The Influence of Pressure Pipe Diameter and Orifice Size of Surge Chamber Optimization on the Pressure at Volute

2014 ◽  
Vol 960-961 ◽  
pp. 534-538
Author(s):  
Peng Yang ◽  
Jian Zhang ◽  
Sheng Chen ◽  
Di Miao
Keyword(s):  
Reference Value ◽  
Security Requirements ◽  
Pipe Diameter ◽  
Hydropower Station ◽  
Long Distance ◽  
Diversion Tunnel ◽  
Numerical Example ◽  
Pressure Pipe ◽  
Tunnel Diameter ◽  
Orifice Size

For a long-distance convey tunnel hydropower station, the changes of its convey tunnel diameter will impact on the pressure at the turbine volute, due to the influence of upper room of surge chamber, surge pressure is difficult to be the controlling value of the pressure at volute, the results also indicate that the influence of pressure pipe diameter on the pressure is more significant than the diversion tunnel diameter. This paper focuses on the pressure pipe diameter by the calculation of a numerical example, the increasing of the pressure at volute caused by the reduction of pressure pipe diameter can be adjusted for security requirements by optimizing the orifice size of surge chamber. Combined with the calculation of the combinational conditions, optimization results are satisfactory. That will reduce the investment of pressure pipe, so it has a certain reference value to the project.

Study on Rockburst Intensity Prediction Based on Efficacy Coefficient Method

2013 ◽  
Vol 353-356 ◽  
pp. 1277-1280 ◽  
Author(s):  
Dao Hong Qiu ◽  
Shu Cai Li ◽  
Le Wen Zhang
Keyword(s):  
Tensile Strength ◽  
Water Diversion ◽  
Hydropower Station ◽  
Energy Index ◽  
Affecting Factors ◽  
Diversion Tunnel ◽  
Evaluation Indexes ◽  
Intensity Prediction ◽  
Efficacy Coefficient Method ◽  
Coefficient Method

Based on the basic principle of the efficacy coefficient method, a model of rockburst intensity prediction was established. Considering the key affecting factors of rockburst, three factors were selected as evaluation indexes including the ratio of maximum tangential stress and rock uniaxial compressive strength, the ratio of compressive and tensile strength of rock and elastic energy index. Finally, the model was applied to the rockburst prediction of water diversion tunnel of Jiangbian hydropower station and the results show that the method is reliable, and it provids a new idea to predict rockburst.

Analysis of Surrounding Rock Deformation Based on M-C Model and Cvisc Model

2013 ◽  
Vol 295-298 ◽  
pp. 2963-2966
Author(s):  
You Xiang Li
Keyword(s):  
Surrounding Rock ◽  
Rock Deformation ◽  
Hydropower Station ◽  
Deformation Characteristics ◽  
Diversion Tunnel ◽  
Software Application ◽  
Jinping Ii Hydropower Station ◽  
Coulomb Model ◽  
Plastic Zones ◽  
Surrounding Rock Deformation

According to the analysis of the surrounding rock deformation of the buried sandy slate, which is 1500-2000m depth of Diversion Tunnel Jinping-II Hydropower Station, the essay uses FLAC software application to analyze the deformation characteristics and plastic zones of the sandy slate, study comparatively the influence of Mohr-Coulomb model and Cvisc model to the surrounding rock, and then draw some conclusions, including that calculations derived by using Cvisc model is more in line with the actual engineering.

Study on Design of Tunnel Section for Danba Diversion Tunnel

2014 ◽  
Vol 501-504 ◽  
pp. 1732-1735
Author(s):  
Jie Liu ◽  
Liang Tang ◽  
Ya Zuo ◽  
Jin Long Guo
Keyword(s):  
Stability Analysis ◽  
Plastic Zone ◽  
Cross Sections ◽  
Surrounding Rock ◽  
Hydropower Station ◽  
Diversion Tunnel ◽  
Rock Stability ◽  
Tunnel Section ◽  
Tunnel Design ◽  
The Stability

Analyzing and Evaluating the stability of the surrounding rock is an indispensable and important part in the tunnel design. In this paper, the surrounding rock stability of Danba hydropower station diversion tunnel is dealt with, FLAC3Dsoftware is used for stability analysis. Selecting three different cross sections for calculation models, comparing with the displacement and principal stress and the plastic zone which calculated by FLAC3D, we can evaluate their stability and get the best diversion tunnel design.

The Research of Communication System of Civil Defense Engineering Based on Siemens PPI Bus

2014 ◽  
Vol 672-674 ◽  
pp. 929-935
Author(s):  
Ming Xing He ◽  
Wei Wang ◽  
Ce Yue Liu ◽  
Yuan Zhang
Keyword(s):  
Communication System ◽  
Data Communication ◽  
Automatic Monitoring ◽  
Civil Defense ◽  
Security Requirements ◽  
Distributed Monitoring ◽  
Long Distance ◽  
Test Analysis ◽  
Remote Monitoring System ◽  
Communication Program

In civil defense engineering, three anti-ventilation, air conditioning dehumidification, power supply and other electrical control equipment have long distance, distributed monitoring area and are not convenient for centralized monitoring. To improve the level of civil air defense system of automatic monitoring, enhance the system's rapid response ability, adapt to the need of modern war, this paper based on data communication problems of distributed electrical system in civil defense engineering, combined with the low communication rate and high security requirements in civil defense engineering, puts forward the communication solutions based in Siemens PPI fieldbus, configures the communications PLC which has powerful functions, compiles multipoint PPI communication program, designs remote monitoring system and gives results of test analysis when it is running. Actual operation results show that the communication system of civil defense engineering based on Siemens PPI fieldbus has fast communication speed, low error rate, strong expansibility and other advantages..

scholarly journals Metal(Loids) Bioaccessibility in Road Dust from the Surrounding Villages of an Active Mine

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 685
Author(s):  
Carla Candeias ◽  
Paula F. Ávila ◽  
Eduardo Ferreira da Silva ◽  
Fernando Rocha
Keyword(s):  
Enrichment Factor ◽  
Reference Value ◽  
Road Dust ◽  
Mineralogical Composition ◽  
Carcinogenic Risk ◽  
Long Distance ◽  
Long Distance Transport ◽  
Value Range ◽  
High Enrichment ◽  
Very High

Human activities, in general, cause a significant impact on the environment and human health. The present study aims to characterize the road dust of villages located near an active mine and to assess metal(loids) bioaccessible fractions. From the collected road dust samples (<250 µm fraction), the pseudo total, gastric (G) and gastrointestinal (GI) phase (UBM assay) concentrations, mineralogical composition, enrichment factor (EF), and risk for humans were determined. The obtained results revealed that arsenic represents the highest risk to humans, with mean pseudototal values higher than the maximum reference value range. The enrichment factor pointed to As as having significant to very high enrichment in all of the villages. In addition, Cd presented the maximum EF values in all of the villages, and was thus classified as having a very high enrichment. Particles enriched in As, Ca, Fe, Cu, Al, and Ti were identified by SEM-EDS in weathered agglomerates, and were linked to mine wastes and long-distance transport through both wind and/or traffic. The arsenic bioaccessibility fraction (%BAF) presented low values in the studied samples, possibly because of the low complex solubility of Fe with adsorbed As, limiting the release of arsenic and reducing its bioaccessibility. The concentrations of bioaccessible Cd for the G and GI phases were within the reference range, while for Cu, they were above and for Pb they were lower than the reference value range. The results show that the pseudototal fraction risk is overestimated when compared with BAF%; nevertheless, the total G and GI risks were above the carcinogenic target risk (1 × 10−6) in most of the samples. The carcinogenic risk of the bioaccessible contaminants showed that As represented the higher risk for developing cancer over a lifetime, with ingestion being the main risk route.

scholarly journals Finite Element Analysis on Lining Structure of Diversion Tunnel in a Hydropower Station

2021 ◽  
Vol 276 ◽  
pp. 02012
Author(s):  
Heng Zhou ◽  
Xiaofan An ◽  
Peng Huang ◽  
Xuguang Chen ◽  
Shengjie Di ◽  
...  
Keyword(s):  
Finite Element ◽  
Water Pressure ◽  
Steel Plates ◽  
Hydropower Station ◽  
Element Analysis ◽  
Diversion Tunnel ◽  
Composite Support ◽  
Lining Structure ◽  
Traditional Structures ◽  
Composite Lining

Aiming at the high internal and external water pressure tunnels built in unfavorable geological bodies, this study proposes a novel type of composite support structure in which steel plates are poured inside concrete linings. Compared with traditional structures, it has the advantages of higher tensile strength, better crack resistance, and impermeability. Taking the diversion tunnel of a hydropower station as an example, based on linear and non-linear finite element simulations, mechanical properties of the steelconcrete composite lining structure for a hydraulic tunnel in soft surrounding rocks are analyzed. On this basis, the concrete crack control under this supporting condition is verified. Research results can provide a reference for the selection of reasonable steel plate thicknesses and reinforcement types in design.

Relation of Textural Stress and Rock Failure of Diversion Tunnel

2011 ◽  
Vol 243-249 ◽  
pp. 3685-3688
Author(s):  
Rui Gao
Keyword(s):  
Stress Concentration ◽  
Stress Distribution ◽  
Stress Field ◽  
Multivariate Regression ◽  
Large Scale ◽  
Regression Method ◽  
Rock Failure ◽  
Hydropower Station ◽  
Diversion Tunnel ◽  
The Stability

The textural stress has great effect on the stability of rock. According to the measured geo-stress data, through FEM and combined with the linear multivariate regression method, the geo-stress field was conducted. Using these methods, a diversion tunnel of a large-scale hydropower station was analyzed to study the stress distribution. It was shown that the stress concentration was located at the bottom of the wall and the arch top, the stress in the wall was little and the failure happened at the bottom of the wall and the arch top, then the bottom board and some areas far from the tunnel. Under the condition without considering textural stress, the stress concentration area located in the wall and the failure happened at the bottom of the wall, then in the middle of the wall and at the arch top.

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