土壤高温储热热湿迁移过程的初步研究

初步建立了土壤高温储热热湿迁移过程的数学模型,并进行了数值求解.结果表明,土壤热湿迁移过程中的湿度场稳定时间明显滞后于温度场,且与土壤类型和水力传导特性等有关.对于水力传导性较差的土壤,在高温储热初期,靠近热源的地方容易产生湿份聚集,使得湿度曲线出现一个短期峰值.与低温储热相比,土壤高温储热时湿度迁移对温度场的影响较大,温度场呈整体降低趋势,降低幅度顺序为:砂土>壤土>粘土.在该文模拟条件下,粘土的热湿迁移过程对于初始湿度的变化不敏感,而砂土的热湿迁移过程则依赖于初始湿度,且影响程度随着初始湿度的增加而增大.

PRELIMINARY STUDY OF HEAT AND MOISTURE TRANSFER DURING HIGH-TEMPERATURE THERMAL STORAGE OF SOILS

A preliminary theoretical model of heat and moisture transfer during high-temperature thermal storage in soils was presented and calculated numerically. Results showed that the steady time of temperature is faster than that of moisture, linked with the soil types and hydraulic properties. For the soils with poor hydraulic conductivity, the moisture content is easy to accumulate nearby the heat source. This is reflected as a temporary peak of the moisture content curve during the initial thermal storage. Compared with the low-temperature thermal storage, the moisture transfer during the high-temperature thermal storage has a greater effect on the temperature distribution, and the soil temperature decreases as the magnitude order: sand > loam > clay. Different from the clay, heat and moisture transfer in sand is dependent strongly on the initial moisture content, and the soil temperature distribution decreases gradually with the increase of initial moisture content.