Numerical study on the dynamical performance of photovoltaic and thermal management system with double-layered 45° staggered truncated wavy microchannel heat sink

Photovoltaic (PV) cell systems generate high local heat during conversion, leading to non-uniform temperature distribution and cell temperature rise, which impairs performance and reduces service life. Microchannel cooling technology can effectively reduce the average temperature of PV cells. An integrated thermal model for PV cells and coolers was established in this paper, with both solar irradiation and forced convection considered. This study selected four typical seasonal days and employed five-year hourly outdoor meteorological data from 2022 to 2026 to investigate the operational behavior of photovoltaic cells deployed in Nanjing, a typical city characterized by hot summers and cold winters. It was demonstrated that elevated environmental wind speeds and reduced ambient temperatures were both conducive to optimizing PV electrical efficiency. Quantitatively, the electrical efficiency exhibited an upward trend, increasing by 0.39% per 1 m/s rise in wind speed. Compared with standard PV cells, a photovoltaic/thermal system utilizing a 45° interleaved truncated double-layer microchannel heat sink yielded a significant drop in cell temperature alongside enhanced efficiency. The incorporation of microcapsules into the working fluid significantly accentuated the heat sink's thermal management capability, particularly at intense solar irradiance and low wind velocities. Under test conditions of 598.8 W/m 2 solar irradiation, 0.47 m/s fluid velocity, 2.36 m/s wind speed, and 26.4 °C ambient temperature, the PV cell reached 53.2 °C with 0.218 efficiency. Integrating the microchannel heat sink successfully suppressed the operating temperature to 28.3 °C, simultaneously boosting electrical efficiency by 12.8% to a peak value of 24.6%.