This paper focuses on the cooling of heat-generating components via MHD mixed convection flow of silver (Ag)-water nanofluid through an L-shaped channel with a porous inner layer. In this channel, four heat-generating components are located on the channel wall opposite to the porous layer. The governing equations with the given initial and boundary conditions are solved using the stabilized mixed finite element method based on the polynomial pressure projection technique. The effect of the thickness of the porous layer and size of the heat-generating components on fluid flow and heat transfer within the channel is investigated. © Springer Nature Singapore Pte Ltd 2018.