Part Load Operation of a Multiple-Injection Dry Low NOx Combustor on Hydrogen-Rich Syngas Fuel in an IGCC Pilot Plant

Author(s):  
Tomohiro Asai ◽  
Satoschi Dodo ◽  
Mitsuhiro Karishuku ◽  
Nobuo Yagi ◽  
Yasuhiro Akiyama ◽  
...  

The successful development of coal-based integrated gasification combined cycle (IGCC) technology requires gas turbines capable of achieving the dry low-nitrogen oxides (NOx) combustion of hydrogen-rich syngas for low emissions and high plant efficiency. Mitsubishi Hitachi Power Systems, Ltd. (MHPS) has been developing a “multiple-injection combustor” to achieve the dry low-NOx combustion of hydrogen-rich syngas. This study suggests an advanced fuel staging comprising a hybrid partial combustion mode to improve the combustor’s part load performance. The purposes of this paper are to present the test results of the combustor with the advanced staging on a syngas fuel in an IGCC pilot plant, and to evaluate its performance. The syngas fuel produced in the plant contained approximately 50% carbon monoxide, 20% hydrogen, and 20% nitrogen by volume. In the test, the advanced staging reduced the maximum NOx at part load to 44 ppm (at 15% oxygen) compared with the initial staging with a maximum NOx of 75 ppm, and attained higher combustion efficiency above 98.7% over the part load range than the initial staging with combustion efficiency above 97.1%. In conclusion, the advanced staging improved the part load performance by achieving lower NOx emissions and higher combustion efficiency.

Author(s):  
Tomohiro Asai ◽  
Satoschi Dodo ◽  
Mitsuhiro Karishuku ◽  
Nobuo Yagi ◽  
Yasuhiro Akiyama ◽  
...  

The successful development of coal-based integrated gasification combined cycle (IGCC) technology requires gas turbines capable of achieving the dry low nitrogen oxides (NOx) combustion of hydrogen-rich syngas fuels for low emissions and high plant efficiency. Mitsubishi Hitachi Power Systems, Ltd. (MHPS) has been developing a “multiple-injection burner” to achieve the dry low-NOx (DLN) combustion of hydrogen-rich syngas fuels. The purposes of this paper are to present the test results of a multican combustor equipped with multiple-injection burners in an IGCC pilot plant, and evaluate combustor performance by focusing on the effects of flame shapes. The syngas fuel produced in the plant contained approximately 50% carbon monoxide, 20% hydrogen, and 20% nitrogen by volume. In the tests, the combustor with slenderer flames achieved lower NOx emissions of 10.9 ppm (at 15% oxygen), reduced combustor liner and burner plate metal temperatures, and lowered combustion efficiency at the maximum gas turbine load. The test results showed that the slenderer flames were more effective in reducing NOx emissions and liner/burner plate metal temperatures. A comparison with the diffusion-flame combustor demonstrated that the multiple-injection combustors achieved the dry low-NOx combustion of the syngas fuel in the plant.


Author(s):  
Tomohiro Asai ◽  
Satoschi Dodo ◽  
Mitsuhiro Karishuku ◽  
Nobuo Yagi ◽  
Yasuhiro Akiyama ◽  
...  

Successful development of oxygen-blown integrated coal gasification combined cycle (IGCC) technology requires gas turbines capable of achieving dry low-nitrogen oxides (NOx) combustion of hydrogen-rich syngas for low emissions and high plant efficiency. The authors have been developing a “multiple-injection burner” to achieve the dry low-NOx combustion of hydrogen-rich syngas. The purposes of this paper are to present test results of the multi-can combustor equipped with multiple-injection burners in an IGCC pilot plant and to evaluate the combustor performance focusing on effects of flame shapes. The syngas fuel produced in the plant contained approximately 50% carbon monoxide, 20% hydrogen, and 20% nitrogen by volume. In the tests, the combustor that produced slenderer flames achieved lower NOx emissions of 10.9 ppm (at 15% oxygen), reduced combustor liner and burner plate metal temperatures, and lowered the combustion efficiency at the maximum load. The test results showed that the slenderer flames were more effective in reducing NOx emissions and liner and burner metal temperatures. These findings demonstrated that the multiple-injection combustor achieved dry low-NOx combustion of the syngas fuel in the plant.


Author(s):  
Tomohiro Asai ◽  
Satoschi Dodo ◽  
Yasuhiro Akiyama ◽  
Akinori Hayashi ◽  
Mitsuhiro Karishuku ◽  
...  

Success of oxygen-blown integrated coal gasification combined cycle (IGCC) technology requires gas turbines capable of achieving dry low nitrogen oxides (NOx) combustion of hydrogen-rich syngas for low emissions and high plant efficiency. The authors have been developing a “multiple-injection burner” to achieve dry low-NOx combustion of such hydrogen-rich fuels using surrogate fuel composed of hydrogen, nitrogen, and methane. The purpose of this paper is to report test results of a multi-can combustor equipped with multiple-injection burners for a practical syngas fuel in an IGCC pilot plant and to evaluate its performance. The syngas fuel consisted of hydrogen, nitrogen, and carbon monoxide up to approximately half of its volume. In the test, the combustor achieved stable and reliable operation from ignition through partial load to the maximum load, and achieved NOx emissions of 15.1 ppm (at 15% oxygen) at the maximum load. These findings demonstrated that the combustor achieves dry low-NOx combustion of the syngas fuel in the IGCC pilot plant.


Author(s):  
Tomohiro Asai ◽  
Satoschi Dodo ◽  
Hiromi Koizumi ◽  
Hirokazu Takahashi ◽  
Shouhei Yoshida ◽  
...  

The successful combination of coal-based integrated gasification combined cycle (IGCC) technology with carbon dioxide (CO2) capture and storage (CCS) requires gas turbines that can achieve dry low-NOx combustion of hydrogen-rich syngas with a wide range of hydrogen concentrations for lower emissions and higher plant efficiency. The authors have been developing a “multiple-injection burner” to achieve dry low-NOx combustion of such hydrogen-rich fuels. The purpose of this paper is to experimentally investigate the combustion characteristics of a multiple-injection burner with a convex perforated plate in order to determine its effectiveness in suppressing combustion oscillation. The experiments were conducted at atmospheric pressure. Three kinds of fuel with hydrogen concentrations ranging from 40 to 84% were tested. The temperature of the combustion gas at the burner exit was 1775 K. The experimental results show that the convex burner was effective in suppressing combustion oscillation: it achieved stable low-NOx emissions of less than 10 ppm for all the test fuels. These findings demonstrate that the convex burner can achieve stable low-NOx combustion of hydrogen-rich fuels with a wide range of hydrogen concentrations by suppressing combustion oscillation.


2021 ◽  
Author(s):  
Silvia Ravelli

Abstract This study takes inspiration from a previous work focused on the simulations of the Willem-Alexander Centrale (WAC) power plant located in Buggenum (the Netherlands), based on integrated gasification combined cycle (IGCC) technology, under both design and off-design conditions. These latter included co-gasification of coal and biomass, in proportions of 30:70, in three different fuel mixtures. Any drop in the energy content of the coal/biomass blend, with respect to 100% coal, translated into a reduction in gas turbine (GT) firing temperature and load, according to the guidelines of WAC testing. Since the model was found to be accurate in comparison with operational data, here attention is drawn to the GT behavior. Hence part load strategies, such as fuel-only turbine inlet temperature (TIT) control and inlet guide vane (IGV) control, were investigated with the aim of maximizing the net electric efficiency (ηel) of the whole plant. This was done for different GT models from leading manufactures on a comparable size, in the range between 190–200 MW. The influence of fuel quality on overall ηel was discussed for three binary blends, over a wide range of lower heating value (LHV), while ensuring a concentration of H2 in the syngas below the limit of 30 vol%. IGV control was found to deliver the highest IGCC ηel combined with the lowest CO2 emission intensity, when compared not only to TIT control but also to turbine exhaust temperature control, which matches the spec for the selected GT engine. Thermoflex® was used to compute mass and energy balances in a steady environment thus neglecting dynamic aspects.


Author(s):  
Katsuyoshi Tada ◽  
Kei Inoue ◽  
Tomo Kawakami ◽  
Keijiro Saitoh ◽  
Satoshi Tanimura

Gas-turbine combined-cycle (GTCC) power generation is clean and efficient, and its demand will increase in the future from economic and social perspectives. Raising turbine inlet temperature is an effective way to increase combined cycle efficiency and contributes to global environmental conservation by reducing CO2 emissions and preventing global warming. However, increasing turbine inlet temperature can lead to the increase of NOx emissions, depletion of the ozone layer and generation of photochemical smog. To deal with this issue, MHPS (MITSUBISHI HITACHI POWER SYSTEMS) and MHI (MITSUBISHI HEAVY INDUSTRIES) have developed Dry Low NOx (DLN) combustion techniques for high temperature gas turbines. In addition, fuel flexibility is one of the most important features for DLN combustors to meet the requirement of the gas turbine market. MHPS and MHI have demonstrated DLN combustor fuel flexibility with natural gas (NG) fuels that have a large Wobbe Index variation, a Hydrogen-NG mixture, and crude oils.


Author(s):  
Maher A. Elmasri

A fast, interactive, flexible computer program has been developed to facilitate system selection and design for gas turbine based power and cogeneration plants. A data base containing ISO performance information on forty-two gas turbines is coupled to an off-design model to predict engine characteristics for different site and installation parameters. A heat recovery steam generator (HRSG) model allows boiler size and cost to be estimated as a function of the system’s technical parameters. The model can handle HRSG’s with up to two live steam pressures plus a third feedheating/deaerating drum. Five basic types of combined cycle are covered with up to four different process steam streams for cogeneration or gas turbine injection. Two additional feedheating steam bleeds are supported for condensing combined cycles. The program is intelligent with some internal decision making capabilities regarding process steam sourcing and flow directions and will automatically select the appropriate heat and mass balance procedures to cover a wide variety of process flow schematics. The program provides plotter outputs to show the cycle process flow schematic, T-s and h-s diagrams, and HRSG temperature profiles. An application of GTPRO in analyzing some technical and economic performance trade-offs for two-pressure combined cycles is presented.


Author(s):  
Dale Grace ◽  
Thomas Christiansen

Unexpected outages and maintenance costs reduce plant availability and can consume significant resources to restore the unit to service. Although companies may have the means to estimate cash flow requirements for scheduled maintenance and on-going operations, estimates for unplanned maintenance and its impact on revenue are more difficult to quantify, and a large fleet is needed for accurate assessment of its variability. This paper describes a study that surveyed 388 combined-cycle plants based on 164 D/E-class and 224 F-class gas turbines, for the time period of 1995 to 2009. Strategic Power Systems, Inc. (SPS®), manager of the Operational Reliability Analysis Program (ORAP®), identified the causes and durations of forced outages and unscheduled maintenance and established overall reliability and availability profiles for each class of plant in 3 five-year time periods. This study of over 3,000 unit-years of data from 50 Hz and 60 Hz combined-cycle plants provides insight into the types of events having the largest impact on unplanned outage time and cost, as well as the risks of lost revenue and unplanned maintenance costs which affect plant profitability. Outage events were assigned to one of three subsystems: the gas turbine equipment, heat recovery steam generator (HRSG) equipment, or steam turbine equipment, according to the Electric Power Research Institute’s Equipment Breakdown Structure (EBS). Costs to restore the unit to service for each main outage cause were estimated, as were net revenues lost due to unplanned outages. A statistical approach to estimated costs and lost revenues provides a risk-based means to quantify the impact of unplanned events on plant cash flow as a function of class of gas turbine, plant subsystem, and historical timeframe. This statistical estimate of the costs of unplanned outage events provides the risk-based assessment needed to define the range of probable costs of unplanned events. Results presented in this paper demonstrate that non-fuel operation and maintenance costs are increased by roughly 8% in a typical combined-cycle power plant due to unplanned maintenance events, but that a wide range of costs can occur in any single year.


Author(s):  
F. L. Robson ◽  
D. J. Seery

The Department of Energy’s Federal Energy Technology Center (FETC) is sponsoring the Combustion 2000 Program aimed at introducing clean and more efficient advanced technology coal-based power systems in the early 21st century. As part of this program, the United Technologies Research Center has assembled a seven member team to identify and develop the technology for a High Performance Power Systems (HIPPS) that will provide in the near term, 47% efficiency (HHV), and meet emission goals only one-tenth of current New Source Performance Standards for coal-fired power plants. In addition, the team is identifying advanced technologies that could result in HIPPS with efficiencies approaching 55% (HHV). The HIPPS is a combined cycle that uses a coal-fired High Temperature Advanced Furnace (HITAF) to preheat compressor discharge air in both convective and radiant heaters. The heated air is then sent to the gas turbine where additional fuel, either natural gas or distillate, is burned to raise the temperature to the levels of modern gas turbines. Steam is raised in the HITAF and in a Heat Recovery Steam Generator for the steam bottoming cycle. With state-of-the-art frame type gas turbines, the efficiency goal of 47% is met in a system with more than two-thirds of the heat input furnished by coal. By using advanced aeroderivative engine technology, HIPPS in combined-cycle and Humid Air Turbine (HAT) cycle configurations could result in efficiencies of over 50% and could approach 55%. The following paper contains descriptions of the HIPPS concept including the HITAF and heat exchangers, and of the various gas turbine configurations. Projections of HIPPS performance, emissions including significant reduction in greenhouse gases are given. Application of HIPPS to repowering is discussed.


Author(s):  
Thomas P. Schmitt ◽  
Herve Clement

Current trends in usage patterns of gas turbines in combined cycle applications indicate a substantial proportion of part load operation. Commensurate with the change in operating profile, there has been an increase in the propensity for part load performance guarantees. When a project is structured such that gas turbines are procured as equipment-only from the manufacturer, there is occasionally a gas turbine part load performance guarantee that coincides with the net plant combined cycle part load performance guarantee. There are several methods by which to accomplish part load gas turbine performance testing. One of the more common methods is to operate the gas turbine at the specified load value and construct correction curves at constant load. Another common method is to operate the gas turbine at a specified load percentage and construct correction curves at constant percent load. A third method is to operate the gas turbine at a selected load level that corresponds to a predetermined compressor inlet guide vane (IGV) angle. The IGV angle for this third method is the IGV angle that is needed to achieve the guaranteed load at the guaranteed boundary conditions. The third method requires correction curves constructed at constant IGV, just like base load correction curves. Each method of test and correction embodies a particular set of advantages and disadvantages. The results of an exploration into the advantages and disadvantages of the various performance testing and correction methods for part load performance testing of gas turbines are presented. Particular attention is given to estimates of the relative uncertainty for each method.


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