H Gas Turbine Combined Cycle Technology and Development Status

1996 ◽  
Author(s):  
James C. Corman
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Environmental Control ◽  
Cooling System ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Significant Advance ◽  
Single Digit ◽  
Cycle System

A revolutionary step has been taken in the development of the Next Advance in Power Generation Systems — “H” Technology Combined Cycle. This new gas turbine combined cycle system increases thermal performance to the 60% level by increasing gas turbine operating conditions to 2600°F (1430°C) at a pressure ratio of 23 to 1. This represents a significant increase in operating temperature for the gas turbine. However, the potential for single digit NOx levels (based upon 15% O2 in the exhaust) has been retained. The combined effect of performance increase and environmental control is achieved by an innovative closed loop steam cooling system which tightly integrated the gas turbine and steam turbine cycles. Although a significant advance has been taken in performance, the new power generation system has been configured with a substantial number of proven concepts and technology programs are ongoing to validate the new features. The technical activities which support the introduction of the new turbine system have reached a point in the development cycle where the results are integrated into the design methods. This has permitted the “H” Technology to achieve a design readiness status and the first unit will be under test in late 1997.

Proposal of Innovative Gas Turbine Combined Cycle Power Generation System

2004 ◽  
Author(s):  
Hideto Moritsuka
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Generation System ◽  
Turbine Inlet Temperature ◽  
Turbine Inlet ◽  
Power Generation System

In order to estimate the possibility to improve thermal efficiency of power generation use gas turbine combined cycle power generation system, benefits of employing the advanced gas turbine technologies proposed here have been made clear based on the recently developed 1500C-class steam cooling gas turbine and 1300C-class reheat cycle gas turbine combined cycle power generation systems. In addition, methane reforming cooling method and NO reducing catalytic reheater are proposed. Based on these findings, the Maximized efficiency Optimized Reheat cycle Innovative Gas Turbine Combined cycle (MORITC) Power Generation System with the most effective combination of advanced technologies and the new devices have been proposed. In case of the proposed reheat cycle gas turbine with pressure ratio being 55, the high pressure turbine inlet temperature being 1700C, the low pressure turbine inlet temperature being 800C, combined with the ultra super critical pressure, double reheat type heat recovery Rankine cycle, the thermal efficiency of combined cycle are expected approximately 66.7% (LHV, generator end).

EFFECT OF OPERATING VARIABLES ON THE PERFORMANCE OF A COMBINED CYCLE COGENERATION SYSTEM WITH MULTIPLE PROCESS HEATERS

2009 ◽  
Vol 33 (1) ◽  
pp. 65-74
Author(s):  
B Law ◽  
B. V. Reddy
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Operating Variables ◽  
Cogeneration System ◽  
Multiple Process ◽  
Process Heat ◽  
Topping Cycle

Combined cycle power plants with a gas turbine topping cycle and a steam turbine bottoming cycle are widely used due to their high efficiencies. Combined cycle cogeneration has the possibility to produce power and process heat more efficiently, leading to higher performance and reduced green house gas emissions. The objective of the present work is to analyze and simulate a natural gas fired combined cycle cogeneration unit with multiple process heaters and to investigate the effect of operating variables on the performance. The operating conditions investigated include, gas turbine pressure ratio, process heat loads and process steam extraction pressure. The gas turbine pressure ratio significantly influences the performance of the combined cycle cogeneration system. It is also identified that extracting process steam at lower pressures improves the power generation and cogeneration efficiencies. The process heat load influences combined cycle efficiency and combined cycle cogeneration efficiency in opposite ways. It is also observed that using multiple process heaters with different process steam pressures, rather than a single process heater, improves the combined cycle cogeneration plant efficiency.

Development of a New Simulation Program for Combined Cycle System

2002 ◽  
Author(s):  
Sepehr Sanaye ◽  
Arash Moradi
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Simulation Program ◽  
Specific Power ◽  
Maximum Efficiency ◽  
Gas Temperature ◽  
Cycle System ◽  
Compressor Inlet ◽  
And Performance

The turbine inlet gas temperature ( Toso ) is an important parameter in design and performance analysis of gas turbine cycles. By increasing Toso, air bleeding for blade cooling increases and it can be about 25 percent of compressor inlet air mass flow rate for Toso equal to 1600 K. Therefore air bleeding has an important impact on thermal efficiency, specific power output and the optimum compressor pressure ratio at which maximum efficiency occurs. For the gas turbine part of a combined cycle, these performance curves are obtained and shown using a developed simulation program (GTE). Also for heat recovery steam generator (HRSG) part of a combined cycle plant, HRSG simulates the transient and steady state temperature distribution of hot gases, steam and tube metal at different parts of HRSG. Any number of pressure levels (high, intermediate and low) and heating elements (superheater, evaporator and economizer) including desuperheater and deaerator can be included. GTE outputs show less than two percent difference from reported measured values. This difference was less than six percent for HRSG model.

Enhancing Energy and Economic Performances of Combined Cycle Power Plants by Means of Gas-Cycle Regeneration

2014 ◽  
Author(s):  
Roberto Carapellucci ◽  
Lorena Giordano
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Waste Heat ◽  
Pressure Ratio ◽  
Unit Cost ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Efficiency Gain ◽  
Gas Power Plant

Efficiency improvement in the gas turbine sector has been mainly driven by increasing the turbine inlet temperature and compressor pressure ratio. For a fixed technology level, a further efficiency gain can be achieved through the utilization of waste thermal energy. Regeneration is an internal recovery technique that allows the reduction of heat input required at combustor, by preheating the air at compressor outlet. Under certain operating conditions, the temperature of exhaust gas leaving the regenerator is still enough high to allow the steam production via an heat recovery steam generator (HRSG). Regeneration in steam-gas power plants (CCGT) has the potential to enhance thermal efficiency, but reduces the margins for external recovery and then the bottoming steam cycle capacity. Moreover, the reduction of exhausts temperature at gas turbine outlet requires the reconsideration of HRSG operating parameters, in order to limit the increase of waste heat at the stack. The aim of this study is to explore the potential benefits that regeneration in the gas cycle gives on the whole steam-gas power plant. The extent of energy and economic performances improvement is evaluated, varying the gas turbine specifications and the layout and operating conditions of HRSG. Hence simple and regenerative configurations based on single and multi-pressure HRSG are compared, focusing on efficiency, specific CO2 emissions and unit cost of electricity (COE).

Energy and Exergy Analyses of a Natural Gas Fired Combined Cycle Cogeneration System

2007 ◽  
Author(s):  
B. Law ◽  
B. V. Reddy
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Operating Variables ◽  
Energy And Exergy ◽  
Cogeneration System ◽  
Multiple Process ◽  
Process Heat

Combined cycle cogeneration systems have the ability to produce power and process heat more efficiently, leading to higher performance and reduced green house gas emissions. In the present work the performance of a natural gas fired combined cycle cogeneration unit with multiple process heaters is investigated to study the effect of operating variables on the performance. The operating conditions investigated include, gas turbine pressure ratio, process heat loads and process steam extraction pressure. The gas turbine pressure ratio significantly influences the performance of the combined cycle cogeneration system. The process heat load influences combined cycle efficiency and combined cycle cogeneration efficiency in opposite ways. The exergy analysis is conducted to identify the exergy destruction and losses in different components of the combined cycle cogeneration unit.

Performance Simulation of a Combined Cycle Power Generation System With Steam Injection in the Gas Turbine Combustion Chamber

2007 ◽  
Author(s):  
B. Law ◽  
B. V. Reddy
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pressure Ratio ◽  
Steam Injection ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Work Output ◽  
Gas Turbine Combustion

In the present work the effect of steam injection in the gas turbine combustion chamber is investigated on gas turbine and steam turbine work output and on thermal efficiency of the combined cycle power plant. The operating conditions investigated include gas turbine pressure ratio and gas turbine inlet temperature. The steam injection decreases the steam cycle output and boosts the gas cycle output and the net combined cycle work output and thermal efficiency significantly.

Integration of a Pressurized-Air Solar Receiver Array to a Gas Turbine Power Cycle for Solar Tower Applications

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Peter Poživil ◽  
Aldo Steinfeld
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Rankine Cycle ◽  
Power Input ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Brayton Cycle ◽  
Power Cycle ◽  
Receiver Array ◽  
Solar Receiver

The thermal performance of an array of pressurized-air solar receiver modules integrated to a gas turbine power cycle is analyzed for a simple Brayton cycle (BC), recuperated Brayton cycle (RC), and combined Brayton–Rankine cycle (CC). While the solar receiver's solar-to-heat efficiency decreases at higher operating temperatures and pressures, the opposite is true for the power cycle's heat-to-work efficiency. The optimal operating conditions are achieved with a preheat stage for a solar receiver outlet air temperature of 1300 °C and an air cycle pressure ratio of 9, yielding a peak solar-to-electricity efficiency—defined as the ratio of the net cycle work output divided by the solar radiative power input through the receiver's aperture—of 39.3% for the combined cycle configuration.

Evaluation of Impact Loads of Clutch Engaging Within Single Shaft Applications for Power Generation

2008 ◽  
Author(s):  
Bernd Lu¨neburg ◽  
Meinolf Klocke ◽  
Stefan Kulig ◽  
Frank Joswig
Keyword(s):  
Power Generation ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Impact Loading ◽  
Power Plants ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Mass Model ◽  
Inertia Effects ◽  
The Impact

Combined Cycle Power Plants (CCPP) in single shaft arrangements consist of a gas turbine, a generator and a steam turbine on one shaft line. In order to enhance the plant availability and operational flexibility, Siemens Fossil Power Generation introduces a switchable clutch between steam turbine and generator. The clutch is a synchronous self-shifting device that engages automatically at rated speed as soon as the steam turbine overruns the gas turbine-generator. It disengages automatically when the steam turbine speed drops below the speed of the gas turbine. A rather complicated mechanism consisting pawls and ratchets and a thread of helical splines including damper mechanisms is used to provide the required coupling functions. The primary reason for the clutch is to ensure independent gas turbine and steam turbine operation below steam turbine rated speed. The clutch is especially advantageous during startup and gas turbine simple-cycle operation. Next to these advantages, the clutch engaging processes could introduce significant impact loading to the shaft components which differ from other. Next to the normal engaging process fault cases like engaging processes after gas turbine trip at high acceleration values due to the gas turbine compressor losses must be sustained by all rotor train components. This paper documents a nonlinear torsional analysis of the single shaft arrangement to assess the impact loading due to clutch engaging processes. A dynamic three-mass-model of the clutch including nonlinear stiffness and damping functions is set up and applied for the simulations. The coupling of the translatory and the rotatory inertia effects of the main sliding component of the clutch has been taken into account. Different load case scenarios in different single shaft component arrangements respectively different inertia ranges of the steam turbine rotor train are investigated in detail by the transient analyses. Based on this procedure, it is ensured that the mechanical layout of the single shaft components is sufficiently designed to withstand all operational loads under normal and faulty operating conditions.

Siemens SGT-800 Industrial Gas Turbine Enhanced to 50MW: Combustor Design Modifications, Validation and Operation Experience

2013 ◽  
Author(s):  
Daniel Lörstad ◽  
Annika Lindholm ◽  
Jan Pettersson ◽  
Mats Björkman ◽  
Ingvar Hultmark
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Cooling System ◽  
Good Condition ◽  
Combined Cycle ◽  
Combustion Stability ◽  
Combustion System ◽  
Design Work ◽  
Engine Operation ◽  
Cooling Air

Siemens Oil & Gas introduced an enhanced SGT-800 gas turbine during 2010. The new power rating is 50.5MW at a 38.3% electrical efficiency in simple cycle (ISO) and best in class combined-cycle performance of more than 55%, for improved fuel flexibility at low emissions. The updated components in the gas turbine are interchangeable from the existing 47MW rating. The increased power and improved efficiency are mainly obtained by improved compressor airfoil profiles and improved turbine aerodynamics and cooling air layout. The current paper is focused on the design modifications of the combustor parts and the combustion validation and operation experience. The serial cooling system of the annular combustion chamber is improved using aerodynamically shaped liner cooling air inlet and reduced liner rib height to minimize the pressure drop and optimize the cooling layout to improve the life due to engine operation hours. The cold parts of the combustion chamber were redesigned using cast cooling struts where the variable thickness was optimized to maximize the cycle life. Due to fewer thicker vanes of the turbine stage #1, the combustor-turbine interface is accordingly updated to maintain the life requirements due to the upstream effect of the stronger pressure gradient. Minor burner tuning is used which in combination with the previously introduced combustor passive damping results in low emissions for >50% load, which is insensitive to ambient conditions. The combustion system has shown excellent combustion stability properties, such as to rapid load changes and large flame temperature range at high loads, which leads to the possibility of single digit Dry Low Emission (DLE) NOx. The combustion system has also shown insensitivity to fuels of large content of hydrogen, different hydrocarbons, inerts and CO. Also DLE liquid operation shows low emissions for 50–100% load. The first SGT-800 with 50.5MW rating was successfully tested during the Spring 2010 and the expected performance figures were confirmed. The fleet leader has, up to January 2013, accumulated >16000 Equivalent Operation Hours (EOH) and a planned follow up inspection made after 10000 EOH by boroscope of the hot section showed that the combustor was in good condition. This paper presents some details of the design work carried out during the development of the combustor design enhancement and the combustion operation experience from the first units.

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