code: def _calculate_Hfr(self, T):
          
  
          if self.isCoal:
              return self._calculate_Hfr_coal(T)
  
          Hfr = 0.0
          for compound in self.material.compounds:
              index = self.material.get_compound_index(compound)
              dHfr = thermo.H(compound, T, self._compound_mfrs[index])
              Hfr = Hfr + dHfr
          return Hfr
docs: Calculate the enthalpy flow rate of the stream at the specified
          temperature.
  
          :param T: Temperature. [°C]
  
          :returns: Enthalpy flow rate. [kWh/h]