地下生态粮仓中粮食温度场的试验与数值仿真

粮温是影响粮食安全的重要因素,论文采用地下模拟试验、工程性试验与数值仿真相结合的方法,研究了地下生态粮仓的粮食温度变化规律。通过在试验仓内布设测温电缆,定时定点监测温度,获取仓内各测点的温度变化规律。以地下储粮环境条件为基础,构建了模拟试验仓的物理模型,用数值方法分析了仓内粮食的温度场,并与试验结果对比,验证了数值方法的有效性。据此对工程性试验仓不同入仓时间的粮食温度场进行了数值分析,发现地下粮仓入粮应优先选择冬季,夏季入粮时因粮温较高应采取适当方式(如机械通风)降低粮食温度,以实现低温储藏。研究表明:埋深较深的工程性试验仓的储粮效果优于模拟试验仓;地下生态粮仓仓内粮食温度随着储存时间的增加基本保持稳定,且逐渐趋于地温;模拟试验仓粮温稳定在20℃左右,工程性试验仓粮温稳定在17℃左右,而对应地上仓平均粮温在25℃左右,局部粮温高达30℃,随季节变化较大。因而地下生态粮仓具有恒低温储粮的优势,有利于保证粮食品质和储粮安全。

Experiment and Numerical Simulation of Grain Temperature Field in Underground Ecological Granary

Grain temperature is an important factor affecting grain security. The variation of grain temperature in underground ecological granary was analyzed by combining simulation test silo, engineering test silo and numerical simulation. The temperature change law of each measuring point was obtained by setting up the measuring cables in the test silo and monitoring the temperature at regular time. Basing on the boundary conditions of grain storage environment, the physical model of underground simulation test warehouse was established, and the grain temperature field in the warehouse was analyzed by numerical method. The effectiveness of numerical simulation method was verified by comparing with the test results. By using the same numerical simulation method, the grain temperature field of underground-engineering-test warehouse with different entry time was analyzed; it was found that loading in winter was better than in summer. In order to realize low temperature grain storage, appropriate ways (such as ventilation in the winter) should be taken for the grain to reduce the grain temperature, because the temperature was high in summer. It was found that the grain storage effect of deep underground silo (engineering test silo) was better than that of shallow depth underground silo (simulation test silo). The grain temperature in the underground ecological granary was gradually tended to be stable with the increasing storage time. The grain temperature of simulation test silo was about 20 degrees. The engineering test silo was about 17 degrees. The above-ground silo was about 25 degrees; the local temperature of the above-ground silo was as high as 30 degrees, and varied greatly with the seasons. Therefore, the underground ecological silo had the advantage of constant low temperature grain storage, which could ensure grain quality and grain storage safety.