CFD Simulation Of The Heat Environment Of Multi-span Greenhouse At Night In Winter Under Heating

In this article, experiment about the heat environment of multi-span greenhouse at night in winter under heating in Beijing district is described. A CFD model about this greenhouse without plants is set up. After that, a CFD simulation is carried out using this CFD model, and the data from the simulation is analyzed and compared. The heat environment in greenhouse under different disposal of heating or thermal screen is also simulated and analyzed.From the experiment about the heat environment of multi-span greenhouse at night in winter, we can see that: The heat preservation and storing up ability of multi-span greenhouse is limited. Without sufficient quantity of heating, air temperature in greenhouse is easily affected by out environment, and the air temperature needed is hard provided. There is difference of air temperature in plane and high direction, which is connected with disposal of heating and heat load of greenhouse. With the thermal screen in using, the difference of air temperature is more higher. The using of the thermal screen can add the greenhouse heat preservation ability obviously.A three dimensional CFD model for the experiment greenhouse is set up. By using the business CFD software of Fluent, the model is computed with RNGk-ε turbulent model. Then internal airflow and air temperature distribution is forecasted. With results of simulation compared with experimental data, the feasibility and veracity of numerical simulation by software of Fluent to multi-span greenhouse is validated.Floor heating is proved to be more efficient and to be more energy saving. When the temperature of environment is reduced, the better performance of thermal screen will save more energy. Also, multiplayer thermal screen will save more energy.