To develop a more efficient water-cooled photovoltaic-thermal system, energy and exergy analysis of a photovoltaic-thermal system with wavy tubes are investigated numerically using different coolant fluids. A comparison between the straight tube and wavy tubes is conducted for various wavelengths and wave amplitudes. The geometrical parameters of the wavy tubes as well as the velocity of the coolant fluid are examined. Besides, the consequences of coolant fluid including water, Ag/water nanofluid, microencapsulated phase change material slurry, and also a new type of cooling fluid called microencapsulated phase change material nano-slurry are studied. The results show that the electrical, thermal, and exergy efficiencies of the photovoltaic-thermal module enhance by using the wavy tubes compared with the corresponding straight tubes. By declining wavelength in a constant wavelength/amplitude, the heat absorbed by the heat transfer fluid raises. For the best configuration, the primary and exergy efficiencies of the module increase by 6.06% and 4.25%, respectively, for the wavy tubes system compared with those for the straight unit. Furthermore, in both configurations, by increasing the inlet velocity, the overall performance of the photovoltaic-thermal module increases due to a higher heat transfer rate. The results also reveal that among different types of cooling fluids, the microencapsulated phase change material nano-slurry has higher performance in terms of both energy and exergy efficiencies due to having higher thermal conductivity and heat capacity. By employing the wavy tube and the novel proposed coolant fluid, the primary and exergy efficiencies increase in comparison with a typical photovoltaic-thermal module.

为了开发更有效的水冷式光伏热系统，使用不同的冷却剂流体对带有波浪管的光伏热系统的能量和火用分析进行了数值研究。对于各种波长和波幅，进行了直管和波浪管之间的比较。检查波浪形管的几何参数以及冷却液的速度。此外，还研究了水，银/水纳米流体，微囊化相变材料浆液等冷却液的后果，以及新型的微囊化相变材料纳米浆液。结果表明，与相应的直管相比，使用波浪形管可以提高光伏热模块的电，热和火用效率。通过以恒定的波长/振幅减小波长，传热流体吸收的热量增加。对于最佳配置，与直管系统相比，波浪管系统的模块的一次效率和火用效率分别提高了6.06％和4.25％。此外，在两种配置中，通过提高入口速度，由于更高的热传递率，光伏热模块的整体性能得以提高。结果还表明，在不同类型的冷却流体中，由于具有更高的导热率和热容量，微囊化相变材料纳米浆料在能量和火用效率方面均具有更高的性能。通过使用波纹管和提出的新型冷却液，