[Contadino Sudato]

Hi everyone!
I'm trying to simulate a solar receiver with Ansys Fluent without good results.
My model is composed by a cilindrical receiver (diam=10mm, h=2mm; copper), insulating material (mineral wood), air and a glass disk.
I drow and try to simulate in 3D, after days of failure i drow in 2D hoping it would be easyer for me and for accellerate the computer computing time.
My BC are:
-heat flux (330000w/m^2) on the upper surface of the reciver
-external temperature (293.15) and heat transfert coefficient for the convection (5 w/m^2*k)
Other informations:
-Energy ON
-Viscous (SST k-omega)
The error i'm having is "temperature limited to 5000K" in the insulate and receiver zone; and also strange heat transfert between different material.
If someone has advice, would be super helpfull

Thanks in advance

Francesco