Advanced Materials Research Vols. 986-987

Abstract: Paper in view of the dense medium coal preparation process control, carefully study the density of heavy medium coal preparation control system of the internal structure, main characteristics, control laws and the design method. Open field bus control structure is adopted in the system, Siemens S7-300 programmable controller is responsible for control, executing agencies responsible for enforcing the orders of the PLC to control the related parameters. Through the practice, this control system is powerful, easy to operate, reliable performance, has certain theoretical significance and practical application value.

Abstract: Designed a set of hydraulic experimental system for testing some performance parameters of oil drilling and production equipments and demonstrating its functions and principles. This system provided hydraulic environment for pumping unit, ESP (Electric Submersible Pump), well control devices, drilling and workover experiments, collected and analyzed experimental data, provided an important platform for the research and development of oil drilling and production equipments and experiment teaching. The functions and principles of hydraulic system’s components are introduced, and some main components are selected and designed in the system.

Abstract: . Aiming at the purification of rotor center’s orbit, a new approach was presented by using ensemble empirical mode decomposition (EEMD). Ensemble empirical mode decomposition decomposed a complicated signal into a series of intrinsic mode functions (IMFs). Then according to prior knowledge of rotating machinery, chose some interested IMFs and reconstructed the needed signal. By doing this the noises would be eliminated successfully. At last the purification of rotor center’s orbit was obtained by extracting the useful signal component. Simulation and practical results show the advantage of EEMD in noise de-noising and purification of rotor center’s orbit. This method also has simple algorithm and high calculating speed; it provides a new way for purification of rotor center’s orbit of rotating machinery.

Abstract: To provide steam of appropriate quality and to improve the efficiency of steam-water separation over corrugated plates, it is necessary to study the condensation behavior of wet steam moving over a corrugated plate separator. In this paper, classical nucleation theory and a droplet growth model are used to describe the process of wet steam condensation on corrugated plates. The CFX software water droplet condensation model was employed to simulate the process and to allow analysis of the characteristics of wet steam condensation. The results show that: (1) the nucleation rate increases gradually over time and exhibits a positive correlation with the temperature of the wet steam, (2) departure from the saturated state decreases gradually along the flow direction, leading to a concurrent decrease in the steam condensation rate and (3) the steam condensation rate is elevated with increases in the local pressure gradient.

Abstract: The exhaust noise, which falls into low-frequency noise, is the dominant noise source of a diesel engines and tractors. The traditional exhaust silencers, which are normally constructed by combination of expansion chamber, and perforated pipe or perforated board, are with high exhaust resistance, but poor noise reduction especially for the low-frequency band noise. For this reason, a new theory of exhaust muffler of diesel engine based on counter-phase counteracts has been proposed. The mathematical model and the corresponding experimental validation for the new exhaust muffler based on this theory were performed.

Abstract: In this paper, a finned tube condenser performance test platform by using hot water as heat transfer medium in the pipe was established. The air side correlations of pressure drop and heat transfer were acquired based on lots of testing datas.A segment by segment model of the finned tube condenser used in these correlations was proposed and a simulation program was developed by using Visual C++ programming tools. Experiment and simulation results show that the air side correlations of pressure drop and heat transfer are fitting well with experimental datas. The deviation between the experimental and calculated values is within ±5%.The deviation of Nu Number is within ±10% and the deviation of the pressure loss is within±15%.

Abstract: Currently, corrosion of offshore crane booms is serious and badly affects equipment performance and working safety. Obviously, analysis of the corrosion is necessary. In this paper, as an actual case, the boom FEM of 320t pipe-laying crane is built to analyze its double points corrosion based on analysis of single point corrosion. By analyzing stress concentration and stress distribution of different distance for double corroded points, which can be axially arranged or circularly arranged, we try to obtain some affected trends.

Abstract: Reliability of IGBT power module is one of the biggest concerns regarding wind power system, which generates the non-uniform distribution of temperature and thermal stress. The effects of non-uniform distribution will cause failure of IGBT module. Therefore, analysis of thermal mechanical stress distribution is crucially important for investigation of IGBT failure mechanism. This paper uses FEM method to establish an electrical-thermal mechanical coupling model of IGBT power module. Firstly, thermal stress distribution of solder layer is studied under power cycling. Then, the effects of initial failure of solder layer on the characteristic of IGBT module is investigated. Experimental results indicate that the strain energy density and inelastic strain are higher which will reduce reliability and lifetime of power modules.

Abstract: The velocity field and the associated tangential tension corresponding to the flow of the viscoelastic fluid over an infinite rigid plate are determined in this paper. The characteristic of the non-Newtonian viscoelastic fluid flow is analyzed using the Stehfest method of the numerical inversion of Laplace transform. It indicates that the flow of the viscoelastic fluid is very sensitive to the material constants. Finally, some comparative diagrams concerning the velocity and tangential tension profiles are presented.

Abstract: By applying the seamless data interface between SolidWorks and ADAMS, the model of the internal combustion compressor was imported. The internal combustion compressor virtual prototype model was established, the kinematics and dynamics analysis were completed, and the dynamic load on crankshaft was given. After we use finite element analysis software ANSYS, the modal analysis of crankshaft were accomplished, the modes of vibration and response frequency in the first five orders were obtained. The mixed body dynamics model was established, and the crankshaft force curves under the rigid body and flexible body morphology were obtained.