| Gas extraction is a fundamental measure to solve the gas disaster prevention and control in mine.Most of coal mine in our country adopt gas extraction water ring vacuum pump,which has a simple and compact structure,can isothermal compression gas,and can effectively draw flammable and explosive gas containing dust water.However,gas extraction pump has obvious shortcomings of low efficiency and high energy consumption.The author’s team carried out research on green energy saving technology of gas extraction system,and adopted polymer drag reducing solution to significantly reduce the power consumption of gas extraction pump.The practical application problem of polymer drag reducer is that there is irreversible shear degradation.Studies over the years have found that biological polysaccharide solution has certain drag reduction ability and shear resistance.Therefore,the study of biological polysaccharide polymer solution is of great significance to the study of the operation drag reduction law and effect of gas extraction water ring pump.In this thesis,laboratory experiment and field engineering application are combined to carry out a study on the drag reduction characteristics of biological polysaccharide solution on gas extraction water ring pump,which provides some reference for the research on green energy saving technology of gas extraction water ring vacuum pump.(1)The rheological properties of five materials and one compound material were studied.According to the results of viscosity test,with the increase of running time,the viscosity of drag reducing solution showed a decreasing trend.With the increase of the concentration of drag reducing solution,the viscosity of drag reducing solution also increased,and the viscosity decreasing rate of drag reducing solution decreased.The decreasing rates of viscosity were 4500 ppm Working medium A solution,Working medium E,Working medium B solution,Working medium D,Working medium C solution,and the decreasing rates were 35.04%,34.23%,33.76%,31.6%,30.85%,respectively.According to the results of viscoelastic test,for Working medium A solution and Working medium C solution,the viscoelastic modulus of the drag-reducing solution increases with the increase of angular frequency,and the viscoelastic is enhanced with the increase of the concentration of the drag-reducing solution.The viscoelastic modulus decreases gradually with the increase of running time.For Working medium D,Working medium B solution and Working medium E,the viscoelastic modulus of drag reduction solution did not change greatly with the change of angular frequency,concentration and time.The drag reduction mechanism of the complex solution has no obvious relationship with viscosity,but with viscoelasticity.(2)The experimental platform of gas extraction water ring pump was built.Drag reduction effects of five different materials at different concentrations were tested respectively,and the changes of running power before and after adding pure water and drag reduction solution were compared.The results show that the higher the concentration of drag reduction solution,the better the energy saving efficiency.With the increase of concentration,the relative energy saving efficiency and shear stability of the solution were also enhanced.The average energy saving efficiency from high to low was 4500 ppm Working medium E,Working medium B solution,Working medium A solution,Working medium C solution,Working medium D solution,respectively corresponding to 13%,12.8%,12.4%,11.7%,11.5%,the average energy saving efficiency of 4500 ppm Working medium E was the best;The average relative energy saving efficiency from high to low is 4500 ppm Working medium C solution,Working medium D,Working medium B solution,Working medium E,Working medium A solution,corresponding to 92%,83%,81%,79%,73%,Working medium C solution of shear stability is the best.In the comprehensive analysis of single drag reduction solution and complex drag reduction solution,the 1:5 Working medium A and Working medium B 4500 ppm complex solution has the best energy saving efficiency and the best comprehensive energy saving effect.(3)The No.1 and No.2 pumping pump systems in Zhangji Coal Mine have been reformed.The polymer extract suitable for the water quality of Zhangji Coal mine was synthesized and the energy saving effect of the pumping pump energy saving system was studied.The field measurement results show that during the operation of the energy saving system,the average power consumption decreases from 17,040kw·h/day to13,440kw·h/day,the power saving is 3,600kw·h/day,and the energy saving rate is21.1%.Further,According to the price of polymer drag reducing liquid,pump liquid consumption and electricity price,calculate the pump net energy saving rate is 17.9%,the net energy saving benefit of a single pump is 700,000 yuan/year,with important economic benefits and environmental benefits.This thesis has 49 figures,14 tables and 67 references. |
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