Research and Development of Viscous Fluid Dampers for Improvement of Seismic Resistance of Thermal Power Plants: Part 1 — Fundamental Analysis and Component Test

2017 ◽  
Author(s):  
Go Tanaka ◽  
Keisuke Minagawa ◽  
Kiyoshi Aida ◽  
Satoshi Fujita
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Fundamental Analysis ◽  
Loading Test ◽  
Proof Construction ◽  
Long Duration ◽  
Component Test ◽  
Fluid Dampers ◽  
Viscous Fluid Dampers ◽  
Suitable Characteristic

In 2011, Great East Japan Earthquake that is the largest earthquake ever observed occurred. The earthquake had large energy, huge tsunami, long duration time and many aftershocks. Devastated area needed retrieval and revival. However, when electric power was lost, the retrieval delayed. It is necessary to improve seismic proof construction for power plants. In this paper, authors proposed vibration control by adding dampers for coal-fired power plant and developed it. Fundamental analysis and component test of the damper were conducted. As the analytical results, characteristic of the damper was searched what kind of performance is more effective for the coal-fired power plants. In the component test, actual scaled prototype of the developed damper was produced and its performance was checked by loading test. As the test results, suitable characteristic of the damper was searched by the analysis. Finally, authors proposed two analytical methods of the developed damper.

Research and Development of Viscous Fluid Dampers for Improvement of Seismic Resistance of Thermal Power Plants: Part 5 — Influence of Damper Properties on Lifetime

2018 ◽  
Author(s):  
Kiyoshi Aida ◽  
Keisuke Minagawa ◽  
Go Tanaka ◽  
Satoshi Fujita
Keyword(s):  
Viscous Fluid ◽  
Seismic Response ◽  
Power Plants ◽  
Thermal Power ◽  
Great East Japan Earthquake ◽  
Thermal Power Plants ◽  
Support Structures ◽  
Long Duration ◽  
Fluid Dampers ◽  
Viscous Fluid Dampers

In 2011, Great East Japan Earthquake that is the largest earthquake ever observed in Japan occurred. The earthquake had large energy, long duration and many aftershocks, and coal-fired thermal power plants were damaged by the earthquake [1]. Boiler structures in coal-fired thermal power plants are generally high-rise structures, and boilers are simply suspended from the top of the support structures in order to allow thermal expansion, so boilers easily vibrate [2]. In order to suppress vibration of boilers during earthquakes, stoppers are generally set between boilers and support structures. The stoppers are made of steel, and dissipate vibration energy by plastic deformation. However aseismic requirements for thermal power plants have been increased as a result of the Great East Japan Earthquake. Thus authors have developed a vibration control damper for coal-fired power plants. The damper is set instead of conventional stopper. Construction of the damper is similar to oil dampers, but inner fluid is viscous fluid. In PVP 2017, the basic performance of the proposed damper was presented [3–5]. In this paper, influence of damper properties on lifetime of the damper was investigated by seismic response analyses. In addition, lifetime of dampers for long period and long duration earthquake waves were investigated by seismic response analyses.

Research and Development of Viscous Fluid Dampers for Improvement of Seismic Resistance of Thermal Power Plants: Part 9 — Investigation Regarding Damage Between Furnace and Cage

2020 ◽  
Author(s):  
Kiyoshi Aida ◽  
Keisuke Minagawa ◽  
Satoshi Fujita
Keyword(s):  
Power Generation ◽  
Seismic Response ◽  
Power Plants ◽  
Seismic Waves ◽  
Thermal Power ◽  
Great East Japan Earthquake ◽  
Thermal Power Plants ◽  
Power Company ◽  
Fluid Dampers ◽  
Viscous Fluid Dampers

Abstract Boilers in coal-fired thermal power plants were often damaged by earthquakes such as the Great East Japan Earthquake in 2011. Since the coal-fired thermal power generation has been one of the main power generation methods after the Great East Japan Earthquake, mitigation of damage of boilers in thermal power plants by earthquakes is the very important subject in order to recover our daily life immediately after strong earthquakes. Meanwhile, a boiler in a coal-fired thermal power plant was damaged by Hokkaido Eastern Iburi Earthquake in 2018, and this damage was one of the causes of Hokkaido’s prefecture-wide blackout. According to a report by an electric power company, a damage occurred between a furnace and a cage of the boiler. In general, lengths, shapes, weights and so on of a furnace are different from a cage, so vibration characteristics and seismic response are different as well. Thus the connecting part between the furnace and the cage is a weak point in the boiler, and the damages often occurred there. Therefore this paper investigates seismic response of a boiler by a numerical analysis using a frame model from the viewpoint of the damage of the furnace and the cage. Various seismic waves were used as input waves in order to investigate the influence of the input wave. A result of a modal analysis was also provided in this paper.

Research and Development of Viscous Fluid Dampers for Improvement of Seismic Resistance of Thermal Power Plants: Part 4 — Experimental Study on Environmental Applicability and Durability of Damper

2018 ◽  
Author(s):  
Go Tanaka ◽  
Keisuke Minagawa ◽  
Kiyoshi Aida ◽  
Satoshi Fujita
Keyword(s):  
Viscous Fluid ◽  
Power Plants ◽  
Pacific Coast ◽  
Thermal Power ◽  
Tohoku Earthquake ◽  
Coal Fire ◽  
Proof Construction ◽  
The Pacific ◽  
Pacific Coast Of Japan ◽  
Fluid Dampers

A purpose of this study is an improvement of seismic proof construction for power plants to supply power stably at an emergency. At present, the most common type of power generation in Japan is thermal. In particular, coal-fire becomes base load power. A proposal of this study is that boiler structure is applied vibration control. The way is that a damper used viscous fluid is set instead of stopper between the boiler and the support structure. However, inside temperature of the boiler structure is higher than the environment of the general because it uses burning of coal and steam. Therefore, this paper shows that the damper has applicability for the environment of the boiler structure. Then it is necessary for structures to endure earthquake with long duration and long period component in Japan. The 2011 off the Pacific coast of Tohoku Earthquake had the largest energy in history of Japan with them. The damage occurred not only in Tohoku but also in far Tokyo and Osaka. Moreover, it is predicted that large earthquakes with them at the south Pacific coast of Japan occur. This paper shows that the developed damper is effective in earthquake with these characteristics by analyses and component tests.

Research and Development of Viscous Fluid Dampers for Improvement of Seismic Resistance of Thermal Power Plants: Part 7 — Evaluation of Lifetime Using Experimental Design Method

2019 ◽  
Author(s):  
Kiyoshi Aida ◽  
Keisuke Minagawa ◽  
Go Tanaka ◽  
Satoshi Fujita
Keyword(s):  
Experimental Design ◽  
Viscous Fluid ◽  
Power Plants ◽  
Design Method ◽  
Thermal Power ◽  
Great East Japan Earthquake ◽  
Thermal Power Plants ◽  
Support Structures ◽  
Long Duration ◽  
Experimental Design Method

Abstract In 2011, Great East Japan Earthquake that was the largest earthquake in Japanese history occurred. The earthquake had large acceleration, long duration and a lot of aftershocks, and coal-fired thermal power plants were damaged by the earthquake. Boiler structures in coal-fired thermal power plants are generally high-rise structures, and boilers are simply suspended from the top of the support structures in order not to restrict thermal expansion. Therefore boilers are easy to vibrate. In order to suppress vibration of boilers during earthquakes, stoppers are generally set between boilers and support structures. The stoppers are made of steel, and dissipate vibration energy by plastic deformation. However aseismic requirements for thermal power plants have been increased as a result of the Great East Japan Earthquake. Thus authors have developed a vibration control damper for coal-fired power plants. The damper is set instead of conventional stopper. Construction of the damper is similar to oil dampers, but inner fluid is viscous fluid. In PVP 2017, the basic performance of the proposed damper was presented. In PVP 2018, influence of dispersion of damper properties was also investigated. In addition, seismic response analyses using various earthquakes that include long period and long duration earthquake waves were carried out. As a result of previous investigations, it was confirmed that the proposed damper has good performance in its lifetime. However, parameters of dampers were selected manually. Therefore, influence of parameters of dampers on the lifetime were evaluated theoretically by using the experimental design method in this paper. The experimental design method is one of the effective techniques for research such as investigation of the influence of the habitat environment on the growth of crops. The selection of damper parameters is complex optimization, because so many variables need to be optimized. Therefore the experimental design method is suitable technique for the evaluation of damper parameters. This paper evaluates lifetime of dampers from the viewpoint of the experimental design method.

Research and Development of Viscous Fluid Dampers for Improvement of Seismic Resistance of Thermal Power Plants: Part 6 — Influence of Damper Properties on Vibration Control Performance

2018 ◽  
Author(s):  
Keisuke Minagawa ◽  
Kiyoshi Aida ◽  
Go Tanaka ◽  
Satoshi Fujita
Keyword(s):  
Viscous Fluid ◽  
Vibration Control ◽  
Power Plants ◽  
Vibration Suppression ◽  
Thermal Power ◽  
Sensitivity Analyses ◽  
Thermal Power Plants ◽  
Control Performance ◽  
Support Structures ◽  
Long Duration

Coal-fired thermal power generation became a very important power source in Japan after Great East Japan Earthquake [1]. Therefore improvement of seismic reliability of the coal-fired thermal power plants is required, because occurrence of very large earthquakes is expected in Japan. Boilers of coal-fired power plants are usually suspended from the upper end of support structures in order to allow thermal expansion of the boilers [2], so boilers easily sway during earthquakes. In order to suppress the vibration, stoppers made of steel are generally installed between boilers and their support structures. Although stoppers made of steel are effective for vibration suppression, further countermeasure for earthquakes having long duration and many aftershocks is required. Authors have developed a vibration control damper for coal-fired power plants. The damper is set instead of conventional stopper. Construction of the damper is similar to oil dampers, but inner fluid is viscous fluid. In PVP2017, the basic performance of the proposed damper was presented [3–5]. In this paper, damper properties were adjusted in order to improve vibration control performance of the damper. Influence of damper properties on the performance was investigated by sensitivity analyses. In addition, influence of dispersion of damper properties was also investigated. Long period and long duration earthquake waves were considered in the analyses.

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.

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