气调保鲜运输车通风系统阻力特性试验

Pressure Drop Characteristics of the Ventilation System in Fresh-keeping Transportation with Controlled Atmosphere

针对液氮气调运输保鲜环境对运输厢体和通风系统的要求,设计了气调保鲜运输车通风系统试验装置。研究了通风风速、开孔隔板开孔率、堆栈方式、回风道长度等因素对气调保鲜运输车通风系统压力损失及能耗的影响,分析了通风系统的阻力特性。结果表明:通风系统的阻力特性可用Ram sin方程表述,通风系统的压差随风速的增大而增大;风速相同时,压差随开孔率的增大而减小;保鲜室内压差分布较均匀;满箱、留中间空隙和留两侧空隙等3种堆栈方式对压力损失的影响不明显;无回风道时压力损失比有回风道时小;气调保鲜运输车开孔隔板的开孔率大于3.89%时,通风系统的压力损失小且能耗较低。

An experimental device of ventilation system was established to meet the requirement of fresh-keeping transportation with controlled atmosphere by liquid nitrogen.The pressure drop characteristics of the ventilation system were studied.The effects of airflow velocity,ratio of open area,stack mode and length of return air channel on the characteristics of pressure drop and energy consumption were analyzed.The pressure drop characteristics could be described by the equation of Ramsin.The pressure drop increased with the addition of airflow velocity.At the same airflow velocity,the pressure drop decreased with the addition of ratio of open area.The distribution of pressure drop in fresh-keeping room was steady.The effect of three stack modes on the pressure drop was not striking.The pressure drop was less when there was no return air channel.When the ratio of open area of the separator with holes in fresh-keeping transportation vehicle was bigger than 3.89%,it could meet low pressure loss and had small energy consumption.The research achievements will be instructive to the design of the ventilation system in fresh-keeping transportation with controlled atmosphere.