Advanced Power Generation System and Related Thermal Engineering Problems

Author(s):  
Mamoru Ozawa ◽  
Ryosuke Matsumoto ◽  
Hisashi Umekawa

Based on the increased attention to “energy security” and “sustainable development”, it is essential to promote clean use of coal as a fuel. Typical advanced technologies are demonstrated by the pressurized fluidized-bed combined cycle (PFBC) and integrated gasification combined cycle (IGCC). Focusing mainly on these two examples as the advanced energy conversion technology, related problems are reviewed. The PFBC technology is a composite technology of conventional fluidized bed and combined-cycle, in which ash, being a typical component of coal, is not melted but is removed mainly in the fluidized bed. On the other hand, the IGCC is much more complicated and ash removal is conducted by melting in the combustor. Heat released there is utilized for gasification process in the reductor installed just downstream the combustor. Even though both systems have very high potential for clean and efficient use of coal, the commercial plants are limited in a very small number or at the stage of just a demonstration plant. To extend and develop clean-coal technology in the electric power generation market, a strategy of the government on the energy technology as well as the long-term competition in the market are indispensable, otherwise related technologies as well as the engineers involved will be lost.

Author(s):  
Di Huang ◽  
Huisheng Zhang ◽  
Shilie Weng ◽  
Ming Su

Gasifier is one of core parts of Integrated Gasification Combined Cycle, which combines clean coal technology with combined cycle through the gasification of solid coal. The conventional lumped parameters simulation model cannot reflect the distribution characteristics in the gasifier. In order to obtain a more realistic model which can depict the dynamic response as well as the distribution characteristics, this paper utilizes the volume-resistance modeling technique and modular modeling method for the gasifier modeling. The gasifier will be divided into several compartments. The parameters in each compartment are uniform, while it has distribution characteristics for a whole gasifier. Thus the pressure and temperature distribution in the gasifier will be incorporated into the gasification process. The gasifier model in this paper can not only be used for the system performance analysis, but also for the control system design and debugging.


Author(s):  
J T McMullan ◽  
B C Williams ◽  
E P Sloan

Power generation in Europe and elsewhere relies heavily on coal as the source of energy and this reliance will increase in the future as other fossil fuels become progressively more expensive. The existing stock of coal-fired power stations mainly use pulverized fuel boilers and present designs based on ultrasupercritical steam cycles are as efficient and as low in SOx and NOx emissions as is possible without incurring excessive additional costs. This paper examines the options for coal-based power generation technologies and compares their technical, environmental and economic performance. These options include atmospheric and pressurized fluidized bed combustion and a range of integrated gasification combined cycle systems. Integrated gasification combined cycles give good efficiency and very low emissions, but further optimization is required to make them economically attractive. Conceptual cycles based on pressurized pulverized combustion, dual fuel hybrid cycles, fuel cells and magnetohydrodynamics are also covered in outline.


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