水利学报2017，Vol.48Issue(11)：1363-1372,10.DOI:10.13243/j.cnki.slxb.20170281
基于热示踪的饱和层状介质水热参数反演
Estimation of hydraulic and thermal parameters in saturated layered porous media based on heat tracing method
摘要
Abstract
Hydraulic and thermal parameters are the most important factors to simulate water and heat transport processes in porous media quantitatively.In this work,a sand box was packed with layered silicon sands and a laboratory experiment was carried out with steady-state flow based on heat tracing theory.Thermocouple and thermal imager were used to monitor inner and surface temperature of porous media at the same time.Temperature from both method were used to estimate parameters,such as saturated hydraulic conductivities,longitudinal and transverse thermal dispersivities at different locations of the sand box via the inverse model of HYDRUS-2D software.The results indicate that thermal images could shoot the behavior of water flow in different sand layers through the early process of transportation.The migration rate of heat front slow down within fine sand layer,so the heat in fine sand layer could expand to a larger space and temperature become more uniform along the way perpendicular to the flow direction.The results also show that temperatures information from both inner and surface is a feasible way to estimate hydraulic and thermal parameters of layered porous media at saturated condition.The estimated saturated hydraulic conductivity and longitudinal thermal dispersivity enlarged with the increasing of diameter of silicon sand,while the estimated transverse thermal dispersivity possessed the opposite tendency.The ratio of longitudinal to transverse thermal dispersivity ranged from 10 to 120.Besides,the heat loss during heat tracing test and relatively lower estimated value of saturated hydraulic conductivity in the fine sand layer were the major reasons for the underestimating of water flux.With the number of observation node in fine sand layer increasing,the relative error between estimated and measured water flux declined from 37.7％ to 20.7％.The result from this experiment provides a method for estimation of hydraulic parameters of heterogeneous porous media using heat tracing.关键词
热示踪/层状介质/参数反演/HYDRUS模型Key words
heat tracing/layered porous media/parameter estimation/HYDRUS-2D software分类
天文与地球科学引用本文复制引用
潘梦绮,黄权中,冯榕,黄冠华..基于热示踪的饱和层状介质水热参数反演[J].水利学报,2017,48(11):1363-1372,10.基金项目
国家自然科学基金项目(51379209,51639009) （51379209,51639009）
