Advanced Materials Research Vols. 610-613

Abstract: An object function of hydraulic efficiency for settling tank is presented in this paper. In order to have a more efficient sedimentation tank, a new settling tank with optimum baffle and inlet configuration is presented. The hydraulic behaviors of two settling tanks with different configurations were simulated using FLUENT. The results indicated that choosing appropriate configuration of settling tank can improve the hydraulic efficiency.

Abstract: Water pinch technology is a process integration technology used for enterprises water system optimization, in order to improve the water reuse rate. Application of water pinch point technology to the whole system analysis and design, to establish a feasible performance index, and then determine the detailed process of design and transformation to achieve the predetermined target performance. This paper presents a technique for simultaneous targeting and design in cooling water systems comprising of at least two cooling towers and several cooling water using operations. Through comprehensive analysis on the cooling water systems with multiple cooling water supplies, determine the corresponding heat transfer process to the cooling tower, obtained better results than literature.

Abstract: Extinguishing performance of portable water mist system was studied in this paper, considering the effects of additive addition and its type. The experimental results were statistically processed and numerically analysed by mathematical software. The results demonstrated that water mist with additive solution can extinguish pool fire efficiently due to physical and chemical mechanisms. The salt solution produces better fire control result than surfactant solution at low concentration, whereas the surfactant solution brings the better one at high concentration. Furthermore, the salt solution and surfactant solution have similar fire expansion behaviours to pure water in fire suppression with portable water mist system. The study, based on the application of the portable water mist system with additives, revealed that the system performed well on fire suppression and could be useful on movable fire control.

Abstract: Form 12 groups times flume experiment of No-plant and plant height of 2,5,9cm simulation, the order of effect that sediment flow characteristics with vegetation growth was investigated. The results show that the vertical velocity distribution of sediment flow with plant is no longer consistent with logarithm distribution with no plants in sediment flow, but for the "S"-type distribution. The Re increases with the decrease of plant height and the increase of flow. The roughness decreases with the increase of plant height and flow.

Abstract: Water hammer is one of the key factors that can cause accidents by the burst of pressure pipeline. Important features and related reasons of accidents caused by water hammer in long-distance water conveyance pipeline system were introduced, and protection measures were presented. An long-distant raw water conveyance pipeline project was taken as an example to study on the influence of protective effect by different placement schemes of air valves based on hydraulic transient simulation and analysis. Results shows that largest number of air valves does not reach the best and unreasonable placement of air valves might be the cause of an accident. It is critical to select the proper location of air valves, it is necessary to pay more attention on local hump in the front of pipeline near the pump and put exhaust valves instead of inlet valves at the back of pipeline (except some higher hump location).

Abstract: Due to the fact that it is not easy to filter out the spectrum overlap noise between noisy signal and noise by using the traditional wavelet method, an adaptive filter model based on the wavelet transform is constructed in this paper. In the new filter, the adaptive filter is used to filter out noise secondary on the basis of wavelet denoising on the original noise signal. The experimental results show that the filter can effectively remove the noise. The new filter is applied to the denoising of the ECG signal, achieving a better filtering effect.

Abstract: This paper focuses on the oscillating water column (OWC) wave energy generator. An overall mathematical model is established comprising of the wave energy capture, drive system, permanent magnet synchronous generators (PMSG), vector control, maximum power point tracking (MPPT), and low voltage ride through (LVRT) control. With this mathematical model, an OWC wave energy generator based on PMSG simulation model is set up in Matlab/Simulink environment. A simulation analysis of the model is carried out which is connected to the grid under the condition of wave changes and power system faults. The simulation facilitates the MPPT and the decoupling control of power for OWC wave energy generator. Results show that the system with back-to- back PWM converter operates in a satisfying way and the model established works correctly and effectively.

Abstract: The mechanism and characteristics of substation transformer noise are introduced in this paper. Based on the recent measured noise data of 220 kV, 500 kV and 750 kV substations, the noise source characteristics of transformer and the attenuation laws in noise transmission are analyzed. It is hoped that this paper can offer some measures and suggestions for controlling the noise of transformer substation. Lastly but not least it will provide some references for noise control during the new substation’s design and construction process.

Abstract: Aerodynamic noise generated by air-moving devices is a common problem. In this paper, the aerodynamic noise around two-dimensional bluff body flow was simulated by Lattice Boltzmann Method. Utilizing blend radius can reduce the aerodynamic noise around the bluff body notably, and the greater the blend radius, the better the noise reduction effect will be. When the basic shape model is simulated and post-processed, the speed nephogram and the streamline chart of the flow field were obtained. Then Sound Pressure Level (SPL) of some key points was tested. Changing the shape of the bluff body’s vertices to blend radius, the results were compared with those of the basic shape, and the aerodynamic noise was reduced.

Abstract: Damping spring damper is a new type of damper and an utility model patent. It has better damping effect than traditional damper because of the new structures and new materials. The paper set a model of damping spring damper and transmission line by ANSYS. The model is loaded by the breeze force. Displacement time curve which is be extracted from ANSYS is the result to compare the difference between the two kinds of damper. At the end, the paper optimizes the structural parameters of damping spring a damper.