We investigate nonlinear thermal transport processes in presence of chemical or electrochemical reactions, where transport processes are treated as peculiar chemical reactions described by their appropriate affinities. The processes considered are nonequilibrium reaction-diffusion systems described by equations with exponential terms with respect to chemical potentials of Planck and temperature reciprocal. Affinity picture - new for transport phenomena - and the traditional Onsagerian picture are shown to be two equivalent representations for kinetics of chemical reactions and transfer processes. In fact, the affinity picture is a particular representation of kinetics with the diagonal conductance matrix. Examples show the applicability of the theory for nonlinear reaction-diffusion and electrochemical systems.