| 引用本文: | 黄汉生,杨何畏,王康.土壤水实验设备负压边界调控方法及其效果研究[J].灌溉排水学报,0,():-. |
| HUANG Hansheng,YANG Hewei,WANG Kang.土壤水实验设备负压边界调控方法及其效果研究[J].灌溉排水学报,0,():-. |
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| 摘要: |
| 对于大型蒸渗仪等土壤水分和溶质迁移模拟实验设备,实现其负压边界条件控制,将显著地提升实验的仿真性。本文根据真空气室-陶瓷膜-土壤多相介质条件下负压传递原理,研发了一种负压边界调控装置。在真空气室控制负压分别为-15kPa、-30kPa和-50kPa条件下,对土壤边界层的负压调控效果、土壤负压控制的均匀性和稳定性进行了测试。结果表明：实验土壤条件下,采用真空气室-陶瓷膜-土壤的负压传递形式,能够形成稳定的土壤负压一类边界条件。负压控制效果主要受土壤质地和陶瓷膜传输性质的影响,土壤与真空气室负压差随真空气室内负压增加而表现出先减小,后增加的趋势,土壤边界负压相比真空气室内的控制负压平均降低了20%。土壤边界均匀性主要受到不同位置控制面形成的负压叠加、以及土壤中负压的传输与土壤基质势均衡速率两个因素的影响,负压控制稳定性主要受土壤介质性质的影响。均匀度的控制水平达到0.7,稳定性系统偏差小于6.8%。所提出的方法能够有效地实现土壤边界的负压控制。 |
| 关键词: 土壤负压边界控制，土壤水势，稳定性与均匀性，大型蒸渗仪 |
| DOI： |
| 分类号:S152.7 |
| 基金项目:国家自然科学基金(51879195) |
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| Adjusting soil potential at the boundary of the lysimeters using the negative pressure controlling device |
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HUANG Hansheng1,2, YANG Hewei2, WANG Kang1
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1.State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University;2.Hubei Water Conservancy and Hydropower Research Institute
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| Abstract: |
| The realization of controlling the negative pressure at the boundaries will significantly improve the simulation functions of the large-scale lysimeters and other soil moisture and solute migration simulation equipments. A negative pressure boundary controlling device was developed and the performances of the device (i.e., the uniformity and stability of soil negative pressure) were evaluated under the conditions that the negative pressures in the vacuum chamber were -15, -30 and -50kPa, respectively. The results showed that under the experimental conditions, the negative pressure transfer in the vacuum chamber-ceramic membrane-soil can maintain soil pressure in the sit value. Compared with the negative pressure in the vacuum chamber, the negative pressure at the regiment boundary reduced 20% due to the influences of soil texture and conductivity of membrane. The uniformity of the soil potential at the boundary was mainly affected by the transmission of negative pressure in the soil, the equilibrium rate of soil matrix potential and the hydraulic properties of the ceramic membrane. The stability of negative pressure control is mainly affected by the properties of soil medium. The uniformity of the device reached 0.7 and the systematic deviation was less than 6.8%, indicating that the device can be used to regulate and control the negative pressure in soil at the boundary layers. |
| Key words: Negative;potential boundary;controlling equipment, Soil;potential, Stability;and uniformity, lysimeter. |
