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

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.

2014 ◽  
Vol 1051 ◽  
pp. 743-747 ◽  
Author(s):  
Rong Jin Xu ◽  
Yan Kai Huo ◽  
Bin Teng ◽  
Si Hai Song

The character of the Fly ash of Circulating Fluidized Bed Boiler (CFB Fly ash) is greatly different from that of Pulverized coal furnace for its high unburned carbon. In order to make effective use of CFB Fly ash in concrete, carbon content was decreased by simulated fluidized bed combustion in laboratory and a series of concerned experiments were carried out on CFB Fly ash. The experimental results indicate that CFB modification Fly ash is possible to be used in concrete to partially replaced cement. It is a valuable reference for CFB Fly ash technical engineers.


2013 ◽  
Vol 291-294 ◽  
pp. 1714-1718
Author(s):  
Guo Li Qi ◽  
Jian Guan ◽  
Hao Leng

116MW circulating fluidized bed hot water boiler performance testing was carried out that found that burning high volatile lignite had post combustion phenomenon of separator yet. The phenomenon of post-combustion research results show that flue gas outlet temperature rise of the separation can be significantly reduced by adjusting the twelve wind ratio; Increasing coal-fired granularity which was able to reduce the separator post combustion phenomenon; Moderate post combustion of separation was able to improve boiler efficiency and reduce N2O. These results can provide guidance for improving boiler operation technology and improving the boiler design standard.


Power Plant ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 48-57
Author(s):  
Redaksi Tim Jurnal

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.


2013 ◽  
Vol 340 ◽  
pp. 382-387 ◽  
Author(s):  
Xiao Li Zhao ◽  
Wei Zhu

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.


2019 ◽  
Vol 11 (2) ◽  
Author(s):  
Prasetiyadi Prasetiyadi ◽  
Wiharja Wiharja ◽  
Sri Wahyono

Proses pembakaran sampah kota melalui insinerator akan menghasilkan uap panas yang bisa dimanfaatkan  untuk membangkitkan energi listrik, akan tetapi pada proses ini juga menghasilkan output berupa flue gas yang didominasi oleh partikel (fly ash) dan gas beracun seperti: HCl, SO2, NOx, HF, Hg, Cd dan Dioxin. Sebelum dibuang ke udara bebas, flue gas tersebut harus diolah agar memenuhi baku mutu lingkungan. Teknologi penanganan partikel dan gas polutan tersedia dan dapat dibuat dengan berbagai kapasitas. Untuk menangani flue gas dari insinerator sampah digunakan Quencher untuk menekan laju pembentukan kembali dioksin dan furan setelah proses pembakaran,  Spray Drying Absorption (SDA) untuk mengikat gas asam dan  logam berat serta bag filter untuk menangkap partikel. Selain itu digunakan ID Fan dan Cerobong Asap untuk pengatasi pressure drop yang terjadi akibat pengoperasian peralatan APC dan melepas ke udara.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3106
Author(s):  
Tomasz Kalak ◽  
Kinga Marciszewicz ◽  
Joanna Piepiórka-Stepuk

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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