The way the temperature sensor is placed in this model will make the heat flux to the ambient always ZERO. The temperature sensor measures the temperature difference between to nodes and let no heat flux going through it. Think of it as a voltage meter.
Other than that, I see potential in this model. If the temperatue is measured properly, it may be used to implement correlations for convections inside and outside the pipe. This would requires the convective heat transfer block to accept h as an input, which can be done by modifying the Simscape code of this block. Should just a few lines of change.
