Mechanism research on coupling effect between dew point corrosion and ash deposition

2013 ◽  
Vol 54 (1) ◽  
pp. 102-110 ◽  
Author(s):  
Yun-Gang Wang ◽  
Qin-Xin Zhao ◽  
Zhi-Xiang Zhang ◽  
Zhi-Chao Zhang ◽  
Wen-Quan Tao
Keyword(s):  
Coupling Effect ◽  
Dew Point ◽  
Ash Deposition ◽  
Mechanism Research

Research on Dew Point Corrosion of Materials

2013 ◽  
Vol 281 ◽  
pp. 441-447 ◽  
Author(s):  
Zhi Yuan Liang ◽  
Qin Xin Zhao
Keyword(s):  
Coupling Effect ◽  
Dew Point ◽  
Ash Deposition ◽  
Exhaust Temperature ◽  
316L Steel ◽  
Superior Corrosion Resistance ◽  
And Control ◽  
Metal Wall ◽  
Tube Metal

To solve the problem of power station boilers' high exhaust temperature and the demand of the dewpoint corrosion prevention and control in the process of flue gas deep cooling, We chose dewpoint corrosion resistant steels BNS, ND and 316L steel as studied objects, which were in situ tested on a boiler of 1000 MW pulverized coal-fired power plant. The results show that 316 L steel is performing superior corrosion resistance. Iron oxides and a small amount of sulphate and chlo-rate are the corrosion products, and the suitable tube metal wall temperature is recommended as 80°C which can avoid the coupling effect between dewpoint corrosion and viscous ash deposition.

scholarly journals The Coupling Effect Research of Ash Deposition and Condensation in Low Temperature Flue Gas

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Lei Ma ◽  
Feng-zhong Sun ◽  
Zhi-min Li ◽  
Pei Chen ◽  
Fei Li
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Low Temperature ◽  
Flue Gas ◽  
Coupling Effect ◽  
Stable State ◽  
Outer Wall ◽  
Deposition Condition ◽  
Ash Deposition ◽  
Acid Vapor

Ash deposition is a key factor that deteriorates the heat transfer performance and leads to higher energy consumption of low pressure economizer working in low temperature flue gas. In order to study the ash deposition of heat exchange tubes in low temperature flue gas, two experiments are carried out with different types of heat exchange tubes in different flue gas environments. In this paper, Nusselt Number Nu and fouling factorεare calculated to describe the heat transfer characteristics so as to study the ash deposition condition. The scanning electron microscope (SEM) is used for the analysis of ash samples obtained from the outer wall of heat exchange tubes. The dynamic process of ash deposition is studied under different temperatures of outer wall. The results showed that ash deposition of heat exchanger will achieve a stable state in constant flue gas environment. According to the condition of condensation of acid vapor and water vapor, the process of ash deposition can be distinguished as mere ash deposition, acid-ash coupling deposition, and acid-water-ash coupling deposition.

scholarly journals Experiment Comparison between Engineering Acid Dew Point and Thermodynamic Acid Dew Point

2018 ◽  
Vol 38 ◽  
pp. 04008 ◽  
Author(s):  
Jinghui Song ◽  
Hui Yuan ◽  
Jianhua Deng
Keyword(s):  
Flue Gas ◽  
Pipe Wall ◽  
Waste Heat ◽  
Coupling Effect ◽  
Dew Point ◽  
Air Preheater ◽  
Heat Utilization ◽  
Actual Operation ◽  
Waste Heat Utilization ◽  
Coal Type

in order to realize the accurate prediction of acid dew point, a set of measurement system of acid dew point for the flue gas flue gas in the tail of the boiler was designed and built, And measured at the outlet of an air preheater of a power plant of 1 000 MW, The results show that: Under the same conditions, with the test temperature decreases, Nu of heat transfer tubes, fouling and corrosion of pipe wall and corrosion pieces gradually deepened. Then, the measured acid dew point is compared with the acid dew point obtained by using the existing empirical formula under the same coal type. The dew point of engineering acid is usually about 40 ℃ lower than the dew point of thermodynamic acid because of the coupling effect of fouling on the acid liquid, which can better reflect the actual operation of flue gas in engineering and has certain theoretical guidance for the design and operation of deep waste heat utilization system significance.

An hourglass-type electromagnetic isolator with negative resistance electromagnetic shunt circuit

2020 ◽  
Vol 64 (1-4) ◽  
pp. 549-556
Author(s):  
Yajun Luo ◽  
Linwei Ji ◽  
Yahong Zhang ◽  
Minglong Xu ◽  
Xinong Zhang
Keyword(s):  
Vibration Isolation ◽  
Electromechanical Coupling ◽  
Coupling Effect ◽  
Negative Resistance ◽  
Isolation System ◽  
Amplitude Vibration ◽  
Vibration Responses ◽  
The Stability ◽  
Isolation Performance ◽  
Shunt Circuit

The present work proposed an hourglass-type electromagnetic isolator with negative resistance (NR) shunt circuit to achieve the effective suppression of the micro-amplitude vibration response in various advanced instruments and equipment. By innovatively design of combining the displacement amplifier and the NR electromagnetic shunt circuit, the current new type of vibration isolator not only can effectively solve the problem of micro-amplitude vibration control, but also has significant electromechanical coupling effect, to obtain excellent vibration isolation performance. The design of the isolator and motion relationship is presented firstly. The electromechanical coupling dynamic model of the isolator is also given. Moreover, the optimal design of the NR electromagnetic shunt circuit and the stability analysis of the vibration isolation system are carried out. Finally, the simulation results about the transfer function and vibration responses demonstrated that the isolator has a significant isolation performance.

Mapping of ferrimagnetic susceptibility for screening of fly ash deposition

2010 ◽  
Author(s):  
C. Fürst ◽  
C. Lorz ◽  
D. Zirlewagen ◽  
F. Makeschin
Keyword(s):  
Fly Ash ◽  
Ash Deposition ◽  
Fly Ash Deposition
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