Muha, your equation for "Fire Profile" should be composed of Eqn's (1), (2) and (3), which I believe you did correctly. The equation you define for "Fire Height" requires the non-dimensional form of heat release rate (HRR) and you have to find information regarding how your "Fire Profile" equation is being non-dimensionalized.

And the equation "Fire Profile" can be defined as follows:

Fire Profile = if(t<600, FireGrowth, if(t<3300, FirePower, FireExtinction))

instead of

Fire Profile= if(t<3300, if(t<600, FireGrowth, FirePower), FireExtinction)