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 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.

Combined Heat and Power: Gas Turbine Operational Flexibility

2013 ◽  
Author(s):  
James DiCampli
Keyword(s):  
Gas Turbine ◽  
Urban Areas ◽  
Gas Turbines ◽  
Heat Recovery ◽  
National Fire Protection Association ◽  
Combined Heat And Power ◽  
Combined Cycle ◽  
Electricity Production ◽  
Exhaust Heat ◽  
Gas Fuel

Combined heat and power (CHP) is an application that utilizes the exhaust heat generated from a gas turbine and converts it into a useful energy source for heating & cooling, or additional electric generation in combined cycle configurations. Compared to simple-cycle plants with no heat recovery, CHP plants emit fewer greenhouse gasses and other emissions, while generating significantly more useful energy per unit of fuel consumed. Clean plants are easier to permit, build and operate. Because of these advantages, projections show CHP capacity is expected to double and account for 24% of global electricity production by 2030. An aeroderivative power plant has distinct advantages to meet CHP needs. These include high thermal efficiency, low cost, easy installation, proven reliability, compact design for urban areas, simple operation and maintenance, fuel flexibility, and full power generation in a very short time period. There has been extensive discussion and analyses on modifying purge requirements on cycling units for faster dispatch. The National Fire Protection Association (NFPA) has required an air purge of downstream systems prior to startup to preclude potentially flammable or explosive conditions. The auto ignition temperature of natural gas fuel is around 800°F. Experience has shown that if the exhaust duct contains sufficient concentrations of captured gas fuel, and is not purged, it can ignite immediately during light off causing extensive damage to downstream equipment. The NFPA Boiler and Combustion Systems Hazards Code Committee have developed new procedures to safely provide for a fast-start capability. The change in the code was issued in the 2011 Edition of NFPA 85 and titled the Combustion Turbine Purge Credit. For a cycling plant and hot start conditions, implementation of purge credit can reduce normal start-to-load by 15–30 minutes. Part of the time saving is the reduction of the purge time itself, and the rest is faster ramp rates due to a higher initial temperature and pressure in the heat recovery steam generator (HRSG). This paper details the technical analysis and implementation of the NFPA purge credit recommendations on GE Power and Water aeroderivative gas turbines. This includes the hardware changes, triple block and double vent valve system (or drain for liquid fuels), and software changes that include monitoring and alarms managed by the control system.

Parameterization of High Solar Share Gas Turbine Systems

2012 ◽  
Author(s):  
Stephan Heide ◽  
Christian Felsmann ◽  
Uwe Gampe ◽  
Sven Boje ◽  
Bernd Gericke ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Planning Process ◽  
Pressure Ratio ◽  
Thermal Power ◽  
Combined Cycle ◽  
Process Models ◽  
Solar Thermal ◽  
Thermal Power Plants ◽  
Solar Thermal Power

Existing solar thermal power plants are based on steam turbine cycles. While their process temperature is limited, solar gas turbine (GT) systems provide the opportunity to utilize solar heat at a much higher temperature. Therefore there is potential to improve the efficiency of future solar thermal power plants. Solar based heat input to substitute fuel requires specific GT features. Currently the portfolio of available GTs with these features is restricted. Only small capacity research plants are in service or in planning. Process layout and technology studies for high solar share GT systems have been carried out and have already been reported by the authors. While these investigations are based on a commercial 10MW class GT, this paper addresses the parameterization of high solar share GT systems and is not restricted to any type of commercial GT. Three configurations of solar hybrid GT cycles are analyzed. Besides recuperated and simple GT with bottoming Organic Rankine Cycle (ORC), a conventional combined cycle is considered. The study addresses the GT parameterization. Therefore parametric process models are used for simulation. Maximum electrical efficiency and associated optimum compressor pressure ratio πC are derived at design conditions. The pressure losses of the additional solar components of solar hybrid GTs have a different adversely effect on the investigated systems. Further aspects like high ambient temperature, availability of water and influence of compressor pressure level on component design are discussed as well. The present study is part of the R&D project Hybrid High Solar Share Gas Turbine Systems (HYGATE) which is funded by the German Ministry for the Environment, Nature and Nuclear Safety and the Ministry of Economics and Technology.

scholarly journals Thermodynamic and Techno-Economic Analyses of a Combined Cycle Power Plant With a Simple Cycle Gas Turbine, the Bottoming Air Turbine Cycle and the Reverse Brayton Cycle

1999 ◽  
Author(s):  
Isaac Shnaid
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Combined Cycle ◽  
Simple Cycle ◽  
Brayton Cycle ◽  
Cycle System ◽  
Air Turbine ◽  
Attractive Option ◽  
Gas Turbine Exhaust ◽  
Economic Analyses

The modem combined cycle power plants achieved thermal efficiency of 50–55% by applying bottoming multistage Rankine steam cycle. At the same time, the Brayton cycle is an attractive option for a bottoming cycle engine. In the author’s US Patent No. 5,442,904 is described a combined cycle system with a simple cycle gas turbine, the bottoming air turbine Brayton cycle, and the reverse Brayton cycle. In this system, air turbine Brayton cycle produces mechanic power using exergy of gas turbine exhaust gases, while the reverse Brayton cycle refrigerates gas turbine inlet air. Using this system, supercharging of gas turbine compressor becomes possible. In the paper, thermodynamic optimization of the system is done, and the system techno-economic characteristics are evaluated.

scholarly journals Rotary Adsorption: Selective Recycling of CO2 in Combined Cycle Gas Turbine Power Plants

2020 ◽  
Vol 8 ◽  
Author(s):  
Laura Herraiz ◽  
Erika Palfi ◽  
Eva Sánchez Fernández ◽  
Mathieu Lucquiaud
Keyword(s):  
Activated Carbon ◽  
Pressure Drop ◽  
Gas Turbine ◽  
Power Plants ◽  
Ambient Pressure ◽  
Ambient Air ◽  
Combined Cycle ◽  
Flue Gases ◽  
Design Assessment ◽  
Exponential Factor

A conceptual design assessment shows that the use of structured adsorbents in a regenerative adsorption wheel is technically feasible for the application of selective exhaust gas recirculation (SEGR) in combined cycle gas turbine (CCGT) power plants. As the adsorber rotates, CO2 is selectively transferred from a flue gas stream to an ambient air stream fed to the gas turbine compressor, increasing the CO2 concentration and reducing the flow rate of the fraction of the flue gases treated in a post-combustion CO2 capture system. It imposes an estimated pressure drop of 0.25 kPa, unlike a pressure drop of 10 kPa reported for selective CO2 membrane systems, preventing a significant derating of the gas turbine. An equilibrium model of a rotary adsorber with commercially available activated carbon evaluates the inventory of the adsorbent and sizes the wheel rotor. Two rotary wheels of 24 m diameter and 2 m length are required per gas turbine—heat recovery steam generator train to achieve an overall CO2 capture level of 90% in a CCGT power plant (ca. 820 MWe) with SEGR “in parallel” to the capture plant. Two to five rotary wheels are required for a configuration with SEGR “in series” to the capture plant. A reduction of 50% in the mass of the adsorbent would be possible with Zeolite 13X instead of activated carbon, yet the hydrophilicity of zeolites are detrimental to the capacity and upstream dehydration of the flue gases is required. A parametric analysis of the equilibrium properties provides guidelines for adsorbent development. It suggests the importance of balancing the affinity for CO2 to allow the regeneration of the adsorbent with air at near ambient pressure and temperature, to minimise the inventory of the adsorbent within practical limits. An adsorbent with a saturation capacity of 8 mol/kg, a heat of adsorption from 24 to 28 kJ/mol CO2 and a pre-exponential factor of the equilibrium constant from 2 × 10–6 to 9 × 10–6 kPa−1 would result in an inventory below 200 kg, i.e., approximately the limit for the use of a single rotary wheel system.

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.

Repowering: An Option for Refurbishment of Old Thermal Power Plants in Latin-American Countries

2010 ◽  
Author(s):  
Washington Orlando Irrazabal Bohorquez ◽  
Joa˜o Roberto Barbosa ◽  
Luiz Augusto Horta Nogueira ◽  
Electo E. Silva Lora
Keyword(s):  
Power Plant ◽  
Natural Gas ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Power Plants ◽  
Thermal Power ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Fuel Oil ◽  
Thermal Power Plants

The operational rules for the electricity markets in Latin America are changing at the same time that the electricity power plants are being subjected to stronger environmental restrictions, fierce competition and free market rules. This is forcing the conventional power plants owners to evaluate the operation of their power plants. Those thermal power plants were built between the 1960’s and the 1990’s. They are old and inefficient, therefore generating expensive electricity and polluting the environment. This study presents the repowering of thermal power plants based on the analysis of three basic concepts: the thermal configuration of the different technological solutions, the costs of the generated electricity and the environmental impact produced by the decrease of the pollutants generated during the electricity production. The case study for the present paper is an Ecuadorian 73 MWe power output steam power plant erected at the end of the 1970’s and has been operating continuously for over 30 years. Six repowering options are studied, focusing the increase of the installed capacity and thermal efficiency on the baseline case. Numerical simulations the seven thermal power plants are evaluated as follows: A. Modified Rankine cycle (73 MWe) with superheating and regeneration, one conventional boiler burning fuel oil and one old steam turbine. B. Fully-fired combined cycle (240 MWe) with two gas turbines burning natural gas, one recuperative boiler and one old steam turbine. C. Fully-fired combined cycle (235 MWe) with one gas turbine burning natural gas, one recuperative boiler and one old steam turbine. D. Fully-fired combined cycle (242 MWe) with one gas turbine burning natural gas, one recuperative boiler and one old steam turbine. The gas turbine has water injection in the combustion chamber. E. Fully-fired combined cycle (242 MWe) with one gas turbine burning natural gas, one recuperative boiler with supplementary burners and one old steam turbine. The gas turbine has steam injection in the combustion chamber. F. Hybrid combined cycle (235 MWe) with one gas turbine burning natural gas, one recuperative boiler with supplementary burners, one old steam boiler burning natural gas and one old steam turbine. G. Hybrid combined cycle (235 MWe) with one gas turbine burning diesel fuel, one recuperative boiler with supplementary burners, one old steam boiler burning fuel oil and one old steam turbine. All the repowering models show higher efficiency when compared with the Rankine cycle [2, 5]. The thermal cycle efficiency is improved from 28% to 50%. The generated electricity costs are reduced to about 50% when the old power plant is converted to a combined cycle one. When a Rankine cycle power plant burning fuel oil is modified to combined cycle burning natural gas, the CO2 specific emissions by kWh are reduced by about 40%. It is concluded that upgrading older thermal power plants is often a cost-effective method for increasing the power output, improving efficiency and reducing emissions [2, 7].

Dual Pressure Steam/Immiscible Liquid Cycles for Gas Turbine Exhaust Heat Recovery

1982 ◽  
Vol 104 (1) ◽  
pp. 77-83
Author(s):  
B. M. Burnside
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Immiscible Liquid ◽  
Heat Extraction ◽  
Exhaust Heat ◽  
Pressure Steam ◽  
Percent Increase ◽  
Combined Cycles ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

A dual pressure steam/immiscible liquid cycle gas turbine bottoming plant is described. Three variants of the cycle are analysed. It is shown that under typical conditions one of these shows a 5 percent higher output than the conventional steam/steam cycle with only a 5 percent increase in heat extraction from the gas turbine exhaust. A larger LP preheater and condenser are required. Attention is drawn to the flexibility this type of cycle brings to the task of matching bottoming plant to gas turbine exhaust of combined cycles.

Development of a Maintenance Program for Major Gas Turbine Hot Gas Path Parts

2000 ◽  
Author(s):  
Hideto Moritsuka ◽  
Tomoharu Fujii ◽  
Takeshi Takahashi
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Thermal Power ◽  
Management Program ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Maintenance Schedule ◽  
Hot Gas ◽  
Turbine Inlet

The thermal efficiency of gas turbine combined cycle power generation plants increase significantly in accordance with turbine inlet temperature. Gas turbine combined cycle power plants operating at high turbine inlet temperature are popular as a main thermal power station among our electric power companies in Japan. Thus, gas turbine hot gas parts are working under extreme conditions which will strongly affect their lifetime as well as maintenance costs for repaired and replaced parts. To reduce the latter is of major importance to enhance cost effectiveness of the plant. This report describes a gas turbine maintenance management program of main hot gas parts (combustor chambers, transition peices, turbine 1st. stage nozzles and 1st. stage buckets) for management persons of gas turbine combined cycle power stations in order to obtain an optimal gas turbine maintenance schedule considering rotation, repair and replacement or exchange of those parts.

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