基于CFD的LED补光灯模型构建与验证

为明确植物工厂CFD环境模拟中LED补光灯的边界条件设置,构建单层LED补光栽培架(原型),并根据原型在CFD软件中建立规格一致的栽培架三维模型,对三维模型进行模拟分析,将得到的模拟值与原型实测值进行对比分析,验证LED灯边界条件设置的可行性。在模型中将LED补光灯分为反应器和灯罩两部分,反应器为LED补光灯的灯板,设置为热源边界条件,根据红、蓝灯珠数量及其对应的电光转化效率计算其单位体积散热量,灯罩为LED补光灯表面的塑料壳,起保护灯珠的作用,设置为导热材料,将三维模型的风速、温度模拟值与栽培架原型的实测风速值、温度值进行对比,结果表明:1)栽培架三维模型中LED补光灯的散热量为34 166 W/m3;2)通过模拟值与实测值对比,30个测点实测风速值与CFD模拟风速值的均方根误差为0.06,46个测点实测温度值与CFD模拟温度值的均方根误差为2.63,模拟值与实测值吻合良好。在植物工厂CFD模拟中,可以将LED补光灯反应器设置为热源、灯罩设置为导热材料。

Simulation and verification of LED lamp model based on CFD

In order to identify boundary condition of LED light in CFD environment simulation of plant factory, a single-layer production system was constructed. According to the prototype, a 3D model of the cultivation frame with the same size was built in CFD software. The 3D model was simulated and analyzed, and the simulated value was compared with the measured value of the prototype, which verified the feasibility of setting LED lamp boundary conditions. In the model, the LED lamp was divided into reactor and lampshade. The reactor was set as the boundary condition of heat source. Based on the numbers of red and blue bulbs and the corresponding electro-optical conversion efficiency, the heat dissipation per unit volume was calculated. The lamp shade is a plastic shell on the surface of the LED lamp, which was set as a heat conduction material. The measured values of airflow speed and temperature on the cultivation system were compared with the simulated values. The feasibility of setting LED lamp reactor as heat source and lamp shade as heat conduction material in CFD model was verified. The results showed that: 1)The heat dissipation per unit volume of LED lamp in the three-dimensional model of cultivation system was 34 166 W/m³; 2)The root-mean-square error of the measured and simulated wind speed values at 30 measurement points is 0. 06 and the root-mean-square error of the measured and simulated temperature value at 46 measurement points is 2. 63. In conclusion, it is feasible to set LED supplementary light reactor as heat source and lamp shade as heat conduction material in CFD simulation of plant factory.