Dynamic Modeling and Simulation of Gasifier Based on Volume-Resistance Characteristics Method

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):  
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.


2020 ◽  
pp. 99-111
Author(s):  
Vontas Alfenny Nahan ◽  
Audrius Bagdanavicius ◽  
Andrew McMullan

In this study a new multi-generation system which generates power (electricity), thermal energy (heating and cooling) and ash for agricultural needs has been developed and analysed. The system consists of a Biomass Integrated Gasification Combined Cycle (BIGCC) and an absorption chiller system. The system generates about 3.4 MW electricity, 4.9 MW of heat, 88 kW of cooling and 90 kg/h of ash. The multi-generation system has been modelled using Cycle Tempo and EES. Energy, exergy and exergoeconomic analysis of this system had been conducted and exergy costs have been calculated. The exergoeconomic study shows that gasifier, combustor, and Heat Recovery Steam Generator are the main components where the total cost rates are the highest. Exergoeconomic variables such as relative cost difference (r) and exergoeconomic factor (f) have also been calculated. Exergoeconomic factor of evaporator, combustor and condenser are 1.3%, 0.7% and 0.9%, respectively, which is considered very low, indicates that the capital cost rates are much lower than the exergy destruction cost rates. It implies that the improvement of these components could be achieved by increasing the capital investment. The exergy cost of electricity produced in the gas turbine and steam turbine is 0.1050 £/kWh and 0.1627 £/kWh, respectively. The cost of ash is 0.0031 £/kg. In some Asian countries, such as Indonesia, ash could be used as fertilizer for agriculture. Heat exergy cost is 0.0619 £/kWh for gasifier and 0.3972 £/kWh for condenser in the BIGCC system. In the AC system, the exergy cost of the heat in the condenser and absorber is about 0.2956 £/kWh and 0.5636 £/kWh, respectively. The exergy cost of cooling in the AC system is 0.4706 £/kWh. This study shows that exergoeconomic analysis is powerful tool for assessing the costs of products.


Author(s):  
S De ◽  
P K Nag

The effect of supplementary firing on the performance of an integrated gasification combined cycle (IGCC) power plant is studied. The results are presented with respect to a simple ‘unfired’ IGCC power plant with single pressure power generation for both the gas and the steam cycles as reference. The gases are assumed as real with variable specific heats. It is found that the most favourable benefit of supplementary firing can be obtained for a low temperature ratio R T only. For higher R T, only a gain in work output is possible with a reverse effect on the overall efficiency of the plant. The second law analysis reveals that the exergy loss in the heat-recovery steam generator is most significant as the amount of supplementary firing increases. It is also noteworthy that, although the total exergy loss of the plant decreases with higher supplementary firing for a low R T (= 3.0), the reverse is the case for a higher R T (= 6.0).


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