Low Load Operation Range Extension by Autothermal On-Board Syngas Generation

2017 ◽  
Author(s):  
Max H. Baumgärtner ◽  
Thomas Sattelmayer
Keyword(s):  
Natural Gas ◽  
Gas Turbines ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Flame Temperature ◽  
Combined Cycle ◽  
Sudden Increase ◽  
Gaseous Emissions ◽  
Fuel Processor ◽  
Burn Out

The increasing amount of volatile renewable energy sources drives the necessity of flexible conventional power plants to compensate for fluctuations of the power supply. Gas turbines in a combined cycle power plant (CCPP) adjust the power output quickly but a sudden increase of CO and UHC emissions limit their turn-down ratio. To extend the turn-down ratio, part of the fuel can be processed to syngas, which exerts a higher reactivity. An autothermal on-board syngas generator in combination with two different burner concepts for natural gas and syngas mixtures are presented in this study. A mixture of natural gas, water vapor and air reacts catalytically in an autothermal reactor test rig to form syngas. At atmospheric pressure, the fuel processor generates syngas with a hydrogen content of ∼30 vol% and a temperature of 800 K within a residence time of 200 ms. One concept for the combustion of natural gas and syngas mixtures comprises a generic swirl stage with a central lance injector for the syngas. The second concept includes a central swirl stage with an outer ring of jets. The combustion is analyzed for both concepts by OH*-chemiluminescence, lean blow out (LBO) limit and gaseous emissions. The central lance concept with syngas injection exhibits an LBO adiabatic flame temperature that is 150 K lower than in premixed natural gas operation. For the second concept an extension of almost 200 K with low CO emission levels can be reached. This study shows that autothermal on-board syngas generation is feasible and efficient in terms of turn-down ratio extension and CO burn-out.

Low Load Operation Range Extension by Autothermal On-Board Syngas Generation

2017 ◽  
Vol 140 (4) ◽  
Author(s):  
Max H. Baumgärtner ◽  
Thomas Sattelmayer
Keyword(s):  
Gas Turbines ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Flame Temperature ◽  
Combined Cycle ◽  
Sudden Increase ◽  
Gaseous Emissions ◽  
Fuel Processor ◽  
Burn Out ◽  
Unburned Hydrocarbons

The increasing amount of volatile renewable energy sources drives the necessity of flexible conventional power plants to compensate for fluctuations of the power supply. Gas turbines in a combined cycle power plant (CCPP) adjust the power output quickly but a sudden increase of CO and unburned hydrocarbons emissions limits their turn-down ratio. To extend the turn-down ratio, part of the fuel can be processed to syngas, which exerts a higher reactivity. An autothermal on-board syngas generator in combination with two different burner concepts for natural gas (NG) and syngas mixtures is presented in this study. A mixture of NG, water vapor, and air reacts catalytically in an autothermal reactor test rig to form syngas. At atmospheric pressure, the fuel processor generates syngas with a hydrogen content of −30 vol % and a temperature of 800 K within a residence time of 200 ms. One concept for the combustion of NG and syngas mixtures comprises a generic swirl stage with a central lance injector for the syngas. The second concept includes a central swirl stage with an outer ring of jets. The combustion is analyzed for both concepts by OH*-chemiluminescence, lean blow out (LBO) limit, and gaseous emissions. The central lance concept with syngas injection exhibits an LBO adiabatic flame temperature that is 150 K lower than in premixed NG operation. For the second concept, an extension of almost 200 K with low CO emission levels can be reached. This study shows that autothermal on-board syngas generation is feasible and efficient in terms of turn-down ratio extension and CO burn-out.

scholarly journals Improvement of the turn-down ratio of gas turbines by autothermal on board syngas generation

2017 ◽  
Vol 1 ◽  
pp. D0HPA5 ◽  
Author(s):  
Max H. Baumgärtner ◽  
Thomas Sattelmayer
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Equivalence Ratio ◽  
Burning Velocity ◽  
Combined Cycle ◽  
Sudden Increase ◽  
High Hydrogen ◽  
Fuel Processor ◽  
Burn Out

Abstract The low reactivity of natural gas leads to a sudden increase of carbon monoxide (CO) and unburned hydrocarbons (UHC) emissions below a certain load level, which limits the part load operation range of current utility gas turbines in combined cycle power plants (CCPP). The feasibility of catalytic autothermal syngas generation directly upstream of gas turbine burners to improve burn-out at low flame temperatures is studied in this paper. The adiabatic reformer is supplied with a mixture of natural gas, air and water and generates syngas with high reactivity, which results in better low-temperature combustion performance. Substitution of part of the natural gas by syngas provides the opportunity of lowering overall equivalence ratio in the combustion chamber and of extending the operation range towards lower minimum power output without violating emission limits. A generic gas turbine with a syngas generator is modelled by analytic equations to identify the possible operating window of a fuel processor constrained by pressure loss, low and high temperature limits and carbon formation. A kinetic study shows good conversion of methane to syngas with a high hydrogen share. A calculation of the one-dimensional laminar burning velocity of mixtures of syngas and methane and the assessment of the corresponding Damköhler number show the potential for lowering the minimum equivalence ratio with full burn-out by fuel processing. The study shows that such a fuel processor has a possible operating range despite the before mentioned constraints and it has potential to reduce the lowest possible load of gas turbines in terms of thermal power by 20%.

Turning NGCC Into IGCC: Cycle Retrofitting Issues

2006 ◽  
Author(s):  
Juan Pablo Gutierrez ◽  
Terry B. Sullivan ◽  
Gerald J. Feller
Keyword(s):  
Natural Gas ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Integrated Gasification Combined Cycle ◽  
Water Steam ◽  
Power Block ◽  
Starting Point ◽  
Natural Gas Combined Cycle ◽  
Gas Plants

The increase in price of natural gas and the need for a cleaner technology to generate electricity has motivated the power industry to move towards Integrated Gasification Combined Cycle (IGCC) plants. The system uses a low heating value fuel such as coal or biomass that is gasified to produce a mixture of hydrogen and carbon monoxide. The potential for efficiency improvement and the decrease in emissions resulting from this process compared to coal-fired power plants are strong evidence to the argument that IGCC technology will be a key player in the future of power generation. In addition to new IGCC plants, and as a result of new emissions regulations, industry is looking at possibilities for retrofitting existing natural gas plants. This paper studies the feasibility of retrofitting existing gas turbines of Natural Gas Combined Cycle (NGCC) power plants to burn syngas, with a focus on the water/steam cycle design limitations and necessary changes. It shows how the gasification island processes can be treated independently and then integrated with the power block to make retrofitting possible. This paper provides a starting point to incorporate the gasification technology to current natural gas plants with minor redesigns.

scholarly journals Feasibility of replacement of nuclear power with other energy sources in the Czech republic

2020 ◽  
Vol 24 (6 Part A) ◽  
pp. 3543-3553
Author(s):  
Pavel Charvat ◽  
Lubomir Klimes ◽  
Jiri Pospisil ◽  
Jiri Klemes ◽  
Petar Varbanov
Keyword(s):  
Czech Republic ◽  
Natural Gas ◽  
Nuclear Power ◽  
Power Plants ◽  
Fossil Fuels ◽  
Renewable Energy Sources ◽  
Combined Cycle ◽  
Energy Sources ◽  
The Czech Republic ◽  
The Moment

The feasibility and consequences of replacing nuclear power plants (NPP) in the Czech Republic with other energy sources are discussed. The NPP produced about one-third of electricity in the Czech Republic in 2017. Renewable energy sources such as hydropower, wind and solar power plants and biomass/biogas burning power plants produced about 11% of electricity in 2017. Due to the geographical and other constraints (intermittency, land footprint, and public acceptance), the renewables do not have the potential to entirely replace the capacity of the NPP. The only feasible technologies that could replace NPP in the Czech Republic in the near future are the power plants using fossil fuels. The combined cycle power plants running on natural gas (NGCC) are technically and environmentally fea-sible alternative for NPP at the moment. However, the natural gas imports would increase by two-thirds and the total greenhouse gas emissions would go up by about 10% if the power production of the NPP was entirely replaced by NGCC in the Czech Republic.

scholarly journals Gas Turbines and Natural Gas Synergism

2013 ◽  
Vol 135 (02) ◽  
pp. 30-35
Author(s):  
Lee S. Langston
Keyword(s):  
Natural Gas ◽  
Electric Power ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Electrical Energy ◽  
Energy Markets ◽  
Combined Cycle ◽  
Energy Information Administration ◽  
Gas Fueled

This article presents a study on new electric power gas turbines and the advent of shale natural gas, which now are upending electrical energy markets. Energy Information Administration (EIA) results show that total electrical production cost for a conventional coal plant would be 9.8 cents/kWh, while a conventional natural gas fueled gas turbine combined cycle plant would be a much lower at 6.6 cents/kWh. Furthermore, EIA estimates that 70% of new US power plants will be fueled by natural gas. Gas turbines are the prime movers for the modern combined cycle power plant. On the natural gas side of the recently upended electrical energy markets, new shale gas production and the continued development of worldwide liquefied natural gas (LNG) facilities provide the other element of synergism. The US natural gas prices are now low enough to compete directly with coal. The study concludes that the natural gas fueled gas turbine will continue to be a growing part of the world’s electric power generation.

scholarly journals Effects of Leading-Edge Modification in Damaged Rotor Blades on Aerodynamic Characteristics of High-Pressure Gas Turbine

Mathematics ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 2191
Author(s):  
Thanh Dam Mai ◽  
Jaiyoung Ryu
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Leading Edge ◽  
Combined Cycle ◽  
Rotor Blades ◽  
Sudden Increase ◽  
Damage Location

The flow and heat-transfer attributes of gas turbines significantly affect the output power and overall efficiency of combined-cycle power plants. However, the high-temperature and high-pressure environment can damage the turbine blade surface, potentially resulting in failure of the power plant. Because of the elevated cost of replacing turbine blades, damaged blades are usually repaired through modification of their profile around the damage location. This study compared the effects of modifying various damage locations along the leading edge of a rotor blade on the performance of the gas turbine. We simulated five rotor blades—an undamaged blade (reference) and blades damaged on the pressure and suction sides at the top and middle. The Reynolds-averaged Navier–Stokes equation was used to investigate the compressible flow in a GE-E3 gas turbine. The results showed that the temperatures of the blade and vane surfaces with damages at the middle increased by about 0.8% and 1.2%, respectively. This causes a sudden increase in the heat transfer and thermal stress on the blade and vane surfaces, especially around the damage location. Compared with the reference case, modifications to the top-damaged blades produced a slight increase in efficiency about 2.6%, while those to the middle-damaged blades reduced the efficiency by approximately 2.2%.

scholarly journals Gas Turbines - Major Greenhouse Gas Inhibitors

2015 ◽  
Vol 137 (12) ◽  
pp. 54-55
Author(s):  
Lee S. Langston
Keyword(s):  
Natural Gas ◽  
Greenhouse Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Electrical Power ◽  
Rankine Cycle ◽  
Hydrocarbon Fuel ◽  
Gas Production ◽  
Combined Cycle

This article explains how combined cycle gas turbine (CCGT) power plants can help in reducing greenhouse gas from the atmosphere. In the last 25 years, the development and deployment of CCGT power plants represent a technology breakthrough in efficient energy conversion, and in the reduction of greenhouse gas production. Existing gas turbine CCGT technology can provide a reliable, on-demand electrical power at a reasonable cost along with a minimum of greenhouse gas production. Natural gas, composed mostly of methane, is a hydrocarbon fuel used by CCGT power plants. Methane has the highest heating value per unit mass of any of the hydrocarbon fuels. It is the most environmentally benign of fuels, with impurities such as sulfur removed before it enters the pipeline. If a significant portion of coal-fired Rankine cycle plants are replaced by the latest natural gas-fired CCGT power plants, anthropogenic carbon dioxide released into the earth’s atmosphere would be greatly reduced.

Prediction of Gas Turbine On- and Off-Design Performance When Firing Coal-Derived Syngas

1992 ◽  
Vol 114 (2) ◽  
pp. 380-385 ◽  
Author(s):  
M. S. Johnson
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Performance Studies ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Surge Margin ◽  
Performance Curves ◽  
Mechanical Durability ◽  
Mass Flow Rates

This paper describes a procedure used to model the performance of gas turbines designed to fire natural gas (or distillate oil) when fired on medium-Btu fuel, such as coal-derived syngas. Results from such performance studies can be used in the design or analysis of Gasification Combined Cycle (GCC) power plants. The primary difficulty when firing syngas in a gas turbine designed for natural gas is the tendency to drive the compressor toward surge. If the gas turbine has sufficient surge margin and mechanical durability, Gas Turbine Evaluation code (GATE) simulations indicate that net output power can be increased on the order of 15 percent when firing syngas due to the advantageous increase in the ratio of the expander-to-compressor mass flow rates. Three classes of single-spool utility gas turbines are investigated spanning firing temperatures from 1985°F-2500°F (1358 K-1644 K). Performance simulations at a variety of part-load and ambient temperature conditions are described; the resulting performance curves are useful in GCC power plant studies.

Past, Present and Future of Combined Cycle Power Plants: From an A/E’s Perspective

2001 ◽  
Author(s):  
Anup Singh
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Gas Turbine ◽  
Rapid Growth ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Electrical Transmission ◽  
Capital Costs ◽  
The U.S

In the 1970s, power generation from gas turbines was minimal. Gas turbines in those days were run on fuel oil, since there was a so-called “natural gas shortage”. The U.S. Fuel Use Act of 1978 essentially disallowed the use of natural gas for power generation. Hence there was no incentive on the part of gas turbine manufacturers to invest in the development of gas turbine technology. There were many regulatory developments in the 1980s and 1990s, which led to the rapid growth in power generation from gas turbines. These developments included Public Utility Regulatory Policy Act of 1978 (encouraging cogeneration), FERC Order 636 (deregulating natural gas industry), Energy Policy Act of 1992 (creating EWGs and IPPs) and FERC Order 888 (open access to electrical transmission system). There was also a backlash from excessive electric rates due to high capital recovery of nuclear and coal-fired plant costs caused by tremendous cost increase resulting from tightening NRC requirements for nuclear plants and significant SO2/NOx/other emissions controls required for coal-fired plants. During this period, rapid technology developments took place in the metallurgy, design, efficiency, and reliability of gas turbines. In addition, U.S. DOE contributed to these developments by encouraging research and development efforts in high temperature and high efficiency gas turbines. Today we are seeing a tremendous explosion of power generating facilities by electric utilities and Independent Power Producers (IPPs). A few years ago, Merchant Power (generation without power purchase agreements) was unheard of. Today it is growing at a very fast pace. Can this rapid growth be sustained? The paper will explore the factors that will play a significant role in the future growth of gas turbine-based power generation in the U.S. The paper will also discuss the methods and developments that could decrease the capital costs of gas turbine power plants resulting in the lowest cost generation compared to other power generation technologies.

Sign in / Sign up

Export Citation Format

Share Document