中文摘要：

为实现对气调保鲜运输厢体内气体成分的自动控制,以液氮充注气调为对象,搭建了液氮充注气调试验平台。设计了基于低温保护优先的气调方案,采用双限值的控制方法,实现了液氮充注气调的自动控制。以香蕉为试验物料,开展液氮充注气调保鲜试验。结果表明：运输厢体气密性对氧气体积分数变化影响较大,气密性差则增加了系统执行机构的工作频率及液氮消耗量;塑料筐和纸皮箱2种香蕉包装条件对液氮充注降氧影响不大;初始温度对液氮充注的降氧时间影响较大,初始温度高时降氧时间短,初始温度低时降氧时间长;系统实现了以温度优先的气调控制策略,系统工作稳定性良好。上述研究为开发液氮充注气调保鲜运输车提供了参考。

英文摘要：

A test platform of controlled atmosphere system based on liquid nitrogen injection was established,so as to control the oxygen and carbon dioxide level automatically in the container.A control scheme prior controlling the temperature was designed with double limited values.Bananas were used as experiment materials for controlled atmosphere system based on liquid nitrogen injection.The results indicated that the change of oxygen level was affected significantly by container tightness.Low container tightness would increase the operation frequency of the actuator and waste liquid nitrogen.The decreased rate of oxygen level was found not distinctly affected by different packages of bananas,whether plastic crate or carton,but mainly affected by different initial temperature.High initial temperature ensured constant liquid nitrogen injection and reduced consumed time,while low intial temperature caused intermittent nitrogen injection and required extra time.This temperature prior strategy was proved stable and could serve as reference for further development of fresh-keeping transportation equipment.