Applied Mechanics and Materials Vol. 472

Abstract: In this paper the experimental research on direct evaporative cooling (DEC) using stainless steel was carried out.The effect of factors that affect cooling efficiency, filler resistance and volumetric heating transfer coefficient. In order to provide reference for the design for use and analysis of DEC, empirical formulas for coefficient of heat transfer and air resistance were established.

Abstract: Introduced a communication equipment room in Xi'an transition season application tubular I/DEC (Indirect and Direct Evaporative Cooling) projects. The analysis the several modes optimized air handling units throughout the year. Finally, according to the operation of the evaporative cooling air conditioning system in the transitional seasons concluded.

Abstract: A design scheme of combine dynamic vehicle navigation terminal based on GPS/GPRS is presented, according to some shortcomings about real-time and the digital map data updating in existing vehicle navigation terminal. The paper focuses on the basic working principle and software flow of work of the CPU core board and the main functional modules. Established TCP/IP communication mode based on GPRS and used data monitoring server, to realize the accurate prediction of traffic flow information. The design of the Vehicle navigation terminal provides an important prerequisite for realizing the urban traffic vehicle global optimization and dynamic navigation.

Abstract: MEMS technology has been widely used in military industry, in order to further expand the scope of the MEMS pressure sensor applications in military industry, to make fuze development toward miniaturization and intelligent, do the study on special fuze MEMS pressure sensor. Environment of MEMS pressure sensor application in fuze is analyzed, consist service treatment environment and using environment, which can provide indicators for the development of the sensor. The paper analyzes several key technology of the fuze MEMS pressure sensor, including the technique of high temperature resistant, acceleration compensation, leadless, high frequency resistant and overload resistant and so on. To sum up, the continuous development of MEMS technology can make its products meet the use environment of fuze, and the development trend of the fuze also needs the support of MEMS technology, so it is necessary and feasible to carry out the research of the fuze MEMS pressure sensor.

Abstract: A micro-fluid turbine has been successfully tested in the laboratory and towing tank. This 2m diametral device is designed to operate in flows with velocity from 0.1m/s to 1m/s. The designed output power varies from 0.3W to 200W. In this design, the low density ocean current energy in deep-sea stored as mechanical energy in plane roll-up spring first. When the spring has enough potential energy, it drives the generator to generate electricity. Through this assistant start approach, the turbine can work in ultra-low-speed current. On the other hand, the non-contact transmission remarkably reduced the drag torque of hubcap. Besides these approaches, some other advanced technologies, such as self-adaptive platform, high efficiency energy storage, and intelligent control, are applied in this turbine. Test results show that the micro-fluid turbine has potential to provide power for instruments and equipment in deep-sea environment.

Abstract: In this study, a numerical study is made on a dual-function solar collector integrated with building when it works in thermosyphon water heating mode with natural circulation. The investigation is achieved to show its thermal effect on the building environment by comparing with cooling/heating loads of the rooms with or without the novel collector for the warm autumn periods. The results show that in autumn the thermal effect of the novel system is not inevitable because the cooling load of the room with the collector has an evidently positive difference and the heating load must reduce.

Abstract: Multi-stage cascaded quasi Z-source inverter (qZSI) features a lesser shoot-through duty ratio for the same boost factor of the input voltage, but the traditional qZSI has the disadvantage of possessing increased shoot-through ratio and very high component stress at the same voltage boost factor. The whole idea of this work is to present a multi-stage cascaded quasi Z-source inverter for application to photovoltaic power system. Three-stage cascaded qZSI is obtained by adding two diodes, two inductances and three capacitances to the traditional quasi Z-source network. Due to the cascaded structure and qZSI topology, the proposed system acquires all the advantages of impedance inverter that can realize boost/buck function in a single-stage with improved reliability, lower component rating, constant DC current from source and good power quality. Besides, the three-stage cascaded solution the shoot-through duty cycle by 25% at the same voltage boost factor. The topological characteristics of three-stage cascaded qZSI system is analysed and operating principles are discussed. An experimental prototype is built to test the three-stage cascaded qZSI module. Simulation and experimental results are presented to demonstrate the validity of the proposed system.

Abstract: This paper gives systematically study on grid-side converter with LCL filter for doubly-fed induction generator in wind power. This paper adopts the parameters of the PI-based controller that is already used for the L-filter-based active rectifier. On the basis of model in the dq coordinate system, the paper proposes a double-closed-loop control strategy. Then the simulation model of PWM rectifier is established in the MATLAB/SIMULINK environment. According to the articles theory imitation of the real system design with good dynamic and static performance.

Abstract: Fossil energy is becoming less and less, as one of new energy, many countries pay more attention on wind energy. Magnus wind turbine has an advantage of simple structure, low cost. It can work well at a very low wind speed and the control system is very simple. As the cylinder blade of traditional Magnus wind turbine has a relatively low lift to drag ratio, This paper provide two new type blade of Magnus wind turbine and it can greatly improve lift to drag ratio of Magnus wind turbine. This paper will use CFD software Fluent, through 2D simulation, compare the lift to drag ratio of cylinder blades. At last, do experiments to compare the performance of these blades.

Abstract: Solar chimney power plant which can realize continuous power generation is a potential power generation technology. Based on the heat transfer theory and hydrodynamics theory, a comprehensive heat transfer and flow model of solar chimney power plant was proposed, and the characteristics of unsteady temperature field and flow field of the system were analyzed. With Manzanares solar chimney power plant as the geometric prototype, the performance of plant generation output and generation stability were studied in condition of different thickness of heat storage layer, different specific heat capacity and thermal conductivity of heat storage medium. The numerical stimulation results showed that above three factors significantly affected the power generation output and generation stability. Thus, the optimization of the three factors was achieved in this paper, which provides the basis for the solar chimney heat storage system design.