Energy transfer in a heat-conducting medium with arbitrary scattering of thermal radiation

An existing model of complex heat exchange with a radiation component and its deficiencies, which are related to the ray approximation, are considered. An equation was derived for the temperature field which is not related to the radiation transfer equation. The transition from one model to the other is demonstrated using the example of a homogeneous material. For the case of small inhomogeneities, a method is given for an approximate consideration of diffraction effects in calculating the radiation coefficient of the medium.