Henan Electrical Power Survey And Design Institute

Zhengzhou, China

Henan Electrical Power Survey And Design Institute

Zhengzhou, China
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Hou F.F.,Henan Electrical Power Survey And Design Institute
Key Engineering Materials | Year: 2017

The microstructure of high-volume fly ash and long-age concrete with HCSA expansive agent at different curing time is studied by means of scanning electron microscope and energy dispersion spectrum analysis. The result shows that wet curing is benefit to the generation of ettringite which is the hydration product of HCSA expansive agent, and also is benefit to the hydration of cement and fly ash, which can fundamentally improve compactness of concrete. For the concrete which mix 6% amount of HCSA expansive agent a 60% amount of fly ash, when it is not cured, the average ratio of Ca to Si is 1.8, and the value is 0.36 after 28d curing. Since the ration of Ca to Si is lower, the hydration rate of binding material is faster. © 2017 Trans Tech Publications, Switzerland.


Geng X.J.,Henan Electrical Power Survey And Design Institute | Hou F.F.,Henan ZhongHui Electrical Power Engineering Consulting Co.
Key Engineering Materials | Year: 2017

The effect of different curing time on internal structure of high-volume fly ash concrete with HCSA expansive agent is studied, and the analysis of that compactness and endurance of concrete could be improved by HCSA expansive agent which could fundamentally compact the internal structure of high-volume fly ash concrete is performed. The result shows that curing is beneficial to generation of ettringite and could accelerate hydration of concrete with expansive agent; the compactness of cured concrete with HCSA is better than which was not cured. The internal porosity was filled by expansive agent after hydration expansion, and concrete was more dense, leading to that the strength and durability of concrete improved. © 2017 Trans Tech Publications, Switzerland.


Zhao W.,North China University of Water Conservancy and Electric Power | Zheng X.,Henan Electrical Power Survey And Design Institute
Advanced Materials Research | Year: 2012

Numerical investigation of large thick and low Reynolds airfoil of wind turbines by mounting indented Gurney flaps was carried out. The influenced rules of the position of Gurney flaps on the aerodynamic performance of airfoil under same height of flaps were achieved, and the optimal position of Gurney flap was presented. At last, the mechanism of wind turbine performance controlled by Gurney flap was discussed. The results can provide the theoretical guidance and technical support to wind turbines control in practical engineering. © (2012) Trans Tech Publications, Switzerland.


Liu J.,Ryerson University | Liu M.,Henan Electrical Power Survey And Design Institute | Zhu Z.,Hohai University
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2012

This paper presents an experimental investigation on soil deformation around uplift plate anchors in sand by using digital image correlation (DIC). The experimental setup consists of a camera, loading frame, plexiglass mold, and computer, which is developed to capture soil deformation during anchor uplifting. A series of model tests are performed to investigate the influence of particle size, soil density, and anchor embedment depth on soil deformation. A set of images captured during anchor uplifting are used to calculate soil displacement fields by DIC. The failure surface is studied by tracking the points with maximum shear strain values. On the basis of this study, it is found that soil deformation and the pullout resistance of plate anchors are substantially influenced by soil density and anchor embedment depth, whereas particle size within the studied range has limited influence. In dense sand, the shape of the failure surface changes from a truncated cone above a shallow anchor to a combined shape of a curved cone and a truncated cone for a deep anchor. In contrast, in loose sand a cone-shaped failure surface is formed within the soil mass above a shallow anchor; however, no failure surface is observed for a deep anchor, where the compressibility of soil is the dominating factor that influences the behavior of deep plate anchors in loose sand. © 2012 American Society of Civil Engineers.


Bai H.-K.,Henan Electric Power Company | Li G.-S.,Henan Electrical Power Survey And Design Institute
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2011

The 220 kV electrical network short-circuit current level enhances quickly along with unceasing enhancement of electrical network structure, open-loop operation mode must be carried out gradually to lower the 220 kV electrical network short-circuit current level. But in the process of electrical network open-loop it often contradicts with some planned electrical network projects. This paper describes the fundamental principles as well as the main method of open-loop. Taking Zhengzhou 500 kV/220 kV electromagnetic ring for example, in accordance with its present situation and long-term network planning, open-loop operation is progressively implemented and the rationality of Zhengzhou long-term network plan has been simultaneously verified. This paper puts forward the idea of using the open-loop planning studies to verify the rationality of electrical network planning, which not only unifies the network planning and open-loop planning rationally to guide the development of electrical network, but also avoids unnecessary construction to save investment.


Bai H.-K.,Henan Electric Power Company | Li G.-S.,Henan Electrical Power Survey And Design Institute
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010

Along with electrical network structure's unceasing enhancement, the short-circuit current level of 220 kV electrical network enhances quickly, to further lower the short-circuit current level, open-loop operation mode must be carried out gradually. When the structure of 500 kV and 220 kV power grid is still not perfect, open-loop operation is often difficult to achieve. This paper proposes a weak open-loop mode, takes Sanmenxia power grid in Henan as an example, and explains this kinds of open-loop form. Conclusion is that the use of weak open-loop way is better than the completely open-loop mode in the transitional period, and it can provide a new mode to safe and reliable operation of power grids.


Chen L.,Henan Electrical Power Survey And Design Institute
Applied Mechanics and Materials | Year: 2013

The failure of elastic perfect cylinders under uniform external pressure is caused by circumferential buckling. The effects of the cylinder length, of the restraining conditions at boundaries and of the length of the pressurized zone all have great influences on the critical buckling load. In the European Standard for Shells EN 1993-1-6 (2007), the critical circumferential buckling stress is obtained by introducing an external buckling factor which takes the influence of different boundary conditions into account. However, the restraint of the meridional rotation at boundaries was not considered separately for the factor. For short cylinders, any restraint of the boundaries affects the buckling mode and buckling strength greatly. In this paper, the effect of meridional end rotations on the buckling strength of short cylinders was studied. The pre-buckling membrane stress state given by membrane theory was assumed for all the analyses. © (2013) Trans Tech Publications, Switzerland.


Chen L.,Henan Electrical Power Survey And Design Institute | Rotter J.M.,University of Edinburgh
Engineering Structures | Year: 2012

Cylindrical shells subjected to non-uniform wind pressure display different buckling behaviours from those of cylinders under uniform external pressure. At different aspect ratios, quite varied and complex buckling patterns occur: the results of linear and nonlinear buckling analysis can also be quite different. By contrast, cylinders under uniform external pressure always experience circumferential buckling and are little affected by changes in geometry, except in very short cylinders or changed boundary conditions.This paper presents a wide-ranging study of anchored stocky and intermediate length cylindrical shells of uniform thickness under wind pressure. Its aim is to produce useful information for the design of silos and anchored tanks against buckling under wind. The finite element analyses indicate that both linear and nonlinear analyses predict the circumferential compression buckling mode in stocky cylinders. For intermediate cylinders, pre-buckling ovalization of the cross-section has an important influence on the buckling strength. Empirical expressions are developed to relate the linear and nonlinear critical stagnation pressures under wind to the classical critical value for uniform external pressure. The effects of yielding and imperfection sensitivity are also briefly explored. © 2012 Elsevier Ltd.


Chen L.,Henan Electrical Power Survey And Design Institute
Applied Mechanics and Materials | Year: 2014

The cylindrical shells under global bending with different geometric parameters display different failure behavior. The size of typical buckles under axial compressive stress regimes is rather small and extends over a very small zone, with the axial compressive stress reaching the critical value. The first estimate of the elastic buckling strength in bending is the condition in which the most compressed fiber reaches the buckling stress for uniform axial compression. For short cylinders, local bifurcation buckling occurs at the middle of the most compressed side of the shell, and geometric nonlinearity has a little effect on the buckling strength, while for medium-length and long cylinders, the geometric nonlinearity and the ovalization of the cross-section should be considered. This paper explores the failure behavior in elastic cylinders in pure bending. © (2014) Trans Tech Publications, Switzerland.


Yao Y.,Henan Electrical Power Survey And Design Institute | Chen S.-S.,Henan Electrical Power Survey And Design Institute
Physica A: Statistical Mechanics and its Applications | Year: 2014

Recent research has identified the heterogeneity as crucial for the evolution of cooperation in spatial population. However, the influence of heterogeneous noise is still lacking. Inspired by this interesting question, in this work, we try to incorporate heterogeneous noise into the evaluation of utility, where only a proportion of population possesses noise, whose range can also be tuned. We find that increasing heterogeneous noise monotonously promotes cooperation and even translates the full defection phase (of the homogeneous version) into the complete cooperation phase. Moreover, the promotion effect of this mechanism can be attributed to the leading role of cooperators who have the heterogeneous noise. These type of cooperators can attract more agents penetrating into the robust cooperator clusters, which is beyond the text of traditional spatial reciprocity. We hope that our work may shed light on the understanding of the cooperative behavior in the society. © 2014 Elsevier B.V. All rights reserved.

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