scholarly journals Design of a Semiclosed Cycle Gas Turbine With Carbon Dioxide-Argon as Working Fluid

1997 ◽  
Author(s):  
Inaki Ulizar ◽  
Pericles Pilidis
Keyword(s):  
Carbon Dioxide ◽  
Gas Turbine ◽  
Pressure Ratio ◽  
Air Separation ◽  
Working Fluid ◽  
Optimum Pressure ◽  
Low Efficiency ◽  
Nozzle Guide ◽  
Main Engine ◽  
No Emissions

The main performance features of a semiclosed cycle gas turbine with carbon dioxide-argon working fluid are described here. This machine is designed to employ coal synthetic gas fuel and to produce no emissions. The present paper outlines three tasks carried out. Firstly the selection of main engine variables, mainly pressure and temperature ratios. Then a sizing exercise is carried out where many details of its physical appearance are outlined. Finally the off-design performance of the engine is predicted. This two spool gas turbine is purpose built for the working fluid, so its physical characteristics reflect this requirement. The cycle is designed with a turbine entry temperature of 1650 K and the optimum pressure ratio is found to be around 60. Two major alternatives are examined, the simple and the precooled cycle. A large amount of nitrogen is produced by the air separation plant associated with this gas turbine and the coal gasifier. An investigation has been made on how to use this nitrogen to improve the performance of the engine by precooling the compressor, cooling the turbine nozzle guide vanes and using it to cool the delivery of the low pressure compressor. The efficiencies of the whole plant have been computed, taking into account the energy requirements of the gasifier and the need to dispose of the excess carbon dioxide. Hence the overall efficiencies indicated here are of the order of 40 percent. This is a low efficiency by current standards, but the fuel employed is coal and no emissions are produced.

Design of a Semiclosed-Cycle Gas Turbine With Carbon Dioxide–Argon as Working Fluid

1998 ◽  
Vol 120 (2) ◽  
pp. 330-335 ◽  
Author(s):  
I. Ulizar ◽  
P. Pilidis
Keyword(s):  
Carbon Dioxide ◽  
Gas Turbine ◽  
Pressure Ratio ◽  
Air Separation ◽  
Working Fluid ◽  
Optimum Pressure ◽  
Low Efficiency ◽  
Nozzle Guide ◽  
Main Engine ◽  
No Emissions

The main performance features of a semiclosed-cycle gas turbine with carbon dioxide–argon working fluid are described here. This machine is designed to employ coal synthetic gas fuel and to produce no emissions. The present paper outlines three tasks carried out. First, the selection of main engine variables, mainly pressure and temperature ratios. Then a sizing exercise is carried out where many details of its physical appearance are outlined. Finally the off-design performance of the engine is predicted. This two-spool gas turbine is purpose built for the working fluid, so its physical characteristics reflect this requirement. The cycle is designed with a turbine entry temperature of 1650 K and the optimum pressure ratio is found to be around 60. Two major alternatives are examined, the simple and the precooled cycle. A large amount of nitrogen is produced by the air separation plant associated with this gas turbine and the coal gasifier. An investigation has been made on how to use this nitrogen to improve the performance of the engine by precooling the compressor, cooling the turbine nozzle guide vanes, and using it to cool the delivery of the low-pressure compressor. The efficiencies of the whole plant have been computed, taking into account the energy requirements of the gasifier and the need to dispose of the excess carbon dioxide. Hence the overall efficiencies indicated here are of the order of 40 percent. This is a low efficiency by current standards, but the fuel employed is coal and no emissions are produced.

Economic and Scenario Analyses of New Gas Turbine Combined Cycles With No Emissions of Carbon Dioxide

2004 ◽  
Author(s):  
R. Gabbrielli ◽  
R. Singh
Keyword(s):  
Carbon Dioxide ◽  
Power Plant ◽  
Gas Turbine ◽  
Scenario Analysis ◽  
Pure Oxygen ◽  
Working Fluid ◽  
Scenario Analyses ◽  
Combined Cycles ◽  
O2 Production ◽  
No Emissions

In this paper economic and scenario analyses of new gas turbine combined cycles with no emissions of carbon dioxide (CO2) and nitrogen oxides are described. The cycles, already presented in a recent paper (ASME GT 2002-30117), have water/steam as working fluid, the compression phase both in liquid and vapour phase, the internal combustion between pure oxygen (O2) and chemically heated natural gas-based syngas, and the CO2 capture and sequestration by water condensation from the exhaust gas. The aim of the economic analyses is to estimate the investment per MW and the levelized discounted cost of the electricity (COE) produced by a power plant based on the cycles here proposed in comparison with a standard reference combined cycle power plant (SRCC). To evaluate the equipment costs, several cost functions of the most important operative parameters have been introduced and tuned with actual data. Using the least square regression technique, explicit functions of the COE have been proposed to highlight the cheapest operative conditions with a derivative approach. Moreover, a wide scenario analysis has been carried out, varying the most important investment parameters, as, for example, the discount rate. In particular, some maps of the COE and break-even carbon tax (BECT) behaviour have been constructed to test the importance of the market uncertainty on the economic results obtained. Finally, the possible technological progress effect on the BECT with a cost reduction of some innovative equipment and the O2 production has been investigated in depth with the 2k factorial design scenario analysis. The O2 production has resulted the most important parameter from the economic point of view.

scholarly journals CO2 Emission Abatement in IGCC Power Plants by Semiclosed Cycles: Part A — With Oxygen-Blown Combustion

1998 ◽  
Author(s):  
Paolo Chiesa ◽  
Giovanni Lozza
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Pressure Ratio ◽  
Air Separation ◽  
Working Fluid ◽  
Auxiliary Equipment ◽  
Separation Unit ◽  
Turbine Engine ◽  
Air Separation Unit ◽  
Syngas Combustion

This paper analyzes the fundamentals of IGCC power plants where carbon dioxide produced by syngas combustion can be removed, liquefied and eventually disposed, to limit the environmental problems due to the “greenhouse effect”. To achieve this goal, a semiclosed-loop gas turbine cycle using an highly-enriched CO2 mixture as working fluid was adopted. As the oxidizer, syngas combustion utilizes oxygen produced by an air separation unit. Combustion gases mainly consist of CO2 and H2O: after expansion, heat recovery and water condensation, a part of the exhausts, highly concentrated in CO2, can be easily extracted, compressed and liquefied for storage or disposal. A detailed discussion about the configuration and the thermodynamic performance of these plants is the aim of the paper. Proper attention was paid to: (i) the modelization of the gasification section and of its integration with the power cycle, (ii) the optimization of the pressure ratio due the change of the cycle working fluid, (iii) the calculation of the power consumption of the “auxiliary” equipment, including the compression train of the separated CO2 and the air separation unit. The resulting overall efficiency is in the 38–39% range, with status-of-the-art gas turbine technology, but resorting to a substantially higher pressure ratio. The extent of modifications to the gas turbine engine, with respect to commercial units, was therefore discussed. Relevant modifications are needed, but not involving changes in the technology. A second plant scheme will be considered in the second part of the paper, using air for syngas combustion and a physical absorption process to separate CO2 from nitrogen-rich exhausts. A comparison between the two options will be addressed there.

Thermodynamic Performance Analysis of New Gas Turbine Combined Cycles With No Emissions of Carbon Dioxide

2002 ◽  
Author(s):  
R. Gabbrielli ◽  
R. Singh
Keyword(s):  
Carbon Dioxide ◽  
Performance Analysis ◽  
Gas Turbine ◽  
Pure Oxygen ◽  
Working Fluid ◽  
Specific Work ◽  
Water Steam ◽  
Thermodynamic Performance ◽  
Combined Cycles ◽  
No Emissions

In the context of the reduction of the carbon dioxide (CO2) emissions as prescribed by the Kyoto protocol, this paper describes a thermodynamic performance analysis of new gas turbine combined cycles with no emissions of CO2 and nitrogen oxides. Three new similar cycles belonging to the same typology are proposed. These cycles use water/steam as working fluid, which is compressed in liquid and vapour phase, and the internal combustion process, which takes place between syngas and pure oxygen. The top Brayton cycle and the bottom Rankine cycle are integrated together. The syngas is produced by steam-natural gas reforming with internal chemical heat recovery. The CO2 produced in the combustion is captured simply by water condensation from the exhaust gas and liquefied to be stored. A simulation analysis has been performed to evaluate the net efficiency and the net specific work of the cycles. Varying the most important operative variables and using the least square regression and 2k factorial design techniques, a very large sensitivity analysis has permitted to highlight the performance behaviour of the cycles. Including the energy penalty due to the liquefaction of CO2 and to the oxygen production and adopting standard operative conditions, the LHV-based net efficiency and the net specific work may exceed 50% and 1000 kJ/kg, respectively.

Thermodynamic Performance Analysis of New Gas Turbine Combined Cycles With No Emissions of Carbon Dioxide

2003 ◽  
Vol 125 (4) ◽  
pp. 940-946 ◽  
Author(s):  
R. Gabbrielli ◽  
R. Singh
Keyword(s):  
Carbon Dioxide ◽  
Performance Analysis ◽  
Gas Turbine ◽  
Pure Oxygen ◽  
Working Fluid ◽  
Specific Work ◽  
Water Steam ◽  
Thermodynamic Performance ◽  
Combined Cycles ◽  
No Emissions

In the context of the reduction of the carbon dioxide CO2 emissions as prescribed by the Kyoto protocol, this paper describes a thermodynamic performance analysis of new gas turbine combined cycles with no emissions of CO2 and nitrogen oxides. Three new similar cycles belonging to the same typology are proposed. These cycles use water/steam as working fluid, which is compressed in liquid and vapor phase, and the internal combustion process, which takes place between syngas and pure oxygen. The top Brayton cycle and the bottom Rankine cycle are integrated together. The syngas is produced by steam-natural gas reforming with internal chemical heat recovery. The CO2 produced in the combustion is captured simply by water condensation from the exhaust gas and liquefied to be stored. A simulation analysis has been performed to evaluate the net efficiency and the net specific work of the cycles. Varying the most important operative variables and using the least-square regression and 2k factorial design techniques, a very large sensitivity analysis has permitted the highlighting of performance behavior of the cycles. Including the energy penalty due to the liquefaction of CO2 and to the oxygen production and adopting standard operative conditions, the LHV-based net efficiency and the net specific work may exceed 50% and 1000 kJ/kg, respectively.

Advances in Computer Aided Engineering for Gas Turbine Research and Development

2021 ◽  
pp. 171-197
Author(s):  
Valeriu Vilag ◽  
Jeni Vilag ◽  
Cleopatra Cuciumita
Keyword(s):  
Carbon Dioxide ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Temperature ◽  
Pressure Ratio ◽  
Thermodynamic Cycle ◽  
Working Fluid ◽  
Atmospheric Air ◽  
Computer Aided ◽  
Main Components

Gas turbines represent energetic machines that operate following the Brayton thermodynamic cycle [6], [16] creating mechanical power and/or thrust. The majority of them use atmospheric air as working fluid but some are working in a closed loop with either air, carbon dioxide or other convenient gas. The main parameters defining the cycle are the combustion temperature and the overall pressure ratio [20]. In principle, the higher the combustion temperature is, the higher the efficiency of the entire gas turbine will be and, for a chosen value of the combustion temperature an optimum overall pressure ratio exists [29]. The main components of the gas turbine are:

Economic and Scenario Analyses of New Gas Turbine Combined Cycles With No Emissions of Carbon Dioxide

2005 ◽  
Vol 127 (3) ◽  
pp. 531-538 ◽  
Author(s):  
R. Gabbrielli ◽  
R. Singh
Keyword(s):  
Carbon Dioxide ◽  
Power Plant ◽  
Gas Turbine ◽  
Scenario Analysis ◽  
Pure Oxygen ◽  
Working Fluid ◽  
Scenario Analyses ◽  
Combined Cycles ◽  
O2 Production ◽  
No Emissions

In this paper economic and scenario analyses of new gas turbine combined cycles with no emissions of carbon dioxide CO2 and nitrogen oxides are described. The cycles, already presented in a recent paper (ASME GT 2002-30117), have water/steam as a working fluid, the compression phase both in liquid and vapor phase, the internal combustion between pure oxygen O2 and chemically heated natural gas-based syngas, and the CO2 capture and sequestration by water condensation from the exhaust gas. The aim of the economic analyses is to estimate the investment per MW and the levelized discounted cost of the electricity (COE) produced by a power plant based on the cycles proposed here in comparison with a standard reference combined cycle power plant (SRCC). To evaluate the equipment costs, several cost functions of the most important operative parameters have been introduced and tuned with the actual data. Using the least square regression technique, explicit functions of the COE have been proposed to highlight the cheapest operative conditions with a derivative approach. Moreover, a wide scenario analysis has been carried out, varying the most important investment parameters, as, for example, the discount rate. In particular, some maps of the COE and break-even carbon tax (BECT) behavior have been constructed to test the importance of the market uncertainty on the economic results obtained. Finally, the possible technological progress effect on the BECT with a cost reduction of some innovative equipment and the O2 production has been investigated in depth with the 2k factorial design scenario analysis. The O2 production has resulted as the most important parameter from an economic point of view.

CO2 Emission Abatement in IGCC Power Plants by Semiclosed Cycles: Part A—With Oxygen-Blown Combustion

1999 ◽  
Vol 121 (4) ◽  
pp. 635-641 ◽  
Author(s):  
P. Chiesa ◽  
G. Lozza
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Pressure Ratio ◽  
Air Separation ◽  
Working Fluid ◽  
Auxiliary Equipment ◽  
Separation Unit ◽  
Turbine Engine ◽  
Air Separation Unit ◽  
Syngas Combustion

This paper analyzes the fundamentals of IGCC power plants where carbon dioxide produced by syngas combustion can be removed, liquefied and eventually disposed, to limit the environmental problems due to the “greenhouse effect.” To achieve this goal, a semiclosed-loop gas turbine cycle using an highly-enriched CO2 mixture as working fluid was adopted. As the oxidizer, syngas combustion utilizes oxygen produced by an air separation unit. Combustion gases mainly consists of CO2 and H2O: after expansion, heat recovery and water condensation, a part of the exhausts, highly concentrated in CO2, can be easily extracted, compressed and liquefied for storage or disposal. A detailed discussion about the configuration and the thermodynamic performance of these plants is the aim of the paper. Proper attention was paid to: (i) the modelization of the gasification section and of its integration with the power cycle, (ii) the optimization of the pressure ratio due the change of the cycle working fluid, (iii) the calculation of the power consumption of the “auxiliary” equipment, including the compression train of the separated CO2 and the air separation unit. The resulting overall efficiency is in the 38–39 percent range, with status-of-the-art gas turbine technology, but resorting to a substantially higher pressure ratio. The extent of modifications to the gas turbine engine, with respect to commercial units, was therefore discussed. Relevant modifications are needed, but not involving changes in the technology. A second plant scheme will be considered in the second part of the paper, using air for syngas combustion and a physical absorption process to separate CO2 from nitrogen-rich exhausts. A comparison between the two options will be addressed there.

scholarly journals Methanol Dissociative Intercooling in Gas Turbines

1982 ◽  
Author(s):  
M. F. Bardon ◽  
J. A. C. Fortin
Keyword(s):  
Carbon Monoxide ◽  
Theoretical Analysis ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Unit Mass ◽  
Cycle Model ◽  
Optimum Pressure ◽  
Heating Value ◽  
Compressor Work

This paper examines the possibility of injecting methanol into the compressor of a gas turbine, then dissociating it to carbon monoxide and hydrogen so as to cool the air and reduce the work of compression, while simultaneously increasing the fuel’s heating value. A theoretical analysis shows that there is a net reduction in compressor work resulting from this dissociative intercooling effect. Furthermore, by means of a computer cycle model, the effects of dissociation on efficiency and work per unit mass of airflow are predicted for both regenerated and unregenerated gas turbines. The effect on optimum pressure ratio is examined and practical difficulties likely to be encountered with such a system are discussed.

Second Law Efficiency of an Intercooled-Reheated-Regenerative-Brayton Cycle With Variable Temperature Heat Reservoirs

2012 ◽  
Author(s):  
Vishal Anand ◽  
Krishna Nelanti ◽  
Kamlesh G. Gujar
Keyword(s):  
Gas Turbine ◽  
Variable Temperature ◽  
Pressure Ratio ◽  
Working Fluid ◽  
Thermodynamic Efficiency ◽  
Second Law ◽  
Brayton Cycle ◽  
Cooling Fluid ◽  
Turbine Engine ◽  
Temperature Heat

The gas turbine engine works on the principle of the Brayton Cycle. One of the ways to improve the efficiency of the gas turbine is to make changes in the Brayton Cycle. In the present study, Brayton Cycle with intercooling, reheating and regeneration with variable temperature heat reservoirs is considered. Instead of the usual thermodynamic efficiency, the Second law efficiency, defined on the basis of lost work, has been taken as a parameter to study the deviation of the irreversible Brayton Cycle from the ideal cycle. The Second law efficiency of the Brayton Cycle has been found as a function of reheat and intercooling pressure ratios, total pressure ratio, intercooler, regenerator and reheater effectiveness, hot and cold side heat exchanger effectiveness, turbine and compressor efficiency and heating capacities of the heating fluid, the cooling fluid and the working fluid (air). The variation of the Second law efficiency with all these parameters has been presented. From the results, it can be seen that the Second law efficiency first increases and then decreases with increase in intercooling pressure ratio and increases with increase in reheating pressure ratio. The results show that the Second law efficiency is a very good indicator of the amount of irreversibility of the cycle.

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