Revamping of 4 x 58 MWth Pulverized Coal-Fired Boilers With Circulating Fluidized Bed Firing

Abstract

A techno-economic feasibility study has been conducted to investigate revamping four 58 MWth (15 MWe) pulverized-coal (PC) boilers with circulating fluidized bed (CFB) firing. The steam generators at Amarkantak Thermal Power Station in Chachai, Madhya Pradesh, are owned by Madhya Pradesh State Electricity Board (MPSEB), supplied by Simmering-Graz-Pauker AG of Vienna, Austria, and commissioned in mid-1965. The study reveals that: (i) CFB revamping of the boilers is technically feasible and economically sound; (ii) Performance improvement of the plant is significant in terms of such indices as plant load factor, forced outage and auxiliary oil consumption, among others. The expected performance improvement is due in large part to the elimination of key outage-prone components such as pulverizers (mills) and burners. (iii) There is significant improvement in emissions performance due to the reduction in emissions of NOx and fly ash; (iv) The financial analysis indicates that the CFB revamping option gives the highest return on investment compared to alternatives.

Ash Analysis of Poultry Litter, Willow and Oats for Combustion in Boilers

“…According to the researchers the major components for the poultry litter are struvite, sylvite, calcite, Weddellite and quartz [24][25][26][27] [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. Figure 5 shows the XRD patterns for poultry litter ash prepared at temperatures 800, 900 and 1000°C.…”

“…Figure 5 shows the XRD patterns for poultry litter ash prepared at temperatures 800, 900 and 1000°C. The peaks at 17, 28, 33 2θ as can be seen from the Fig 5 represents the crystalline structure of struvite (NH 4 MgPO 4 ·6H 2 O) [24][25][26][27], which with the increase in temperature, the height of the peak increases. This can be attributing to the increase in relative amount of crystalline structure in the sample with the increase in combustion temperature.…”

Experimental investigation into cavity-type inertial separators—a novel technique for development of subcompact circulating fluidized bed boilers

“…However, all of these additional heat absorption surfaces are expensive and do not make any contribution to gas-solid separation required in a CFB boiler. Lately, revamping/ retrofitting of pulverized coal (PC)-fired boilers with CFB firing is also being considered as an effective means of inexpensively rehabilitating old power plants (Basu and Talukdar, 2001;Sen et al, 2003). Because of the characteristic high heat flux of PC-fired boiler furnaces, a CFB revamped boiler requires additional heat absorption surfaces in the CFB loop to retain the boiler throughput after conversion.…”