New Technology Trends for Improved IGCC System Performance

Author(s):  
A. K. Anand ◽  
C. S. Cook ◽  
J. C. Corman ◽  
A. R. Smith

The application of gas turbine technology to IGCC systems requires careful consideration of the degree and type of integration used during the system design phase. Although gas turbines provide the primary output and efficiency gains for IGCC systems, as compared with conventional coal fired power generation systems, they are commercially available only in specific size ranges. Therefore, it is up to the IGCC system designer to optimize the IGCC power plant within the required output, efficiency and site conditions by selecting the system configuration carefully, particularly for air separation unit (ASU) integration incorporated with oxygen blown gasification systems. An IGCC system, based on a generic, entrained flow, oxygen blown gasification system and a GE STAG 109FA combined cycle has been evaluated with varying degrees of ASU integration, two fuel equivalent heating values and two gas turbine firing temperatures to provide net plant output and efficiency results. The data presented illustrate the system flexibility afforded by variation of ASU integration and the potential performance gains available through the continued use of gas turbine advances. Emphasis is place on system design choices which favor either low initial investment cost or low operating cost for a given IGCC system output.

1996 ◽  
Vol 118 (4) ◽  
pp. 732-736 ◽  
Author(s):  
A. K. Anand ◽  
C. S. Cook ◽  
J. C. Corman ◽  
A. R. Smith

The application of gas turbine technology to IGCC systems requires careful consideration of the degree and type of integration used during the system design phase. Although gas turbines provide the primary output and efficiency gains for IGCC systems, as compared with conventional coal-fired power generation systems, they are commercially available only in specific size ranges. Therefore, it is up to the IGCC system designer to optimize the IGCC power plant within the required output, efficiency, and site conditions by selecting the system configuration carefully, particularly for air separation unit (ASU) integration incorporated with oxygen blown gasification systems. An IGCC system, based on a generic, entrained flow, oxygen blown gasification system and a GE STAG 109FA combined cycle has been evaluated with varying degrees of ASU integration, two fuel equivalent heating values and two gas turbine firing temperatures to provide net plant output and efficiency results. The data presented illustrate the system flexibility afforded by variation of ASU integration and the potential performance gains available through the continued use of gas turbine advances. Emphasis is placed on system design choices that favor either low initial investment cost or low operating cost for a given IGCC system output.


1997 ◽  
Vol 119 (2) ◽  
pp. 298-304 ◽  
Author(s):  
A. R. Smith ◽  
J. Klosek ◽  
D. W. Woodward

The commercialization of Integrated Gasification Combined Cycle (IGCC) Power has been aided by concepts involving the integration of a cryogenic air separation unit (ASU) with the gas turbine combined-cycle module. Other processes, such as coal-based ironmaking and combined power/industrial gas production facilities, can also benefit from the integration. It is known and now widely accepted that an ASU designed for “elevated pressure” service and optimally integrated with the gas turbine can increase overall IGCC power output, increase overall efficiency, and decrease the net cost of power generation when compared to nonintegrated facilities employing low-pressure ASUs. The specific gas turbine, gasification technology, NOx emission specification, and other site specific factors determine the optimal degree of compressed air and nitrogen stream integration. Continuing advancements in both air separation and gas turbine technologies offer new integration opportunities to improve performance and reduce costs. This paper reviews basic integration principles and describes next-generation concepts based on advanced high pressure ratio gas turbines, Humid Air Turbine (HAT) cycles and integration of compression heat and refrigeration sources from the ASU. Operability issues associated with integration are reviewed and control measures are described for the safe, efficient, and reliable operation of these facilities.


Author(s):  
Arthur R. Smith ◽  
Joseph Klosek ◽  
Donald W. Woodward

The commercialization of Integrated Gasification Combined Cycle (IGCC) power has been aided by concepts involving the integration of a cryogenic air separation unit (ASU) with the gas turbine combined-cycle module. Other processes, such as coal-based ironmaking and combined power/industrial gas production facilities, can also benefit from the integration. It is known and now widely accepted that an ASU designed for “elevated pressure” service and optimally integrated with the gas turbine can increase overall IGCC power output, increase overall efficiency, and decrease the net cost of power generation when compared to non-integrated facilities employing low pressure ASU’s. The specific gas turbine, gasification technology. NOx emission specification, and other site specific factors determine the optimal degree of compressed air and nitrogen stream integration. Continuing advancements in both air separation and gas turbine technologies offer new integration opportunities to improve performance and reduce costs. This paper reviews basic integration principles and describes next-generation concepts based on advanced high pressure ratio gas turbines, Humid Air Turbine (HAT) cycles and integration of compression heat and refrigeration sources from the ASU. Operability issues associated with integration are reviewed and control measures are described for the safe, efficient and reliable operation of these facilities.


2013 ◽  
Vol 34 (4) ◽  
pp. 137-159 ◽  
Author(s):  
Łukasz Bartela ◽  
Janusz Kotowicz

Abstract In the paper the results of analysis of an integrated gasification combined cycle IGCC polygeneration system, of which the task is to produce both electricity and synthesis gas, are shown. Assuming the structure of the system and the power rating of a combined cycle, the consumption of the synthesis gas for chemical production makes it necessary to supplement the lack of synthesis gas used for electricity production with the natural gas. As a result a change of the composition of the fuel gas supplied to the gas turbine occurs. In the paper the influence of the change of gas composition on the gas turbine characteristics is shown. In the calculations of the gas turbine the own computational algorithm was used. During the study the influence of the change of composition of gaseous fuel on the characteristic quantities was examined. The calculations were realized for different cases of cooling of the gas turbine expander’s blades (constant cooling air mass flow, constant cooling air index, constant temperature of blade material). Subsequently, the influence of the degree of integration of the gas turbine with the air separation unit on the main characteristics was analyzed.


Author(s):  
Erwin Zauner ◽  
Yau-Pin Chyou ◽  
Frederic Walraven ◽  
Rolf Althaus

Power generation in gas turbines is facing three main challenges today: • Low pollution prescribed by legal requirements. • High efficiency to obtain low operating cost and low CO2 emissions. • High specific power output to obtain low product and installation cost. Unfortunately, some of these requirements are contradictory: high efficiency and specific power force the development towards higher temperatures and pressures which increase NOx emissions and intensify the cooling and material strength problems. A breakthrough can be achieved by applying an energy exchanger as a topping stage. Inherent advantages are the self-cooled cell-rotor which can be exposed to much higher gas temperature than a steady-flow turbine and a very short residence time at peak temperature which keeps NOx emissions under control. The basic idea has been proposed long time ago. Fundamental research has now led to a new energy exchanger concept. Key issues include symmetric pressure-wave processes, partial suppression of flow separation and fluid mixing, as well as quick afterburning in premixed mode. The concept has been proven in a laboratory-scale engine with very promising results. The application of an energy exchanger as a topping stage onto existing gas turbines would increase the efficiency by 17% (relative) and the power by 25%. Since the temperature level in the turbine remains unchanged, the performance improvement can also be fully utilized in combined cycle applications. This process indicates great potentials for developing advanced gas turbine systems as well as for retrofitting existing ones.


1984 ◽  
Vol 106 (3) ◽  
pp. 645-653
Author(s):  
P. A. Dupuy

The LM2500 Gas Turbine is used for propulsion of naval ships from 220 tons to 14,000 tons displacement. Those ships from 220 to 4000 tons have used combined diesel or gas turbine (CODOG) systems in all but one ship class. Destroyers and larger ships, 7000 tons and up, have all used solely LM2500 turbines as Combined Gas Turbine and Gas Turbine (COGAG). Recently, the diesel engine industry has announced the advent of technological developments whereby diesel engine specific power can be significantly increased. Thus it is being suggested that with this new technology, all diesel propulsion (CODAD) can replace various propulsion systems currently using combined diesels with gas turbines. This paper explores the desired mission objectives for corvette/frigate class ships and develops an analytical comparison of all diesel and combined propulsion abilities to satisfy the ship’s missions. The comparison assesses the system’s relative impact upon propulsion system acquisition and life operating cost, system operational flexibility, ship’s detectability, and overall ability of the ship to perform the broadest range of mission requirements.


2000 ◽  
Author(s):  
Zelong Liu ◽  
Hongguang Jin ◽  
Rumou Lin

Abstract Integrated Gasification Combined Cycle (IGCC) is considered as one of the advanced clean coal power technologies. Here, we have investigated an IGCC with air separation unit (ASU) on the basis of exergy analysis, and clarified the distribution of exergy destruction in sub-systems including air separation unit, coal gasifier, coal gas clean-up unit, air compressor, combustor of gas turbine, gas turbine, heat recovery steam generation and steam turbine. Particularly, we have focused on the interaction between the ASU and the gas turbine (GT). The results obtained disclosed the significant role of the integration between air separation unit and air compressor in the GT, and the effect of nitrogen injection to the combustor on IGCC overall performance. The study also points out that larger exergy destruction take place in the processes of gasification, combustion in GT, and air separation, and so does the change of exergy destruction distribution with the air integration degree and the nitrogen injection ratio. We have demonstrated the potential for improving the IGCC system. This investigation will be valuable for the synthesis of next-generation IGCC.


Author(s):  
David W. Donle ◽  
Robert C. Kiefer ◽  
Thomas C. Wright ◽  
Ugo A. Bertolami ◽  
Denis G. Hill

This paper describes the development, application, and performance verification of a new patented technology for cleaning and cooling combustion air to a gas turbine. A two (2) year in-depth research program at Dow Chemical Company in Freeport, Texas resulted in the development of this technology. At the conclusion of the research and development program, full-scale application of the hardware was made on a 100 MW combined cycle gas turbine, and its performance monitored for two (2) years. Application of the new technology resulted in increased power output, higher reliability, NOx emission reduction, reduced maintenance costs, and higher total system efficiency. Since the new technology has produced very large cost savings, Dow is using the new technology on three new combined cycle machines currently being installed, and further is exploring conversion of existing combined cycle gas turbines to this new technology.


Author(s):  
Y. S. Kim ◽  
J. J. Lee ◽  
K. S. Cha ◽  
T. S. Kim ◽  
J. L. Sohn ◽  
...  

An IGCC (integrated gasification combined cycle) plant couples a power block to a gasification block. The method of integrating a gas turbine with a gasification process is the major design option. Matching between the gas turbine and the air separation unit is especially important. This study analyzes the influences of IGCC design options on the operability and performance of the gas turbine. Another research focus is given to the estimation of the change of turbine metal temperature in the IGCC operating environment. For this purpose, a full off-design analysis of the gas turbine is used with the turbine blade cooling model. Four different syngas fuels are considered. As the integration degree becomes lower, the gas turbine power and efficiency increase. However, a lower integration degree causes a reduction of the compressor surge margin and overheating of the turbine metal. Only near 100% integration degree designs are almost free of those two problems. The syngas property also affects the gas turbine operation. As the heating value gets lower, the problems of surge margin reduction and metal overheating become more severe. Modifications of the compressor (adding a couple of stages) and the turbine (increasing gas path area) could solve the compressor surge problem. However, the turbine overheating problem still exists. In particular, the turbine modification is predicted to overheat turbine metal considerably.


Author(s):  
Takao Hashimoto ◽  
Katsuhiro Ota ◽  
Takashi Fujii

Integrated Coal Gasification Combined Cycle (IGCC) is attracting considerable attention as clean coal technology for several reasons, including rising natural gas price, escalating environmental scrutiny and fuel diversification. Mitsubishi Heavy Industries, Ltd. (MHI) has developed an air-blown two stage entrained bed coal gasifier, which realizes the highest net plant efficiency by using a smaller ASU (Air Separation Unit), dry coal feed, and excellent reliability with a membrane water wall structure. A 250 MW demonstration plant is currently under construction in Japan and scheduled to start operation in 2007. This plant will validate MHI Air Blown technology under dispatching conditions. In the mean time, responding to increasing interest on this technology around the world, MHI is expediting the design of a 500MW IGCC plant to be operated with G class gas turbines. The MHI air blown gasifier concept is particularly attractive to the US market, not only because of the higher efficiency, when compared with oxygen blown designs, but because of its capability to handle a wide variety of coals including PRB. This paper will discuss what kind of IGCC will soon be commercially available and how it will fit practical needs in the US market showing the time schedule of realization of commercial plants and economical evaluation in addition to the technical integrity. MHI believes that IGCC is one of the most important clean coal technologies to contribute to worldwide energy security and environmental needs.


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