矿用钻孔超声流量自适应检测技术

为了更好地实现煤矿井下瓦斯抽采钻孔端流量监测，针对管路内介质成分复杂、纯净度差、稳定性差等因素对抽采流量参数测量准确性影响的问题，提出以时差法为测量原理，以双阈值比较法为检测方法，设计了一套矿用钻孔超声流量自适应检测系统。通过分析影响双阈值比较法测量准确性的关键问题出发，设计了检测系统的总体方案，并对其中激励信号放大电路、接收信号调理电路及由峰值检波电路与增益控制电路构成的自适应电路几项关键模块进行了详细地介绍，叙述了检测系统运行软件的工作流程。通过工况环境适应能力测试与准确度性能检验，对检测系统的功能与性能进行了检验，检验结果表明，该系统能够适应瓦斯抽采钻孔管路内的工况需求，实现高精度的气体流量测量。 

The adaptive detection technology of ultrasonic flow in mining boreholes

For a better flow monitoring at the borehole of underground gas drainage in coal mines, and in response to the influence of factors such as complex composition, poor purity and poor stability of the medium in the pipeline on the measurement accuracy of drainage flow parameters, a set of adaptive detection system of ultrasonic flow for mining boreholes is designed with the time difference method as the measurement principle and the double threshold comparison method as the detection method. The overall scheme of the detection system is designed based on the analysis of the key problems affecting the measurement accuracy of the double threshold comparison method, and several key modules of the excitation signal amplification circuit, the received signal conditioning circuit and the adaptive circuit composed of the peak detection circuit and gain control circuit are discussed in detail. The workflow of the operation software of the detection system is described. The function and performance of the detection system are tested through the test of adaptability to working conditions and environment and the accuracy performance test. The test results show that the system can adapt to the working conditions in the gas drainage drilling pipeline and realize high-precision gas flow measurement.