SPECIFICS OF DIAGNOSTICS OF TECHNICAL CONDITION OF TRANSPORT AND TECHNOLOGICAL SYSTEM “MINING GAS PIPELINE – MINE WORKING”

The purpose of the paper is to analyze a deformation mechanism of the mine degassing pipelines to forecast their spatial changes in terms of intensification of underground mining of coal-gas seams. Methodology. The paper deals with expert assessment of the available approaches to diagnostics of technical condition of mine degassing pipelines, which are constructed within the in-seam underground mine workings with the floor rocks prone to heaving. The results of scheduled surveying measurements of technical condition of in-seam development workings have helped identify the potentially hazardous zones of rock mass deformation and indices of changes in spatial location of section degassing pipelines mounted in those mine workings. To determine the operating modes of a degassing pipeline under such operating conditions, a computer model of interaction of the elements of transport-technological system “mine gas pipeline – mine working” has been developed Findings. Diagnostics of technical conditions of the mine gas transmission lines and examination of their dismantled components have helped understand that deflections, mainly resulting in water accumulation zones, intensive corrosion of internal pipe walls, and mechanical depositions of coal and rock dust take place right within the flange connection areas. Formation of such zones is argued by health of the degassing pipeline as well as mine air inflow. Availability of internal corrosion, water accumulations, and mine air inflow decreases substantially capacity of the underground gas transmission line inclusive of qualitative characteristics of the captured methane-air mixture and efficiency of MDS on the whole. Originality. New approaches to diagnostics of technical condition of mine degassing gas pipeline in difficult mining and geological conditions of development of gas-bearing coal seams are substantiated and it is offered to consider indicators of their functioning as interacting in space and time transport-technological system "mine gas pipeline - mining". Practical implications. The operational parameters of mine degassing systems notes that the equipment performance with the least underpressure losses created by vacuum pipes requires that the degassing pipeline should have minimum hydraulic resistance of the gas transmission network. Pipeline aeration from the mine workings and water accumulations should be prevented by means of qualitative hermetic sealing of its flange connections as well as the pipeline straightness with the corresponding pitches. Consequently, the basic requirements for operating mine degassing pipelines involve their design profile, tightness of flange connections of pipes as well as operative control of the facility health.

How to analyse the injury based on 24Model: a case study of coal mine gas explosion injury

BackgroundCoal mine gas explosion injury has caused mass casualties, which have resulted in widespread concern.MethodsIn order to prevent gas explosion injury in coal mine, 24Model is proposed to analyse the risk in this paper. 24Model is a human-oriented and organisation-oriented risk analysis method. Based on the 24Model, we propose a general procedure for analysing the causes of injury within the organisation.ResultsA coal mine gas explosion case was analysed using the 24Model and the proposed analysis method, and the evolution of injury and the interaction of various causes was showed, and 6 unsafe conditions, 25 unsafe acts, 13 safety knowledge, 13 safety management systems and 13 safety cultures were obtained.ConclusionCase analysis results show that by using the 24Model and analysis method the proposed effect can help employees to clearly see the evolution and identify the causes of the injury, to better understand the logical relationship with the causes of the injury, improve the effectiveness of training and effectively prevent similar injury. The case study provides a practical procedure for injury investigation and analysis, and thus, preventive measures can be made according to the various causations at different levels.