An experimental and simulative study on a novel photovoltaic-thermal collector with micro heat pipe array (MHPA-PV/T)

• A novel photovoltaic-thermal collector with micro heat pipe array is proposed.
• The mathematical model of the collector is developed based on the heat transfer process.
• The thermal efficiency of the collector is affected significantly by seasons.
• The annual experimental value of the daily average thermal efficiency α and the heat loss coefficient U are 0.30 and 0.105, respectively.
• In an entire year, the total efficiency of the collector fluctuates between 30% and 50%.

An increase in temperature dramatically decreases the performance of photovoltaic (PV) panel. Hence, a micro heat pipe array (MHPA) technology is developed to regulate the working temperature by retrofitting the PV panel into the PV-thermal (MHPA-PV/T) collector. A mathematical model of the MHPA-PV/T collector was developed based on the heat transfer process. The accuracy of the model was verified by comparison with the experimental data. The performance of the collector was studied and analyzed through a series of experiment and simulation. Results showed that the thermal efficiency of the collector is significantly affected by seasonal temperature, reaching up to 40% in summer and down to less than 20% in winter. When the initial temperature in the water tank was equal to the average ambient temperature, the thermal efficiency was approximately 30%. However, the electrical efficiency was relatively stable at approximately 13% compared with thermal efficiency. The total efficiency of the MHPA-PV/T collector for the entire year fluctuated between 30% and 50%.