scholarly journals A boil-off gas utilization for improved performance of heavy duty gas turbines in combined cycle

2018 ◽  
Vol 233 (1) ◽  
pp. 96-110 ◽  
Author(s):  
Stefano Mazzoni ◽  
Srithar Rajoo ◽  
Alessandro Romagnoli
Keyword(s):  
Heat Transfer ◽  
Natural Gas ◽  
Ambient Temperature ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Liquefied Natural Gas ◽  
Combined Cycle ◽  
Cooling Power ◽  
Heavy Duty ◽  
Cold Energy

The storage of the natural gas under liquid phase is widely adopted and one of the intrinsic phenomena occurring in liquefied natural gas is the so-called boil-off gas; this consists of the regasification of the natural gas due to the ambient temperature and loss of adiabacity in the storage tank. As the boil-off occurs, the so-called cold energy is released to the surrounding environment; such a cold energy could potentially be recovered for several end-uses such as cooling power generation, air separation, air conditioning, dry-ice manufacturing and conditioning of inlet air at the compressor of gas turbine engines. This paper deals with the benefit corresponding to the cooling down of the inlet air temperature to the compressor, by means of internal heat transfer recovery from the liquefied natural gas boil-off gas cold energy availability. The lower the compressor inlet temperature, the higher the gas turbine performance (power and efficiency); the exploitation of the liquefied natural gas boil-off gas cold energy also corresponds to a higher amount of air flow rate entering the cycle which plays in favour of the bottoming heat recovery steam generator and the related steam cycle. Benefit of this solution, in terms of yearly work and gain increase have been established by means of ad hoc developed component models representing heat transfer device (air/boil-off gas) and heavy duty 300 MW gas turbine. For a given ambient temperature variability over a year, the results of the analysis have proven that the increase of electricity production and efficiency due to the boil-off gas cold energy recovery has finally yield a revenue increase of 600,000€/year.

A Comparative Analysis of Single Nozzle and Multiple Nozzles Arrangements for Syngas Combustion in Heavy Duty Gas Turbine

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Shi Liu ◽  
Hong Yin ◽  
Yan Xiong ◽  
Xiaoqing Xiao
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Heavy Duty ◽  
Gas Turbine Combustor ◽  
Integrated Gasification Combined Cycle ◽  
Wide Range ◽  
Heavy Duty Gas Turbine ◽  
Integrated Gasification

Heavy duty gas turbines are the core components in the integrated gasification combined cycle (IGCC) system. Different from the conventional fuel for gas turbine such as natural gas and light diesel, the combustible component acquired from the IGCC system is hydrogen-rich syngas fuel. It is important to modify the original gas turbine combustor or redesign a new combustor for syngas application since the fuel properties are featured with the wide range hydrogen and carbon monoxide mixture. First, one heavy duty gas turbine combustor which adopts natural gas and light diesel was selected as the original type. The redesign work mainly focused on the combustor head and nozzle arrangements. This paper investigated two feasible combustor arrangements for the syngas utilization including single nozzle and multiple nozzles. Numerical simulations are conducted to compare the flow field, temperature field, composition distributions, and overall performance of the two schemes. The obtained results show that the flow structure of the multiple nozzles scheme is better and the temperature distribution inside the combustor is more uniform, and the total pressure recovery is higher than the single nozzle scheme. Through the full scale test rig verification, the combustor redesign with multiple nozzles scheme is acceptable under middle and high pressure combustion test conditions. Besides, the numerical computations generally match with the experimental results.

Low CO2 Combustion System Retrofits for Existing Heavy Duty Gas Turbines

2008 ◽  
Author(s):  
Peter J. Stuttaford ◽  
Khalid Oumejjoud
Keyword(s):  
Power Plant ◽  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Premixed Combustion ◽  
Combustion System ◽  
Heavy Duty ◽  
Fuel Processing

CO2 emissions generated by power plants make up a significant portion of global carbon emissions. Although there has been a great deal of focus on new power sources incorporating state of the art environmental protection systems, there has been little focus on addressing the issues of existing power plants. The purpose of this work is to address the options available to existing gas turbine based power plants to retrofit CO2 reduction measures cost effectively at the source of emissions, the combustor. Pre-combustion decarbonization is a highly efficient method of carbon removal, as only a small fraction of the gas turbine system flow needs to be addressed. This results in the requirement to burn a hydrogen based fuel, which presents challenges due to its highly reactive nature. The properties of hydrogen/syngas combustion are reviewed with emphasis on solutions for premixed combustion systems. Premixed combustion as opposed to diffusion combustion systems are key to retrofit solutions for existing gas turbines. Premixed systems provide the life cycle cost benefit, and heat rate benefit of not requiring the addition of diluent to the cycle to control emissions. Fuel flexibility is critical for retrofit systems, allowing operators to run on high hydrogen fuels as well as back-up standard natural gas to maximize power plant availability. Pre-combustion decarbonization may occur remote from the power plant at a centralized fuel processing facility, or it may be integrated into the combined cycle gas turbine power plant. Existing combined cycle power plants operating on natural gas could be modified to incorporate fuel decarbonization into the cycle, minimizing the parasitic loss of such a system while capturing carbon credits which are likely to become of increasing monetary value. An example cycle to address such integrated systems is presented. The focus of this work is to present a cycle to provide decarbonized fuel, cost effectively, from existing natural gas systems, as well as centralized coal/petcoke based fuel processing facilities. An additional focus is on the combustion system design requirements to burn such fuels, which are retrofitable to existing heavy duty gas turbine based power plants.

Efficiency Analysis of Gas Turbine Combined-Cycle Fed with Synthetic Natural Gas (SNG) and Mixture of Syngas and SNG

2015 ◽  
Vol 656-657 ◽  
pp. 113-118
Author(s):  
Hsiu Mei Chiu ◽  
Po Chuang Chen ◽  
Yau Pin Chyou ◽  
Ting Wang
Keyword(s):  
Natural Gas ◽  
Simulation Model ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combined Cycle ◽  
System Level ◽  
Minimum Requirement ◽  
Synthetic Natural Gas ◽  
System Level Simulation

The effect of synthetic natural gas (SNG) and mixture of syngas and SNG fed to Natural Gas Combined-Cycle (NGCC) plants is presented in this study via a system-level simulation model. The commercial chemical process simulator, Pro/II®V8.1.1, was used in the study to build the analysis model. The NGCC plant consists of gas turbine (GT), heat recovery steam generator (HRSG) and steam turbine (ST). The study envisages two analyses as the basic and feasibility cases. The former is the benchmark case which is verified by the reference data with the GE 7FB gas turbine. According to vendor’s specification, the typical net plant efficiency of GE 7FB NGCC with two gas turbines to one steam turbine is 57.5% (LHV), and the efficiency is the benchmark in the simulation model built in the study. The latter introduces a feasibility study with actual parameters in Taiwan. The SNG-fed GE 7FB based combined-cycle is evaluated, and the mixture of SNG and syngas is also evaluated to compare the difference of overall performance between the two cases. The maximum ratio of syngas to SNG is 0.14 due to the constraint for keeping the composition of methane at a value of 80 mol%, to meet the minimum requirement of NG in Taiwan. The results show that the efficiency in either case of SNG or mixture of SNG and syngas is slightly lower than the counterpart in the benchmark one. Because the price of natural gas is much higher than that of coal, it results in higher idle capacity of NGCC. The advantage of adopting SNG in Taiwan is that it could increase the capacity factor of combined-cycles in Taiwan. The study shows a possible way to use coal and reduce the CO2emission, since coal provides nearly half of the electricity generation in Taiwan in recent years.

Utilization of Cryogenic Exergy of LNG by MGT (Mirror Gas Turbine)

2000 ◽  
Author(s):  
Y. Tsujikawa ◽  
K. Kaneko ◽  
S. Fujii
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
High Efficiency ◽  
Electric Energy ◽  
Liquefied Natural Gas ◽  
Combined Cycle ◽  
Brayton Cycle ◽  
Exhaust Gas ◽  
Topping Cycle ◽  
Very High

In the course of the worldwide efforts to suppress the global warming, the saving energy becomes more important. Recently, the LNG (liquefied natural gas) terminals in our country have received more than 50 million tons of LNG per year. Therefore, the utilization of the cryogenic exergy in connection with the regasification of LNG gains more and more importance. The aim of this paper is the recovery of the energy consumed in liquefaction using the MGT (Mirror Gas Turbine), which is a kind of new combined cycle of a conventional gas turbine worked as a topping cycle and TG (inverted Brayton cycle) as a bottoming cycle. The optimum characteristics have been calculated and it is shown that this cycle is superior to the current-use gasification systems in employing seawater heats in terms of thermal efficiency and specific output. In the present cycle, the cold of LNG is used to cool the exhaust gas from a turbine of TG, and then the exergy of the liquefied natural gas is transformed to electric energy with a very high efficiency. The main feature of this new concept is the removal of an evaporation system using seawater.

Performance and Cost Analysis of Advanced Gas Turbine Cycles With Precombustion CO2 Capture

2008 ◽  
Vol 131 (2) ◽  
Author(s):  
Stéphanie Hoffmann ◽  
Michael Bartlett ◽  
Matthias Finkenrath ◽  
Andrei Evulet ◽  
Tord Peter Ursin
Keyword(s):  
High Pressure ◽  
Power Plant ◽  
Natural Gas ◽  
Gas Turbine ◽  
Co2 Capture ◽  
Gas Turbines ◽  
High Efficiency ◽  
Combined Cycle ◽  
Co2 Separation ◽  
The Cost

This paper presents the results of an evaluation of advanced combined cycle gas turbine plants with precombustion capture of CO2 from natural gas. In particular, the designs are carried out with the objectives of high efficiency, low capital cost, and low emissions of carbon dioxide to the atmosphere. The novel cycles introduced in this paper are comprised of a high-pressure syngas generation island, in which an air-blown partial oxidation reformer is used to generate syngas from natural gas, and a power island, in which a CO2-lean syngas is burnt in a large frame machine. In order to reduce the efficiency penalty of natural gas reforming, a significant effort is spent evaluating and optimizing alternatives to recover the heat released during the process. CO2 is removed from the shifted syngas using either CO2 absorbing solvents or a CO2 membrane. CO2 separation membranes, in particular, have the potential for considerable cost or energy savings compared with conventional solvent-based separation and benefit from the high-pressure level of the syngas generation island. A feasibility analysis and a cycle performance evaluation are carried out for large frame gas turbines such as the 9FB. Both short-term and long-term solutions have been investigated. An analysis of the cost of CO2 avoided is presented, including an evaluation of the cost of modifying the combined cycle due to CO2 separation. The paper describes a power plant reaching the performance targets of 50% net cycle efficiency and 80% CO2 capture, as well as the cost target of 30$ per ton of CO2 avoided (2006 Q1 basis). This paper indicates a development path to this power plant that minimizes technical risks by incremental implementation of new technology.

Dry, Low Emissions for the ‘H’ Heavy-Duty Industrial Gas Turbines: Full-Scale Combustion System Rig Test Results

2003 ◽  
Author(s):  
Geoff Myers ◽  
Dan Tegel ◽  
Markus Feigl ◽  
Fred Setzer ◽  
William Bechtel ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Full Scale ◽  
Combustion System ◽  
Heavy Duty ◽  
Test Program ◽  
Industrial Gas Turbines ◽  
Inlet Conditions

The lean, premixed DLN2.5H combustion system was designed to deliver low NOx emissions from 50% to 100% load in both the Frame 7H (60 Hz) and Frame 9H (50 Hz) heavy-duty industrial gas turbines. The H machines employ steam cooling in the gas turbine, a 23:1 pressure ratio, and are fired at 1440 C (2600 F) to deliver over-all thermal efficiency for the combined-cycle system near 60%. The DLN2.5H combustor is a modular can-type design, with 14 identical chambers used on the 9H machine, and 12 used on the smaller 7H. On a 9H combined-cycle power plant, both the gas turbine and steam turbine are fired using the 14-chamber DLN2.5H combustion system. An extensive full-scale, full-pressure rig test program developed the fuel-staged dry, low emissions combustion system over a period of more than five years. Rig testing required test stand inlet conditions of over 50 kg/s at 500 C and 28 bar, while firing at up to 1440 C, to simulate combustor operation at base load. The combustion test rig simulated gas path geometry from the discharge of the annular tri-passage diffuser through the can-type combustion liner and transition piece, to the inlet of the first stage turbine nozzle. The present paper describes the combustion system, and reports emissions performance and operability results over the gas turbine load and ambient temperature operating range, as measured during the rig test program.

Aeroderivative Combined Heat and Power Fundementals and Applications

2012 ◽  
Author(s):  
James DiCampli
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Energy System ◽  
Combined Heat And Power ◽  
Combined Cycle ◽  
Draft Guidance ◽  
Distributed Energy ◽  
Improve Energy Efficiency ◽  
Exhaust Heat

Combined heat and power (CHP), is an application that utilizes the exhaust heat generated from a gas turbine and converts it into a useful energy source for heating & cooling, or additional electric generation in combined cycle configurations. Compared to simple-cycle plants with no heat recovery, CHP plants emit fewer greenhouse gasses and other emissions, while generating significantly more useful energy per unit of fuel consumed. Clean plants are easier to permit, build and operate. Because of these advantages, Aeroderivative gas turbines will be a major part of global CHP growth, particularly in China. In order to improve energy efficiency and reduce CO2 emissions, China is working to build ∼1000 new plants of Natural Gas Distributed Energy System (NG-DES) in the next five years. These plants will replace conventional coal-fired plants with combined cooling, heating and power (CCHP) systems. China power segments require an extensive steam supply for cooling, heating and industrial process steam demands, as well as higher peak loads due to high population densities and manufacturing growth rates. GE Energy Aero recently entered the CCHP segment in China, and supported the promotion of codes and standards for NG-DES policy, and is developing optimized CCHP gas turbine packages to meet requirements. This paper reviews those policies and requirements, and presents technical case studies on CCHP applications. Appendix B highlights China’s draft “Guidance Opinions on Developing Natural-Gas Distributed Energy.”

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.

Sign in / Sign up

Export Citation Format

Share Document