煤炭地下气化火焰工作面高温气体作用于气化通道周边煤岩体，使其呈单向受热状态，煤岩体法线方向的热损伤和热破裂呈现明显的梯度分布规律。为了对煤岩体在单向高温热作用下的热损伤特性规律进行研究并提供新的实验手段，自主研发设计了煤岩单向加热模拟试验装置，该装置主要包括加热和温控单元、温度和热应力监测单元、声发射监测单元、约束和加载单元4个部分。采用的试样尺寸为50 mm×100 mm，最大单向加热温度为600 ℃，热应力监测量程5 MPa。介绍了试验装置的主要功能和技术参数、结构与关键技术以及研制过程中的技术难点和解决方案等，并使用本试验装置开展了相关实验。本试验装置的显著特点包括:① 实现单向高温加热和单向约束，模拟煤岩体受热状态;② 实现加热过程的温度、热应力和声发射的多信息同步监测，便于多因素耦合分析;③ 边界加热温度程序可控，可模拟不同类型受热边界条件。采用该试验装置进行砂岩的单向高温加热试验，可以揭示煤岩体试样单向受热条件下高度方向上温度、轴向热应力以及热破裂声发射特性规律，并通过主频分析，进一步揭示煤岩体热破裂的演化规律。该试验装置适用于地热开发、煤炭地下气化等特殊环境下煤岩体受单向高温热源作用的热物理现象和规律的探索研究，为其提供新的实验手段。

The high temperature gas in the flame working face of underground coal gasification (UCG) acts on the coal and rock mass around the gasification channel,which makes it in a unidirectional heating state.The thermal damage and thermal fracture in the normal direction of the coal and rock mass present an obvious gradient distribution law.In order to study the thermal damage characteristics of coal and rock mass under unidirectional high temperature and provide new experimental means,a unidirectional heating simulation test device for coal and rock mass was independently developed and designed.The device mainly includes four parts:heating and temperature control unit,temperature and thermal stress monitoring unit,acoustic emission monitoring unit,constraint and loading unit.The size of the sample used is 50 mm×100 mm,maximum one way heating temperature is 600 ℃,and the range of thermal stress monitoring is 5 MPa.The main functions,technical parameters,structure and key technologies of the test device,as well as the technical difficulties and solutions in the development process were introduced,and relevant experiments were carried out with the test device.The remarkable features of the test device include:① Realizing unidirectional high temperature heating and unidirectional constraint to simulate the heating state of coal and rock mass;② Realizing multi information synchronous monitoring of temperature,thermal stress and acoustic emission in the heating process,which is convenient for multi factor coupling analysis;③ The boundary heating temperature program is controllable,which can simulate different types of thermal boundary conditions.The unidirectional high temperature heating tests of sandstone were carried out by using the test device developed,which can reveal the characteristics of temperature,axial thermal stress and acoustic emission characteristics of thermal fracture in the height direction of coal and rock samples under unidirectional heating conditions,and further reveal the evolution law of thermal fracture of coal and rock bodies through dominant frequency analysis.The experimental device is suitable for exploring and studying the thermophysical phenomena and laws of coal and rock mass under the action of unidirectional high temperature heat source under the special environment of geothermal mining and underground coal gasification,and provides a new experimental means.

1 试验装置主要功能与技术参数

   1.1 主要功能

   1.2 主要技术参数

2 试验装置的结构与关键技术

   2.1 加热和温控单元

   2.2 温度和热应力监测单元

   2.3 声发射监测单元

   2.4 约束和加载单元

3 设备研制的技术难点

   3.1 单向加热和固定边界约束

   3.2 加热方式

4 砂岩单向加热特性试验

   4.1 试样准备

   4.2 试验步骤

   4.3 高温下砂岩热损伤和热破裂特性

5 结论