摘要
本文采用理论建模与实验验证分析相结合的方式,研制了一套可有效控制箱内温度变化的细胞低温储存系统。该系统在已知低温箱内温度变化要求的情况下,获得系统运行工质调节阀门开度变化规律,选取定流量和定焓差两种特殊情况进行讨论。理论分析表明,箱内降温需求为15 min之内从280 K降至160 K,焓差固定时,氮气侧的质量流量从初始的0.018 kg/s单调递减至约0.003 kg/s,液氮侧的质量流量先增大后减少,12 min达到最小值0.003 kg/s;在混合出口流量固定的情况下,氮气侧的质量流量先增后减,在7 min达到最大值为0.008 kg/s,而液氮侧的流量先减后增,在7 min达到最小值为0.002 kg/s。通过理论与实验数据的对比分析,模拟值与实验值的变化趋势基本一致,最大误差不超过10%。
In this paper,a combination of theoretical modeling and experimental verification is used to develop a low-temperature cell storage system that can effectively control the temperature changes in the box.The valve capable of automatically adjusting the cooling medium can be obtained under the condition that the temperature change in the low-temperature chamber is known.Two cases for discussion(i.e.constant mixing outlet flow rate and constant enthalpy difference)are selected in this paper.When the cooling demand is to reduce the temperature from 280 K to 160 K within 15 minutes,and the enthalpy difference is fixed,the mass flow rate on the nitrogen side decreases monotonically from the initial 0.018 kg/s to about 0.003 kg/s.The mass flow rate on the liquid nitrogen side has experienced a process of first increasing and then decreasing,reaching the maximum value of 0.003 kg/s at about the 12th minute;when the mixing outlet flow rate is fixed,the mass flow rate on the nitrogen side first increases and then decreases,and the maximum value of 0.008 kg/s is reached at about 7th minute,and the mass flow rate on the liquid nitrogen side has experienced a process of first decreasing and then increasing,and the minimum value obtained at about 7th minute is 0.002 kg/s.Through the comparative analysis of theoretical and experimental data,the maximum error does not exceed 10%.
作者
廖毅飞
吴静怡
黄一也
陈国珍
蔡爱峰
LIAO Yifei;WU Jingyi;HUANG Yiye;CHEN Guozhen;CAI Aifeng(Institute of Refrigeration and Cryogenics,Shanghai Jiao Tong University,Shanghai 200240,China)
出处
《制冷技术》
2021年第3期31-36,共6页
Chinese Journal of Refrigeration Technology
关键词
低温模拟系统
控制策略
气化器
板式换热器
Low temperature simulation system
Control strategy
Gasifier
Plate heat exchanger