Hi Mughees,
Although there are no dedicated blocks in Simulink for Depth-to-Temperature conversion and modelling TEG, the blocks used in the model for Depth-to-Temperature is a Lookup Table and that for the TEG is a Subsystem.
The Subsystem consists of other simpler blocks which can be dragged and dropped to the Simulink model if we know the relationship between the input and output of the blocks.
Hope this helps!