Analysis on aerodynamic performance of mine horizontal axis wind turbine with air duct based on breeze power generation

Developing wireless sensor networks based on breeze power generation is of great significance to promote the development of intelligent mines. In this paper, a small horizontal axis wind turbine with air duct was designed for the underground environment of coal mine. The aerodynamic performance of the wind turbine was analyzed by constructing a three-dimensional solid model of the wind turbine. The results show that under the condition of low wind speed underground, the air flow entering the air duct in the outer basin is accelerated and rectified, and the velocity near the impeller increases. The pressure value at the front end of the blade is the largest and the pressure value at the rear end of the blade is the smallest. A certain range of negative pressure zone is formed at the rear end of the impeller, which is conducive to the operation of the wind turbine. After the air flow passes through the impeller, the speed decreases and the speed is the lowest near the rotating shaft of the impeller. Inner basin: the air flow velocity increases gradually along the radial direction of the impeller centre. The pressure at the front end of the blade is greater than the atmospheric pressure, which is conducive to promoting the stability and sustainability of the wind flow and facilitating the operation of the wind turbine. When the wind speed reaches the rated wind speed of the wind turbine, the power, torque and output power of the wind turbine increase, which can provide effective power generation. Compared with other aerofoils, NACA5505 air foil has higher lift drag ratio and thrust coefficient, and is more suitable for downhole low wind environment. Compared with the wind turbine without air duct, the wind turbine with air duct has higher wind energy conversion and output power at low Reynolds number, which verifies the feasibility of the wind turbine with air duct. In the case of low incoming wind speed and no expansion of the size of the wind turbine, improve the output power of the wind turbine and meet the intrinsic safety requirements of the wind turbine. The research can provide technical support for the continuous power supply of wireless intelligent sensors in the mine environment, and provide scientific basis for mine safety production and fine management, which has long-term economic and social benefits.