摘要
随着植物工厂规模的不断扩大,传统环控方式难以实现各处均匀通风,环控效果难以保证,能源利用效率较低。该研究针对这一问题,提出了根际通风方法,使植物工厂环境空气流经水培系统中营养液面与栽培板之间的空气层后进入植物冠层下部,实现高效的通风。该文以成熟期的生菜作为试材,在同一环境条件下对低速连续通风(LCRV)、高速间隔通风(HIRV)与传统通风方式(CEC)下生菜冠层及根际环境参数变化进行对照,测试其通风调温效果。结果表明,各处理空气层温度均低于环境温度,湿度则普遍高于环境。其中,LCRV温度最低,与环境温差能够达到4.07℃;CEC湿度最高,可达100%。在冠层下部,LCRV温度低于环境3.47℃;CEC湿度较环境提高27.56%;该区域CO2浓度在LCRV作用下较CEC高139×10^(-6)。随着高度的增加与冠层遮挡的减小,根际通风对冠层上部环境参数的影响逐渐削弱,LCRV温度仍为最低,但其温差已经缩小至0.75℃,CEC温度则高于环境0.84℃;各处理相对湿度与环境的差异也有所减小,数值最高的LCRV较环境高15.8%。在营养液中,LCRV液温较CEC降低4.03℃;HIRV大幅减缓了溶解氧下降趋势,试验结束时仍维持在3.8 mg/L,同期LCRV和CEC处理只有1.8 mg/L。由此可见,传统环控方式下冠层与环境参数差异明显,以环境参数作为调控依据不够准确;相比之下,根际通风在解决传统环控方式通风温控不均匀的同时,对地上部及地下部多种微环境参数调控起到了积极作用,降低环控要求,提高空调温控效率,具有推广价值。
The plant factory has been developed for many years,a series of theory and approach of environmental control in such facilities have been established.However,the environmental parameters closed to the plants were significantly affected by the physiological activity of leaves and boundary layer resistance of the canopy,leading to suboptimal microclimate deviated from the set values,poor ventilation uniformity and inefficiency of air conditioning.In this study,a new environmental control technic was proposed to introduce the regulated ambient air into the interlayer between cultivation plates and nutrient solution surface in a deep flow hydroponic system,then flow out upward into the internal canopy through the reserved vent hole units on cultivation plates,which was called root zone ventilation(RV).By adjusting the fan speeds and their running modes,low rotation rate continuous root zone ventilation(LCRV)and high rotation rate intermittent root zone ventilation(HIRV)treatments were proposed.The effects of these treatments on microclimate change of mature butterhead lettuce(Lactuca sativa var.capitata)were examined,and the performances on environmental regulation were evaluated by comparison with conventional environment control(CEC)under identical ambient environment conditions at the same time.RV treatments were carefully isolated by black films to prevent airflow impact from ambient.The CEC cultivation area was in an open state,under the air distribution of the plant factory,air flowed over the canopy from one side to another,formed the traditional side ventilation mode.The results showed that the interlayer air temperature of all treatments were lower than ambient value,while higher in relative humidity(RH).Specifically,LCRV earned the lowest temperature,which was 2.67°C lower than ambient.RH of CEC was the highest,which was 100%.Identical trend was also observed in the internal canopy,where LCRV temperature was 3.47℃lower than ambient,and the RH of CEC was 27.56%higher.The CO2 concentration in such area und
作者
李琨
邹志荣
Li Kun;Zou Zhirong(College of Horticulture,Northwest A&F University,Key Laboratory of Protected Horticultural Engineering in Northwest,Ministry ofAgriculture,Yangling 712100,China;Institute of Environment and Sustainable Development in Agriculture,Chinese Academy ofAgricultural Science,Beijing 100081,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2019年第7期178-187,共10页
Transactions of the Chinese Society of Agricultural Engineering
基金
陕西省科技计划项目(2017ZDXM-NY-057)
国家自然科学基金(31701969)
中央级科研院所基本科研业务费专项(Y2019XK21-01)
关键词
温度
湿度
环境控制
空气层
微环境
能耗
temperature
humidity
environment control
interlayer
microclimate
energy consumption
