÇÇÑ ÅÊÅ© ¿ÜºÎ¿¡¼­ÀÇ hcµµ ¾Ë¾Æ¾ß ÇÕ´Ï´Ù. 

´ÙÇàÀÎ °ÍÀº hc´Â º¸¿ÂÀç Ç¥¸é°ú °ø±âÀǿµµÂ÷¿¡ ÀÇÇØ °è»êÇÏ´Â ¼ö½ÄÀÌ ¿¬±¸µÇ¾î À־  (1)½ÄÀÇ ¸Ç ¿ìÃø ¼ö½Ä¸¸À¸·Î °è»êÇÒ ¼ö ÀÖ´Â ¹æ¹ýÀÌ Æí¸®ÇÕ´Ï´Ù .  ´Ü º¸¿ÂÀç Ç¥¸éÀÇ ¿Âµµ¸¦ °¡Á¤ÇØ¾ß ÇÏÁö¿ä.

ºñ·Ï Á¤È®µµ´Â ¶³¾îÁöÁö¸¸  ÀÌ ¹æ¹ýÀÌ °¡Àå ÈçÈ÷ ÀÌ¿ëµÇ´Â ¹æ¹ý¿¡ ÇØ´çÇÕ´Ï´Ù .  µû¶ó¼­  U, hi,  km,  tm µîÀº °í·ÁÇÏÁö ¾Ê¾Æµµ µÇ°í »ç½Ç»ó À̵éÀÇ ÀúÇ×Àº ¿ÜºÎ Àü¿­ ÀúÇ׿¡ ºñÇÏ¿© ¹«½ÃÇÒ ¸¸ÇÑ °ªÀ̶󼭠 ¹«½ÃÇÏ°í °è»êÇÒ ¼ö ÀÖ½À´Ï´Ù.

ÀÌ°÷ (https://en.wikipedia.org/wiki/Heat_transfer_coefficient )¿¡¼­ Vertical Plane¿¡¼­ÀÇ Convectional Heat Transfer Coefficient ¸¦ °è»êÇÏ´Â ¼ö½ÄÀ» Âü°íÇϼ¼¿ä.

À¯»çÇÑ Âü°í ÀÚ·á·Î´Â J.M SmithÀÇ Heat Transmission,  EncroperaÀÇ¿­Àü´Þ ¼­Àû (http://www.yes24.com/Product/Goods/57883242)¿¡¼­ Heat Loss from vertical/horizontal Surface¸¦ ã¾Æº¸¼¼¿ä.
¼³°èÀïÀÌ skymanggo   20-09-15 15:29
Àúµµ Tank Heat Loss °øºÎ ÁßÀ̸ç, °è»ê ½ÃÆ®¸¦ ´Ù½Ã ¸¸µé°í ÀÖ´Â ¼³°è»çÀÔ´Ï´Ù.

Á¤¸®ÇÏ´Â ÁßÀÌ¶ó¼­ ´ë·«ÀûÀÎ ³»¿ë °øÀ¯µå¸³´Ï´Ù.

1. ÇØ´ç °è»ê¹æ¹ý(Sheet)´Â Tank Heat Loss¸¸ °è»êÇϵµ·Ï µÇ¾î ÀÖÀ»°ÍÀÔ´Ï´Ù.
¶ÇÇÑ ÇØ´ç Sheet´Â ¾Æ·¡¿Í °°Àº Á¶°ÇÀÌ °É·ÁÀÖ½À´Ï´Ù.
- Storage Tank ¸¸ °è»ê
- Internal Coil
- Agitator°¡ ¾ø´Â ÀÚ¿¬´ë·ù·Î °è»ê
- Internal Coil ÇüÅ Horizontal Type
- Tank Heat Loss¸¸ °è»ê

2. ¹«½ÃÇصµ °á°ú°ª¿¡ Å« ¿µÇâÀ» ÁÖÁö ¾Ê½À´Ï´Ù. °á°ú °ªÀÌ ¹ÌºñÇÕ´Ï´Ù.

3. ÇØ´ç Factor´Â ¾Æ·¡¿Í °°½À´Ï´Ù.
- tw : wall surface temperature
- ts : insulation surface temperature (uninsulation ; ts = tw)
- hi : inside film coefficient
- r_i : insulaiton thermal resistance
- hc : forced conv. at oustide wall by wind
- hr : radiantion from wall to surround
- ho = hc + hr (outside film coefficient)
- ÇØ´ç Sheet´Â S»ç ¸Þ´º¾óÀ» ÀÌ¿ëÇؼ­ ¸¸µç°ÍÀ̱⠶§¹®¿¡, ÇØ´ç ¼ö½Ä¿¡ ´ëÇؼ­ °øºÎÇϽǰŶó¸é,
ÁÖº¯ºÐ²² ¹®ÀÇÇؼ­ ¹Þ¾Æ¾ßÇÒ°ÍÀÔ´Ï´Ù. (Á» ¿À·¡µÈ Manual ÀÚ·áÀÓ)
- Âü°í·Î Ÿ Major °è»ê Sheetµµ È®ÀÎÇغ¸¾ÒÀ¸³ª, ±âº» Base´Â S»ç ¸Þ´º¾ó¿¡¼­ Modifiy µÈ °ÍÀ¸·Î È®ÀÎÇÏ¿´½À´Ï´Ù.
   

Copyright 1999.07.10-Now ChemEng.co.kr & 3D System Engineering. (mail : ykjang@naver.com, call 010-4456-8090)