Advanced Materials Research Vols. 201-203

Abstract: The multifunction evaluation system for coal-bed gas adsorption isothermal and pollution of drilling fluids is used for detecting the isothermal curves of adsorption and desorption needed in coal-bed gas exploration and development, at the same time, the system is used for studying the influences of external conditions applied on the coal bed such as reservoir temperature, moisture in the coal, the component of adsorbed gas, the drilling fluids and fracturing fluids on the coal beds, and pertaining to the technical area of the test instruments of coal-bed gas for drilling, exploration and development. Structure of the system is rational with advanced performance and high automation, its pressure and temperature are controlled by high precision sensors, and the microcomputer matched with the instrument has functions of rapid data acquisition, data process and chart plotting. This evaluation system can not only be used for detecting the isothermal curves of adsorption and desorption of single component gases, also can be used for detecting the isothermal curves of multi-component gases and deriving the diffusion coefficient of gas in the coal beds. Also the system can be used for evaluating the restoration value of the coal-bed desorption ability both before and after being polluted by drilling fluids and estimating the influence of drilling fluid and fracturing fluid, by which the shortcomings of unicity of adsorption and desorption test of coal bed gas, low automation level and low accuracy at present are eliminated, and it has the characteristics of clear flow-sheet, easy operation, modules of experiment software and standardization of experiment data.

Abstract: In order to get the total Degree of Engineering Changes for product family (EDC_KBOM), which can help enterprise to select a scheme of Engineering Changes (EC) with a minor EDC_KBOM and analyze the type of change propagation for the CE in the product family, the Knowledge-body based on Bill of Material (KBOM) model was built for representing domain-specific knowledge, which was described as trial(GUS, CUS, GUR) and manifested as an AND/OR tree structure. Then, a complete solution system based on recursive algorithm was designed to compute the EDC_KBOM. Finally, an example was given, and the approach was proved to be efficient and practical.

Abstract: The similarity theory and similarity criterion are applied to the series design of non-standard mechanical products. The series design method has been developed by using series design criterion; the similarity criterion of mechanical components or systems is transformed into the series design criterion of product. The series design method of mechanical product is more scientific and faster. The series design criterion is established for the single part of the non-standard mechanical product, and then is extended to the single and complex mechanical system. The series design method with main system and main parameter is put forward, and it is valuable for the complex mechanical system. The series design of rolling pulverization system is carried on by using this method, and the design criterions of the major parts in the system are given.

Abstract: Energy saving and environment protection are two most important issues that today’s internal combustion engine industry must tackle with. Lots of heat energy waste with the exhaust gas when the engine is running. Organic Rankine cycle (ORC) is a good method to recover the waste heat of the engine exhaust. In this paper, the mathematical model of ORC was built up in Matlab and the parameters were optimized using genetic algorithm (GA). Eight pure component organic working fluids were selected and compared. The results indicate that the evaporating pressure of the working fluid and the condensing temperature are two important parameters for ORC; the super heater also can enhance the system thermal efficiency slightly.

Abstract: This paper reviews the principle of power production, and analyses the influnece on aerodynamic load and output power due to the variation of pitch angle. For three-bladed upwind horizontal axis wind turbine, the blade pitch control is used primarily to adjust the power coefficient and obtain the optimal power at high wind speed, but it also make aerodynamic load, such as edgewise, flapwise and torsion moment, change during variable pitch control. Hydraulic mechanism is used in a process requiring large driving forces and torques, fast response and high stiffness. Therefore, the variable pitch mechanism is operated using electro-hydraulic proportional technology in this paper. Simulation results are presented and analysed to show that aerodynamic load and output power are sensitivity to pitch angle for wind turbine blade. These works lay foundation for the further studying of individual pitch, power control, fatigue and dynamical stability for wind turbine.

Abstract: The traditional motorcycle meters are driven by the separate motors, these devices are simple and easy to be controlled, stable performance, but dial space has not been fully utilized. This paper introduces the double index show of motorcycle speed and speed，focus on analysis of dual-axis stepper motor driven connections, drive mode and the driver circuit design. The results of experiment and application shows that the coaxial two-pointer motorcycle display instrument has good repeatability, good linear scale, fast response, no jitter, high reliability and relatively small size and many other advantages, instrumentation stepper motor driver with dual-axis motor instrument design meet the relevant requirements of motorcycle meter, can be easily to achieve motor servo system driven synchronous control of double axis step-drive electromotor.

Abstract: According to the analysis of heat balance, about 1/3 of the fuel combustion heat is taken away into the ambience by exhaust gas of diesel engine. In this article, to improve the using level of the fuel’s combustion heat, a two stage single screw expander organic Rankine cycle (ORC) system has been used to recover the waste heat from exhaust gas of a certain turbine diesel engine. In this article, physical model of the recovery system was built at first, then the T-S curve was drawn, at last, REFPROP was used to calculate thermodynamics parameter in different state point of this system, and analyze the whole system’s thermodynamics character. By analyzing, the evaporation temperature of this system should be optimized to get the relatively evaporation press; by calculating, it could be seen that the middle heater in this system should be taken away to improve the economy of this scheme. This scheme should supply a direction for the exhaust heat recovery of diesel engine.

Abstract: The working principle of the adjustment device of the weaving density for the knitting machine is briefly introduced. Compared to the limitation from the adjustment device of the hand-cranked knitting machine, this paper presents another design method that the device is automatically controlled by the stepping motor to change the weaving density.

Abstract: According to the requirements of heavy commercial compressed natural gas (CNG) vehicle to satisfy China’s rapid economic development, the authors develop and test a new high energy direct ignition system of heavy CNG engine. Hardware and software of the high energy direct ignition system are designed and debugged. Based on the tradition test bench, an optimal test bench for this CNG engine is established. Ignition advance angle is calibrated and analyzed, which has the economy and power performances effects on CNG engine matched the developed high energy direct ignition system. To test the effects on engine emissions by high energy direct ignition system, ignition control strategy is simplified and optimized. In addition, high ignition energy is directly determined by current time of ignition coil power. A test study about torque, power and fuel consumption of this engine is accomplished. The final test results indicate that this developed high energy ignition direct system can satisfy the comprehensive performance objectives of heavy CNG engine.

Abstract: Combining the present condition of HS-WEDM technology, paper puts forward four projects to optimize machine, which involves optimization of the main body of machine, improvement of workpiece process, making better control system and updating additional function. It also analyses all kinds of technical parameters in detail to improve the working specifications. The result shows that the application of HS-WEDM can narrow the gap with developed countries of WEDM and satisfy the market demand.