Heat transfer btw two plates

[kubixxx]

Hi, I have an easy problem for you I think but I'm not a specialist in thermo problems.
Here is my problem.

Homework Statement

2 plates in aluminum, one at T1=230°C and the other one at T2=30°C. In between, some air or something else (I don’t know yet).

Homework Equations

Equation of conduction but I don't really understand how to use it... Is it the only one to use?

The Attempt at a Solution

So I would like to know what would be the evolution of T2 depending of the time and the distance btw the two plates.

Thx in advance for your help!
Max

 

[supratim1]

explain your question clearly. you can use radiation transfer too, but relevant info for that is not given in the question.

 

[kubixxx]

Hi,

Ok sorry, I do it again.

I have a heating element which warm up a plate of aluminium to 230°C. Then I have a other plate of aluminum I want to heat up to a different temperature. So I would like to find the gap between the two plates I need to reach my temperature for the 2nd plate (If I suppose that I have only air in between and the needed temperature is about half of T1).

That's the only informations I have. I don't ask you to give me the answer but to give me what I need to resolve the problem. As I said before, I got the conduction equation but I not even sure that it's relevant with air...

Thanks for your help!
Max

 

[supratim1]

value of thermal conductivity of air and the separation between plates is needed to solve the problem. the question is still vague.

 

[kubixxx]

As the thermal conductivty depends of the temperature, I would just just 0.3 for this value. The gap is what I want to define if I want to get a temperature T2 of 150°C...
What equation(s) should I use then?

 

[supratim1]

thermal conductivity depends on temperature? does it?

 

[kubixxx]

http://www.engineeringtoolbox.com/air-properties-d_156.html

PS: By the way, I'm not english so sorry if sometimes I don't get some points or say something that doesn't have any points...