The fluxes of energy supplied to the thermal plastic waste recycling system are shown on the left hand side of equation (1). As assumed in the design, the main flux of energy supplied to the system consists of plastic waste (E_pw). The LCV of the supplied waste is so high that the incineration is stable. Therefore, under the circumstances, there is no need for additional fuel (natural gas).
The burning process is autothermal. The values of the physical en- thalpies of air fluxes supplied to the combustion chambers (E_amw- cch) and the secondary (aftercombustion) chamber (E_ ag-dch) change depending on the amount of air required for the correct incinera- tion of waste, the aftercombustion of generated gases and the temperature of the environment from which the air is taken. It is assumed that the supply of additional fluxes of chemical enthalpy in the form of additional fuel (E_ ng-cch) and (E_ ng-dch) is necessary only in the system start-up period. The air enthalpy fluxes (E_ ang-cch, E_ ang- dch) used for natural gas burning (supplied to the burners) depend on the temperature of the environment from which the air is taken and on the amount required for correct gas burning.