Theoretical Predictions of the Full-and Part-Load Performance of an Air-Blown Fluidized Bed Gasification Combined Cycle

1994 ◽  
Vol 208 (3) ◽  
pp. 191-197
Author(s):  
J E Davison ◽  
C D Soothill
Keyword(s):  
Fluidized Bed ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Coal Gasification ◽  
Combined Cycle ◽  
Base Case ◽  
Generation Process ◽  
Part Load ◽  
Wide Range ◽  
Topping Cycle

It is important that any future power generation process should have a high thermal efficiency, be able to operate over a wide range of conditions and have low environmental emissions. This paper presents the results of work carried out by the British Coal Research Establishment (CRE) and European Gas Turbines (EGT) to evaluate the overall performance of an air-blown fluidized bed coal gasification combined cycle (topping cycle). This evaluation formed part of a major appraisal of the topping cycle chaired by EGT and which was carried out for the Department of Trade and Industry (DTI). Performance predictions for commercial plants based on topping cycle technology were produced using a computer flowsheet modelling package developed at the CRE. The predicted full-load thermal efficiency of a base case plant using commercially available gas and steam turbines was 46.9 per cent. An evaluation of different options for providing the input air to the gasifier and the effects of likely future emission limits were also evaluated. The part-loaded performance of the base case plant was predicted and it was shown to be capable of operating efficiently at power outputs down to 35 per cent or less. This flexibility means that the process should be suitable not only for base-load operation but also for locations where part-load operation may be required.

Part-Load Operation of Gas Turbines Induced by Co-Gasification of Coal and Biomass in an Integrated Gasification Combined Cycle Power Plant

2021 ◽  
Author(s):  
Silvia Ravelli
Keyword(s):  
Power Plant ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Inlet Guide Vane ◽  
Inlet Temperature ◽  
Fuel Quality ◽  
Integrated Gasification Combined Cycle ◽  
Part Load ◽  
Wide Range ◽  
Integrated Gasification

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.

System Evaluation and LBTU Fuel Combustion Studies for IGCC Power Generation

1995 ◽  
Vol 117 (4) ◽  
pp. 673-677 ◽  
Author(s):  
C. S. Cook ◽  
J. C. Corman ◽  
D. M. Todd
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Coal Gasification ◽  
Flame Temperature ◽  
Combined Cycle ◽  
Gas Turbine Combustor ◽  
Gas Cleaning ◽  
Wide Range ◽  
Cycle Systems ◽  
Combined Cycles

The integration of gas turbines and combined cycle systems with advances in coal gasification and gas stream cleanup systems will result in economically viable IGCC systems. Optimization of IGCC systems for both emission levels and cost of electricity is critical to achieving this goal. A technical issue is the ability to use a wide range of coal and petroleum-based fuel gases in conventional gas turbine combustor hardware. In order to characterize the acceptability of these syngases for gas turbines, combustion studies were conducted with simulated coal gases using full-scale advanced gas turbine (7F) combustor components. It was found that NOx emissions could be correlated as a simple function of stoichiometric flame temperature for a wide range of heating values while CO emissions were shown to depend primarily on the H2 content of the fuel below heating values of 130 Btu/scf (5125 kJ/NM3) and for H2/CO ratios less than unity. The test program further demonstrated the capability of advanced can-annular combustion systems to burn fuels from air-blown gasifiers with fuel lower heating values as low as 90 Btu/scf (3548 kJ/NM3) at 2300°F (1260°C) firing temperature. In support of ongoing economic studies, numerous IGCC system evaluations have been conducted incorporating a majority of the commercial or near-commercial coal gasification systems coupled with “F” series gas turbine combined cycles. Both oxygen and air-blown configurations have been studied, in some cases with high and low-temperature gas cleaning systems. It has been shown that system studies must start with the characteristics and limitations of the gas turbine if output and operating economics are to be optimized throughout the range of ambient operating temperature and load variation.

The effect of gas turbine coolant modulation on the part load performance of combined cycle plants. Part 1: Gas turbines

1997 ◽  
Vol 211 (6) ◽  
pp. 443-451 ◽  
Author(s):  
T S Kim ◽  
S T Ro
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Part Load ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Wide Range ◽  
Control Schemes ◽  
Load Characteristics ◽  
Simulation Programme

This paper demonstrates a favourable influence of turbine coolant modulation on the part load performance of gas turbines. A general simulation programme is developed, which is capable of accurately estimating the design and part load performance of modern heavy-duty gas turbines characterized by intensive turbine blade cooling Investigations are made for a typical gas turbine and two distinct load control schemes are considered: the fuel-only control and the variable compressor geometry control. Maintaining blade temperatures as high as possible whose purpose is to minimize coolant consumption is simulated. It is found that the coolant modulation makes the part load characteristics deviate from usual behaviours and creates a considerable enhancement of part load thermal efficiency. For the fuel-only control with coolant modulation, it is predicted that efficiency can be higher than design efficiency over a wide range of part load operation.

Performance of IGFC With Exergy Recuperation

2014 ◽  
Author(s):  
Norihiko Iki ◽  
Osamu Kurata ◽  
Atsushi Tsutsumi
Keyword(s):  
Power Generation ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Coal Gasification ◽  
Combined Cycle ◽  
Solid Oxide ◽  
Low Grade ◽  
Efficient System ◽  
Steam Reformer ◽  
Exhaust Heat

The Integrated coal Gasification Combined Cycle (IGCC) is considered to be a very clean and efficient system for coal-fired power generation. And given the development of 100 MW-scale solid oxide fuels cells (SOFCs), the integrated coal Gasification Fuel Cell combined cycle (IGFC) would be the most efficient coal-fired power generation system. However, more energy efficient power generation systems must be developed in order to reduce CO2 emissions over the middle and long term. Thus, the authors have proposed the Advanced Integrated coal Gasification Combined Cycle (A-IGCC) and Advanced IGFC (A-IGFC) systems, which utilize exhaust heat from solid oxide fuel cells (SOFCs) and/or gas turbines as a heat source for gasification (exergy recuperation). The A-IGCC and A-IGFC systems utilize a twin circulating fluidized bed coal gasifier consisting of three primary components: a pyrolyzer, steam reformer and partial combustor. The temperature of the steam reformer is 800 °C, and that of the partial oxidizer is 950 °C. Since the syngas, produced by pyrolysis and the reforming process involving volatile hydrocarbons, tar and char, contains carbon monoxide and hydrogen, the A-IGCC technology has considerable potential for higher thermal efficiency while utilizing low-grade coals. The coal types utilized in the study were bituminous Taiheiyo, sub-bituminous Adaro and Loy Yang coal. Milewski’s formula was used to model the circuit voltage of the SOFC. Cool gas efficiency increases, in order, from Taiheiyo coal to Adaro coal to Loy Yang coal. The A-IGFC system has the potential to achieve high thermal efficiency using various coals, with Loy Yang coal achieving the highest thermal efficiency. However, the drying process for Loy Yang and Adaro coal is an important issue.

System Evaluation and LBTU Fuel Combustion Studies for IGCC Power Generation

1994 ◽  
Author(s):  
C. S. Cook ◽  
J. C. Corman ◽  
D. M. Todd
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Coal Gasification ◽  
Flame Temperature ◽  
Combined Cycle ◽  
Gas Turbine Combustor ◽  
Gas Cleaning ◽  
Wide Range ◽  
Cycle Systems ◽  
Combined Cycles

The integration of gas turbines and combined cycle systems with advances in coal gasification and gas stream cleanup systems will result in economically viable IGCC systems. Optimization of IGCC systems for both emission levels and cost of electricity is critical to achieving this goal. A technical issue is the ability to use a wide range of coal and petroleum-based fuel gases in conventional gas turbine combustor hardware. In order to characterize the acceptability of these syngases for gas turbines, combustion studies were conducted with simulated coal gases using full scale advanced gas turbine (7F) combustor components. It was found that NOx emissions could be correlated as a simple function of stoichiometric flame temperature for a wide range of heating values while CO emissions were shown to depend primarily on the H2 content of the fuel below heating values of 130 Btu/scf (5125 kJ/NM3) and for H2/CO ratios less than unity. The test program further demonstrated the capability of advanced can-annular combustion systems to burn fuels from air-blown gasifiers with fuel lower heating values as low as 90 Btu/scf (3548 kJ/NM3) at 2300 F (1260 C) firing temperature. In support of ongoing economic studies, numerous IGCC system evaluations have been conducted incorporating a majority of the commercial or near commercial coal gasification systems coupled with “F” series gas turbine combined cycles. Both oxygen and air-blown configurations have been studied, in some cases with high and low temperature gas cleaning systems. It has been shown that system studies must start with the characteristics and limitations of the gas turbine if output and operating economics are to be optimized throughout the range of ambient operating temperature and load variation.

scholarly journals Effect of Pressure and Turbine Inlet Temperature on the Efficiency of Pressurized Fluidized Bed Power Plants

1980 ◽  
Author(s):  
R. L. Graves
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Fluidized Bed ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Development Effort ◽  
Turbine Inlet Temperature ◽  
Turbine Inlet ◽  
Wide Range

The difficulties encountered in past and present efforts to operate direct coal-fired gas turbines are substantial. Hence the development effort required to assure a reliable, high-temperature pressurized fluidized bed (PFBC) combined cycle may be very expensive and time consuming. It is, therefore, important that the benefit of achieving high-temperature operation, which is primarily increased efficiency, be clearly understood at the outset of such a development program. This study characterizes the effects of PFBC temperature and pressure on plant efficiency over a wide range of values. There is an approximate three percentage point advantage by operating at a gas turbine inlet temperature of 870 C (1600 F) instead of 538 C (1000 F). Optimum pressure varies with the gas turbine inlet temperature, but ranges from 0.4–1.0 MPa (4–10 atm). An alternate PFBC cycle offering high efficiency at a peak temperature of about 650 C (1200 F) is also discussed.

A Variable-Geometry Power Turbine for Marine Gas Turbines

1989 ◽  
Author(s):  
Karl W. Karstensen ◽  
Jesse O. Wiggins
Keyword(s):  
Fuel Consumption ◽  
Gas Turbines ◽  
Part Load ◽  
Surface Ship ◽  
Marine Propulsion ◽  
Medium Speed ◽  
Power Turbine ◽  
Wide Range ◽  
Electrical Generator ◽  
Variable Power

Gas turbines have been accepted in naval surface ship applications, and considerable effort has been made to improve their fuel consumption, particularly at part-load operation. This is an important parameter for shipboard engines because both propulsion and electrical-generator engines spend most of their lives operating at off-design power. An effective way to improve part-load efficiency of recuperated gas turbines is by using a variable power turbine nozzle. This paper discusses the successful use of variable power turbine nozzles in several applications in a family of engines developed for vehicular, industrial, and marine use. These engines incorporate a variable power turbine nozzle and primary surface recuperator to yield specific fuel consumption that rivals that of medium speed diesels. The paper concentrates on the experience with the variable nozzle, tracing its derivation from an existing fixed vane nozzle and its use across a wide range of engine sizes and applications. Emphasis is placed on its potential in marine propulsion and auxiliary gas turbines.

scholarly journals Second Round of Studies on Advanced Power Generation Based on Combined Cycle Using a Single High-Pressure Fluidized Bed Boiler and Consuming Biomass

2012 ◽  
Vol 6 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Marcio L. de Souza-Santos ◽  
Juan Villanueva Chavez
Keyword(s):  
Power Generation ◽  
Fluidized Bed ◽  
Flue Gas ◽  
Gas Turbines ◽  
Sugar Cane Bagasse ◽  
Combined Cycle ◽  
Present Stage ◽  
Added Water ◽  
Preliminary Study ◽  
Process Simulator

Following a preliminary study of power generation processes consuming sugar-cane bagasse; this second round indicates the possibility of almost doubling the current efficiency presently obtained in conventional mills. A combined cycle uses highly pressurized fluidized bed boiler to provide steam above critical temperature to drive steam-turbine cycle while the flue-gas is injected into gas turbines. The present round also shows that gains over usual BIG/GT (Biomass In-tegrated Gasification/Gas Turbine) are very likely mainly due to the practicality of feeding the biomass as slurry that can be pumped into the pressurized boiler chamber. Such would avoid the cumbersome cascade feeding of the fibrous bio-mass, usually required by other processes. The present stage assumes slurry with 50% added water. Future works will concentrate on thicker slurries, if those could be achieved. All studies apply a comprehensive simulator for boilers and gasifiers [CSFMB™ or CeSFaMB™] and a process simulator (IPES) to predict the main features of the steam and gas tur-bine branches.

scholarly journals Development of a Low-NOx LBG Combustor for Coal Gasification Combined Cycle Power Generation Systems

1989 ◽  
Author(s):  
M. Sato ◽  
T. Abe ◽  
T. Ninomiya ◽  
T. Nakata ◽  
T. Yoshine ◽  
...  
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Coal Gasification ◽  
Combined Cycle ◽  
Generation System ◽  
Combustion Technology ◽  
Power Generation System ◽  
Combustion Tests ◽  
Power Generation Systems

From the view point of future coal utilization technology for the thermal power generation systems, the coal gasification combined cycle system has drawn special interest recently. In the coal gasification combined cycle power generation system, it is necessary to develop a high temperature gas turbine combustor using a low-BTU gas (LBG) which has high thermal efficiency and low emissions. In Japan a development program of the coal gasification combined cycle power generation system has started in 1985 by the national government and Japanese electric companies. In this program, 1300°C class gas turbines will be developed. If the fuel gas cleaning system is a hot type, the coal gaseous fuel to be supplied to gas turbines will contain ammonia. Ammonia will be converted to nitric oxides in the combustion process in gas turbines. Therefore, low fuel-NOx combustion technology will be one of the most important research subjects. This paper describes low fuel-NOx combustion technology for 1300°C class gas turbine combustors using coal gaseous low-BTU fuel as well as combustion characteristics and carbon monoxide emission characteristics. Combustion tests were conducted using a full-scale combustor used for the 150 MW gas turbine at the atmospheric pressure. Furthermore, high pressure combustion tests were conducted using a half-scale combustor used for the 1 50 MW gas turbine.

scholarly journals Thermodynamic analysis of high temperature nuclear reactor coupled with advanced gas turbine combined cycle

2019 ◽  
Vol 23 (Suppl. 4) ◽  
pp. 1187-1197 ◽  
Author(s):  
Marek Jaszczur ◽  
Michal Dudek ◽  
Zygmunt Kolenda
Keyword(s):  
High Temperature ◽  
Power Plant ◽  
Gas Turbine ◽  
Thermodynamic Analysis ◽  
Thermal Efficiency ◽  
Nuclear Power ◽  
Coal Gasification ◽  
Nuclear Reactor ◽  
Combined Cycle ◽  
Oil Processing

One of the most advanced and most effective technology for electricity generation nowadays based on a gas turbine combined cycle. This technology uses natural gas, synthesis gas from the coal gasification or crude oil processing products as the energy carriers but at the same time, gas turbine combined cycle emits SO2, NOx, and CO2 to the environment. In this paper, a thermodynamic analysis of environmentally friendly, high temperature gas nuclear reactor system coupled with gas turbine combined cycle technology has been investigated. The analysed system is one of the most advanced concepts and allows us to produce electricity with the higher thermal efficiency than could be offered by any currently existing nuclear power plant technology. The results show that it is possible to achieve thermal efficiency higher than 50% what is not only more than could be produced by any modern nuclear plant but it is also more than could be offered by traditional (coal or lignite) power plant.

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