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  ¹æ¿­ ¼Õ½Ç½Ã ´ë·ù¿­Àü´Þ°è¼ö ¹®ÀÇÀÔ´Ï´Ù.
  ±Û¾´ÀÌ : romanus   °íÀ¯ID : soongu99     ³¯Â¥ : 08-01-02 18:06     Á¶È¸ : 9205    
¾È³çÇϼ¼¿ä.½ºÅ×Æijë´Ô. »õÇØ º¹ ¸¹ÀÌ ¹ÞÀ¸½Ã±¸¿ä.
 
Ç×»ó ¿©±â¼­ ¸¹Àº ±Ã±ÝÁõÀ» ±ú¿ìÄ¡°í ÀÖ½À´Ï´Ù.^^
 
±×·¡¼­ ±×·±Áö ¿©±â µé¸±¶§¸¶´Ù ¸Å¹ø ÀúÀÇ ¹«Áö¸¦ ¹Ý¼ºÇÏ°í ÀÖ½À´Ï´Ù.
 
¾Æ¹«ÂÉ·Ï, ¿ÃÇصµ ¸¹Àº µµ¿ò ºÎŹµå¸®°Ú½À´Ï´Ù.
 
º»·ÐÀ¸·Î µé¾î°¡¸é,
 
°Ô½ÃÆÇ¿¡µµ ¾ð±ÞµÈ(07-09-19~20) ¿Â¼ö tankÀÇ ¿Ü±âÀÇ ´ë·ù¿¡ ÀÇÇÑ ¹æ¿­ ¼Õ½Ç°ü·ÃÀÔ´Ï´Ù.
 
°Ô½ÃÆÇ¿¡¼­ ±â¼úµÈ ¼ö½Ä°ú µ¿ÀÏÇÑ ¸ðµ¨À̶ó Àúµµ ±× ¼ö½ÄÀ¸·Î ¹®Á¦¸¦ Ç®¾ú½À´Ï´Ù.
 
±×·±µ¥, h(´ë·ù¿­Àü´Þ°è¼ö)¸¦ Á¤È®È÷ ¼³Á¤Ä¡ ¸øÇؼ­ ´äÀ» µµÃâÇÏÁö ¸øÇϰڳ׿ä.
 
»óȲÀº ³ôÀÌ 20mÀÌ»ó¿¡ ÀÖ´Â ¿Â¼ötankÀÌ¸ç ¿Ü±â¿Âµµ t=0µµ À϶§Àε¥, ¿ÜºÎÀÇ Ç³¼Ó¿¡ µû¶ó h°ªÀÇ Â÷ÀÌ°¡
 
Ŭ °ÍÀ¸·Î »ý°¢µË´Ï´Ù. °ü·Ã ¼­ÀûÀ» ¸¹ÀÌ Ã£¾ÆºÁµµ ¸íÄèÇÑ ´äÀ» ãÁö ¸øÇؼ­, ½ºÅ×ÆÄ³ë ´Ô²² ¿©Âã´Âµ¥¿ä.
 
dz¼Ó¿¡ µû¸¥ h°ªÀÌ ¾î¶»°Ô µÉÁö ±Ã±ÝÇÕ´Ï´Ù. Á¶¾ð ºÎŹµå¸³´Ï´Ù.

½ºÅ×Æijë Stefano   08-01-06 17:17
»õÇØ º¹ ¸¹ÀÌ ¹ÞÀ¸¼¼¿ä

(1) ´ë±â·ÎÀÇ ¹æ¿­¼Õ½ÇÀº ¾Æ·¡ÀÇ ´Ù¼¸°¡Áö ¿ä¼Ò¿¡ µû¶ó ¿­Àü´Þ°è¼ö(Convectional Surface Heat Transfer Coefficient)°¡ ´Þ¶óÁý´Ï´Ù. 
¤¡) Heat LossÀΰ¡ Cold LossÀΰ¡
¤¤) ¹æ¿­¸éÀÌ ¼öÁ÷Àΰ¡ ¼öÆòÀΰ¡
¤§) ¼öÆòÀÎ °æ¿ì ¹æ¿­¸éÀÌ ÇÏÇâ¸éÀΰ¡ »óÇâ¸éÀΰ¡(°ø±â°¡ ¹æ¿­¸éÀÇ »óºÎÀΰ¡ ÇϺÎÀΰ¡)
¤©) ¼öÁ÷ÀÎ °æ¿ì ¹Ù´Ú¿¡¼­ÀÇ ³ôÀÌ´Â ¾î¶²°¡?
¤±) ´ë±â¿ÍÀÇ ¿ÂµµÂ÷°¡ ¾î¶°ÇÑ°¡(Ç¥¸é¿Âµµ¿Í ´ë±â¿Âµµ´Â ¾ó¸¶Àΰ¡?)
¤²) ¹Ù¶÷ÀÇ Ç³¼ÓÀº ¾î¶°ÇÑ°¡

(2) ÀÌÁß ¤¡~¤±Àº Willam H. McAdamsÀÇ Heat Transmission, MGH ¿¡¼­ ´ÙÀ½ÀÇ Keywords ¸¦ ÀÌ¿ëÇÏ¿© ã¾Æº¼ ¼ö ÀÖ½À´Ï´Ù. : Horizontal Natural Convection, Upward or Downward Plane, Vertical Natural Convection

(3) Áú¹®¿¡¼­ ¾ð±ÞÇÑ Ç³¼Ó¿¡ µû¸¥ ´ë±â³ëÃâÇ¥¸é¿¡¼­ÀÇ ¿­¼Õ½Ç°è¼ö´Â ASTM C 680¿¡¼­ »ç¿ëÇÏ°í ÀÖ´Â ´ÙÀ½ ½ÄÀ» ¸¹ÀÌ ÀοëÇÕ´Ï´Ù.  ÀÌ ¼ö½ÄÀº 2001³âÆÇ ASHRAE Handbook Ch25  (p. 25.15)¿¡µµ ÀοëµÇ¾î ÀÖ½À´Ï´Ù.

(h)cv =C*d^(-0.2)*T^(-0.181)*(¥ÄT)0.266*(1+0.7935*(WIND))^(0.5).....................................................(1)

(h)cv: Convectional Heat Transfer Coefficient on Various Surfaces, W/m2/K
C=¾Æ·¡ÀÇ ¿©·¯ Æò¸é ¸ð¾ç¿¡ µû¸¥ »ó¼ö
    C= 15.89 for Vertical Plates,
    C= 10.15 for Horizontal Warm Plates facing air downwards,  20.40 -ditto- upwards
    C= 11.58 for Horizontal Cylinders or Pipes, 14.08 for Vertical Cyliners or Pipes

d=½Ç¸°´õ Á÷°æ, mm;  d>600mm ÀÎ ½Ç¸°´õÀ̰ųª Ç¥¸éÀÌ Æò¸é ¸ð¾çÀÎ °æ¿ì d=600 mm¸¦ »ç¿ë
T=Bulk Air Temperature¿Í Ç¥¸é¿Âµµ¿ÍÀÇ Æò±Õ Àý´ë¿Âµµ = (Ts+Ta)/2, K
Ts, Ta=Ç¥¸é¿Âµµ, °ø±â¿Âµµ, K
¥ÄT=Ç¥¸é°ú °ø±âÀÇ ¿ÂµµÂ÷ = |(Ts-Ta)|, K
WIND =°ø±â(¹Ù¶÷)¼Óµµ(½Ã¼Ó), km/h
romanus soongu99   08-01-15 11:52
´äº¯ °í¸¿½À´Ï´Ù.½ºÅ×Æijë´Ô.

Àúµµ °è»êÀ» Çغ¸´Ï »ý°¢º¸´Ù ¼öÄ¡°¡ ³ô°Ô ³ª¿À³×¿ä.

h=100w/m2/k ÀÌ»ó ³ª¿À´Âµ¥, --> ÀÌ°Ç Á¦°¡ °ÅÀÇ ¿øÇÏ´ø ¼öÄ¡´Â ¸Â½À´Ï´Ù.^^

Ãß°¡·Î ±Ã±ÝÇÑ »çÇ×ÀÌ ÀÖ½À´Ï´Ù.

»ó±â ½Ä¿¡ d°ªÀ» ³ÖÀ»¶§  1) d°ªÀÌ ½Ç¸°´õ Á÷°æÀÌ d>600mmÀ̰ųª, 2) Ç¥¸éÀÌ Æò¸é ¸ð¾çÀÏ °æ¿ì 1), 2) ¸ðµÎ d=600mm¸¦ »ç¿ëÇÑ´Ù°í Çϼ̴µ¥,

Ç¥¸éÀûÀÌ ¾ó¸¶³ª µÇ°Ç °£¿¡ d=600mm À¸·Î °è»êÇϴ°ÍÀÌ
´Ù ¸Â´Â°ÍÀÎÁö ±Ã±ÝÇÕ´Ï´Ù.
Stefano    08-03-01 21:36
½Ç¸°´õ Á÷°æÀÌ 600mm ÀÌ»óÀ¸·Î Ä¿Áö¸é Æò¸éÀ¸·Î ºÁµµ µÈ´Ù´Â ÀǹÌÀÔ´Ï´Ù.
   

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