Multiphase Flow Cylindrical Model Test System for Thermal Soil Vapor Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing thermal enhanced soil vapor extraction devices cannot exert a certain vertical force on the soil layer, affecting the simulation of pollutant displacement at a certain buried depth, and existing flexible wall triaxial specimen tests face issues with effective liquid isolation, head difference and pressure influence, and inadequate characterization of seepage deformation.
Innovation Solution
A multiphase flow cylindrical model test system is developed, comprising a loading structure, a multiphase flow displacement model bucket, a data acquisition and analysis system, a flexible seepage model bucket, and a dynamic control system, which allows for independent operation of test functions, including vertical force application and multiphase flow simulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If existing thermal enhanced soil vapor extraction devices are used, then the extraction process can be performed, but they cannot exert a certain vertical force on the soil layer, affecting the simulation of pollutant displacement at a certain buried depth
Solution Approach 1:
The test system is divided into independent functional modules: loading device for applying vertical force, multiphase flow displacement model bucket for pollutant displacement simulation, flexible seepage model bucket for permeability testing, and data acquisition system. This segmentation allows each module to perform its specific function independently while contributing to the overall simulation reliability.
Solution Approach 2:
The test system integrates multiple functions into a unified platform: it can apply vertical loads to simulate burial depth, conduct multiphase flow displacement tests, perform permeability tests with bidirectional water head control, and monitor various parameters simultaneously. This multi-functionality ensures reliable simulation of pollutant displacement under different burial depths and flow conditions.
2Object-generated harmful factors
If existing flexible wall triaxial specimen test is used, then the test can be conducted, but the polluted liquid brought out during the seepage process cannot be effectively isolated, which will greatly damage the function of the test equipment
Solution Approach 1:
The system extracts and isolates the polluted liquid from the test process using a collection and treatment device that separates contaminated water from the test chamber. This extracted liquid is then treated or disposed of separately, preventing it from damaging the test equipment while maintaining the integrity of the permeability and displacement tests.
3Reliability
If existing flexible wall triaxial specimen test is used, then the permeability test can be performed, but the influence of head difference and head pressure on the permeability test at the same time are not taken into consideration, and thus the obtained results cannot be used for reliable analysis of garbage dams under the action of upper and lower water heads
Solution Approach 1:
The system introduces water head adjustment devices with bidirectional control capability as intermediaries between the water source and the permeability test chamber. These devices independently control both head difference (pressure gradient) and head pressure (confining pressure), allowing simultaneous consideration of their influences on permeability while maintaining reliable test conditions for garbage dam analysis.
4Measurement precision
If existing flexible wall triaxial specimen test is used, then the seepage test can be conducted, but the seepage deformation cannot be quantitatively characterized or the seepage deformation is not considered, and thus the research on the deformation of fluid-solid coupling cannot be satisfied
Solution Approach 1:
The system employs visualization techniques including color-coded strain gauges or dye injection methods to track and quantify seepage-induced deformation of the soil specimen. This allows direct observation and measurement of deformation patterns during multiphase flow displacement and permeability tests, enabling quantitative characterization of fluid-solid coupling effects without excessive system complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system enables array-type measurement of specimen deformation during thermal enhanced soil vapor extraction, measures temperature, conductivity, moisture, and pressure distributions, and simulates permeability tests with bidirectional water head control, effectively overcoming the limitations of existing technologies.
Implementation Method 1
a thermal enhanced soil vapor extraction pipe is arranged on the axis of a bottom plate of the multiphase flow displacement model
Implementation Method 2
thermal enhanced soil vapor extraction technology
Implementation Method 3
a horizontal beam loading mechanism moves up and down with the lead screw and the guide shaft on both sides to apply a load to the multiphase flow displacement model bucket
Implementation Method 4
a data acquisition and analysis system, wherein... a combined temperature-conductivity-moisture content sensor
Implementation Method 5
a soil pressure sensor and a pore water pressure sensor are inserted into the specimen through circular sensor sockets arranged in four columns and three rows on the side wall surface of the multiphase flow displacement model bucket
Implementation Method 6
the influence of head difference and head pressure on the permeability test at the same time are not taken into consideration
Implementation Method 7
a permeable plate is arranged on an upper part of the bottom plate so as to collect liquid formed in a process of thermal enhanced soil vapor extraction through the permeable plate
Data Source
AI summary
A multiphase flow cylindrical model test system includes a loading structure, a multiphase flow displacement model bucket, a data acquisition and analysis system, a flexible seepage model bucket and a dynamic control system. A multi-parameter test method in the displacement process of pollutants in three-dimensional multi-field and multiphase media is reasonably configured based on the sequential and superimposed application requirements of heat and steam in the thermal enhanced soil vapor extraction process. The disclosure has the following effects: it can conduct array-type measurement of deformation of specimen during the thermal enhanced soil vapor extraction process, measure the temperature field, conductivity field, moisture field, matrix suction distribution, soil pressure distribution, pore water pressure distribution and pollutant discharge rate of the specimen during the test, and realize the flexible wall permeability triaxial test with bidirectional control of the water head and overcome the influence of the polluted liquid on the test equipment.