Vibration response difference of caving mechanism under coal rock impact based on mechanical–hydraulic coupling

Abstract

Top coal caving in fully mechanized caving mining will cause an irregular impact on the caving mechanism of hydraulic support. The vibration response of the caving mechanism varies under different forms of impact. This response difference is a prerequisite for new coal rock identification technology in intelligent mining. Therefore, this work studies the difference in vibration response of the caving mechanism under different forms of impact. An innovative mechanical–hydraulic coupling system model of the caving mechanism impact by coal rock is established. The metal plate impact test proved the significant difference in vibration response of the caving mechanism under coal rock impact of different materials. Afterward, a more improved mechanical–hydraulic co-simulation model analyzed the difference in the vibration response of the caving mechanism under different rock materials, volumes, velocities and impact positions. The results show that the vibration response is more intense under rock impact than under coal impact. A lower position, a faster velocity and a larger volume correspond to a more noticeable response difference in the caving mechanism. The vibration and fault sensitive areas of the caving mechanism are determined. This study has a reference significance for improving the caving mechanism's structural design and failure prevention. The conclusions provide guidance for a new intelligent coal rock identification technology based on vibration signals.

Top coal drawing law for an extra thick coal seam under the single round group drawing method

“…To achieve the highest economic benefits of mining and sorting, the IGC threshold at the drawing openings was set to 35% (openings should be immediately closed when the volume of gangue reaches approximately 1/3). To accurately monitor the IGC at the openings, hyperspectral and coal gangue impact–vibration–signal recognition technologies were used to identify the coal gangue at the drawing openings during drawing 32 . When the IGC reached 35%, the drawing openings were closed.…”

Application of an Automated Top Coal Caving Control System: The Case of Wangjialing Coal Mine

“…An internal circular buffer is initialized during system operations to facilitate storage of the collected signals in a first-in, first-out manner. The algorithm processing thread retrieves and processes the data from one end of the buffer while marking the retrieved data blocks [35]. The workflow for data processing and analysis in the system is depicted in Figure 4.…”

“…Depending on the different frequency ranges of the electromagnetic waves, ground-penetrating radar [25][26][27], terahertz signals [28,29], and electron resonance identification [30] are additional modalities of detection. In the context of coal caving, numerous scholars have introduced and experimented with various techniques involving radiation [31], visuals [32,33], vibrations [34,35], sounds [36], and infrared spectroscopy recognition [37][38][39] to accurately identify the realtime caving status of coal and gangue. These technological principles have provided valuable experience for the automated control of top coal caving in LTCC mining.…”

Coupling vibration analysis of heat exchanger tube bundles under different stiffness conditions

“…Heat exchangers occupy a large proportion of industrial investment, accounting for about 30% of the total investment in chemical equipment, 40% of the total investment in oil refining production equipment, and 20% of the total investment in nuclear power plant equipment. The shell-and-tube heat exchangers have the highest application rate in the industrial heat transfer field, accounting for about 70% of the current heat exchange equipment 4 , 5 .…”