The present work describes the numerical simulation of a heat pump refrigeration system, working with a mixture of refrigerant (R134a) and nanolubricant. The latter is composed of Polyolester (POE) oil as the base fluid containing TiO2 nanoparticles in suspension. In order to take into account the local variation of the two-phase heat transfer coefficient on the refrigerant side, the heat exchangers, condenser and evaporator, were divided into control volumes and, for each one of them, the fundamental equations of mass, energy and momentum were applied. A semi-empirical model was used to model the compressor. The resulting system of non-linear algebraic equations was implemented on the EES (Engineering Equation Solver) platform and an algorithm for the numerical solution was developed. The model was verified against experimental data available in the literature. A minimum error of 0,68 percent on the heat transfer rate in the evaporator, and a maximum of 11,3 percent for the energy consumption, were obtained. The error of the discharge temperature varied between 2,9 and 8,83 degrees Celsius.