How to design canal to reduce stream temperature?

[satyadangin]

If i have atm temperature around 32 deg Celsius, volumetric flow 6000m3/h, fluid temperature inlet 47 deg Celcius. How to get minimum possible dimension for my canal if its maximum possible length is 180 m and fluid temperature outlet at least 40 deg Celcius?

 

[anorlunda]

This site has a calculator that you may be able to use to calculate the answer yourself.

http://www.engineeringtoolbox.com/evaporation-water-surface-d_690.html

 

[JBA]

The air will not be the only possible heat source. You will need to include the surrounding ground temperature and heat conduction rate for the walls and bottom of your channel. Additionally, The solution may result in either laminar or turbulent flow through your channel; for which, there will be different heat transfer coefficients both for the channel and the air contact surfaces. You will also have wind velocity to consider and even if the air is stagnant it will be a "forced convection" fluid to air contact heat transfer situation due to the motion of the water alone.