Simulation and experiment of air-duct heating equipment using electricity in a sheep barn using computational fluid dynamics

The temperature inside the sheep barn has a significant effect on sheep growth; therefore, providing a suitable thermal environment for the barn is essential. Considering the uneven heating problem of existing heating equipment in livestock barns, we designed an air-duct heating equipment using electricity to ensure a comfortable temperature for sheep with a suitable airflow rate. A computational fluid dynamics (CFD) method was used to simulate the temperature and velocity fields inside the sheep barn, check the heating effectiveness, and ensure uniformity. To determine the optimal opening direction and size of the heating equipment, simulation tests with various opening directions and sizes were conducted using the flow velocity and uniformity of the flow field as the key factors. The CFD simulation results showed that for the investigated sheep barn, a downward opening with diameter of 60 mm was the most effective for heating. Finally, in winter, a heating test was conducted during the decreasing, stable, and increasing periods of outdoor temperatures to verify the heating effectiveness in the experimental sheep barn. During the decreasing and stable periods of outdoor temperature, the indoor temperatures increased by 2 and 5 ℃, respectively, in 70 min. Conversely in the increasing period of outdoor temperature, the temperature inside the barn increased by 11 ℃ and continued to rise. Our results showed that the expected heating effect of sheep barns was achieved, which can provide a reference for the environmental regulation of livestock barns.