Research On Cuttability Of Coal Based On Single Pick Cutting Experiment

At present,China's coal mining is gradually transferred to the deep part.Automatic mining of deep dangerous coal seam is a scientific problem to be solved urgently.Cutting property of coal and rock is the key technical factor of the self-adaptive cutting of the shearer.In order to achieve the unmanned surface mining,it is necessary to realize the intelligent perception cutting.Specific energy of cutting is an important index to evaluate the cuttability of the coal and rock.In this paper,the cuttability of coal and rock is studied through single pick experiment.The main conclusions are as follows:1)Cutting temperature and cutting parameters during cutting process are analyzed.(1)The relationship between cutting temperature and cutting speed: there is a positive correlation between cutting temperature and cutting speed.The relationship between cutting depth and cutting temperature: with the increase of cutting depth,most of the cutting temperature curve is "Z" curve.In a few cases,the curve of "lower concave" rises.The relationship between cutting temperature and F value shows that the cutting temperature decreases with the decrease of F value of coal rock.(2)Through the sensitivity analysis of the cutting parameters,the sensitivity of the parameters to the cutting temperature is shown as cutting depth > cutting speed > coal rock properties(prhi hardness).Therefore,the regulation priority of the cutting temperature is in turn: cutting depth,cutting speed,and coal properties(prinir hardness).2)Analyze the cutting specific energy consumption during the cutting experiment,and draw the following conclusions.(1)Theoretical analysis of the cutting ratio energy consumption is carried out,and the calculation method of the real time cutting ratio energy consumption is derived theoretically,and it is pointed out that the real time cutting ratio energy consumption can be measured by the existing means.(2)The variation of coal cutting specific energy consumption with cutting depth is mainly manifested as the average cutting energy consumption decreases with the increase of cutting depth.The "critical cutting depth" appeared in both H3 and H2 coal,that is,with the cutting depth increasing before the "critical cutting depth",the reduction rate of the cutting ratio is larger than the energy consumption,and the average cutting rate is smaller than the energy consumption after the "critical cutting depth".In the experiment,the cutting specific energy consumption of L1 coal decreased with the increase of cutting depth,and the cutting specific energy consumption gradually decreased,and the specific energy consumption decreased little.The cutting specific energy consumption showed a trend of decreasing first and then increasing with the change of coal hardness.3)By analyzing the sensitivity analysis of coal rock cutting ratio energy consumption and cutting parameters,and the sensitivity analysis of cutting temperature change rate and cutting parameter,it is proved that it is feasible to evaluate the temperature change rate in the cutting process as the coal rock cutability evaluation,and can provide the basis for the real-time evaluation of coal rock cutting property.