Regenerative solar soil sterilizing system with the Fresnel lens concentrator

Abstract

Soil disinfection is an important way of improving crop yields and quality, but either nowadays, both physical and chemical disinfection methods have some shortcomings. Physical methods lead to high energy consumption, and chemical methods leave the pesticide residues on the crop and pollute the environment. For this situation, a regenerative solar soil disinfection system with industrialized Fresnel lens proposed in this paper can uninterruptedly sterilize soil. Firstly, the structure and operation principle of the system are introduced. Secondly, the receiver location and the optical performance of the system are researched respectively on the basis of the experiment and optical simulation. Thirdly, depending on the thermodynamic model of the system, the thermal performance of the system is analyzed by using the simulation software, MATLAB. The paper shows the variation of the disinfection soil mass flow and the system energy efficiency under different solar irradiance and diameter of the outer tube. The research shows that for the regenerative solar soil sterilization system with Fresnel lens, when the solar zenith angle is within 2°, and the azimuth angle changes between −35°and 35°, the light acceptance rate of the system is above 0.99. Besides, when the maximum disinfection temperature is 85 °C and the solar irradiance is 1000 W/m2, the disinfection soil mass flow is 1.36 kg/s and the efficiency in the tube with 6 m in length is 64.2%.