Experimental study and performance enhancement of micro heat pipe PV/T system

Abstract

The integration of photovoltaic/thermal (PV/T) systems, which enable the simultaneous conversion of solar energy into both electricity and thermal energy, holds great promise in the solar-rich northwest region of China. This study aims to assess the performance of a micro heat pipe (MHP) PV/T system through comprehensive experiments conducted over the four seasons in Lanzhou. The experimental setup involved the measurement of various parameters including environmental temperature, surface temperature of the PV/T panel, back temperature of the PV/T panel, and water temperature, as well as the determination of the power collection efficiency (PCE) and thermal conversion efficiency (TCE). The PV/T system was installed at a tilt angle of 45°, resulting in an average PCE of 12.42 % and TCE of 34.7 %. To further understand the system performance, a two-dimensional mathematical model was developed and validated using the experimental data, demonstrating good agreement between the simulated and actual results. The simulation provided valuable insights into the temperature distribution across different components of the PV/T module, such as the glass cover, solar cell, and single shell of the MHP. The findings revealed that increasing the number of MHPs from 12 to 20 led to a modest improvement of 0.21 % and 2.72 % in the PCE and TCE, respectively. Similarly, raising the flow rate from 0.108 L/s to 0.128 L/s resulted in a corresponding increase of 0.25 % and 3.01 % in the PCE and TCE, respectively. These experimental investigations and numerical simulations established a solid scientific foundation and offered practical guidance for the implementation of MHP-PV/T systems, thereby facilitating the efficient utilization of solar energy in future applications.