Integrated Oxygen-Free Gasification-Gas Turbine Power Concept: A Low-Emissions Alternative for Small-Scale Coal Plants

2011 ◽  
Author(s):  
Rory F. D. Monaghan ◽  
Monem H. Alyaser
Keyword(s):  
Sensitivity Analysis ◽  
Gas Turbine ◽  
Heat Recovery ◽  
Power Plants ◽  
Electrical Energy ◽  
Small Scale ◽  
Base Case ◽  
System Sensitivity ◽  
Spreadsheet Model ◽  
Feedstock Preparation

A power plant concept with the potential to replace the large fleet of ageing, small-scale (< 50 MWe), inefficient, polluting, and soon-to-be obsolete coal-fired power plants is proposed. The proposed plant comprises a bituminous coal-fed oxygen-free gasifier, low-temperature syngas cleanup system and an open-cycle gas turbine with heat recovery. Heat is supplied to the gasifier through combustion of a portion of the cleaned syngas produced by it. Since the proposed plant employs only a gas turbine, with no steam bottoming cycle, heat recovery from the gas turbine and its integration with the rest of the plant is crucial. A thermodynamic model of the plant has been created to assess its feasibility based on overall efficiency and emissions of CO2, SO2, mercury and particulates. The model comprises submodels for feedstock composition and enthalpy, as well as first-order thermodynamic models for each of the plant components including the gasifier, feedstock preparation, heat exchangers and steam generators, contaminant removal, combustors and turbomachinery. The results of the analysis show base case plant thermal efficiency of 38.2% on a HHV basis, which is roughly 5% points higher than that for a similarly-sized pulverized coal combustion (PCC) plants. Emissions of CO2, SO2, mercury and particulates per unit electrical energy produced in the base case are: 0.774 kg/kWh, 47.2 g/MWh, 2.37 g/GWh and 28.2 g/MWh, respectively. These values are well below emissions from similarly-sized PCC plants, which have been assessed using a spreadsheet model. The model of the proposed plant has been used to assess overall performance when torrefied pine wood is co-gasified with coal. Results show a slight decrease in plant efficiency with increasing co-gasification, with large decreases in CO2, SO2 and mercury emissions. Emissions of particulates increase slightly with co-gasification. Finally the model has been used to perform sensitivity analysis on the proposed system. Sensitivity analysis highlights the need for greater understanding of gasifier performance under a range of conditions.

scholarly journals Gas Turbine Heat Recovery Steam Generators for Combined Cycles Natural or Forced Circulation Considerations

1988 ◽  
Author(s):  
Akber Pasha
Keyword(s):  
Gas Turbine ◽  
Steam Generator ◽  
Heat Recovery ◽  
Power Plants ◽  
Natural Circulation ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Steam Generators ◽  
Forced Circulation ◽  
Gas Turbine Exhaust

In recent years the combined cycle has become a very attractive power plant arrangement because of its high cycle efficiency, short order-to-on-line time and flexibility in the sizing when compared to conventional steam power plants. However, optimization of the cycle and selection of combined cycle equipment has become more complex because the three major components, Gas Turbine, Heat Recovery Steam Generator and Steam Turbine, are often designed and built by different manufacturers. Heat Recovery Steam Generators are classified into two major categories — 1) Natural Circulation and 2) Forced Circulation. Both circulation designs have certain advantages, disadvantages and limitations. This paper analyzes various factors including; availability, start-up, gas turbine exhaust conditions, reliability, space requirements, etc., which are affected by the type of circulation and which in turn affect the design, price and performance of the Heat Recovery Steam Generator. Modern trends around the world are discussed and conclusions are drawn as to the best type of circulation for a Heat Recovery Steam Generator for combined cycle application.

scholarly journals ОСОБЕННОСТИ ПРИМЕНЕНИЯ ПРОДУКТОВ КОНВЕРСИИ МЕТАНОЛА В СУДОВОЙ ГАЗОТУРБИННОЙ УСТАНОВКЕ С ТЕРМОХИМИЧЕСКОЙ РЕГЕНЕРАЦИЕЙ СБРОСНОГО ТЕПЛА

2019 ◽  
pp. 28-34 ◽  
Author(s):  
Александр Константинович Чередниченко
Keyword(s):  
Energy Efficiency ◽  
Gas Turbine ◽  
Heat Recovery ◽  
Power Plants ◽  
Low Carbon ◽  
Steam Conversion ◽  
Working Pressure ◽  
Fixed Temperature ◽  
Heat Potential ◽  
Thermochemical Heat Recovery

The research’s subject is the processes of energy transformation of fuel in the ship gas turbine plant with thermochemical regeneration. Modern approaches to assessing the energy efficiency of ship power plants were considered. The characteristics of traditional and alternative marine fuels were analyzed. The use of methanol as a low-carbon marine fuel is discussed. It is proposed to increase the efficiency of methanol use by using synthesis gas obtained through thermochemical heat recovery of secondary energy resources of ship engines. The main objective of the study is to analyze the effects on the energy efficiency of steam thermochemical transformation of methanol of the limitations associated with the system of supplying gaseous fuel to the engine. The influence of pressure in the thermochemical reactor on the steam’s efficiency of reforming of methanol was analyzed. The design schemes of two variants of the ship gas turbine installation with thermochemical heat recovery by steam conversion of methanol are presented. The methanol conversion efficiency was determined by the heat potential of the exhaust gases and was calculated based on the thermal balance of the thermochemical reactor. The reactor’s model is two- component. The mathematical model of the turbocompressor unit is based on an enlarged calculation taking into account the total pressure loss in all elements of the gas-air duct. The results of mathematical modeling of processes in plants based on gas turbine engines of simple and regenerative cycles under conditions of fixed methanol’s consumption, the fixed temperature of the gas in the turbine’s front for environmental parameters according to ISO 19859: 2016 are presented. The efficiency of the scheme which used steam conversion of methanol at pressures corresponding to the working pressure in the combustion chamber was revealed. The increase in the energy efficiency of the installation is 3 ... 5 % with basic parameters and 10 ... 11 % for higher conduction temperatures or for catalytic reactors. The research results can be used in the promising power plants designing.

scholarly journals A Small Scale Biomass Fueled Gas Turbine Engine

1998 ◽  
Author(s):  
Joe D. Craig ◽  
Carol R. Purvis
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Small Scale ◽  
Brayton Cycle ◽  
Prime Mover ◽  
Turbine Engine ◽  
Rice Hulls ◽  
Turbine Component ◽  
The Cost ◽  
New Generation

A new generation of small scale (less than 20 MWe) biomass fueled, power plants are being developed based on a gas turbine (Brayton cycle) prime mover. These power plants are expected to increase the efficiency and lower the cost of generating power from fuels such as wood. The new power plants are also expected to economically utilize annual plant growth materials (such as rice hulls, cotton gin trash, nut shells, and various straws, grasses, and animal manures) that are not normally considered as fuel for power plants. This paper summarizes the new power generation concept with emphasis on the engineering challenges presented by the gas turbine component.

Performance Assessment of Steam Injection Gas Turbine With Inlet Air Cooling

1997 ◽  
Author(s):  
Carlo M. Bartolini ◽  
Danilo Salvi
Keyword(s):  
Ambient Temperature ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Power Plants ◽  
Waste Heat ◽  
Cooling System ◽  
Steam Injection ◽  
Maximum Efficiency ◽  
Air Cooling

The steam generated through the use of waste heat recovered from a steam injection gas turbine generally exceeds the maximum mass of steam which can be injected into steam injection gas turbine. The ratio between the steam and air flowing into the engine is not more than 10–15%, as an increase in the pressure ratio can cause the compressor to stall. Naturally, the surplus steam can be utilized for a variety of alternative applications. During the warmer months, the ambient temperature increases and results in reduced thermal efficiency and electrical capacity. An inlet air cooling system for the compressor on a steam injection gas turbine would increase the rating and efficiency of power plants which use this type of equipment. In order to improve the performance of steam injection gas turbines, the authors investigated the option of cooling the intake air to the compressor by harnessing the thermal energy not used to produce the maximum quantity of steam that can be injected into the engine. This alternative use of waste energy makes it possible to reach maximum efficiency in terms of waste recovery. This study examined absorption refrigeration technology, which is one of the various systems adopted to increase efficiency and power rating. The system itself consists of a steam injection gas turbine and a heat recovery and absorption unit, while a computer model was utilized to evaluate the off design performance of the system. The input data required for the model were the following: an operating point, the turbine and compressor curves, the heat recovery and chiller specifications. The performance of an Allison 501 KH steam injection gas plant was analyzed by taking into consideration representative ambient temperature and humidity ranges, the optimal location of the chiller in light of all the factors involved, and which of three possible air cooling systems was the most economically suitable. In order to verify the technical feasibility of the hypothetical model, an economic study was performed on the costs for upgrading the existing steam injection gas cogeneration unit. The results indicate that the estimated pay back period for the project would be four years. In light of these findings, there are clear technical advantages to using gas turbine cogeneration with absorption air cooling in terms of investment.

Gas Turbine Power Plants of Large Unit Capacity in Standard Construction

1977 ◽  
Author(s):  
K. H. Lange ◽  
H. J. Heinecke
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Power Plants ◽  
Large Unit ◽  
Exhaust Heat ◽  
Standard Construction ◽  
Engineering Department ◽  
The Common ◽  
Exhaust Heat Recovery ◽  
Standard Concept

Contrary to the common practice in the U.S.A. it was usual in Europe to build Gas Turbine Power Plants individually. Kraftwerk Union AG now reports on a new pre-engineered standard concept which has been designed by its Engineering Department. This paper describes the pre-engineered concept and the standardization of components. Furthermore, it indicates the possibility of extending this standard plant to a KWU Exhaust Heat Recovery Plant.

Technical Evaluation and Applications of Heat Recovery From Simple Cycle Gas Turbine Exhaust Systems

2020 ◽  
Author(s):  
Bouria Faqihi ◽  
Fadi A. Ghaith
Keyword(s):  
Pressure Drop ◽  
Gas Turbine ◽  
Heat Recovery ◽  
Power Plants ◽  
Thermal Power ◽  
Combined Cycle ◽  
Heat Extraction ◽  
Simple Cycle ◽  
System Pressure ◽  
Exhaust Heat

Abstract In the Gulf Cooperation Council region, approximately 70% of the thermal power plants are in a simple cycle configuration while only 30% are in combined cycle. This high simple to combined cycle ratio makes it of a particular interest for original equipment manufacturers to offer exhaust heat recovery upgrades to enhance the thermal efficiency of simple cycle power plants. This paper aims to evaluate the potential of incorporating costly-effective new developed heat recovery methods, rather than the complex products which are commonly available in the market, with relevant high cost such as heat recovery steam generators. In this work, the utilization of extracted heat was categorized into three implementation zones: use within the gas turbine flange-to-flange section, auxiliary systems and outside the gas turbine system in the power plant. A new methodology was established to enable qualitative and comparative analyses of the system performance of two heat extraction inventions according to the criteria of effectiveness, safety and risk and the pressure drop in the exhaust. Based on the conducted analyses, an integrated heat recovery system was proposed. The new system incorporates a circular duct heat exchanger to extract the heat from the exhaust stack and deliver the intermediary heat transfer fluid to a separate fuel gas exchanger. This system showed superiority in improving the thermodynamic cycle efficiency, while mitigating safety risks and avoiding undesired exhaust system pressure drop.

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.

Design and Optimization of Turbomachinery Components for Parabolic Dish Solar Hybrid Micro Gas Turbine

2020 ◽  
Author(s):  
Maulana Arifin ◽  
Markus Schatz ◽  
Damian M. Vogt
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Computational Cost ◽  
Three Dimensional ◽  
Cycle Performance ◽  
Small Scale ◽  
Micro Gas Turbine ◽  
Parabolic Dish ◽  
Fully Coupled

Abstract The application of power plants based on renewable energy sources is attractive from an ecological viewpoint. Micro Gas Turbine (MGT) combined with solar energy is a highly promising technology for small-scale electric power generations in remote areas. In MGT state-of-the-art development, the necessity of the numerical optimization in turbomachinery components becomes increasingly important due to its direct impact on the MGT cycle performance. The present paper provides the multidisciplinary design optimization (MDO) of a radial turbine and radial compressor for a 40 kW Solar Hybrid Micro Gas Turbine (SHGT) with a 15m diameter parabolic dish concentrator. The objectives of MDO are to maximize the stage efficiency, to minimize the maximum stress and the inertia, and to enhance the operational flexibility. Preliminary design and performance map prediction using one-dimensional (1D) analysis are performed for both turbine and compressor at various speed lines followed by full three-dimensional (3D) Computational Fluid Dynamics (CFD), Finite Element (FE) analyses and 3D parameterization in the MDO simulations. The purpose of 1D analysis is to set the primary parameters for initial geometry such as rotor dimensions, passage areas, diffuser and volute size. The MDO has been performed using fully coupled multi-stream tube (MST), 3D CFD and FE simulations. MST is used for calculating the load on the blade and the flow distribution from hub to shroud and linearized blade-to-blade calculations based on quasi-three dimensional flow. Thereafter, 3D CFD simulations are performed to calculate efficiencies while the structural stresses are simulated by means of FE analyses. In the current studies, Numeca Fine/Turbo is used as a CFD solver and Ansys Mechanical as a FEA solver, together with Axcent™ as an interface to Fine/Design 3D for geometry parameterization. Furthermore, the cycle analysis for SHGT has been performed to evaluate the effect of the new turbomachinery components from the MDO on the SHGT system performance. It is found that using the MST fully coupled with CFD and FE analysis can significantly reduce the computational cost and time on the design and development process.

Micro Gas-Turbine Design for Small-Scale Hybrid Solar Power Plants

2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Lukas Aichmayer ◽  
James Spelling ◽  
Björn Laumert ◽  
Torsten Fransson
Keyword(s):  
Pressure Drop ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Small Scale ◽  
Receiver Design ◽  
Low Carbon ◽  
Micro Gas Turbine ◽  
Solar Power Plants ◽  
Electricity Costs

Hybrid solar micro gas-turbines are a promising technology for supplying controllable low-carbon electricity in off-grid regions. A thermoeconomic model of three different hybrid micro gas-turbine power plant layouts has been developed, allowing their environmental and economic performance to be analyzed. In terms of receiver design, it was shown that the pressure drop is a key criterion. However, for recuperated layouts, the combined pressure drop of the recuperator and receiver is more important. In terms of both electricity costs and carbon emissions, the internally-fired recuperated micro gas-turbine was shown to be the most promising solution of the three configurations evaluated. Compared to competing diesel generators, the electricity costs from hybrid solar units are between 10% and 43% lower, while specific CO2 emissions are reduced by 20–35%.

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