锂电池极片干燥箱风刀内流特性的试验与数值模拟对比研究

Comparative Study on Experiment and Simulation of the Flow Characteristics of Air Nozzles Used in Lithium Battery Film Drying Device

为获得锂电池极片干燥箱中所用风刀的均流特性与阻力特性及验证数值模拟结果的正确性,依据几何相似,使用有机玻璃材质,制作与数值仿真模型相同结构尺寸的风刀性能试验箱体。采用与数值模拟一致的进口流量和出口压力为边界条件,实现运动相似。通过对不同流量下进出口压差的测量,得出风刀的阻力特性;利用热线风速仪沿风刀出口逐点测取风速值,求得风刀对空气的均流特性。试验结论与数值模拟结果具有较好的一致性：在同样整体尺寸和运行工况下,带有底部筛板及内胆的风刀阻力较小,进出口压差在33~524 Pa,其均流性最好,出口气流均匀性在95%以上;带有顶部出风圆孔且无内胆的风刀阻力最小,进出口压差在24~354 Pa,其均流性最差,出口气流均匀性为80.4%,达不到使用要求;无底部筛板和内胆且出风口狭小的风刀阻力最大,进出口压差在203~3 234 Pa,达不到减阻要求,其均流性较好,出口气流均匀性为91.1%。探讨风刀均流作用与压力损失之间的内在联系,提出在实际生产中风刀形式的选择与调整原则。

For the purpose of getting the resistance characteristics and flow equalization characteristics of air nozzles used in lithium battery film drying device and verifying the trueness of numerical simulation results, the experimental cases for nozzles characteristics which have the same structure and size as simulation models are built with acryl glass according to the geometric similarity. The kinematic similarity is ensured through using the inlet flow rate and outlet pressure equal to numerical simulation as boundary conditions. The air nozzles＇ resistance characteristics are obtained by calculating the differential pressure between the inlet and outlet under different flow rate. The wind velocities along the nozzles＇ outlets are measured by hot wire anemometer and the air nozzles＇ flow equalization characteristics on air are obtained. The experimental results have a higher compatibility with numerical simulation results：Under the same whole size and running conditions, the air nozzle which has bottom sieve plate and inner stopper has a lower resistance and the highest flow equalization characteristics, the differential pressure range between the inlet and outlet is 33-524 Pa and the uniformity index is above 95%. The air nozzle which has upper round air outlets and bottom sieve plate but has not the inner stopper has the lowest resistance and the lowest flow equalization characteristics, the differential pressure range between the inlet and outlet is 24-354 Pa and the uniformity index is 80.4% and can not reach the operating requirements. The air nozzle which has not bottom sieve plate and inner stopper but has many narrow outlets has the highest resistance which can not reach the drag reduction requirements and a higher flow equalization characteristics, the differential pressure range between the inlet and outlet is 203-3 234 Pa and the uniformity index is above 91.1%. The internal relations between the flow equalization action and the pressure loss are discussed. The principle for the selection and adjustment of air nozzles in working is proposed.