PREDICTION SULPHURIC ACID AND WATER VAPOUR DEW POINT TEMPERATURES OF FLUE GASES AND COMBUSTION ANALYSIS FOR SOLID FUELS IN TURKEY

Abstract

In the study, the combustion analysis is examined for the solid fuels in Turkey. The principal aim of the analysis is determined the limits and obstacles in the design heat exchanger to avoid the corrosion risk on the heat exchanger surfaces in the latent heat recovery applications from waste flue gas. To do this, in which regions of the heat exchanger the flue gas temperature reached to the sulphuric acid and water vapour dew point temperatures are required to predict. In order to predict the condensing zone, an air preheater for the coal-fired boiler in a heating system is designed using finite difference method. Designed the air preheater is consists of the counter-cross flow, Ushaped stainless steel tube bundle. The tube is discredited 200 cells to one-dimensional during the flow. The heat transfer rates, the flue gas and air inlet and outlet temperatures, surface temperatures of the tube wall, the mole fractions of water and sulphuric acid vapour, the other non-condensing gases in the flue gas are calculated in each discrete cell. According to the results of the study, while the dew point temperature of the water vapour changes over the range 30-40 °C, the acid dew point temperature waves to 125 °C from 140 °C for the coal types mined in Turkey.

Keywords

• Solid Fuels
• Combustion Analysis
• Acid Dew Point Temperature
• Heat Recovery from Flue Gas
• Air Preheater

References

1. [1] Wei W, Sun F, Shi Y, Ma L. Theoretical prediction of acid dew point and safe operating temperature of heat exchangers for coal-fired power plants. Applied Thermal Engineering 2017;123:782-790. https://doi.org/10.1016/j.applthermaleng.2017.05.051.
2. [2] Xiang B, Tang B, Wu Y, Yang H, Zhang M, Lu J. Prediction acid dew point with a semi-empirical model. Applied Thermal Engineeing 2016;106:992-1001. https://doi.org/10.1016/j.applthermaleng.2016.06.040.
3. [3] Blanco JM, Pena F. Increase in the boiler’s performance in terms of the acid dew point temperature:Environmental advantages of replacing fuels. Applied Thermal Engineering 2008;28:777-784. https://doi.org/10.1016/j.applthermaleng.2007.06.024.
4. [4] Pena F, Blanco JM. Evaluation of the physical dew point in the economizer of a combined cycle burning natural gas. Applied Thermal Engineering 2007;27:2153-2158. https://doi.org/10.1016/j.applthermaleng.2006.12.021.
5. [5] Ding Q, Tang XF, Yang ZG. Failure analysis on abnormal corrosion of economizer tubes in a waste heat boiler. Engineering Failure Analysis 2017;73:129-138. https://doi.org/10.1016/j.engfailanal.2016.12.011.
6. [6] Luo Y, Woolley E, Rahimiford S, Simeone A. Improving energy efficiency within manufacturing by recovering waste heat energy. Journal of Thermal Engineering 2015;1:337-344. https://doi.org/10.18186/jte.49943.
7. [7] Han H, He YL, Tao WQ. A numerical study of the deposition characteristics of sulfuric acid vapor on heat exchanger surfaces. Chemical Engineering Science 2013;101:620-630. https://doi.org/10.1016/j.ces.2013.07.024.
8. [8] Vainio E, Kinnunen H, Lauren T, Brink A, Yrjas P, DeMartini N, Hupa M. Low-temperature corrosion in cocombustion of biomass and solid recovered fuels. Fuel 2016; 184:957-965. https://doi.org/10.1016/j.fuel.2016.03.096.

9. [9] ZareNezhad B, Aminian A. Accurate prediction of the dew points of acidic combustion gases by using an artificial neural network model. Energy Conversion and Management 2011;52:911-916. https://doi.org/10.1016/j.enconman.2010.08.018.
10. [10] Li X, Wu Z, Zhang L, Liu X, Zhu X, Hu H, Luo G, Hu Z, Liu W, Yao H. An updated acid dew point temperature estimation method for air-firing and oxy-fuel combustion processes. Fuel Processing Technology 2016;154:204-209. https://doi.org/10.1016/j.fuproc.2016.08.033.
11. [11] Shi Y, Dai C, Ma Z, Guo Z. Experimental investigation of heat transfer with ash deposition in ultra-low temperature WHRS of coal-fired power plant. Applied Thermal Engineering 2017;123:1181-1189. https://doi.org/10.1016/j.applthermaleng.2017.05.190.
12. [12] Cengel YA, Boles MA. Thermodynamics an engineering approach. Guven Scientific Press; 2008.
13. [13] Bilgen S. Bazı yakıtların kimyasal ekserji değerlerinin hesaplanması. Yüksek Lisans Tezi 2000. Karadeniz Teknik Üniversitesi, Trabzon, Türkiye.