Advanced Materials Research Vols. 712-715

Abstract: Nonlinear dynamic-behavior analysis of rotor system under different parameters is presented. The derivation of nonlinear dynamic equations under the action of rub-impact force is set up basing on Jeffcott model, and the system bifurcation characteristics and influences has been investigated under the ratio of operating angular velocity and the rotor’ natural angular velocity influence by numerical analysis. Bifurcation and dynamical behaviors of nonlinear of system with the changes of argument (that is the ratio of operating angular velocity and the rotor’ natural angular velocity) under several specific parameters are analyzed. The results show that the ratio, rotor eccentricity and rotor stiffness have great effect on the dynamical behaviors of nonlinear system.

Abstract: In drainage and mining of the coal bed methane(CBM),pump valve jams caused by the settlement of pulverized coal particles directly affect the normal production of the coal bed methane(CBM).From the study of the pulverized coal particle size,this paper summarizes the law of the pulverized coal particle size change in various stages of the coal bed methane(CBM) production well drainage and ming.By analyzing the pulverized coal particle velocity distribution along the pump cylinder,the viewpoint that the pulverized coal particle has a higher axial velocity in the central part of the settlement and has a lower velocity near the wall surface is put forward to.Based on the theory,the motion track equation of the pulverized coal particle can be got by calculation.Under the condition of considering buoyancy,fluid resistance and pressure drag,instant drop speed of the pulverized coal in water is calculated.

Abstract: Port tyre cranes have the drawbacks of high energy consumption and serious pollution, whose potential is the most important latent energy being wasted. Some attempts to recycle the potential of tyre crane have attained certain energy-saving result, but their stability and reliability need to be verified. Based on the specific conditions of port tyre cranes with complex structure, a novel potential energy recycling system was proposed, with new applications such as a coaxial motor with dual armatures and variable torque and the nonlinear weighted coding dynamic magnetic technology. The results show that this system has characteristics of high energy utilization, excellent energy-saving effect and stability.

Abstract: To open up a new way of green energy, the piezoelectric harvesting technology from road vibration is proposed. Research status at home and abroad is reviewed, some existed problems are pointed out. With the software of ANSYS, the arrayed space between piezoelectric vibrators and the material and thickness of substrate are chosen in the light of higher harvesting energy and better coupling properties. From the simulation results, can a unit of 280*280*20mm be determined. When it is embedded under 40mm asphalt concrete pavement, 1.785MW electric power can be harvested from each traffic lane and per kilometer. This shows that application of the piezoelectric harvesting unit has very nice optimistic prospects.

Abstract: The auxiliary heating system with heating power of 6 MW has been built on HL-2A Tokamak. The High-Voltage modulators based on TM703FB vacuum tube are introduced, including the principle of modulator, system composing, and experiment results. Moreover, the waveform of protection while short-cirtuit is shown.

Abstract: The computer numerical simulation of swirling burner in cold state was taken in this paper. The swirling intensity and the expansion cone angle of the secondary air were the main simulation content. The outlet flow field and form of the combustor were got through the simulation, and the comparison of the airflow diffusion angle and the return flow zone were analyzed, and then the guidance suggestions on the design modification and operation adjustment of the existing swirl burner were proposed.

Abstract: Previous research on thick pastes such as coal slime was using two-cylinder piston pump as power equipment.Since the pressure fluctuation was big,flow measurement was not that accurate. In order to solve the problem, this paper will presents a feasibility study on conveying coal slime by single-screw pump. We used a single-screw pump as power equipment which conveying the coal slime with mass concentration of 64.5%-67.5% . Furthermore, we measured flow rate by self-developed flow meter and completed four groups of test. Through the data such as pressure, flow characteristic obtained from the tests, we have summed up the maximum mass concentration,pressure and flow rate.The results demonstrate the feasibility of conveying coal slime by single-screw pump.The original experimental data and the processing results conform to the theory of law.This paper provides the useful reference for the application of single-screw pump in the field of coal slime pumping.

Abstract: The diaphragm valve is the key component of the deashing device in a pulse bag filter. It affects the investment cost, operation cost and the floor area, as well as the wide application of the dust removers on jetting performance directly. The development of a low pressure valve with a diameter of 100 was optimized by orthogonal test. The large-sized low-pressure diaphragm valve with the jetting and technical economic performance has been widespread used in market, it was better than small-sized one by parameter comparison between another similar one, the valve body resistance is decreased with the rise of diameter.

Abstract: Modal analysis is one way of studying the dynamic characteristics of the mechanical. In order to study the dynamic characteristics of machine tool,numerical machine model is set up with finite element analysis software,of which validity is verified by experimental modal analysis.The experimental test also provide the boundary conditions, so as to further structure modification and dynamic characteristic design

Abstract: In this paper, a Hamiltonian formulation of the Cosserat rod model is proposed. The model, based on the Cossert rod theory incorporates shear, elongation, flexure and twist deformation, is of multi-symplectic structure. A multi-symplectic algorithm is employed to discretize the equation and a numerical example is giving.