An Experimental Study on Ash Deposition Problem of Low-Low Temperature Flue Gas System

2021 ◽  
pp. 897-909
Author(s):  
Yu Yan ◽  
Jiahao Jiang ◽  
Jin Guo ◽  
Yuesheng Li ◽  
Lei Deng ◽  
...  
2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Lei Ma ◽  
Feng-zhong Sun ◽  
Zhi-min Li ◽  
Pei Chen ◽  
Fei Li

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.


Author(s):  
Lei Ma ◽  
Fengzhong Sun ◽  
Wei Wei ◽  
Jiayou Liu ◽  
Yuetao Shi

The ash deposition on low-temperature heat transfer surface is a key factor that deteriorates the heat transfer performance and leads to corrosion in the low pressure economizer. In the low temperature flue gas, ash deposition is closely related with acid condensation. The sulfuric acid vapor and water vapor contained in the flue gas will condense on heat transfer surface under low flue temperature, which will aggravate ash deposition. In order to evaluate the influence factors of ash deposition on low-temperature heat transfer surface, a laboratory experiment is carried out in this paper. The acid concentration of flue gas, the ash content, the ash component, the flue temperature and the temperature of heat transfer surface are considered to be the most important influence factors on ash deposition characteristics. The viscosity of ash deposition samples on the outer wall of the double-pipe is measured to describe ash deposition characteristics. The fouling factor is calculated. Meanwhile, the scanning electron microscope SEM is used to the analysis of ash samples obtained from the outer wall of the double-pipe. As conclusion, the changing regulation of viscosity of ash deposition on low-temperature heat transfer surface is obtained. (CSPE)


2017 ◽  
Vol 142 ◽  
pp. 3307-3312 ◽  
Author(s):  
Yubo Zhang ◽  
Yu Yan ◽  
Jianhua Liu ◽  
Qingwen Qi ◽  
Lei Deng ◽  
...  

Actuators ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 98
Author(s):  
Chao-Yong Shen ◽  
Xiang-Yun Huang ◽  
Yang-Yang Chen ◽  
Yu-Hong Ma

In this research we conducted a sensitivity experimental study where we explored the dependency of the shear strain on the seismic properties of bearings, namely lead rubber bearing (LRB) and super high damping rubber bearing (SHDR). The factors studied were vertical pressure, temperature, shear modulus of the inner rubber (G value), loading frequency, and loading sequence. Six specimens were adopted, i.e., three LRBs and three SHDR bearings. A series of test plans were designed. The seismic characteristics of the bearings were captured through a cyclic loading test, which included post-yield stiffness, characteristic strength, area of a single cycle of the hysteretic loop, equivalent stiffness, and equivalent damping ratio. A whole analysis of variances was then conducted. At the same time, to explore certain phenomena caused by the factors, an extended discussion was carried out. Test results showed that the temperature is the most dominant feature, whereas the G value is the least contributing factor, with the effect of the loading frequency and the loading sequence found between these two. The increment of the post-yielded stiffness for LRB from 100% to 25% is a significant reduction from a low temperature to high one. The slope of the characteristic strength versus the shear strain for LRB under high temperature is larger than the one under low temperature.


Fuel ◽  
2020 ◽  
Vol 259 ◽  
pp. 116306 ◽  
Author(s):  
Chenghang Zheng ◽  
Cong Luo ◽  
Yong Liu ◽  
Yifan Wang ◽  
Yan Lu ◽  
...  
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