Exit Temp / Heat Loss in External Pipework

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SUMMARY

The discussion focuses on calculating heat loss and exit temperature for 100ml of water in a 19mm diameter, 3m long external pipe at -10°C air temperature. The water, initially at 20°C, flows at approximately 0.5m/s and is released via a siphon over 7 seconds. Key parameters include water density (998 kg/m³), thermal conductivity (0.598 W/m·°C), and specific heat capacity (Cp = 4182 J/kg·°C). The user successfully solved the problem and indicated that the thread can be deleted.

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sam...wise
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I have been trying to establish what the heat loss and exit temp (in deg C) for 100ml of water traveling down a pipe located externally to a building and subjected to -10degC air temperatures will be if:

The pipe has an internal diameter of 19mm and a length of 3m.
100ml of water with initial temp of 20degC is traveling in the pipe at approximately 0.5m/s. (The pipe is not full of water).
The 100ml water is being released from a siphon, which takes approximately 7seconds. Flow rate = approx. 14.3ml/s.
Assuming material is temp of external air and thickness is negligible.

Both conduction and convection heat losses will be occurring, but I am not sure which is the greater.

Using, the below for water at 20degC:
density = 998kg/m^3
thermal conductivity = 0.598 W/m.degC
Dynamic viscosity = 1.002 kg/m.s
Kinematic viscosity = 1.004 x10-6
Cp = 4182 J/kg.degC
Pr = 7.01

For convection calcs I have been trying to use Texit = (Tsurface - Tin)e^-(h.A/mdot.Cp) but I could do with clarification of my results, as I am not sure they are correct.

Thank you for any assistance. Please let me know if additional information is required.
 
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