摘要
为解决保鲜运输用液氮充注气调产生的果蔬低温伤害问题,建立了液氮充注气调试验装置,通过改变液氮罐出液阀孔径、汽化盘管长度、横管开孔方向、开孔隔板开孔率、通风风速、回风道长度等因素,研究各因素对液氮充注温度调节性能的影响,优化液氮充注气调的温度调节性能。结果表明:当液氮罐出液阀孔径为1.5mm,汽化盘管长度为4m,横管开孔吹向风机,开孔隔板开孔率为4.03%,通风风速为8m/s,回风道长度为1.5m,厢体内氧气体积分数自20.95%降至5%时,液氮气调的温度调节性能较优,开孔隔板出气口最大温差仅为1.3℃,开孔隔板出口处与回风道内的最大温差仅为2.72℃。液氮充注气调在43min内可快速将厢体内氧气体积分数由20.95%降至5%,还可利用液氮的冷量为保鲜环境降温。研究结果对果蔬液氮气调保鲜运输车的设计具有一定的参考价值。
An experimental platform with atmosphere controlled system by liquid nitrogen injection was established to study and solve the cold damage problem caused by liquid nitrogen during the transportation.The bore diameter of the outlet valve on the liquid nitrogen tank,the length of the vaporization coiled pile,the aperture direction on the horizontal pile,the ratio of opening area on the perforated partition,the airflow velocity and the length of the air return channel were chosen as variables to analyze their effects on the temperature regulating characteristics of liquid nitrogen and the parameters were optimized.The best regulation performance was obtained under the condition with the bore diameter of the outlet at 1.5 mm,the length of the vaporization coiled pile at 4 m,the aperture direction on the horizontal pile towards the draught fan,the ratio of the opening area on the partition at 4.03%,the airflow velocity at 8 m/s,and the length of the air return channel at 1.5 m.Under this condition,the O2 concentration was reduced from 20.95% to 5%,the maximum temperature difference among the outlets of the perforated partition was only 1.3℃,and the maximum temperature difference between the outlet of perforated partition and the air return channel was only 2.72℃.The liquefied-nitrogen atmosphere controlled system could rapidly reduce the oxygen concentration in the container from 20.95% to 5% in 43 min,while cooling the internal environment of the container.The results can provide valuable references for the design of fresh-keeping vehicle with controlled atmosphere system
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2012年第13期237-243,共7页
Transactions of the Chinese Society of Agricultural Engineering
基金
现代农业产业技术体系建设专项资金(CARS-33-13)
国家自然科学基金项目(31101363)
广东省自然科学基金资助项目(10151064201000038)
广州市农业科技项目(2011)
广东省科技计划项目(2011B020312003)
广东省扶持农业机械化发展专项项目(粤农计﹝2011)150号)
关键词
温度
运输
优化
保鲜
气调
液氮
temperature, transportation, optimization, fresh-keeping, controlled atmosphere, liquid nitrogen
