Advanced Materials Research Vols. 468-471

Abstract: Three experiment factors including outlet blade angle β2, b2 and impeller wrapping angle θ are selected for optimal design of a non-overload pump. Numerical simulation with CFD is employed to reduce the cost and shorten the design period. The time-averaged Navier-Stokes equations of 3D steady flow in the pump are calculated by CFD based on the SST k-ω turbulence model and standard wall function. The structured grids of different qualities are used in one scheme for comparison to confirm that the results are not influenced by the quality of mesh. The optimal scheme is obtained when β2, b2, θ are 20 degrees, 7mm, 170 degrees, respectively. Its pressure head is 89.75m achieving the pump efficiency of 57% at maximum. The performances of NCPs at other working conditions satisfy the requirement of heads and efficiencies from China National Standard. The shaft power reaches to 15kW at 1.5QR (35.5m3/h), showing that the non-overload performance is also significantly improved. The impeller is considered as the optimal scheme and produced for experiments. Experiment data prove that it is effective and reliable to improve a non-overload pump’s performance by maximum flow design method and non-overload pump design method. The results provide a reference for increasing the efficiencies and pressure heads of non-overload pumps at multiple operating conditions.

Abstract: Because of large equipment with complicated structure, many kinds of components and tough management, various factors which impacting the equipment exerting its effectiveness level and techniques of handling for their quantification are discussed and the consumed law is studied aiming at fully exerting the equipment’s effectiveness. The fuzzy matrixes are determined and the comprehensive evaluation matrix calculated by the theory and methods of fuzzy comprehensive evaluation. Based on the results from quantitative analysis, the spares’ importance in the process of management and supply is made certain. It provides basis for the spares’ scientific management and supply.

Abstract: With the aim of reducing the energy consumption in the cobalt crust crushing process, the spiral mining head energy consumption is taken as the objective function. And mining head diameter, cutting pick intercept, width of cutting edge and cutting pick installation angle are selected as the optimum design variables. The constraints of each parameter is given. Genetic algorithm is applied to optimize this model. The optimized results suggest that the energy consumption is reduced by 38.3%. And it also improves the performance and economic efficiency of the spiral mining head.

Abstract: The nonlinear contact mathematic model is constructed for the bolt joint structure on the fixed end of the Gelin column of die casting machinery and the FEM model and optimization mathematic model for the bolt joint structure are realized by software of ANSYS and the APDL language embedded in it. The structural parameters of different type of thread in Gelin column are optimized. After the comparison of equivalent contact stress in the region of the different type of the bolt joint in Gelin column, it is shown that there is more even load-bearing characteristics with the trapezoidal thread than zigzag thread and the maximum of the equivalent contact stress with the trapezoidal thread is decreased about 41% of that in zigzag thread which can effectively improve lifecycle and anti-fatigue performance of the threaded joint in the gelin column.

Abstract: According to the transverse plate electrostatic precipitator with high velocity collect dust theory, established the laboratory scale transverse plate ESP combines the hydrodynamic, static electrics. In this paper, experiment of ion concentration are carried using the transverse plate ESP. (The laboratory scale transverse plate electrostatic precipitator self-designed) system. The influence rules of the factors to ion concentration are examined such as distance between the export, the discharge electrode, applied voltage, internal of dust collection plates and the gas velocity. According to the experiment result, the ion concentration can increase about 109/cm3, when the working voltage is 18kV, the gas velocity is 4m/s, the distance of effective dust collecting plate is 40mm. The ion concentration of electrostatics precipitator system reaches the maximum and is above 109.

Abstract: On the basis of hydrogeology investigation, the groundwater, river water, seawater and the medium in the lower reaches of the Dagu River were collected respectively, their compositions and nature were determined, then the permeability and the regularity of the main ions were determined during simulating seawater intrusion with transfusion installment. Finally, hydro-geochemical action was studied with the numerical simulation method during seawater intrusion. The result indicts that the mineral dissolution and precipitation take place with ion exchanges, Calcite is in a supersaturated situation after the percent of seawater reaches 40％; the saturation index of Gypsum arises gradually at first, and then decreases after the peak, finally it increases again but it is always in unsaturated condition from beginning to the end.

Abstract: UIG regional cooperative innovation could integrate the resources of Universities, Enterprise and government, Complement each other, and achieve sustainable development. This paper analyses the effects of UIG regional cooperative innovation based on sustainable development, builds a comprehensive and integrated evaluation system, and evaluates the effects comprehensively by using rough sets theory and support vector machines method. The results show that, the mode of UIG cooperative innovation is suitable for China's current economic and social development, adapts to the need of national innovation system construction, and has a good development prospect.

Abstract: Optimized operation of compressor stations is of great importance for energy saving of Sichuan-East transmission pipeline at high flow rate. However, it is difficult to build an accurate mathematical model to describe the performance curves of centrifugal compressor due to the wide range of rotary speed. The achievements of this thesis are shown as follows. Firstly, the mathematic models for performance curves of the Euramerican centrifugal compressors were established. The optimized regression coefficients were solved rapidly and accurately by Zhan Chong-xi method. Secondly, the compressor ratio, polytropic efficiency, shaft power, outlet pressure, polytropic head and outlet temperature of centrifugal compressors at different flow rates and rotating speeds were calculated accurately. These results provides excellent modeling methods and reliable mathematics models of operating and managing compressor of Sichuan-East gas transmission pipeline. It was found that the lowest correlative index of six optimized models was 0.9772, and the maximum error is 4.2869%.

Abstract: The aim of this work was to develop an optimization tool consisting of a two dimensional heat transfer model and an optimization algorithm to determine the improved cooling conditions for the sprays zones of a real continuous caster. The mathematical model of cooling process was used to calculate the strand temperatures along the machine. An optimization algorithm based on an Adaptive Evolutionary Particle Swarm Optimization (AEPSO) approach was used to solve an optimal control of secondary cooling water distribution according to certain metallurgical criteria and some technological constraints, which enhance the global exploratory capability and avoid pre-mature convergence. The simulation results show that it can improve the repeatability and quality of solution.

Abstract: The working conditions for construction vehicles (wheel loader, bulldozer, etc.) are very complicated and the operating loads change frequently and sharply. This result will lead to lower powertrain efficiency. In order to maintain the high efficiency of construction vehicles equipped with automatic transmission, an optimal efficiency shift (OES) schedule with 3-parameter (vehicle speed, throttle opening, and hydraulic pump pressure) is proposed and designed by creating and analyzing the powertrain model. A dynamic simulation model using the OES schedule for the construction vehicle has been established by MATLAB/Simulink. The simulation results show that the 3-parameter shift (3PS) schedule is superior to the 2-parameter (vehicle speed and throttle opening) shift (2PS) schedule in energy saving.