# How to calculate heat flux in a hot water tank

Hi.
I wish to calculate the heat flux on a bottom plate of a hot water tank. Would simply (m*c*t)/area give me the correct results.

## Answers and Replies

Related Other Physics Topics News on Phys.org
Is the bottom plate sitting on the ground or elevated? Is the tank insulated?

Thank you for your response.
Yes the tank is insulated,and sitting on ground.

Now the upper surface of plate is in contact with the fluid (hot water). How can i find the heat flux?

Thank you for your response.
Yes the tank is insulated,and sitting on ground.

Now the upper surface of plate is in contact with the fluid (hot water). How can i find the heat flux?
There are some nice "freeware" packages that will compute this. PM me if you are interested.

If you want to calculate it yourself, do this:

q = U A (T-water - T-outisde)

where,

q = heat loss
U = heat transfer coefficient
A = surface area
T-water = water temperature inside tank
T-outside = outside air temperature.

The heat transfer coefficient is given by:

U = 1 / [ 1/hi + twall/kwall + tins/kins + 1/ho ]

where,

hi = natural convection heat transfer coefficient on inside of tank
twall = tank wall thickness
kwall = tank thermal conductivity
tins = insultation thickness
kins = insulation thermal conductivity
ho = natural convection heat transfer coefficient on outside of tank

Let me know if you need any help figure these values out.