Evaluación del Rendimiento de una Bomba de Calor de Expansión Directa Asistida por Energía Solar Mediante Simulación Numérica del Proceso de Estrangulamiento en el Dispositivo de Expansión

The performance evaluation of a direct expansion solar-assisted heat pump (DX-SAHP) was analyzed using numerical simulation about the throttling process in the expansion device. The experimental system operation parameters were validated by normality test with 95 % confidence. An E2V09SSF expansion valve was modeled for numerical analysis in the ANSYS software Fluent module. The best meshing of the valve generated 263 524 elements and 50 449 nodes with an excellent skewness metric of 0.2334. Refrigerant temperature and pressure were defined as boundary conditions at valve inlet, besides its velocity. Continuity, momentum and energy equations were used, considering a k-epsilon RNG model. The pressure values of the refrigerant at the expansion device outlet, obtained by simulation, were compared to experimental values that were determined in the DX-SAHP prototype system. The refrigerant pressure, obtained by simulation for a heating time of 0 to 40 minutes, was 161.61, 186.50 and 238.33 kPa. The absolute error between theexperimental and simulated pressure was 4.07 kPa, while the relative error was less than 2 %.