人工光植物工厂风机和空调协同降温节能效果

Energy saving effect on cooperating cooling of conditioner and air exchanger in plant factory with artificial light

为减少人工光植物工厂中空调降温耗电量,该文利用风机引进外界低温空气与空调协同降温方式,以低功率的风机减少高功率空调的运行时间。结果表明,与仅利用空调进行降温的对照植物工厂相比,利用风机和空调协同降温的试验植物工厂节能效果明显,当植物工厂内部明、暗期空气温度分别设定在25℃和15℃,外界空气温度在-4～12℃时,明期耗电量的节省率为24.6%～63.0%,暗期为2.3%～33.6%,其节能效果随着外界空气温度的降低而增加;并且该降温方式可以将植物工厂内空气温度控制在目标值。因此,采用风机与空调协同方式对植物工厂内空气温度进行调控,可以减少植物工厂降温耗电量,降低其运行成本。

In recent years, the use of plant factory with artificial light （PF） for plant production is gradually increasing in many countries due to its incomparable advantages compared with other plant production systems, such as improving the utilization efficiencies of water and land, improving work conditions. However, the higher initial construction and operation costs limit the further use of the PF. The main electric-energy consumption by air conditioner （AC） for cooling accounts for 15%-25% of the total energy consumption in the PF. In this experiment, the objective of this study is to reduce the electric-energy consumption for cooling in the PF. The air temperature inside the two PFs （floor area： 10.5 m2） was maintained at 25°C and 15°C during photoperiod and dark period, respectively. In one PF, an air exchanger （AE, air quantity： 250 m3/h） was used along with an AC to maintain the inside air temperature at the set-point. The air exchanger was used to exchange the air inside with that outside when the air temperature outside was lower than a certain degree. When the inside air temperature could not maintained at the set-point, the AC would start. In another PF only an AC was used. The results showed that the electric-energy consumption in the PF with AE reduced by 24.6%~63.0% and 2.3%~33.6% when the outside air temperature ranged from -4°C to 12°C, and the runtime of air conditioner reduced by 36.6%~82.0%and 16.3%~64.2% when the outside air temperature ranged from -4°C to 6°C, during photoperiod and dark period, respectively, compared with the electric-energy consumption in the PF only with AC. And the reduction rates of electric consumption and the runtime of air conditioner increased with the decrease of the air temperature outside. Moreover, the air temperature inside the PF with AE could be maintained at the set-point. The above results indicate that the electric-energy consumption for cooling can be reduced by using the AE compared with the AC. Thus, the use of AE in the PF will be an effective way to reduce electric-energy consumption for cooling and the operation cost.