Study on the Seismic Response of Cable Tray Considering Sliding Motion of Cable

2014 ◽  
Author(s):  
Tomohiro Ito ◽  
Yasuhiko Azuma ◽  
Atsuhiko Shintani ◽  
Chihiro Nakagawa
Keyword(s):  
Power Plants ◽  
Structural Integrity ◽  
Thermal Power ◽  
Vertical Direction ◽  
Inertia Force ◽  
System Response ◽  
Seismic Responses ◽  
Sliding Motion ◽  
Highly Nonlinear ◽  
Supporting Structures

In various industrial plants such as thermal power plants, nuclear power plants, and chemical plants, many cable trays are generally used to support cables for control signals. Cable trays are very long, and thus are supported from ceilings or walls by many supporting structures. When the cable trays are subjected to strong seismic excitations, the trays or the supporting structures vibrate with large amplitudes. In the worst cases, they can collapse, and plants can lose control of systems, which can lead to severe accidents. Therefore, it is very important to maintain the structural integrity of cable trays during seismic events including recent severe earthquakes such as the East Japan Earthquake in 2011. Cable trays are generally made of thin steel plates with sides folded in the vertical direction, and with cables simply placed on the tray. Thus, cables can slide when the inertia force on the cables exceeds the friction force between the tray and cables. The mass of the cables is relatively large compared to that of a tray, thus the natural frequency of the tray will change significantly due to the cable sliding motion. Consequently, seismic responses of cable tray will also depend on the sliding motion of cables. Therefore, cable trays are seen as highly nonlinear structural systems. In this study, seismic responses of cable trays are investigated analytically considering cable sliding motions. A cable tray is modeled by a two-degree-of-freedom system. Response acceleration, and the displacements of the tray and the cable are evaluated for both sinusoidal and seismic inputs by varying the cable mass or friction coefficient between the tray and cables. It is confirmed that the sliding motion of the cable has a very large influences on the seismic responses of the cable-tray system.

Moving Boundary Model of Once Through Boiler Evaporators

2003 ◽  
Author(s):  
F. Ahnert ◽  
P. Colonna ◽  
J. F. Kikstra
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Moving Boundary ◽  
Thermal Power ◽  
Staggered Grid ◽  
System Response ◽  
Steam Quality ◽  
On Line ◽  
Aspen Custom Modeler ◽  
Boundary Model

Dynamic modeling and simulation of steam power plants is often adopted as a tool for control design, personnel training, efficiency improvement and on-line diagnostic. The boiler is possibly the most complex component of the thermal power plant. A usual boiler configuration is the so-called Once-Through arrangement. A common problem in 2-phase systems modeling is the correct calculation of the phase boundary. This is technically interesting in such boilers: the location of the phase transition changes rapidly depending on load conditions and temperature distribution along the walls. A lumped parameters, one-dimensional evaporator model implementing a moving boundary approach is presented and first validation results are discussed. The model takes into account the influence of radiation and convection on the gas side. The flow inside the pipes is divided into 3 regions (sub-cooled, 2-phase, superheated) and the model calculates the locations of the 2-phase transitions and the average steam quality along the pipes. The system is discretized using a staggered grid for higher numerical stability and is implemented in the computer program Aspen Custom Modeler (ACM). Results include the calculation of the system response to input signals simulating a load variation and a validation by comparison with a model implemented in a commercial software for power plant simulations (MMS). Input data, parameters and geometry are taken from an existing plant operating in Uppsala, Sweden.

Analysis on a Steel-Concrete Hybrid Structure Temperature Effect and Supporting Block Design

2010 ◽  
Vol 29-32 ◽  
pp. 1862-1865 ◽  
Author(s):  
Ze Liang Yao ◽  
Guo Liang Bai ◽  
Fa Ning Dang
Keyword(s):  
Temperature Effect ◽  
Power Plants ◽  
Industrial Structure ◽  
Block Design ◽  
Thermal Power ◽  
Vertical Direction ◽  
Fem Analysis ◽  
Internal Force ◽  
Hybrid Structure ◽  
Steel Truss

The steel-concrete hybrid structure is a new special industrial structure in large thermal power plants. It is composed of a spatial steel truss and steel-concrete tubular columns. Its stiffness and mass is highly non-uniform at vertical direction. Its temperature effect is obvious because its steel truss is a high order statically indeterminate structure. Types and characteristics of temperature load prescribed in codes are introduced. Temperature effect of the steel-concrete hybrid structure is calculated by FEM analysis software SAP2000 in four different supporting blocks. The structural internal force and distortion under temperature effect is analyzed. The influence of supporting blocks on the structual temperature effect is analyzed. The structural supporting block form to advantageously release its temperature effect is presented. Some advice is presented based on the analysis results.

scholarly journals EXPERIMENTAL EVALUATION OF DYNAMIC BEHAVIOR OF PIPELINE SYSTEMS OF THERMAL POWER PLANTS EXPOSED TO SEISMIC LOADS

2008 ◽  
Vol 08 (02) ◽  
pp. 339-355
Author(s):  
LJUBOMIR TASKOV ◽  
LIDIJA KRSTEVSKA ◽  
BRATICA TEMELKOSKA
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Vertical Direction ◽  
Field Testing ◽  
Model Testing ◽  
Shaking Table ◽  
Ambient Vibration ◽  
Pipeline System ◽  
Adequate Model ◽  
Earthquake Motion

This paper deals with the experimental results obtained by in situ and model testing of a segment of the pipeline system of a thermal power plant. The field testing has been performed by using the forced and ambient vibration method. The model testing has been performed by means of a shaking table. The model was designed and constructed to the scale of 1/3 and tested on the seismic shaking table in the IZIIS' laboratory. The adopted modeling concept was an adequate model with artificial mass simulation, using the same material as that of the prototype. The spring hangings, as well as the special rolling support, have also been simulated. The model was subjected to random, harmonic and earthquake motion in horizontal, vertical and biaxial directions. The results show that the support springs can accept displacements in both the horizontal and the vertical direction in the elastic range of deformation, while the stop point base support is sensitive to the intensity of earthquake motion and is required to be limited to the horizontal and vertical directions.

A Review on Utilization of Fly- Ash and Pond-Ash as a Partial Replacement of Cement in Concrete Mix Design

2018 ◽  
pp. 413-418
Author(s):  
Harshkumar Patel ◽  
Yogesh Patel
Keyword(s):  
Fly Ash ◽  
Electricity Generation ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Thermal Power ◽  
Strength Test ◽  
Partial Replacement ◽  
Pond Ash ◽  
Research Activities ◽  
Ash Disposal

Now-a-days energy planners are aiming to increase the use of renewable energy sources and nuclear to meet the electricity generation. But till now coal-based power plants are the major source of electricity generation. Disadvantages of coal-based thermal power plants is disposal problem of fly ash and pond ash. It was earlier considered as a total waste and environmental hazard thus its use was limited, but now its useful properties have been known as raw material for various application in construction field. Fly ash from the thermal plants is available in large quantities in fine and coarse form. Fine fly ash is used in construction industry in some amount and coarse fly ash is subsequently disposed over land in slurry forms. In India around 180 MT fly is produced and only around 45% of that is being utilized in different sectors. Balance fly ash is being disposed over land. It needs one acre of land for ash disposal to produce 1MW electricity from coal. Fly ash and pond ash utilization helps to reduce the consumption of natural resources. The fly ash became available in coal based thermal power station in the year 1930 in USA. For its gainful utilization, scientist started research activities and in the year 1937, R.E. Davis and his associates at university of California published research details on use of fly ash in cement concrete. This research had laid foundation for its specification, testing & usages. This study reports the potential use of pond-ash and fly-ash as cement in concrete mixes. In this present study of concrete produced using fly ash, pond ash and OPC 53 grade will be carried. An attempt will be made to investigate characteristics of OPC concrete with combined fly ash and pond ash mixed concrete for Compressive Strength test, Split Tensile Strength test, Flexural Strength test and Durability tests. This paper deals with the review of literature for fly-ash and pond-ash as partial replacement of cement in concrete.

Improving the efficiency and reliability of electric power generation at incineration plants

2020 ◽  
Vol 12 (4) ◽  
pp. 281-285
Author(s):  
A. V. Martynov ◽  
N. E. Kutko
Keyword(s):  
Low Temperature ◽  
Power Plants ◽  
Thermal Power ◽  
Moscow Region ◽  
Capital Costs ◽  
Working Medium ◽  
The Creation ◽  
Working Media ◽  
Near Future ◽  
Efficiency And Reliability

The article deals with the problem of waste disposal and, accordingly, landfills in the Moscow Region, which have now become the number 1 problem for the environment in Moscow and the Moscow Region. To solve this problem, incineration plants (IP) will be established in the near future. 4 plants will be located in the Moscow Region that will be able to eliminate 2800 thousand tons of waste per year. Burning of waste results in formation of slag making 25% of its volume, which has a very high temperature (1300.1500°C). An arrangement is considered, in which slag is sent to a water bath and heats the water to 50.90°C. This temperature is sufficient to evaporate any low-temperature substance (freons, limiting hydrocarbons, etc.), whereupon the steam of the low-temperature working medium is sent to a turbine, which produces additional electricity. The creation of a low-temperature thermal power plant (TPP) increases the reliability of electricity generation at the IP. The operation of low-temperature TPPs due to the heat of slag is very efficient, their efficiency factor being as high as 40.60%. In addition to the efficiency of TPPs, capital costs for the creation of additional devices at the IP are of great importance. Thermal power plants operating on slag are just such additional devices, so it is necessary to minimize the capital costs of their creation. In addition to equipment for the operation of TPPs, it is necessary to have a working medium in an amount determined by calculations. From the wide variety of working media, which are considered in the article, it is necessary to choose the substance with the lowest cost.

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