Advanced Materials Research Vols. 201-203

Abstract: The 2D axisymmetric, real gas model was developed to calculate the ejector in the ejector cooling system. The calculation of the real gas model occupies more computer resources, but its result can be more authentic. The CFD model was validated with available experimental data. Predictions at the operating conditions in the ejector cooling system were discussed. The aim of the prediction is to obtain the ejector performance in the non-design condition and variable operating condition. There is an optimum evaporator condition te=20°C (Pe=0.65bar) with the giving geometry parameters. In the calculation range, when te increase, the entrainment ratio would increase, and the system mechanical COP would also increase. In the paper, the cause of the result was analyzed using the CFD technique. The ejector entrainment ratio was affected by the operation condition and the ejector structure in the same time.

Abstract: Center injection in pentroof combustion chamber can reduce wall wetting and unburned hydrocarbon emission in wall guided combustion system, which is generally employed in DISI (Direct Injection Spark Ignition) engines. Once liquid phase LPG (Liquefied Petroleum Gas) is injected at a high pressure, flash boiling occurs severely, promotes mixing and reduces wall wetting in wall guided engine. Based on validating the feasibility of the models, this paper numerically simulates the mixing process of a center injection wall guided DISI engine in different conditions. The results show that a stratified charge can obtained at part load with late injection, whereas at high load the early injection can achieve a homogeneous mixture at the end of compression stroke.

Abstract: According to the structural characteristics of non-ball mill, using the neural network theory to select and measure point, set the failure mode, analyze and determine the cause of malfunction. The newly developed fault detection system was used to simulative detect fault. Through data processing, the results can be directly derived which could be fed back into the design of non-ball mill, thereby improving the design.

Abstract: This paper mainly introduces a novel linear air conditioner compressor which is driven by the linear oscillatory motor with two divided moving body, of which the Cylinder-piston assembly presents symmetrical distribution along the axial direction. The compressor dynamics equations were built and solved numerically with the fourth order Runge-Kutta method. in the meantime, this paper emphatically analyzes the influence of those factors, such as the intake pressure, the exhaust pressure, the suction gas superheat, the cooling degree, on the compressor performance at varied operating conditions. These works shows that improving the suction gas pressure and reducing the exhuast pressure can help to increase the refrigeration capacity and energy efficiency ratio of the air conditioner compressor. Those analysis results provide theory foundation for design,development, and engineering application of this linear air-conditioner compressor.

Abstract: Inertial confinement fusion has been concerned in the year 1963. It was from the 1970s that China began to study inertial confinement fusion devices, and got lots of achievements in recent decades. The development of Inertial Confinement Fusion has an important and special meaning, whether to the national economy, military applications or for basic research. This paper comprehensively discussed the process of several large-scale ICF laser devices, the major technical indicators and the main experiment related to the devices.

Abstract: SNCR (Selective Non Catalytic Reduction) system is proposed, with 40% methylamine aqueous solution as reducing agent to reduce NOx in diesel exhaust gas. The effect of injection position and volume on the reduction efficiency through the test bench is systematically researched. A three-dimensional model of a full-sized diesel SNCR system generated by CFD software FIRE is used to investigate the reduction efficiency under different temperatures. The simulated results have a good agreement with the test results, and it can be used to optimize SNCR system. The results can indicate the practical application of this technology.

Abstract: This paper puts forward a new kind of bidirectional DC/DC topological structure which is used in technology of lithium batteries .It adopts two-stage bidirectional topological structure which called half-bridge bidirectional converter and buck-boost bidirectional converter. This structure can achieve the transformation in the case of large voltage difference between input voltage and output voltage by DSP taking control of buck-boost bidirectional converter. This topological structure is authenticated in the environment of MATLAB/SIMLINK .The result demonstrates that the converter is stable, and can effectively realize bi-directional transformation between 3V battery voltage and 400V bus bar voltage.

Abstract: The task of this study is to find the optimal condition of designed High Concentration Reflected Photovoltaic (HCRPV) module by simulation method whose concentration ratio is set to be 872. This simulated optimal condition was then utilized to fabricate HCRPV module. In simulation, the focal length of first and secondary mirror, the slope angle and the length of light guide tube were the main parameters to be optimized. From simulation, the light collective efficiency, the energy uniformity, the shape of light spot diagrams can be obtained. It was found that square based pyramid light guide tube can effectively improve the uniformity of light. When the slope angle of square based pyramid shape of light guide tube is set to be 3 degree, the focal length of the first mirror is 60mm and the secondary mirror vertex distance is designed to be 93.1mm, the HCRPV module have the best performance. It was also found that the light collective efficiency can be reached to about 97.7% with these conditions. The Aluminum HCRPV module was then fabricated according to the optimal simulated conditions. As the solar energy of illumination is 650 W/m², the voltage on the multi-junction solar cell was measured to be 2.56V, the current was measured to be 0.68A. The corresponding power was about 1.74W. When the HCRPV module was coated with silver material, the voltage on the multi-junction solar cell was measured to be 2.7V, the current was measured to be 2.83A, as the solar energy of illumination is 800 W/m². The corresponding power is about 7.64W.

Abstract: When the large equipments and structures are installed, the flange joint type is one quick way. But how to make the two flanges concentric is one difficult problem. In the paper, a localization sensor and an auxiliary equipment is designed to make the two flanges automatic alignment based on the method of detecting the center of a half-baked circle.

Abstract: A new experimental fluidized bed reactor was investigated and designed which has been widely utilized for fast pyrolysis under different temperatures (T=727–973 K).The stresses of the reactor cylinder are analyzed using finite element method(FEM, ANSYS Inc., U.S.A ) based on the safety assessment, and the cylinder is designed for installing scheme. The result of ANSYS analysis shows that the stress unstable positions are nearby both ends of the cylinder. The results of analysis are shown that the designing stresses are not beyond the allow able ones. So the designing parameters can possess sufficient reliability, and the design scheme can completely satisfy the strength requirement. Certainty of the stress could offered the valuable instruction for the application of the equipment on industrial scale-up.