Advanced Materials Research Vol. 507

Abstract: Principles and characteristics of internal model control (IMC) are illustrated. It has a simple and general structure such as that of a PID controller. Applications of IMC based on single loop PID controller tuning in main steam temperature of boiler in power plant were investigated. It can also become easier to achieve in a distributed control system (DCS) via control module configuration. It was applied in boiler of power plant to tune the main steam temperature PID parameters. The application results demonstrate the validity of the proposed method.

Abstract: Now the nonlinear control strategy used by a lot of power electronic converters is not dependent on the mathematical model of the system. They are only based on the error of control variables to control the output voltage or other variables, and this leads to the shortcomings of poor control and not easy to optimize. The fundamental reason is that they are not based on the mathematical model of converter topology structure. This paper presents a new way to build mathematical model. The paper established the unified mathematical model of the three-phase Boost converter topology structure by studied the three-phase Boost converter topology structure deeply and based on the law of conservation of energy and combined with small-signal modeling analysis method, and done the systematic analysis for it. The analysis method is also applicable to other converter topology, such as the buck, buck-boost, etc., and the model not only can be used in the controller design, can also provide a theoretical basis for the applications of a new nonlinear control strategy.

Abstract: At present, the trend of extreme product miniaturization is created. With increasing product compactness, the demand for precision miniature components is driven higher and the ability to manufacture these components accurately, swiftly and cost effectively is critical for manufacturers to maintain market competitiveness. The millimeter-scale machine tool (MMT) is on of the effective tool .This paper presents the error analysis for MMT which developed in our laboratory. The error model is developed and capability test is also implemented. The result shows that our MMT is very effective.

Abstract: In the paper the calculation of electric field and magnetic field considering the influence caused by the sag is investigated. The method to analyze the influence caused by the transmission lines sag is presented firstly. A 110 four-circuit transmission lines in Chongqing was taken as an example, the electric field and magnetic field in 2D space and 3D space were calculated respective, and comparison was conducted. Result indicate that the electric and magnetic fields obtained in 2D space has an error of 11.2% for electric field, and 7.1% for magnetic field.

Abstract: A test soil-bin is an effective device to test the whole or components of the agricultural machinery. A new computer control and test system featuring PLC control and PXI bus has been designed to control the whole soil bin system including motion control and correlative date processing. This paper introduces the software design as well as the hardware design of the electric control system and test system. The result of the present work implied that soil-bin testing platform can provide reliable data for agricultural machinery research, which has a significant effect on the agricultural machinery technology innovation and saving the cost of research and development.

Abstract: Pipe failure accidents (bulging, bursting) are frequent in thermal power plants, and severely influence the safe and economic running. The authors analyzed the possible causes and features of low-temperature superheater pipe bulging. Taking the low-temperature superheater pipe bulging accident in a power plant for an example, the authors conducted macroscopic topography analysis, running environment analysis, metallurgical analysis, chemical composition analysis and strength analysis of the bulged pipe. Paper’conclusion was that the cause of low-temperature superheater pipe bulging wasn’t superheating, and the cause of bulging was flame straightening of the pipe during installation. The paper's innovation is material and dynamics analysis of the accident cause.

Abstract: This document explains and demonstrates the problem that currently the installment of ceiling project’s bearing reaction is non-standard, combined with the example of the civil fitness center decoration project in Jinan which shows that all the ceilings should be installed with bearing reactions. This paper illustrate a construction program that by the use of L40 × 4 angle iron to enhance the bearing reactions based on the "GB50210-2001 code for construction quality acceptance of building decoration". Practice has proved that the stability and immobility of the ceiling’s bearing rations addition at the base of this program all meet the regulatory requirements. The program can be applied to all the ceiling projects that the bearing reactions are reburied when the boom is longer than 1.5m.

Abstract: In this paper, a type of high efficient ultra-thick high-chromium cast iron surfacing flux-cored wire of a diameter of 6mm is designed to solve the technological problem that the processing property of ultra-thick flux-cored wire can not meet the welding requirement, and “inter twist connection” and “inner wire” technologies were adopted. The effect of alloying elements Cr and C in the powder on the microstructure and property of deposited metal was researched. The results showed that when Cr content is 39% and C content is 5.7% in the powder, the microstructure of deposited metal is nearly eutectic, of which the hardness and wear resistance are higher. The test of engineering application of surfacing was carried out on bucket in wheel loader. It is proved that the wear-resisting property and the service life of the bucket can be significantly improved.

Abstract: Structural optimization model is the key problem of a systems engineering design process. This paper, based on the core of the Moldflow software, with complex cell phone casing injection model as an example, studies the analog simulation problems of the injection molding process, and the optimization of the proposed system engineering design optimization method and the optimum algorithm.

Abstract: With the rapid development of power type LED, the issue of the cooling of LED has been prominent. How to make the heat generated by LED chip go out quickly in order to cool the LED chip has become an urgent problem. The form of heat goes through the substrate has been widely used and has become the best way to solve the heat problem. There are three types of LED substrate. They are metal substrate, ceramic substrate and composite substrate. At first, In this paper I analyze the theoretical of three-dimensional non-steady state and steady state heat conduction equation, then the three-dimensional model is simplified as one-dimensional model and I get the results of heat conduction equation under the one-dimensional stationary and non-steady state.