scholarly journals PENGARUH FOULING TERHADAP LAJU PERPINDAHAN PANAS PADA SUPERHEATER BOILER CFB PLTU SEBALANG

Power Plant ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 48-57
Author(s):  
Redaksi Tim Jurnal
Keyword(s):  
High Temperature ◽  
Fly Ash ◽  
Chemical Composition ◽  
Low Temperature ◽  
Fluidized Bed ◽  
Flue Gas ◽  
Circulating Fluidized Bed

Salah satu unit yang paling penting dalam produksi uap pada PLTU adalah boiler. Salah satu boileh jenis PLTU sering digunakan adalah boiler tipe CFB (Circulating Fluidized Bed), dan jenis bahanbakar batu bara yang digunakan banyak mengandung zat basa. Superheater merupakan salah satu komponen terpenting pada boiler. Superheater berfungsi untuk memanaskan uap agar kandungan energi panas dan kekeringannya bertambah sehingga menjadi uap superheat. Permasalahan yang sering terjadi pada superheater yaitu penumpukan abu (fouling) yang terjadi pada tube superheater tersebut. Unsur yang paling berpengaruh pada fouling adalah material basa terutama kadar Na2O. Bila kadar abu batubara banyak, kemudian unsur basa dalam abu juga banyak, ditambah kadar Na2O yang tinggi, maka fouling akan mudah terjadi. Kadar sulfur yang tinggi cenderung mendorong timbulnya fouling. Fouling dapat menyebabkan penurunan laju perpindahan panas antara flue gas dengan steam pada superheater. Potensi fouling dapat diukur menggunakan suatu persamaan, tetapi persamaan tersebut hanya memperhitungkan chemical composition dari batubara tersebut. Dari penelitian diperoleh hasil terjadi penurunan laju perpindahan panas untuk high temperature superheater dari sootblowing satu ke sootblowing selanjutnya sebesar 511,8458 kW atau sekitar 3,012%. Sedangkan penurunan laju perpindahan panas untuk low temperature superheater dari sootblowing satu ke sootblowing selanjutnya sebesar 3421,506 kW atau sekitar 13,028%. Unsur yang paling berpengaruh pada fouling adalah material basa terutama Na, yang dalam hal ini kadar Na2O. Potensi terjadinya fouling yang dihitung dari data analisis fly ash menunjukkan nilai potensi fouling sebesar 4,0069 yang masuk dalam kategori potensi fouling tinggi pada fly ash lignit.

scholarly journals Combustion adjustment and operation optimiztion of a 240 t/h circulating fluidized bed boiler

2020 ◽  
Vol 24 (5 Part A) ◽  
pp. 2689-2698
Author(s):  
Xuemin Liu ◽  
Songsong Zhang ◽  
Yongqiang Chang ◽  
Zhongwei Wang ◽  
Guoli Qi
Keyword(s):  
Fly Ash ◽  
Pressure Drop ◽  
Fluidized Bed ◽  
Flue Gas ◽  
Circulating Fluidized Bed ◽  
Air Flow ◽  
Nox Emission ◽  
Unburned Carbon ◽  
Boiler Efficiency ◽  
Co Concentration

The influence of main operating parameters on boiler performance was studied, such as bed pressure drop, primary air-flow and secondary air-flow. Combustion adjustment tests were carried out on a circulating fluidized bed boiler with rated capacity of 240 t/h. From the test results, it can be seen that the loss due to exit flue gas is the largest heat loss of the boiler, accounting for more than 70% of the total heat losses. For coal fired boilers, compared with the loss due to unburned solids, the loss due to unburned gases is quite small. The unburned carbon con-tent in bottom ash is far lower than the value in fly ash. The trend of CO concentration in the exit flue gas is similar to that of the unburned carbon content in fly ash. To achieve higher boiler efficiency, the bed pressure drop is suggested to be maintained in about 8.5-9.0 kPa and the oxygen content in exit flue gas around 4%. The NOx emission concentration usually presents a negative correlation with CO concentration in exit flue gas. Through combustion adjustment and operation optimization, the NOx emission can be decreased by about 30% without affecting the boiler efficiency.

Effect of Desulfurization Ash with Different Desulfurization Temperature and Gypsum Content on the Fluidity, Strength and Rebar Protection of Cement Based Materials

2010 ◽  
Vol 168-170 ◽  
pp. 940-944
Author(s):  
Xiao Dong Wen ◽  
Guo Song Li ◽  
Jiu Yong Song ◽  
Zhi Nan Gao
Keyword(s):  
High Temperature ◽  
Fly Ash ◽  
Low Temperature ◽  
Flue Gas ◽  
Development Trend ◽  
Weight Percentage ◽  
Steel Rebar ◽  
High Temperature Furnace ◽  
Gypsum Content ◽  
Temperature Furnace

Depending on the desulfurization reaction temperature，it can be divided into fly ash generated at high-temperature furnace zone and at low-temperature flue gas zone. For simulating those two kinds of desulfurization ash, the ordinary fly ash mixed with different weight percentage of CaSO4•2H2O is divided into 2 groups, the first group is followed by calcining at 900 , another drying at 100 . And then by the experiment of workability, strength and steel rebar protection, the effect of morphology and amount of gypsum on material properties and the pretreatment method are studied. The results show that: compared with ordinary fly ash, those two kinds of desulfurization ash can improve workability, but the improving ability of desulfurization ash at high-temperature furnace zone weaker than another’s, in addition, amount of gypsum in desulfurization ash on fluidity has a threshold; Secondly, desulfurization ash can decrease strength, and the early strength of desulfurization ash at high-temperature furnace zone higher than another’s, but the development trend of later strength is in the opposite direction. Thirdly, those two kinds of desulfurization ash are harmless for steel rebar, and the steel rebar’s passive film compactness is followed desulfurization ash formed at low-temperature flue gas zone＞desulfurization ash formed at high-temperature furnace zone＞ordinary fly ash.

Emission Characteristicsof of PCBs of Combustion of Sludge-Coal Water Slurry in Fluidized Bed

2013 ◽  
Vol 340 ◽  
pp. 382-387 ◽  
Author(s):  
Xiao Li Zhao ◽  
Wei Zhu
Keyword(s):  
Fly Ash ◽  
Fluidized Bed ◽  
Flue Gas ◽  
Circulating Fluidized Bed ◽  
Bottom Ash ◽  
Emission Characteristics ◽  
Emission Standard ◽  
Water Slurry ◽  
Sludge Incineration ◽  
Coal Water Slurry

Sludge-coal water slurry (SCWS) can be produced by mixing coal water slurry (CWS) with sewage sludge according to differenct ratio. This paper focuses on the combustive feasibility of SCWS in a commercial circulating fluidized bed, and on the emission characteristics of polychlorinated biphenyls (PCBs) in flue gas fly ash and bottom ash during combustion of SCWS. The results indicated that incineration can do very well with the temperature 1000 degree, sludge coal water slurry (SCWS) can be effective in improving sludge incineration rate, if the proportion of sludge is 20%~30%,amounts of PCBs is relatively small in flue gas fly ash and bottom ash. So the best burning rate is 20%-30%. Although incineration flue gas fly ash and bottom ash emission standard don't have PCBs regulations, but since PCBs are toxic organic pollutants, it should be strictly regulated.

Optimization of the Composition of the Binder Based on CFBC Fly Ash

2018 ◽  
Vol 760 ◽  
pp. 184-192 ◽  
Author(s):  
Petr Formáček ◽  
Rostislav Šulc
Keyword(s):  
High Temperature ◽  
Fly Ash ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Computer Programs ◽  
Fluidized Bed Combustion ◽  
Slaked Lime ◽  
Cfbc Fly Ash ◽  
Main Components ◽  
Circulating Fluidized Bed Combustion

This paper is bound to previous research of materials based on fly ash. The main objective was to design an optimal ternary (three-component) binder based on fly ash from Circulating fluidized Bed Combustion (CFBC). The design of the binder is based on the optimization of individual components. Main components of the binder are CFBC fly ash, high-temperature fly ash and slaked lime. The binder was progressively designed and optimized. The strength characteristics of the various binders were measured, evaluated and the results were inserted into computer programs Surfer 8 and Grapher 8 from which ternary diagrams with strength maps were created. The best binder mixture were selected from the optimization process.

scholarly journals Highly Effective Adsorption Process of Ni(II) Ions with the Use of Sewage Sludge Fly Ash Generated by Circulating Fluidized Bed Combustion (CFBC) Technology

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3106
Author(s):  
Tomasz Kalak ◽  
Kinga Marciszewicz ◽  
Joanna Piepiórka-Stepuk
Keyword(s):  
Fly Ash ◽  
Sewage Sludge ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
Fluidized Bed Combustion ◽  
Nickel Ions ◽  
Suitable Material ◽  
Circulating Fluidized Bed Combustion

Recently, more and more attention has been paid to the removal of nickel ions due to their negative effects on the environment and human health. In this research, fly ash obtained as a result of incineration of municipal sewage sludge with the use of circulating fluidized bed combustion (CFBC) technology was used to analyze the possibility of removing Ni(II) ions in adsorption processes. The properties of the material were determined using analytical methods, such as SEM-EDS, XRD, BET, BJH, thermogravimetry, zeta potential, SEM, and FT-IR. Several factors were analyzed, such as adsorbent dose, initial pH, initial concentration, and contact time. As a result of the conducted research, the maximum sorption efficiency was obtained at the level of 99.9%. The kinetics analysis and isotherms showed that the pseudo-second order equation model and the Freundlich isotherm model best suited this process. In conclusion, sewage sludge fly ash may be a suitable material for the effective removal of nickel from wastewater and the improvement of water quality. This research is in line with current trends in the concepts of circular economy and sustainable development.

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