Thermal performances evaluation of a flat-plate solar collector using microencapsulated phase-change slurry as heat transfer medium

Microencapsulated phase-change slurry (MPCS) is composed of microencapsulation phase-change materials (MPCM) and carrying medium (water), which can be used for heat transfer and thermal energy storage. Some theoretical and experimental works have been proposed on the thermal energy storage and flow performance of MPCS. However, there are few studies on the performances of MPCS in the thermal energy devices (eg, solar collector). In present work, the numerical model of a flat-plate solar collector with MPCS as the thermal energy storage fluid was established. Then, the effects of mass fraction of MPCS, latent heat and solar radiation on thermal efficiency, and pumping power consumption of the solar collector model were studied. The simulations indicated that the thermal efficiency of the solar collector model was positively correlated with the mass fraction and latent heat, but decreased with the increase of solar radiation. When the inlet flow rate, mass concentration, latent heat and solar radiation of the MPCS were set to 0.01 m/s, 5.90%, 88 kJ/kg and 300 W/m(2), respectively, thermal efficiency of the solar collector model was the largest, which was 0.711. Moreover, the pumping power consumption was mainly affected by inlet flow rate and mass fraction of MPCS.