煤岩体应力-渗流-温度多过程耦合试验系统

The stress-seepage-temperature multi-process coupling test system for coal and rock mass

自主研制了煤岩体应力-渗流-温度多过程耦合试验系统,可以实现不同地应力、温度、流体压力等条件下煤岩体应力变形-瓦斯解吸/扩散-气体运移-温度传输等行为的试验模拟.该系统主要包括岩芯夹持子系统、流体控制子系统、温度控制子系统、操作控制及数据分析子系统等.岩心夹持器的煤岩样通过液体自动加压泵精准控制加载应力;特制的橡胶套包裹煤岩体有效阻隔了外界液体与煤岩样的接触,应变片直接贴敷在煤岩样上,克服了许多传统仪器应力-应变参数的非接触式测量和仪器操作过程复杂等问题;采用程序控温和电热毯联合加热的方法,实现了试验管路和煤岩样环境温度的可调可控,突破了普通水浴控温温度低于100℃的限制;采用labVIEW可视化的图形编程语言和平台开发了系统操作界面,可以实现实验数据的实时采集与分析.该试验系统的力学和渗透性测试结果的准确性分别通过了MTS815岩石力学试验系统和标准渗透率岩心的验证.应用该系统开展了温度-应力耦合下煤体渗透性演化和应力加载下型煤吸附/解吸CO2的连续性力学-吸附/解吸过程相关的实验,实验结果与理论-实际的认知相吻合.

A stress-seepage-temperature multi-process coupling test system for coal-rock mass was developed autonomously.It can be used to simulate the stress deformation of coal-rock mass,gas desorption/diffusion,gas migration and temperature transmission under different ground stress,temperature and fluid pressure.The system mainly includes core clamping subsystem,fluid control subsystem,temperature control subsystem,operation control and data analysis subsystem.The loading stress of coal-rock sample in the core gripper is controlled accurately by the liquid automatic pressure pump.The special rubber sleeve can effectively block the contact between the external liquid and the coal rock sample by wrapping coal rock mass.The strain gauge is directly applied on the coal-rock sample,which overcomes the problem of non-contact measurement of stress-strain parameters and complex operation processes of many traditional instruments.The combined heating method of programmed temperature control and electric blanket is adopted to realize the controllable and adjustable environment temperature of test pipeline and coal-rock sample,and break the temperature limit which is lower than 100℃ during water-bath heating.The system operation interface is developed based on LabVIEW visual graphic programming language and platform,which can collect and analyze data in real time.The mechanical and permeability reliability of the test system was verified through the MTS815 test system and the standard permeability core.This system was applied to carry out experiments related to coal permeability evolution under temperature-stress coupling and CO2 ad/desorption process under stress loading.The experimental results are consistent with the theoretical and practical cognition.