Experimental Study on Heat Transfer Performance of the Solar Collector with an Inserted Heat Pipe Using Magnetic Nano-fluids as the Working Fluid

The heat transfer system of glass evacuated solar collector with an inserted heat pipe was established and researched experimentally. Two different kinds of heat collector device with heat pipe using magnetic nano-fluids and water as the working fluid respectively were researched at different aspects of tilt angles, climate conditions and total solar radiations. The exprimental results show that the solar collector with an inserted heat pipe using magnetic nano-fluids as the working medium has the lower heat loss coefficient, the higher average daily efficiency and instantaneous efficiency. The results provide a new idea to improve the heat transfer performance of solar collectors.