Corrosion of Tail Heated Surface Tube under Flue Gas Medium in LNG Power Station HRSG

2013 ◽  
Vol 331 ◽  
pp. 74-78
Author(s):  
Zhong Bing Chen ◽  
Yu Hui Chen ◽  
Bo Yan Li ◽  
Xiao Yun Zeng ◽  
Yi Shi Lv ◽  
...  
Keyword(s):  
Stress Corrosion ◽  
Flue Gas ◽  
Heated Surface ◽  
Outer Wall ◽  
Influential Factors ◽  
Corrosion Products ◽  
Dew Point ◽  
Feed Water ◽  
Power Station ◽  
Gas Medium

Corrosion type, reasons and influential factors of the tail heated surface tube of the low carbon steel under the flue gas medium in LNG(Liquefied Natural Gas) power station HRSG(Heat Recovery Steam Generator) were researched through cracks morphology observation, corrosion products analysis, corrosion elements measurement and tube wall temperature field FEM calculation. Results showed that the crack initiated from the outer wall of the tube and propagated toward the inner wall with the arborescent morphology. Intergranular embrittlement ruptured. Rock type feature and secondary crack were observed on the fracture. Mud pattern and polygonal figure of the corrosion products were present. According to these morphology characteristics, the crack was identified as stress corrosion crack, and corrosion type was SCC(Stress Corrosion Cracking). Reasons of SCC were that low feed water or flue gas temperature during a certain period of the unit startup and shutdown for peaking operation brought about the temperature of the outer wall of tube below the flue gas dew point, and the flue gas became dew and corrosion solution emerged on the outer wall of tube. The SCC component was CO2 solution according to the corrosion products. S and Cl elements were found in the outer wall of tube, but their effects on SCC are still needed more researches.

Inhibiting stress corrosion cracking by removing corrosion products from the Mg-Zn-Zr alloy pre-exposed to corrosion solutions

2021 ◽  
Vol 205 ◽  
pp. 116570
Author(s):  
Evgeniy Merson ◽  
Vitaliy Poluyanov ◽  
Pavel Myagkikh ◽  
Dmitri Merson ◽  
Alexei Vinogradov
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Corrosion Products ◽  
Zr Alloy

Stress Corrosion Cracking of SA-543 High-Strength Steel in All-Volatile Treatment Boiler Feed Water

2015 ◽  
Vol 24 (10) ◽  
pp. 3773-3782
Author(s):  
R. Rihan ◽  
M. Basha ◽  
A. Al-Meshari ◽  
A. Bayramov ◽  
G. van Zyl ◽  
...  
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
High Strength Steel ◽  
High Strength ◽  
Corrosion Cracking ◽  
Feed Water ◽  
Boiler Feed Water

scholarly journals Embedded Fuzzy Based Boiler Control

2016 ◽  
Vol 5 (2) ◽  
pp. 105
Author(s):  
Celin S
Keyword(s):  
Fuzzy Logic ◽  
Embedded System ◽  
Power Plants ◽  
Operating Conditions ◽  
Project Work ◽  
Feed Water ◽  
Steam Temperature ◽  
Fuzzy Logic Controllers ◽  
Power Station ◽  
Fuzzy Logic Technique

<p>Boiler control in a power station is a very important criteria in regulation of uninterrupted electricity. In existing power plants, the control of its features and parameters are done by PI and PD controllers. The parameters that control the regulation of boiler conduction are drum level, steam flow, feed water flow, steam temperature and light intensity. It is necessary to produce the steam required to run the generator. When the load in the generator changes, there must be corresponding change in the steam volume. This may cause adverse effect in the boiler. In order to avoid the effect in the boiler, the parameters mentioned above must be maintained constant, which is attained by regulating the corresponding valves. This project work has a feasibility of using fuzzy logic controllers in the place of conventional controllers is done by using embedded system. It is found that the rule based fuzzy logic technique can be implemented by stringent operating conditions. </p>

Review of flue gas acid dew-point and related low temperature corrosion

2020 ◽  
Vol 93 (4) ◽  
pp. 1666-1677 ◽  
Author(s):  
Wujun Zuo ◽  
Xiaoyu Zhang ◽  
Yuzhong Li
Keyword(s):  
Low Temperature ◽  
Flue Gas ◽  
Dew Point

scholarly journals Corrosion of High-Strength Steel Wires under Tensile Stress

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4790
Author(s):  
Shanglin Lv ◽  
Kefei Li ◽  
Jie Chen ◽  
Xiaobin Li
Keyword(s):  
Tensile Stress ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Immersion Time ◽  
High Strength ◽  
Corrosion Cracking ◽  
Corrosion Products ◽  
Corrosive Solution ◽  
Steel Wires ◽  
The Impact

The stress corrosion cracking is the central issue for high-strength wires under high tensile stress used in civil engineering. This paper explores the resistance of stress corrosion cracking of three typical steel wires of high-strength carbon through a laboratory test, combining the actions of tensile stress and corrosive solution. Besides, the impact of tensile stress and immersion time are also investigated. During the tests, the wires were subject to electrochemical measurements of potentiodynamic polarization and electrochemical impedance spectroscopy, and the microstructure analysis was performed on the fractured cross sections. The obtained results show the following: the high-strength wire, conforming to GB/T 5224, has higher resistance to the combined actions of tensile stress and corrosive solution; tensile stress of 70% fracture strength and longer loading-immersion time make the film of corrosion products on steel surface unstable and weaken the corrosion resistance; the surface film consisted of the iron oxide film and the corrosion products film whose components are mainly iron thiocyanate and iron sulphide.

Numerical Prediction of Erosion of Mild Steel Surfaces by Boiler Fly Ash Particles

Volume 1 ◽  
2004 ◽  
Author(s):  
John G. Mbabazi ◽  
Thomas J. Sheer
Keyword(s):  
Fly Ash ◽  
Mild Steel ◽  
Flue Gas ◽  
Gas Flow ◽  
Erosive Wear ◽  
Test Facility ◽  
Experimental Investigations ◽  
Power Station ◽  
Erosion Rates ◽  
Steel Surfaces

Fly ash particles entrained in the flue gas from boiler furnaces in coal-fired power stations can cause serious erosive wear on steel surfaces along the downstream flow path. This paper describes research into fly ash impingement erosion on such surfaces, with particular reference to the heat transfer plates in rotary regenerative air heaters. The effect of the ash particle impact velocity and impact angle on the erosive wear of mild steel surfaces was determined through experimental investigations, using three different power station ash types. The experimental data were used to calibrate a fundamentally-derived model for the prediction of erosion rates. This erosion model was incorporated into a particle-tracking CFD flow simulation of the ash-laden flue gas flow through the complex channels between corrugated air heater plates. The predicted erosion rates were compared with measured erosion rates obtained using a large accelerated-erosion test facility located at a power station. Good agreement was obtained, the predictions generally being within 20 percent of the measured values.

Analysis on the Calculation Methods of Acid Dew Point of Flue Gas

2014 ◽  
Vol 960-961 ◽  
pp. 414-421
Author(s):  
Chen Zong ◽  
Xiao Hui Zhang ◽  
Qi Min Wang
Keyword(s):  
Soviet Union ◽  
Flue Gas ◽  
Former Soviet Union ◽  
Bituminous Coal ◽  
Dew Point ◽  
Thermal Calculation ◽  
Calculation Methods ◽  
Typical Instance ◽  
New Formula

At present, there are lots of calculation methods of acid dew point of flue gas; formula of acid dew point in the thermal calculation from the former U.S.S.R has been widely applied in China. But this formula still has some problems, such as the desulphurization ability of different fuels, classification of sulfur content in fuel and the factors of SO2 transferred into SO3.In order to solve these problems,the formula of the acid dew point in the thermal calculation from the former U.S.S.R is adjusted. It was found that the precision of A.G.O kkes formula is the highest by comparing several formulas. So the last will be the compilation of the new formula and A.G.O kkes formula, the former Soviet union formula and the calculation of burning lean coal,bituminous coal and lignite typical instance of 600 MW,it was found that the precision of new formula calculation has improved.

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