Research On Liquefaction Transmission And Stability Mechanism Of Coal

Since the fundamental of China in last century to present time,because advantages of convenient,flexible,easy to co-ordinate arrangements and so on,the main method of short distance transportation of coal basically relies on highway.With the development of society and the raising of the public awareness,a series of short comes of the highway transportation has appeared at the time.Solid waste and gas exhausting in the highway transporting take the primary environment contamination.Car,the moving source,owns the shortcome of difficult to contamination control and management Meanwhile,this straightforward transportation has encouraged fixed bed combustion technology,while holding back the more efficiency and more economy combustion technology—fluidized bed combustion technology.Therefore,there is a significance of novel transportation technology construct.This research takes reference of hydraulic fracture transmission technology—using viscoelastic liquid to transport coal powders,cracked precisely,as same as proppant transportation—establishes a novel transportation technology which is called coal liquefied transportation.Liquid characteristics changing are required so as to achieve the transportation goal.According to the Stokes sedimentation law,the sedimentation velocity is controlled by three primary factors,diameter contribute of coal powder,viscosity of liquid and the density differences of powder and liquid.Due to the coal density is a constant,the research turns to study the density of liquid.The experiments' result provides the changing range of those three factors,combined with the economic cost—decision-making object,and coal powder suspension or not—constraint condition,a multiple objective programming question for coal liquefied transportation optimal was built.MATLAB software is used to solve the problem,the result shows the best scheme is coal mesh numbers contribute ranges 100 to 120,xanthan gum concentration is 0.25%and the liquid density is 1.15g/cm3.The exact programming languages are given in the article.Surfactant influence experiment shows that ionic surfactant do expend the sedimentation time of coal powder,and the reason why coal powder turn to more stable is that lipophilic group of surfactant link to the surface of powder and ionic hydrophilic group arrangement makes the outside become electriferous,which leads to compressing twin electrical layers structure that stabilize the powder in solution.Sodium dodecyl benzene sulfonate(SDBS),anti-calcium surfactant,does have ability to stabilize the powder,but no economic value.The temperature influence on powder stability relies on the influence of xanthan gum viscosity.The viscosity-temperaturecurve shows that as the temperature goes high,the viscosity of the solution decrease;which provides negative influence of powder stability,in another word,temperature should be as low as possible.Liquid for liquefy transportation can be gel-broken easily by adding 1000mg/L hydrogen peroxide(H2O2),and the viscosity of gel-breaking liquid is as low as 2mPa-s,besides the solution can be used cicely.In this work,a novel transportation technology has been constructed for coal transporting,and experimental studies give the basic information of factor range,which helps computer to solve the problem,using mathematic method to optimal the project.This transportation technology overcomes the environment contamination of past highway transportation from the source and encourages the application of fluidized bed combustion technology,which has important significance in Cleaner Production.