This study aims to optimize thermal management in electronic components by utilizing Nano-Encapsulated Phase Change Materials (NEPCM) and combined heat transfer through convection and radiation. The system consists of a cavity containing three heat-generating blocks, each producing the same amount of heat, supported by a conductive plate. This plate divides the cavity into two sections: a porous zone on the left and an air zone on the right. Numerical modeling, based on the Galerkin finite element method, investigates the cooling efficiency under various parameters, including Darcy number (10−5 ≤ Da ≤ 10−2), Stefan number (0.2 ≤ Ste ≤ 1), thickness separation plate (0.04 cm ≤ e ≤ 0.24 cm), and emissivity (0.1 ≤ ɛ ≤ 0.9). The results show that for Da ranging from 10−5 to 10−2, Tmax decreases by 19.19 K (5.42%). For Ste ranging from 0.2 to 1.0, the decrease is 3.99 K (1.15%), and for ɛ ranging from 0.1 to 0.9, it is 4.15 K (1.12%). Finally, for a separation plate thickness from 0.04 cm to 0.24 cm, Tmax drops by 29.63 K (7.96%).