Need Help with Thermo Energy Transfer problem

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SUMMARY

The discussion focuses on calculating the temperature difference across a 0.2-meter-thick concrete wall, given a steady-state energy transfer rate of 0.15 kW through a 1 m² area. The correct application of Fourier's law of heat conduction is essential for solving this problem. The heat flux, represented as Qx, is defined as the rate of heat transfer per unit area, which is crucial for determining the temperature difference across the wall. Participants emphasized the importance of understanding the thermal conductivity coefficient (k) for concrete to accurately complete the calculations.

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A 0.2-m-thick plane wall is constructed of concrete. At steady state the energy transfer rate by conduction through a 1-m^2 area of the wall is 0.15 kW. If the temperature distibution is linear through the wall, what is the temperature difference across the wall, in K?

i don't even know where to start, anything will help...
 
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I have been doing some work on this.. and i have came up with an answer, I am pretty sure its not right though..

Using Fourier's law:

Qx= -kA[T2-T1/L]

we know that the Qx is .15kW per 1 m^2, and the thickness of the concrete plane is .2 m

If .15kW of energy enter 1.0 m^2, then only .03 kW enter the area of .2 m??

right now i have .03kW= -k(T2-T1/ .2m)

im stuck..
 
If .15kW of energy enter 1.0 m^2, then only .03 kW enter the area of .2 m??

Why is this? I don't think you understand the concept of "heat flux" which you represent as Qx. Heat flux is the rate of heat transferred given an area. In math form thats

q" = [tex]\frac{dQ}{dt}[/tex] = Qx

So if you have 0.15kw of energy being transferred over 1m^2 of area, what is your heat flux going to be?

You are also going to need to look up the transfer coefficient (k) for concrete. I imagine this is in your book somewhere.
 

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