Design of Wind Turbine Vibration Monitoring System

In order to ensure safety of wind turbine operation and to reduce the occurrence of faults as well as to improve the reliability of wind turbine operation, a vibration monitoring for wind turbine is developed. In this paper, it analyses the enlargement of all the parts of the structure and the working mechanism, the research method of wind turbine operation vibration is introduced, with the focus being the use of the sensor principle. Finally the hardware design and software of this system is introduced and the main function of this system is described, which realizes condition monitoring of the work state of wind turbines

Hysteresis Modeling of Magnetic Shape Memory Alloy Actuator Based on Krasnosel'skii-Pokrovskii Model

As a new type of intelligent material, magnetically shape memory alloy (MSMA) has a good performance in its applications in the actuator manufacturing. Compared with traditional actuators, MSMA actuator has the advantages as fast response and large deformation; however, the hysteresis nonlinearity of the MSMA actuator restricts its further improving of control precision. In this paper, an improved Krasnosel'skii-Pokrovskii (KP) model is used to establish the hysteresis model of MSMA actuator. To identify the weighting parameters of the KP operators, an improved gradient correction algorithm and a variable step-size recursive least square estimation algorithm are proposed in this paper. In order to demonstrate the validity of the proposed modeling approach, simulation experiments are performed, simulations with improved gradient correction algorithm and variable step-size recursive least square estimation algorithm are studied, respectively. Simulation results of both identification algorithms demonstrate that the proposed modeling approach in this paper can establish an effective and accurate hysteresis model for MSMA actuator, and it provides a foundation for improving the control precision of MSMA actuator

Charging and Accounting for Grid Computing System

Abstract. Grid computing is the key technology of next generation Internet. Today grid research is mostly focus on the communication, security, resource manangement and information management. Charging and accounting is a base activity in a economy society, so that it should become a part of grid computing system in computational economy environment. In this paper, we introduce charging and accounting item in a grid computing system, and propose a method for calculating the cost of a grid usage. This method gives out how to calculate the standardization technology cost of the usage of a job and how to translate the standardization technology cost into currency cost. Further more, we analyse the demands of a charging and accounting system in a computional economy based grid. A architecture of charging and accounting system and its support system is designed in this paper.

An Improved Ganglia-like Clusters Monitoring System 1

Abstract. Ganglia [1] is a scalable distributed monitoring system for high performance computing systems such as clusters and Grids. We propose an improved Ganglia-like clusters monitoring system, which has more reliability with federation node and associated link failures; some monitoring data is accessed by permission; adding control functions such as restart or shutdown confusion processes; send email or pager to cluster administrator when important event occurs; and optionally select some data to federation node based on user policy in order to speedup the WAN access. We have implemented a prototype system.

Experimental and Numerical Study on the Dynamic and Flow Characteristics of a Reciprocating Pump Valve

The structure and dynamics of a reciprocating pump liquid end affect the volumetric efficiency and net positive suction head. To match the kinematics with theoretical parameters, reciprocating pump valve motion and flow visualization tests and computational fluid dynamics (CFD) analyses were performed on a wing-guided bevel discharge valve in a horizontal quintuple single-acting reciprocating pump. The valve motion test results showed that the maximum pump valve displacement and the pump valve opening and closing durations were approximately 8.3 mm, 29 ms, and 38 ms, respectively. The corresponding flow visualization test results were 11.4 mm, 9.5 ms, and 35.5 ms. The valve closing durations obtained from the valve motion and flow visualization tests are approximately twice as high as the U-Adolph prediction. The maximum displacement obtained from the valve motion test is consistent with the U-Adolph prediction. Three-dimensional CFD analyses were performed to investigate the flow states, pressure, and velocity characteristics of the discharge valve opening. Finally, the proposed method was applied to develop a new horizontal quintuple single-acting reciprocating pump with a rated flow rate of 1250 L/min and pressure of 40 MPa. This developed pump exhibited good performance and excellent reliability

Research on System Optimizing of AAO-BAF Wastewater Treatment Process

To meet the more strict discharging standard, some combined processes have emerged to realize denitrification and phosphorus removal of wastewater more efficiently. Among them, AAO-BAF combined process was an efficient one. The AAO-BAF system was composed of AAO reactor and BAF. The AAO process was the main unit to complete phosphorus removal and denitrification. The BAF process, external nitrification unit, was mainly used to provide enough electron acceptor for denitrifying bacteria in AAO reactor, which could enhance the efficiency of denitrification of the whole system. So the system optimizing was essential to AAO-BAF combined process. In this paper, the research progress of AAO-BAF wastewater treatment system was summarized and some system optimizing methods were raised too

Research on lateral flow treatment technology to enhance phosphorus removal of AAO process

Removing efficiently and recycling of phosphorus in the wastewater, was not only an effective means to prevent and cure the eutrophication of water, but also an important way to realize the recovery of phosphorus resources. In the traditional AAO process, the discharge of phosphorus rich sludge could reach the goal of phosphorus removal. However, the treatment of phosphorus rich sludge was difficult and could not achieve the goal of phosphorus recovery. The lateral flow phosphorus removal treatment technology, building on the side of the traditional AAO system, was an efficient process to realize high efficiency phosphorus removal and phosphorus resources recovery by forming phosphate precipitation or crystallization. In this paper, by summarizing and analyzing the existing technology of lateral flow phosphorus recovery wastewater treatment based on AAO mainstream technology, the future development of this technology was also prospected

Comparative evaluation of wear behavior of tribo-pairs in reciprocating pumps with multiple materials under different conditions

In the study of wear behavior of tribo-pairs in reciprocating pumps, the tribo-pairs can be considered as contact pairs consisting of a disc and pin. In this paper, pin-on-disc wear tests were carried out by using two types of cast iron pin specimens with different materials. Additionally, the effects of the lubrication condition, test load, diamond-like carbon (DLC) coating and plateau honing cross-hatch pattern on wear behavior of the tribo-pairs were investigated. Experimental results based on surface topography analysis and scanning elec- tron micrograph (SEM) analysis show that the lubricant and DLC coating have a positive effect on wear resistance of test specimens. Disc specimens of three material types (i.e. ISO 185/JL/250, tin-bronze, zirconia) are able to show good anti-wear behavior. The tribo-pairs composed of spheroidal graphite cast irons as well as implementation of the plateau honing cross hatch on disc specimens have no significant effect on the wear resistance. The Archard model was used to estimate abrasive wear under dry conditions, which was over-predicted compared to the experimental results