scispace - formally typeset
Search or ask a question
Author

Liu Yujing

Bio: Liu Yujing is an academic researcher from North China Electric Power University. The author has contributed to research in topics: Baffle & Vibration. The author has an hindex of 2, co-authored 3 publications receiving 9 citations.

Papers
More filters
Book ChapterDOI
01 Jan 2009
TL;DR: In this article, the effect of bad vibration on the efficiency of electrostatic precipitators was analyzed by using the rule of ash-deposition and the influence of boiler load, fly ash coefficient, carbon content in fly ash and dust content consistency in flue gas on vibration period was analyzed.
Abstract: The normal operation of the vibration equipment and the dust removing equipment of EP is an important factor to ensure EP in a safe, stable and efficient running and has a direct influence on the efficiency of EP and the working life of the related equipments. According to statistics, in electrostatic precipitators which collection efficiencies were less than 95%, it was mostly caused by the bad vibration effect. The vibration periods of each electric field were analyzed by researching the rule of ash-deposition; the influence of boiler load, fly ash coefficient, carbon content in fly ash and dust content consistency in flue gas on vibration period was analyzed by calculating with vibration period calculation formula; giving an example to show the EP at a coal-fired boiler, the vibration periods of each electric field with were calculated theoretically based on the coal and the evaporation capacity were compared with the actual vibration periods to ensure and adjust vibration periods.

5 citations

Book ChapterDOI
01 Jan 2009
TL;DR: In this article, the authors proposed that baffle plates should be added on the air current distribution boards in inlet box in order to form skewed gas flow, and the simulation was conducted by Software FLUENT.
Abstract: This article proposed that baffle plates should be added on the air current distribution boards in inlet box in order to form skewed gas flow. Air distribution was simulated and studied by Software FLUENT. The k − e2 equation model was taken in the Flow field simulation, and the computation was based on SIMPLE algorithm. There are five sorts of baffle plates which have different fixing angles and fixing spaces to simulate skewed gas flow. Eventually the simulative results indicated that setting baffle plates could form the skewed gas flow and the simulation accorded with the experimental data at 45 degree, space 504 mm. Comprehensively analysed, the angle of 55° was more ideal. All of these offer a basis to design, running and improving of electrostatic precipitator (ESP).

3 citations

Book ChapterDOI
01 Jan 2009
TL;DR: In this paper, the dust removal efficiency formula reflecting the characteristics of high voltage power supply, efficiency enhancing and energy saving and intelligent optimization control was studied based on theoretical reaching rate, operating status quo of EP and successful study and extension of HVPP facility with efficiency enhancing, energy saving, and spark setting.
Abstract: Based on theoretical reaching rate, operating status quo of EP and successful study and extension of high voltage power supply facility of EP with efficiency enhancing and energy saving, the dust removal efficiency formula reflecting the characteristics of high voltage power supply, efficiency enhancing and energy saving and intelligent optimization control was studied. It was indicated that the effective reaching rate and the dust removal efficiency were in the direct ratio to the peak and the minimum of the secondary voltage under the working manner of high efficiency and energy saving and the working manner of spark setting through the formula. The basis can be provided for the optimization and the efficiency enhancing and energy saving of high voltage power supply facilities of EP by the formula.

1 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: Through the study of volt-ampere characteristics, electrical and capacitive properties, and electrical breakdown characteristics of coal-fired fly ash, it is found that the V–I characteristics of ash samples in thermal power plant do not strictly follow the formula.
Abstract: China is the biggest consumer of coal. Every year, half or more of China’s coal is used in the power industry. Most thermal power plants in China use electrostatic precipitators to treat solid particulate matter in flue gas. The efficiency of the electrostatic precipitator in removing dust has a considerable influence on atmospheric pollutants. However, the most important factor affecting the efficiency of the electrostatic precipitator in removing dust is the dielectric properties of the fly ash. Through the study of volt-ampere characteristics, electrical and capacitive properties, and electrical breakdown characteristics of coal-fired fly ash, it is found that the V–I characteristics of ash samples in thermal power plant do not strictly follow the formula ( $$ R=\frac{U}{I} $$ ), the type of coal, and the chemistry of coal. Ingredients are related; disparate types of ash samples have disparate capacitances, and the measurement of capacitive contrast resistance has a certain influence.

18 citations

Journal ArticleDOI
TL;DR: In this paper, the effect of baffles on flow distribution inside the ESP is investigated computationally and the result shows that baffles have significant influence on fluid flow pattern and the efficiency of ESP.

8 citations

Journal ArticleDOI
TL;DR: In this paper, an electrostatic precipitators (ESP) with high electric field, which does not use corona discharge, was investigated, and the collection efficiency at the electrode length of 450 mm was 77.6% at 12.5 kV when the ratio of the input power was lower than 0.33 W/(m3/s).
Abstract: In this article, an electrostatic precipitators (ESP) with high electric field, which does not use corona discharge, was investigated. The ESP had a parallel plate configuration composed of a high voltage application plate electrode and grounded plate electrode with a gap of 5 mm. The electrode length was between 150 and 450 mm. The air was flowed at the gas velocity between 0.5 and 5 m/s in the ESP by a fan. A voltage up to 12.5 kV was applied to the high voltage application electrode, whereby the electric field intensity of 25 kV/cm was generated between the electrodes. The particle concentration in the air for the particle size between 0.3 and 5 μ m was measured to calculate the collection efficiency. The collection efficiency in a conventional two-stage type ESP was also measured, and compared to the result in the ESP with high electric field. As a result, the collection efficiency at the electrode length of 450 mm was 77.6% at 12.5 kV, when the ratio of the input power was lower than 0.33 W/(m3/s), in the ESP with high electric field. On the other hand, the collection efficiency in the conventional ESP was 65.6% or 82.0% at the input power of 14.2 W/(m3/s) or 24.8 W/(m3/s). Therefore, it is revealed that the ESP with high electric field is effective for energy saving.

4 citations

01 Jan 2015
TL;DR: In this article, two different shapes of baffles inside the ESP have been considered to assess their influence on the flow pattern using computational fluid dynamics (CFD) code "ANSYS FLUENT".
Abstract: Electrostatic Precipitators (ESP) are the most reliable emission control devices that are used in coal fired power plants to capture fine particles for reducing exhaust emission. Its efficiency is more than 99% or more. However, capturing submicron particles are still a problem due to complex flow distributions and design limitations of ESP. In this study, two different shapes of baffles inside the ESP have been considered to assess their influence on the flow pattern using computational fluid dynamics (CFD) code ‘ANSYS FLUENT’.. Due to different shapes, the flow distribution will be changed inside the ESP which is expected to affect and increase the residence time of flue gas. The results of this paper indicate that the proposed shapes can influence in collecting more fine particles INTRODUCTION Most of the coal power plants and other process industries generally use Electrostatic Precipitators (ESP) because of their effectiveness and reliability in controlling emission of particulate matter. Before being released into the environment, flue gas flows through the ESP where particles are collected. The ESP is used as a cleaning device. For separating the dust particles from the flue gas, an electrical field is created and used by the ESP. A rectangular collection chamber which is known as the inlet evase and an outlet convergent duct known as the outlet evase are the key components of an ESP. For flow distribution, perforated plates are placed inside the inlet and outlet evase. A number of discharge electrodes (DE) and collection electrodes (CE) are positioned inside the collection chamber. Figure 1 presents an ESP arrangement and shows the section of a typical wire-plate ESP channel where a set of discharge electrodes is suspended vertically and the gas flows through this channel. By using an electric field, particles from the flow are attracted to the electrodes and thus they are separated. In this paper the influence of different shapes baffles on flow pattern is discussed. Flow pattern has a significant impact on particle collection and is also an important parameter for designing and adjusting the operation of an ESP [1]. Figure 1 A typical arrangement of an ESP in the power plant[1] Particle emissions have become one of the major concerns to power industry [2]. Particulates contain such materials (PM > 2.5) that can affect our health severely because they may go into the deeper parts of the respiratory tract [3]. Power stations always desire to control the particulate emissions at a minimum cost in spite of having 99.5% capture capability of particles bigger than PM>2.5 micron by the electrostatic precipitators. Currently, the particles of size PM (Particulate Matter) 2.5 or less may escape the ESP. However, it is anticipated that the new EPA regulation will soon be imposed for mandatory capture of these particles. Recent studies that have been undertaken on ESP modelling include work by Shah [4] Gallimberti [5], C. Ruttanachot [6], B.Y. Guo [7], Z. Al-Hamouz[8], Sayem [9]. It appears that there is a need to further improve ESP’s ability and efficiency by capturing these smaller particles. One idea of achieving this is to increase the particle residence time within the ESP. Introduction of column of baffles to increase the residence time of exhaust fluid flow inside the ESP has been considered in this study. Fluid flow which is influenced by vorticity created by the baffles has been examined by a computational fluid dynamics (CFD) analysis. 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics

2 citations

Journal ArticleDOI
TL;DR: In this paper, the authors have presented FEA concept of modelling and analysis of collecting electrodes of an Electrostatic Precipitator by Implicit Transient Dynamic Analysis (IDEA).
Abstract: Electrostatic Precipitator is the device used for controlling air pollution. This is used for cleaning of boiler process gases. Process gases contain suspended dust particles. These dust particles are collected on collecting electrodes. The effectiveness of Electrostatic Precipitators is affected by various factors. Periodic cleaning of collecting system plays a major role. Dust gets deposited on collecting electrodes and dislodged by means of vibrations of collecting electrodes. For huge volume of process gas the size of Electrostatic Precipitator will also be large. Since space is major constraints the ultimate solution will to go vertically i.e. increase the height and accordingly the collection area. Since the height is increased old methods of rapping will be ineffective and hence the new methods introduced to increase the vibration. Time is another major constraint for checking of such continuous improvements. So simulation and further physical measurement is more practical method. This paper presents FEA concept of modelling and analysis of collecting electrodes of an Electrostatic Precipitator by Implicit Transient Dynamic Analysis. Experimental testing is done for validation. The results of FEA concept and physical measurements are discussed.

2 citations