Ventilation Optimization And Thermal Environment Analysis Of Plant Factory Pipeline Based On CFD

Plant factory has the characteristics of controllable environment,safety and health,and not affected by external environment,which has been widely concerned by scholars at home and abroad.At present,in plant factories,it is easy to have uneven airflow and temperature,and environmental parameters can not reach the suitable growth range of crops.In view of this problem,this paper is based on the designed pipeline ventilation system with full heat exchange,fresh air,temperature regulation and constant humidity functions.Computational fluid mechanics(CFD)simulation is used to explore the distribution of air field and temperature fields in plant plants under different ventilation modes.And further optimize the pipeline ventilation device,in order to achieve the plant plant temperature and humidity,airflow uniform,promote the effect of crop growth.1.The environmental parameters of traditional air conditioning system and pipe full heat exchange temperature and constant humidity system are analyzed.It is found that when the traditional air conditioning system is ring controlled,the temperature is in part of high temperature,the relative humidity is in part of low humidity or high humidity,and the wind speed is small and can not reach the appropriate wind speed range.When the system is ring-controlled,part of the temperature is in the high temperature state,and the relative humidity part is in the high humidity state.Although the wind speed is small and cannot reach the suitable wind speed range,it is higher than the average wind speed of the traditional air conditioning system.Through the comparative analysis of COP value,it is found that the pipeline full heat exchange temperature and humidity control system COP is better than the traditional air conditioning system.The pipeline full heat exchange temperature and humidity regulation system is more conducive to crop growth.2.In order to explore the loop control situation of the pipeline all-heat exchange temperature control system,the regulated plant factory environment is simulated by CFD technology.By comparing the measured temperature and wind speed and the simulated value,we found that the average relative error of wind speed and temperature is 10.87%and 10.05% respectively,which matches the measured and simulation.Three kinds of supply wind speed are set to further optimize the plant factory environment.It is found that the plant plant temperature parameters are basically within the suitable temperature range for crop growth,and the temperature distribution is uniform.When the supply wind speed is 5 m/s,the average wind speed parameter of the canopy area reaches the appropriate wind speed range,and the percentage of the suitable area is better.3.In order to further optimize the environment of the plant factory and be more conducive to the growth of crops,the pipeline ventilation device is optimized,and three kinds of air supply wind speed are set.Using CFD technology to simulate and analyze the optimized different pipeline air supply modes,and found that the temperature parameters in the plant factory are basically within the suitable area range,the temperature distribution is uniform,and the air supply wind speed of 4 m/s is better,which is more suitable for crop growth.The temperature field distribution of the original and the optimized pipeline ventilation devices is uniform with little difference.When the supply wind speed is 3,4 and5 m/s respectively,the percentage of suitable wind speed in the canopy area of the optimized pipeline ventilation device increases by 1.94%,10.76% and 5.16% respectively,the average wind speed in the canopy plane increases by 0,0.09 and 0.03 m/s respectively,and the coefficient of variation in the canopy plane decreases by 8.2%,2.12% and 7.88%respectively.Therefore,the optimized pipeline ventilation device is more favorable for crop growth when the supply air wind speed is 4 m/s.