氮气气调仓进气量对粮堆氮气浓度的影响

在压力半衰期为165 s的三级气调仓，研究氮气气调储粮氮气浓度衰减与时间的关系，探讨粮堆中氮气浓度与氮气进气量、粮堆温度的相关性。结果表明，仓内氮气浓度达到目标浓度98.0%后，随着时间的延长氮气浓度逐渐降低。粮堆内氮气浓度是氮气泄露量和补气量平衡的结果，粮堆内氮气浓度的升高要求氮气的补气量大于泄漏量。当粮堆内无氮气补充进去时，氮气浓度月下降趋势为1.6%；当粮堆内氮气月补气量大于粮堆孔隙体积的12.4%时，粮堆内氮气浓度增加0.1%~0.9%；月补气量大于粮堆孔隙体积的27.0%，粮堆内氮气浓度大于1.0%。此外，氮气充气过程氮气补气量与粮温无直接影响。

Effect of Nitrogen Flow Rate on the Concentration of Nitrogen in Controlled-atmosphere Warehouse

The decay and holding time of nitrogen concentration was characterized in a controlled-atmosphere warehouse with half life of pressure of 165 s. The relationship of nitrogen concentration, nitrogen holding timeand grain temperature was further studied. The results showed that, the nitrogen concentration gradually decreases with the time, when the nitrogen concentration in the controlled-atmosphere warehouse reached to the target concentration of 98.0%. The concentration of nitrogen was related to nitrogen leakage and sorption. An increase of the nitrogen concentration required that the amount of supplemental nitrogen is greater than the amount of leakage. When there is no nitrogen supplement in the controlled-atmosphere warehouse, the monthly decrease of nitrogen concentration is 1.6%; when the monthly nitrogen supplement is greater than 12.4% of the grain warehouse volume, the nitrogen concentration will increase by 0.1% ~ 0.9%; the monthly nitrogen supplement is greater than 27.0% of the grain warehouse volume, the nitrogen concentration will greater than 1.0%. In addition, the amount of nitrogen supplementation has no direct effect on the temperature of the grain.