Aerodynamic Turbine Design for an Oxy-Fuel Combined Cycle

2016 ◽  
Author(s):  
Adrian Dahlquist ◽  
Magnus Genrup
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Thermal Power ◽  
Design Methods ◽  
Combined Cycle ◽  
Working Fluid ◽  
3D Analysis ◽  
Conventional Design ◽  
Turbine Design

The oxy-fuel combined cycle (OCC) is one of several carbon capture and sequestration (CCS) technologies being developed to reduce CO2 emissions from thermal power plants. The OCC consists of a semi-closed topping Bryton cycle, and a traditional bottoming Rankine cycle. The topping cycle operates with a working medium mixture of mainly CO2 and H2O. This CO2-rich working fluid has significantly different gas properties compared to a conventional open gas turbine cycle, which thereby affects the aerodynamic turbine design for the gas turbine units. The aerodynamic turbine design for oxy-fuel gas turbines is an unexplored research field. The topic of this study was therefore to investigate the aerodynamic turbine design of turbines operating with a CO2-rich working fluid. The investigation was performed through a typical turbine aero-design loop, which covered the 1D mid-span, 2D through-flow, 3D blade profiling design and the steady-state 3D analysis. The design was performed through the use of conventional design methods and criteria in order to investigate if any significant departures from conventional turbine design methods were required. The survey revealed some minor deviations in design considerations, yet it showed that the design is feasible with today’s state-of-the-art technology by using conventional design practice and methods. The performance of the oxy-fuel combined cycle was revised based on the performance figures from the components design. The expected total performance figures for the oxy-fuel combined cycle were calculated to be a net electrical power of 119.9 MW and a net thermal efficiency of 48.2%. These figures include the parasitic consumption for the oxygen production required for the combustion and the CO2 compression of the CO2 bleed stream.

scholarly journals Whisper and Roar

2014 ◽  
Vol 136 (07) ◽  
pp. 38-43
Author(s):  
Lee S. Langston
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
High Efficiency ◽  
Thermal Power ◽  
Electrical Power ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Marine Applications ◽  
Almost All

This article focuses on the use of gas turbines for electrical power, mechanical drive, and marine applications. Marine gas turbines are used to generate electrical power for propulsion and shipboard use. Combined-cycle electric power plants, made possible by the gas turbine, continue to grow in size and unmatched thermal efficiency. These plants combine the use of the gas turbine Brayton cycle with that of the steam turbine Rankine cycle. As future combined cycle plants are introduced, we can expect higher efficiencies to be reached. Since almost all recent and new U.S. electrical power plants are powered by natural gas-burning, high-efficiency gas turbines, one has solid evidence of their contribution to the greenhouse gas reduction. If coal-fired thermal power plants, with a fuel-to-electricity efficiency of around 33%, are swapped out for combined-cycle power plants with efficiencies on the order of 60%, it will lead to a 70% reduction in carbon emissions per unit of electricity produced.

Evaluation for Scalability of a Combined Cycle Using Gas and Bottoming SCO2 Turbines

2015 ◽  
Author(s):  
Leonid Moroz ◽  
Petr Pagur ◽  
Oleksii Rudenko ◽  
Maksym Burlaka ◽  
Clement Joly
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Supercritical Co2 ◽  
Power Plants ◽  
Combined Cycle ◽  
Electricity Production ◽  
Working Fluid ◽  
Gas Temperature ◽  
Cycle System ◽  
Gas Turbine Exhaust

Bottoming cycles are drawing a real interest in a world where resources are becoming scarcer and the environmental footprint of power plants is becoming more controlled. Reduction of flue gas temperature, power generation boost without burning more fuel and even production of heat for cogeneration applications are very attractive and it becomes necessary to quantify how much can really be extracted from a simple cycle to be converted to a combined configuration. As supercritical CO2 is becoming an emerging working fluid [2, 3, 5, 7 and 8] due not only to the fact that turbomachines are being designed significantly more compact, but also because of the fluid’s high thermal efficiency in cycles, it raises an increased interest in its various applications. Evaluating the option of combined gas and supercritical CO2 cycles for different gas turbine sizes, gas turbine exhaust gas temperatures and configurations of bottoming cycle type becomes an essential step toward creating guidelines for the question, “how much more can I get with what I have?”. Using conceptual design tools for the cycle system generates fast and reliable results to draw this type of conclusion. This paper presents both the qualitative and quantitative advantages of combined cycles for scalability using machines ranging from small to several hundred MW gas turbines to determine which configurations of S-CO2 bottoming cycles are best for pure electricity production.

scholarly journals Comparative analysis of the Allam cycle and the cycle of compressorless combined cycle gas turbine unit

2020 ◽  
Vol 209 ◽  
pp. 03023
Author(s):  
Mikhail Sinkevich ◽  
Anatoliy Kosoy ◽  
Oleg Popel
Keyword(s):  
Comparative Analysis ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Thermal Power ◽  
District Heating ◽  
Combined Cycle ◽  
Working Fluid ◽  
District Heating System ◽  
Wide Range

Nowadays, alternative thermodynamic cycles are actively studied. They allow to remove CO2, formed as a result of fuel combustion, from a cycle without significant energy costs. Calculations have shown that such cycles may meet or exceed the most advanced power plants in terms of heat efficiency. The Allam cycle is recognized as one of the best alternative cycles for the production of electricity. Nevertheless, a cycle of compressorless combined cycle gas turbine (CCGT) unit is seemed more promising for cogeneration of electricity and heat. A comparative analysis of the thermal efficiency of these two cycles was performed. Particular attention was paid to ensuring equal conditions for comparison. The cycle of compressorless CCGT unit was as close as possible to the Allam cycle due to the choice of parameters. The processes, in which the difference remained, were analysed. Thereafter, an analysis of how close the parameters, adopted for comparison, to optimal for the compressorless CCGT unit cycle was made. This analysis showed that these two cycles are quite close only for the production of electricity. The Allam cycle has some superiority but not indisputable. However, if cogeneration of electricity and heat is considered, the thermal efficiency of the cycle of compressorless CCGT unit will be significantly higher. Since it allows to independently regulate a number of parameters, on which the electric power, the ratio of electric and thermal power, the temperature of a working fluid at the turbine inlet depend. Thus, the optimal parameters of the thermodynamic cycle can be obtained in a wide range of operating modes of the unit with different ratios of thermal and eclectic powers. Therefore, the compressorless CCGT unit can significantly surpass the best steam turbine and combined cycle gas turbine plants in district heating system in terms of thermal efficiency.

Aerodynamic Gas Turbine Compressor Design for an Oxy-Fuel Combined Cycle

2015 ◽  
Author(s):  
Adrian Dahlquist ◽  
Magnus Genrup
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Thermal Power ◽  
Combined Cycle ◽  
Working Fluid ◽  
3D Analysis ◽  
Fuel Gas ◽  
Compressor Design ◽  
Ccs Technologies ◽  
Design Calculations

A number of different CCS-technologies are currently being developed to reduce CO2 emissions from thermal power stations. One of these technologies is based on the oxy-fuel combined cycle process, the basics of which have been described in several publications. The key difference in this cycle is the working fluid, which requires further investigation. The working fluid in the topping gas turbine cycle of an OCC mainly consists of CO2 (80–95 wt%) and steam (5–15 wt%), with a few percentage of enriched N2 and Ar. The gas properties of this working fluid differ significantly from those of a conventional air-breathing gas turbine; hence, the gas turbine has to be designed accordingly. The isentropic exponent is lower, for example, with the result that a higher pressure ratio is required in an oxy-fuel combined cycle gas turbine than in a conventional combined cycle to achieve exhaust gas conditions that fit the design of a conventional bottoming steam cycle. This higher pressure ratio results in additional challenges in the design of the aerodynamic compressor. The amount of information in the public domain about designing an oxy-fuel gas turbine is sparse and is mainly limited to the cycle design. The main objective of this work is therefore to demonstrate the feasibility of achieving the aerodynamic compression in a single-spool compressor design, suitable for an oxy-fuel combined cycle application, with the aim of bringing the technology closer to commercialization. The aerodynamic compressor design includes 1D mid-span and 2D through-flow design calculations, and a steady-state 3D analysis calculation for validation. The compressor’s design suits an oxy-fuel combined cycle with a net plant power of 115 MWel.

Efficiency Entitlement for Bottoming Cycles

2006 ◽  
Author(s):  
Douglas C. Hofer ◽  
S. Can Gulen
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
New Method ◽  
Working Fluid ◽  
Generating Capacity ◽  
Topping Cycle ◽  
Cycle Efficiency ◽  
Steam Cycle

A significant portion of the new electrical generating capacity installed in the past decade has employed heavy-duty gas turbines operating in a combined cycle configuration with a steam turbine bottoming cycle. In these power plants approximately 1/3 of the power is generated by the bottoming cycle. To ensure that the highest possible combined cycle efficiency is realized it is important to optimize the bottoming cycle efficiency and doing so requires a solid understanding of the efficiency entitlement. This paper describes a new technique for calculating the theoretical efficiency entitlement for a bottoming cycle that corresponds to the maximum possible bottoming cycle work and maximized combined cycle work and efficiency. This new method accounts for the decrease in ideal efficiency as the gas turbine exhaust is cooled as it transfers heat energy to the working fluid in the bottoming cycle. The new definition is compared to conventional definitions, including that of Carnot and an Exergy based second law efficiency, and shown to provide a simple and accurate analytical expression for the entitlement efficiency in a bottoming cycle. For representative cycle conditions, the entitlement efficiency for the bottoming cycle is calculated to be ∼45% compared to the Carnot efficiency for the same conditions of ∼67%. Although the new method is applicable to any power cycle obtaining its heat input from the exhaust stream of a topping cycle, special attention is given to the steam bottoming cycle traditionally used in modern gas turbine combined cycle power plants. Comparisons are made between the ideal bottoming cycle and variants of a steam cycle including a single pressure non-reheat and a three pressure reheat cycle. These comparisons explore the unavoidable loss in efficiency associated with constant temperature heat addition that occurs in the steam cycle.

Integration of Modern F, G, H and J Class in Combined Cycle Applications: An EPC Contractor Perspective

2016 ◽  
Author(s):  
Justin Zachary ◽  
Vinod Kallianpur ◽  
Byungsik So
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Traditional Approach ◽  
Combined Cycle ◽  
Reference Architecture ◽  
Design Concepts ◽  
Industrial Gas Turbines ◽  
Turbine Design ◽  
Industrial Gas Turbine

The traditional approach for developing new and upgrade model large frame industrial gas turbines is changing rather dramatically. Large industrial gas turbine design evolutions have typically been built around a basic core design concept that remained unchanged. The departure from tradition has been, in some cases, sparked by the merger between erstwhile competitors. Thus the models that follow a merger benefit from leveraging the best of available knowledge from both companies: specialized design methods, manufacturing practices, materials, combustion, etc. Another recent trend in GT development is to transfer select portions of design concepts and related experience, and integrate that knowledge into a new model. Both these trajectories of development involve some changes to the core design reference architecture: e.g. number of rows in turbine section, rotor design architecture, flow path shape, blade locking approach, exhaust diffuser, inlet scroll, etc., and needing more attention to detail by the EPC for being able to meet the customer expectations for life cycle costs, performance degradation, reliability and availability. The expanded technical capability of the OEMs to accelerate new technical innovations for propelling the next economic growth engine is indeed a very exciting prospect for EPC contractors. Already, modern “H” and “J” class gas turbines are commercially available for over 60 per cent net efficiency in combined cycle power plant application. This paper shares an EPC contractor’s experience in developing Combined Cycle Power Plants with two advanced commercially available gas turbine models in Korea (Mitsubishi’s M501J model) and Malaysia (Siemens SGT. 5-8000H model).

Novel High-Performing Single-Pressure Combined Cycle With CO2 Capture

2010 ◽  
Vol 133 (4) ◽  
Author(s):  
Nikolett Sipöcz ◽  
Klas Jonshagen ◽  
Mohsen Assadi ◽  
Magnus Genrup
Keyword(s):  
Natural Gas ◽  
Electric Power ◽  
Gas Turbine ◽  
Co2 Capture ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Working Fluid ◽  
Market Demand ◽  
Combined Cycles

The European electric power industry has undergone considerable changes over the past two decades as a result of more stringent laws concerning environmental protection along with the deregulation and liberalization of the electric power market. However, the pressure to deliver solutions in regard to the issue of climate change has increased dramatically in the last few years and has given rise to the possibility that future natural gas-fired combined cycle (NGCC) plants will also be subject to CO2 capture requirements. At the same time, the interest in combined cycles with their high efficiency, low capital costs, and complexity has grown as a consequence of addressing new challenges posed by the need to operate according to market demand in order to be economically viable. Considering that these challenges will also be imposed on new natural gas-fired power plants in the foreseeable future, this study presents a new process concept for natural gas combined cycle power plants with CO2 capture. The simulation tool IPSEpro is used to model a 400 MW single-pressure NGCC with post-combustion CO2 capture using an amine-based absorption process with monoethanolamine. To improve the costs of capture, the gas turbine GE 109FB is utilizing exhaust gas recirculation, thereby, increasing the CO2 content in the gas turbine working fluid to almost double that of conventional operating gas turbines. In addition, the concept advantageously uses approximately 20% less steam for solvent regeneration by utilizing preheated water extracted from heat recovery steam generator. The further recovery of heat from exhaust gases for water preheating by use of an increased economizer flow results in an outlet stack temperature comparable to those achieved in combined cycle plants with multiple-pressure levels. As a result, overall power plant efficiency as high as that achieved for a triple-pressure reheated NGCC with corresponding CO2 removal facility is attained. The concept, thus, provides a more cost-efficient option to triple-pressure combined cycles since the number of heat exchangers, boilers, etc., is reduced considerably.

Novel High-Perfoming Single-Pressure Combined Cycle With CO2 Capture

2010 ◽  
Author(s):  
Nikolett Sipo¨cz ◽  
Klas Jonshagen ◽  
Mohsen Assadi ◽  
Magnus Genrup
Keyword(s):  
Natural Gas ◽  
Electric Power ◽  
Gas Turbine ◽  
Co2 Capture ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Working Fluid ◽  
Market Demand ◽  
Combined Cycles

The European electric power industry has undergone considerable changes over the past two decades as a result of more stringent laws concerning environmental protection along with the deregulation and liberalization of the electric power market. However, the pressure to deliver solutions in regard to the issue of climate change has increased dramatically in the last few years and given the rise to the possibility that future natural gas-fired combined cycle (NGCC) plants will also be subject to CO2 capture requirements. At the same time, the interest in combined cycles with their high efficiency, low capital costs and complexity has grown as a consequence of addressing new challenges posed by the need to operate according to market demand in order to be economically viable. Considering that these challenges will also be imposed on new natural gas-fired power plants in the foreseeable future, this study presents a new process concept for natural gas combined cycle power plants with CO2 capture. The simulation tool IPSEpro is used to model a 400 MW single-pressure NGCC with post-combustion CO2 capture, using an amine-based absorption process with Monoethanolamine. To improve the costs of capture the gas turbine, GE 109FB, is utilizing exhaust gas recirculation, thereby increasing the CO2 content in the gas turbine working fluid to almost double that of conventional operating gas turbines. In addition, the concept advantageously uses approximately 20% less steam for solvent regeneration by utilizing preheated water extracted from HRSG. The further recovery of heat from exhaust gases for water preheating by use of an increased economizer flow results in an outlet stack temperature comparable to those achieved in combined cycle plants with multiple pressure levels. As a result, overall power plant efficiency as high as that achieved for a triple-pressure reheated NGCC with corresponding CO2 removal facility is attained. The concept thus provides a more cost-efficient option to triple-pressure combined cycles since the number of heat exchangers, boilers, etc. is reduced considerably.

scholarly journals Electrically Charged

2002 ◽  
Vol 124 (06) ◽  
pp. 50-52
Author(s):  
Lee Longston
Keyword(s):  
Electric Power ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Nuclear Reactor ◽  
The United States ◽  
Combined Cycle ◽  
Working Fluid ◽  
Closed Cycle ◽  
Wide Range

This article focuses on gas turbines that were produced in 2001 spanning a wide range of capacities. As the engineer's most versatile energy converters, gas turbines producing thrust power continued in 2001 to propel most of the world's aircraft, both military and commercial. The largest commercial jet engines today can produce as much as 120,000 pounds thrust, or some 534,000 Newton. More natural gas pipeline capacity will be added to feed the surge in gas-driven electric power plants that have been corning online in the United States and other parts of the world. The gas turbine may come to be used in a new, commercially promising closed-cycle configuration. A South African company has been working on plans to build and test a prototype of a closed-cycle electric power gas turbine, which uses helium gas as the working fluid and a helium-cooled nuclear reactor to provide heat to power the cycle. If the gas turbine-nuclear reactor power plant is successful, the gas turbine may be the key to yet another energy conversion device, as it has been with record-setting numbers of combined-cycle plants installed worldwide.

Dynamic Behavior of a Solar Hybrid Gas Turbine System

2015 ◽  
Author(s):  
Christian Felsmann ◽  
Uwe Gampe ◽  
Manfred Freimark
Keyword(s):  
System Dynamics ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Thermal Power ◽  
Commercial Application ◽  
Worst Case ◽  
Electric Generator ◽  
New Findings ◽  
Component Development

Solar hybrid gas turbine technology has the potential to increase the efficiency of future solar thermal power plants by utilizing solar heat at a much higher temperature level than state of the art plants based on steam turbine cycles. In a previous paper the authors pointed out, that further development steps are required for example in the field of component development and in the investigation of the system dynamics to realize a mature technology for commercial application [1]. In this paper new findings on system dynamics are presented based on the simulation model of a solar hybrid gas turbine with parallel arrangement of the combustion chamber and solar receivers. The operational behavior of the system is described by means of two different scenarios. The System operation in a stand-alone electrical supply network is investigated in the first scenario. Here it is shown that fast load changes in the network lead to a higher shaft speed deviation of the electric generator compared to pure fossil fired systems. In the second scenario a generator load rejection, as a worst case, is analyzed. The results make clear that additional relief concepts like blow-off valves are necessary as the standard gas turbine protection does not meet the specific requirements of the solar hybrid operation. In general the results show, that the solar hybrid operational modes are much more challenging for the gas turbines control and safety system compared to pure fossil fired plants due to the increased volumetric storage capacity of the system.

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