Advanced Materials Research Vols. 383-390

Abstract: In order to improve the technical economy of direct air-cooled system, based on the thermodynamic model of the air-cooled system, taking the annual total cost as the objective function, the face velocity of air and the ITD (initial temperature difference) value as parameters, this article has researched the optimal ITD of direct air-cooled system in theory, and given the uncertainty analysis in the end to reflect the influence of economic parameters. The results shows that the technical economy of direct air-cooled system can achieve optimal under the condition of economic parameters change. Thus, the results of studying will provide helpful guidance for the optimization of direct air-cooled system.

Abstract: For the growing importance of future emission restrictions and the expanding requirement for a better fuel economy, the internal combustion engines are forced to be improved for the high strengthening direction. However, the heat loads of the engine is increasing according to the increasing of engine speed and power density, hence, the cooling system is faced to more challenge. For the cooling system is one of the key system which has more effect on the engine efficiency, fuel economy, and exhaust heats; optimize the matching control cooling system becomes one of the key technology to improve the engine performance. In this paper, several overall schemes of the cooling system are analyzed and discussed, and then one design scheme is determined to the optimal for the current diesel engine. A whole engine system is established by the software GT-Power, and the cooling system in the engine system is established by GT-Cool based on the above optimal scheme. During the simulation, the influence on the heat dissipating capability brought by the control parameters, injection advance angle, power, and torque are investigated. At last, the requirement of the heat released under full conditions is analyzed, and the relationship of the fuel consumption and the control parameters is investigated.

Abstract: One method of parametric design on combustion chamber is used in this paper. Several independent geometrical parameters of ω type and double swirl combustion chamber are brought forward. Different series of ω type and double swirl combustion chambers have been designed by using this method. The effect of the independent geometrical parameters on the performance of diesel engine has been studied by using CFD code AVL FIRE. According to this method of parametric design and calculation result, two pistons with ω type and double swirl combustion chamber has been designed with the target of the highest indicated heat efficiency. The test result shows that, contrasting with ω type chamber, BSFC and main combustion duration of double swirl combustion chamber is lower by 7.5 and 6.9 percent respectively, while indicated heat efficiency is 7.1 percent higher. And the calculation result has coherence with the experiment. It is proved that the method of parametric design on combustion chamber can satisfy the requirement of designing. At the same time, this method can be extended to design other combustion chambers.

Abstract: To test the Electric equipment’s immunity to voltage disturbances, a special power quality disturbances generator was needed. According to the principles of power quality disturbances generator, they were divided into the following types: the form of arbitrary waveform generator adds amplifier, the combination of transformers in series or parallel mode, regulating transformer tap position, thyristor controlled reactor, AC/DC/AC converter and the other traditional methods in this paper. This paper discusses the main technology characteristics of implementations in detail, describes different kinds of equipment using occasions, summarizes the advantages and disadvantages of all principles and points out the using prospect and promotion of all kinds generators in future.

Abstract: This paper, through the analysis of the limitation of the ultrasonic sensor in the underground drilling robot which obstacle avoidance, puts forward the solving scheme, emphasizes the compensation of temperature and humidity to ultrasonic sensor, attempts to use Elman feedback neural network approach function. Elman network hidden layer adopts Tan-sigmoid transfer function, and output layer transfer function adopts linear function, which guarantee that the network can approaches wanton function with wanton precision once it has enough layers. Proved by experiments that the measure precision of ultrasonic ranging raises two orders of grade after carrying on the temperature and humidity compensate, improves the working efficiency of obstacle avoidance in the system greatly and the ability of drilling robot’s obstacle avoidance.

Abstract: Landing is the most important stage of the Flight of UAV, the study of automatic landing of UAVs has important engineering significance. In this paper, the UAV landing trajectory is divided into approach phase, steep glide phase and flare phase; a cascade control structure controller of height tracking was applied and the landing control law was designed. The digital simulation was done in the MATLAB / simulink environment. The results of simulation indicated that UAV can track the designed landing trajectory very well under the control law of automatic landing and safe landing can be achieved.

Abstract: As Oil & Gas Pipeline of Long Distance has potential mechanical risks caused by geologic hazards, based on sensing technique, Fiber Bragg Grating (FBG) strain sensor, for which unstressed grating temperature compensation method is adopted, is designed to solve problems of FBG temperature and strain cross sensitivity. According to experimental tests, strain sensitive coefficients of the sensor before and after sticking on pipeline sample are 1.20 pm/με and 1.09 pm/με in separate. Finally, applied to a landslide area for monitoring pipeline stress, the sensor got the impact of Wenchuan Earthquake on May 12, 2008 on the pipeline.

Abstract: Distillation temperature control system is characteristics of nonlinear time-varying and we use dynamic fuzzy neural network to model the temperature of distillation. Firstly, we introduce the structure and algorithm of dynamic fuzzy neural network; Second, after data preprocessing of distillation process, we use dynamic Fuzzy neural network modeling the temperature of distillation. Dynamic fuzzy neural network adopt dynamic learning algorithm, and characteristic of approximation. The simulation results show the effect and accuracy of Dynamic fuzzy neural network model ing method.

Abstract: Lithium battery has been employed widely in many industrial applications. Parameter mismatches between lithium batteries along a series string is the critical limits of the large-scale applications in high power situation. Maintaining equalization between batteries is the key technique in lithium batteries application. This paper summarizes normal equalization techniques and proposed a new type of lithium Battery Equalization and Management System (BEMS) employing the isolated DC-DC converter structure. The system is integrated both equalization functions and management functions by using distributed 3-level controlled structure and digital control technique. With this control method the flexibility of the balance control strategy and the compatibility for different battery strings are both improved dramatically. The experimental results show optimizing equalization, efficiency and the battery string life span has been extended.

Abstract: The remoter of welding machine transfers control signals by technology: FSK in electric power and MCU, it overcomes the shortcomings of wire controller. It indicates that the remoter can be used more conveniently, the control signals transfer more accurately, and has better anti-jamming by the application of FSK technology.