temperature drop

hello all,
does anyone know which formula to use for calculating temperature loss along
a pipe.
for ex: i have a medium grade steel pipe of 1m and diameter 65mm , at the
start of the pipe the temperature is 7 degrees celsius.
how can i know the temperature at the end of the pipe and hence the drop in
temperature?
(assuming no insulation )
thx
--
Hasta Luego
Irshaad
(Faster than Bruce Lee)
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Reply to
Irshaad
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Dear Irshaad:
What can you tell us about the environment for this pipe? What temperature is the outside of the pipe exposed to?
David A. Smith
Reply to
dlzc1.cox
you need to know velocities inside and outside also.
Reply to
Alan O'Neill
thx for replying, the outside temperature is 32 degrees celsius and the velocity of the chilled water in the pipe is 1.6 m/s which gives a flow rate of 5 L/s the thermal conductivity,k, for steel is 46 W/m K
-- Hasta Luego
Irshaad (Faster than Bruce Lee)
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temperature
Reply to
Irshaad
There really is no closed form "forumula" for what you want. You need to perform an energy balance along the length of the pipe. Your modes of heat transfer are: forced convection inside the pipe, conduction through the pipe walls, and free convection on the outside of the pipe. Your wall thickness is an important parameter. Also, you must make some assumptions on the heat transfer coefficients. With this said, assuming a high free convection heat transfer coefficient, assuming a Reynolds type analogy on the internal pipe flow to estimate convective heat transfer coefficient (smooth wall, fully turbulent flow), and assuming a typical pipe thickness, your temperature drop for these conditions in 1 meter length of pipe will be small, only a fractional of a degree.
Reply to
Steve S

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