Evaluation Method of Impulse Discharge Performance of Ground Electrode Based on Soil Discharge Image

In this paper, numerical simulations of the heat transfer in molten-slag flow with free surface and phase change (solidification) is carried out, and we propose a new evaluation method for discharging performance of the molten-slag from coal gasifier. A stable operation of the coal gasifier requires that the molten-slag should be discharged from the slag-hole continuously. In the maintenance of discharging a molten slag, it is necessary to keep the molten-slag temperature higher than an ash fluid temperature, and to hold the fluidity of the molten-slag. From the viewpoint of gasification performance, if the air ratio is set low in order to raise the cold gas efficiency, the molten-slag is not able to get enough heat for its discharge, because of the lowering of gas temperature in the coal gasifier. To strike a balance between the maintenance of continuity on the molten-slag discharge and the improvement in gasification performance, it is important to develop a prediction and evaluation method for discharge performance of the molten-slag from coal gasifier.

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Positive Switching Impulse Discharge Performance and Voltage Correction of Rod-Plane Air Gap Based on Tests at High-Altitude Sites

IEEE Transactions on Power Delivery ◽

10.1109/tpwrd.2008.2002969 ◽

2009 ◽

Vol 24 (1) ◽

pp. 302-310 ◽

Cited By ~ 3

Author(s):

Xingliang Jiang ◽

Lichun Shu ◽

Jianlin Hu ◽

Zhijin Zhang ◽

Shaohua Wang ◽

...

Keyword(s):

High Altitude ◽

Air Gap ◽

Discharge Performance ◽

Impulse Discharge

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Study on Evaluation Method of Impulse Dispersion Performance of Grounding Device Using X-Ray Imagining System

Energies ◽

10.3390/en14165124 ◽

2021 ◽

Vol 14 (16) ◽

pp. 5124

Author(s):

Xiaoyan Han ◽

Donghui Luo ◽

Xin Zhang ◽

Yongxing Cao ◽

Yu Zhang ◽

...

Keyword(s):

Evaluation Method ◽

Spark Discharge ◽

Soil Conditions ◽

Grounding System ◽

X Ray ◽

Impulse Discharge ◽

Quantitative Analysis Method ◽

Grounding Electrode ◽

Discharge Efficiency ◽

Different Soils

When the lightning current enters the ground through the grounding system, the impulse dispersion performance can be observed by the phenomenon of soil spark discharge, which is fundamentally determined by the nearby soil. At present, engineers use an empirical formula to convert the soil spark discharge to the impulse coefficient of impulse grounding resistance. Therefore, there is no available quantitative analysis method to evaluate soil impulse dispersion performance. To solve this problem, this paper proposes an evaluation method for the impulse discharge efficiency of soil by using X-ray images, define VI as the parameter, which is the ratio of the volume of the discharge area to the peak current. Then, the rationality and validity of the method are verified. Finally, the variation rules of impulse discharge efficiency are analyzed in different soils. Results show that the VI can reflect the change rules of impulse dispersion performance more clearly under different soil conditions, and this parameter provides a new idea for enhancing the impulse dispersion performance of soil near the grounding electrode.

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Evaluation method for imaging plate resolution by means of phase contrast transfer function

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100139688 ◽

1995 ◽

Vol 53 ◽

pp. 662-663 ◽

Cited By ~ 1

Author(s):

T. Oikawa ◽

H. Kosugi ◽

F. Hosokawa ◽

D. Shindo ◽

M. Kersker

Keyword(s):

Transfer Function ◽

Phase Contrast ◽

Evaluation Method ◽

Amorphous Film ◽

Imaging Plate ◽

X Rays ◽

Special Shape ◽

Contrast Transfer Function ◽

Contrast Image ◽

Specimen Shape

Evaluation of the resolution of the Imaging Plate (IP) has been attempted by some methods. An evaluation method for IP resolution, which is not influenced by hard X-rays at higher accelerating voltages, was proposed previously by the present authors. This method, however, requires truoblesome experimental preperations partly because specially synthesized hematite was used as a specimen, and partly because a special shape of the specimen was used as a standard image. In this paper, a convenient evaluation method which is not infuenced by the specimen shape and image direction, is newly proposed. In this method, phase contrast images of thin amorphous film are used.Several diffraction rings are obtained by the Fourier transformation of a phase contrast image of thin amorphous film, taken at a large under focus. The rings show the spatial-frequency spectrum corresponding to the phase contrast transfer function (PCTF). The envelope function is obtained by connecting the peak intensities of the rings. The evelope function is offten used for evaluation of the instrument, because the function shows the performance of the electron microscope (EM).

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Combining Values

Guides Newsletter ◽

10.1001/amaguidesnewsletters.2002.marapr01 ◽

2002 ◽

Vol 7 (2) ◽

pp. 1-4, 12 ◽

Cited By ~ 1

Author(s):

Christopher R. Brigham

Keyword(s):

Lower Extremity ◽

Upper Extremity ◽

Evaluation Method ◽

Proximal Phalanx ◽

Common Error ◽

The Third ◽

Whole Person ◽

Impairment Ratings ◽

Upper Extremity Impairment ◽

The Individual

Abstract To account for the effects of multiple impairments, evaluating physicians must provide a summary value that combines multiple impairments so the whole person impairment is equal to or less than the sum of all the individual impairment values. A common error is to add values that should be combined and typically results in an inflated rating. The Combined Values Chart in the AMA Guides to the Evaluation of Permanent Impairment, Fifth Edition, includes instructions that guide physicians about combining impairment ratings. For example, impairment values within a region generally are combined and converted to a whole person permanent impairment before combination with the results from other regions (exceptions include certain impairments of the spine and extremities). When they combine three or more values, physicians should select and combine the two lowest values; this value is combined with the third value to yield the total value. Upper extremity impairment ratings are combined based on the principle that a second and each succeeding impairment applies not to the whole unit (eg, whole finger) but only to the part that remains (eg, proximal phalanx). Physicians who combine lower extremity impairments usually use only one evaluation method, but, if more than one method is used, the physician should use the Combined Values Chart.

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