Quality Key Numbers of Gas Turbine Combined Cycles

2020 ◽  
Author(s):  
Hans E. Wettstein
Keyword(s):  
Gas Turbine ◽  
Quality Level ◽  
Published Data ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Contemporary History ◽  
Cooling Design ◽  
Combined Cycles ◽  
Exergy Losses ◽  
Turbine Blading

Abstract The most relevant quality key numbers for the largest and most efficient Gas Turbine Combined Cycles (GTCC) are not (only) the data published by the original engine manufacturers OEM’s. Additional numbers are here evaluated with educated guesses based on published data of the latest announcements of the “big four OEM’s” [8]. Such data are of interest for potential customers but also for nailing down the current state-of-the-art for all kind of further cycle studies using turbomachinery components and also as a contemporary history record. Making educated guesses means thermodynamic 1D simulation based on additional assumptions for pressure losses and other cycle data, which have a limited influence on the (unpublished) target quality numbers, such as: • Mixed turbine inlet temperature Tmix. This is a key value describing the technology level. It can be derived independently of the (unpublished) TCLA value. It is a quality number for the general cooling design and for the secondary air systems. • Polytropic efficiency of the compressor blading. This number describes the aerodynamic quality of the compressor blading. • Polytropic efficiency of the turbine blading. It describes the quality level of both the blading aerodynamics and of the open air cooling design. • Distribution of the exergy losses within the GT and in the bottoming cycle. The exergy losses describe the remaining opportunities for further improvements in the thermodynamic cycle design. But they also indicate its limits. However already the determination of the Tmix is tricky. It depends on the analysis method and on the fluid data applied. The polytropic efficiency of the turbine blading and the exergy losses will depend both on the used methods and on the Tmix found. Achieving a trustable result therefore requires a transparent and reproducible method. In case of application of the found results for performance prediction of similar cycles the same method has to be applied in order to avoid mistakes. In this paper real gas data with consideration of dissociation in equilibrium are used, while the polytropic efficiencies are determined with an incremental method based directly on the classic definitions of Stodola [3] and Dzung [4]. Therefore the still most used method using semi-perfect gas properties and corresponding formulas is bypassed. In order to keep it as simple as possible the evaluation is limited to base load at ISO ambient condition (15°C, 60% relative humidity, sea level). The fuel is limited to pure methane according to the practice in current catalogue data. The main focus is on the gas turbine with its components. The steam bottoming cycle is captured with its effect on the overall exergy and energy balance of the GTCC, which identifies exhaust and condensation losses.

Thermodynamic Performance of Complex Gas Turbine Cycles

2002 ◽  
Author(s):  
Sanjay ◽  
Onkar Singh ◽  
B. N. Prasad
Keyword(s):  
Gas Turbine ◽  
Specific Power ◽  
Turbine Engines ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Gas Turbine Engines ◽  
Current State ◽  
Thermodynamic Performance ◽  
Internal Convection ◽  
Plant Efficiency

This paper deals with the thermodynamic performance of complex gas turbine cycles involving inter-cooling, re-heating and regeneration. The performance has been evaluated based on the mathematical modeling of various elements of gas turbine for the real situation. The fuel selected happens to be natural gas and the internal convection / film / transpiration air cooling of turbine bladings have been assumed. The analysis has been applied to the current state-of-the-art gas turbine technology and cycle parameters in four classes: Large industrial, Medium industrial, Aero-derivative and Small industrial. The results conform with the performance of actual gas turbine engines. It has been observed that the plant efficiency is higher at lower inter-cooling (surface), reheating and regeneration yields much higher efficiency and specific power as compared to simple cycle. There exists an optimum overall compression ratio and turbine inlet temperature in all types of complex configuration. The advanced turbine blade materials and coating withstand high blade temperature, yields higher efficiency as compared to lower blade temperature materials.

Advanced and Transformational Hydrogen Turbines for Integrated Gasification Combined Cycles

2016 ◽  
Author(s):  
Walter W. Shelton ◽  
Robin W. Ames ◽  
Richard A. Dennis ◽  
Charles W. White ◽  
John E. Plunkett ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Carbon Capture ◽  
Combined Cycle ◽  
Plant Performance ◽  
System Level ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Reference Case ◽  
Advanced Technologies ◽  
Integrated Gasification

The U.S. Department of Energy’s (DOE) provides a worldwide leadership role in the development of advanced fossil fuel-based energy conversion technologies, with a focus on electric power generation with carbon capture and storage (CCS). As part of DOE’s Office of Fossil Energy, the National Energy Technology Laboratory (NETL) implements research, development, and demonstration (RD&D) programs that address the challenges of reducing greenhouse gas emissions. To meet these challenges, NETL evaluates advanced power cycles that will maximize system efficiency and performance, while minimizing CO2 emissions and the costs of CCS. NETL’s Hydrogen Turbine Program has sponsored numerous R&D projects in support of Advanced Hydrogen Turbines (AHT). Turbine systems and components targeted for development include combustor technology, materials research, enhanced cooling technology, coatings development, and more. The R&D builds on existing gas turbine technologies and is intended to develop and test the component technologies and subsystems needed to validate the ability to meet the Turbine Program goals. These technologies are key components of AHTs, which enable overall plant efficiency and cost of electricity (COE) improvements relative to an F-frame turbine-based Integrated Gasification Combined Cycle (IGCC) reference plant equipped with carbon capture (today’s state-of-the-art). This work has also provided the basis for estimating future IGCC plant performance based on a Transformational Hydrogen Turbine (THT) with a higher turbine inlet temperature, enhanced material capabilities, reduced air cooling and leakage, and higher pressure ratios than the AHT. IGCC cases from using system-level AHT and THT gas turbine models were developed for comparisons with an F-frame turbine-based IGCC reference case and for an IGCC pathway study. The IGCC pathway is presented in which the reference case (i.e. includes F-frame turbine) is sequentially-modified through the incorporation of advanced technologies. Advanced technologies are considered to be either 2nd Generation or Transformational, if they are anticipated to be ready for demonstration by 2025 and 2030, respectively. The current results included the THT, additional potential transformational technologies related to IGCC plant sections (e.g. air separation, gasification, gas cleanup, carbon capture, NOx reduction) are being considered by NETL and are topics for inclusion in future reports.

scholarly journals Thermal Performance and Efficiency of a Mineral Oil Immersed Server Over Varied Environmental Operating Conditions

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Richard Eiland ◽  
John Edward Fernandes ◽  
Marianna Vallejo ◽  
Ashwin Siddarth ◽  
Dereje Agonafer ◽  
...  
Keyword(s):  
Flow Rate ◽  
Thermal Performance ◽  
Data Center ◽  
Mineral Oil ◽  
Operating Conditions ◽  
Published Data ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Bulk Fluid ◽  
Oil Immersion

Complete immersion of servers in dielectric mineral oil has recently become a promising technique for minimizing cooling energy consumption in data centers. However, a lack of sufficient published data and long-term documentation of oil immersion cooling performance make most data center operators hesitant to apply these approaches to their mission critical facilities. In this study, a single server was fully submerged horizontally in mineral oil. Experiments were conducted to observe the effects of varying the volumetric flow rate and oil inlet temperature on thermal performance and power consumption of the server. Specifically, temperature measurements of the central processing units (CPUs), motherboard (MB) components, and bulk fluid were recorded at steady-state conditions. These results provide an initial bounding envelope of environmental conditions suitable for an oil immersion data center. Comparing with results from baseline tests performed with traditional air cooling, the technology shows a 34.4% reduction in the thermal resistance of the system. Overall, the cooling loop was able to achieve partial power usage effectiveness (pPUECooling) values as low as 1.03. This server level study provides a preview of possible facility energy savings by utilizing high temperature, low flow rate oil for cooling. A discussion on additional opportunities for optimization of information technology (IT) hardware and implementation of oil cooling is also included.

Analysis of Intermediate Temperature Combined Cycles With a Carbon Dioxide Topping Cycle

2008 ◽  
Author(s):  
R. Chacartegui ◽  
D. Sa´nchez ◽  
F. Jime´nez-Espadafor ◽  
A. Mun˜oz ◽  
T. Sa´nchez
Keyword(s):  
Carbon Dioxide ◽  
Power Plant ◽  
Gas Turbine ◽  
High Efficiency ◽  
Solar Power ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Pressure Drops ◽  
Combined Cycles ◽  
Topping Cycle

The development of high efficiency solar power plants based on gas turbine technology presents two problems, both of them directly associated with the solar power plant receiver design and the power plant size: lower turbine intake temperature and higher pressure drops in heat exchangers than in a conventional gas turbine. To partially solve these problems, different configurations of combined cycles composed of a closed cycle carbon dioxide gas turbine as topping cycle have been analyzed. The main advantage of the Brayton carbon dioxide cycle is its high net shaft work to expansion work ratio, in the range of 0.7–0.85 at supercritical compressor intake pressures, which is very close to that of the Rankine cycle. This feature will reduce the negative effects of pressure drops and will be also very interesting for cycles with moderate turbine inlet temperature (800–1000 K). Intercooling and reheat options are also considered. Furthermore, different working fluids have been analyzed for the bottoming cycle, seeking the best performance of the combined cycle in the ranges of temperatures considered.

Comparative Analysis of Different Inlet Air Cooling Technologies Including Solar Energy to Boost Gas Turbine Combined Cycles in Hot Regions

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Ahmed Abdel Rahman ◽  
Esmail M. A. Mokheimer
Keyword(s):  
Comparative Analysis ◽  
Gas Turbine ◽  
Output Power ◽  
Power Output ◽  
Combined Cycle ◽  
Air Cooling ◽  
Absorption Chiller ◽  
Absorption Chillers ◽  
Combined Cycles ◽  
Net Power Output

Cooling the air before entering the compressor of a gas turbine of combined cycle power plants is an effective method to boost the output power of the combined cycles in hot regions. This paper presents a comparative analysis for the effect of different air cooling technologies on increasing the output power of a combined cycle. It also presents a novel system of cooling the gas turbine inlet air using a solar-assisted absorption chiller. The effect of ambient air temperature and relative humidity on the output power is investigated and reported. The study revealed that at the design hour under the hot weather conditions, the total net power output of the plant drops from 268 MW to 226 MW at 48 °C (15.5% drop). The increase in the power output using fogging and evaporative cooling is less than that obtained with chillers since their ability to cool down the air is limited by the wet-bulb temperature. Integrating conventional and solar-assisted absorption chillers increased the net power output of the combined cycle by about 35 MW and 38 MW, respectively. Average and hourly performance during typical days have been conducted and presented. The plants without air inlet cooling system show higher carbon emissions (0.73 kg CO2/kWh) compared to the plant integrated with conventional and solar-assisted absorption chillers (0.509 kg CO2/kWh) and (0.508 kg CO2/kWh), respectively. Also, integrating a conventional absorption chiller shows the lowest capital cost and levelized electricity cost (LEC).

Comparative Investigation of Advanced Combined Cycles

2006 ◽  
Author(s):  
Hiwa Khaledi ◽  
Kazem Sarabchi
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Air Cooling ◽  
Actual Behavior ◽  
Exhaust Temperature ◽  
Blade Cooling ◽  
Large Influence ◽  
Combined Cycles ◽  
Cooling Technology ◽  
Turbine Exhaust

Combined cycles, at present, have a prominent role in the power generation and advanced combined cycles efficiencies have now reached to 60 percent. Examination of thermodynamic behavior of these cycles is still carried out to determine optimum configuration and optimum design conditions for any cycle arrangement. Actually the performance parameters of these cycles are under the influence of various parameters and therefore the recognition of the optimum conditions is quiet complicated. In this research an extensive thermodynamic model was developed for analyzing major parameters variations on gas turbine performance and different configurations of advanced steam cycles: dual and triple pressure cycles with and without reheating in steam turbine sections. In this model it is attempted to consider all factors that affect on actual behavior of these cycles such as blade cooling (air cooling) in gas turbine and different formulations for Heat Recovery Steam Generator (HRSG) performance calculation. Results show good agreement with manufactures data. In the case of gas turbine cycle, location of coolant extraction has large influence on cycle performance. For extraction from compressor end, improving blade cooling technology is suitable than increasing TIT. For mid stage extraction, improving blade cooling technology and TIT has similar effects on efficiency, while power is more sensitive to TIT. Coolant air precooling has large positive effect in high TIT and medium blade cooling technology, but always it increases power. Turbine exhaust temperature has large influence on optimum layout and configuration of HRSG, while for low exhaust temperatures increasing number of pressure levels increase power and heat recovery greatly, for high exhaust temperatures this leads lower enhancement in power and recovery. Second law efficiency of HRSG is proportional to power production in steam cycle. It decreases with increasing gas turbine exhaust temperature.

On Thermodynamics of Gas-Turbine Cycles: Part 3—Thermodynamic Potential and Limitations of Cooled Reheat-Gas-Turbine Combined Cycles

1986 ◽  
Vol 108 (1) ◽  
pp. 160-168 ◽  
Author(s):  
M. A. El-Masri
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Closed Loop ◽  
Elevated Temperatures ◽  
Pressure Ratio ◽  
Air Cooling ◽  
Full Potential ◽  
Evaporative Water ◽  
Combined Cycles ◽  
Cooling Technology

Reheat gas turbines have fundamental thermodynamic advantages in combined cycles. However, a larger proportion of the turbine expansion path is exposed to elevated temperatures, leading to increased cooling losses. Identifying cooling technologies which minimize those losses is crucial to realizing the full potential of reheat cycles. The strong role played by cooling losses in reheat cycles necessitates their inclusion in cycle optimization. To this end, the models for the thermodynamics of combined cycles and cooled turbines presented in Parts 1 and 2 of this paper have been extended where needed and applied to the analysis of a wide variety of cycles. The cooling methods considered range from established air-cooling technology to methods under current research and development such as air-transpiration, open-loop, and closed-loop water cooling. Two schemes thought worthy of longer-term consideration are also assessed. These are two-phase transpiration cooling and the regenerative thermosyphon. A variety of configurations are examined, ranging from Brayton-cycles to one or two-turbine reheats, with or without compressor intercooling. Both surface intercoolers and evaporative water-spray types are considered. The most attractive cycle configurations as well as the optimum pressure ratio and peak temperature are found to vary significantly with types of cooling technology. Based upon the results of the model, it appears that internal closed-loop liquid cooling offers the greatest potential for midterm development. Hybrid systems with internally liquid-cooled nozzles and traditional air-cooled rotors seem most attractive for the near term. These could be further improved by using steam rather than air for cooling the rotor.

Development of an Air Cooled G Class Gas Turbine (the M501GAC)

2009 ◽  
Author(s):  
Toshishige Ai ◽  
Carlos Koeneke ◽  
Hisato Arimura ◽  
Yoshinori Hyakutake
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Inlet Temperature ◽  
Air Cooling ◽  
National Project ◽  
Commercial Operation ◽  
Steam Cooling ◽  
Verification Test ◽  
Verification Process ◽  
Verification Plan

Mitsubishi Heavy Industries (MHI) G series gas turbine is the industry pioneer in introducing steam cooling technology for gas turbines. The first M501G unit started commercial operation in 1997 and to date, with 62 G units sold, MHI G fleet is the largest steam cooled fleet in the market. The existing commercial fleet includes 35 commercial units with more than 734,000 accumulated actual operating hours, and over 9,400 starts. Upgraded versions have been introduced in the 60 and 50Hz markets (M501G1 and M701G2 respectively). On a different arena, MHI is engaged since 2004 in a Japanese National Project for the development of 1,700°C (3092°F) class gas turbine. Several enhanced technologies developed through this Japanese National Project, including lower thermal conductivity TBC, are being retrofitted to the existing F and G series gas turbines. Retrofitting some of these technologies to the existing M501G1 together with the application of an F class air cooled combustion system will result in an upgraded air-cooled G class engine with increased power output and enhanced efficiency, while maintaining the same 1500°C (2732°F) Turbine Inlet Temperature (TIT). By using an open air cooling scheme, this upgraded machine represents a better match for highly cyclic applications with G class efficiency, while the highly reliable and durable steam cooled counterpart is still offered for more base-loaded applications. After performing various R&D tests, the verification process of the air cooled 60 Hz G gas turbine has moved to component testing in the in-house verification engine. The final verification test prior to commercial operation is scheduled for 2009. This article describes the design features and verification plan of the upgraded M501G gas turbine.

Parametric Analysis of Small Scale Recuperated SOFC/Gas Turbine Cycles

2004 ◽  
Author(s):  
Stefano Campanari
Keyword(s):  
Gas Turbine ◽  
Small Scale ◽  
Quality Level ◽  
Performance Potential ◽  
Sensitivity Assessment ◽  
Wide Range ◽  
Real Performance ◽  
Combined Cycles ◽  
Gas Turbine Power Plant ◽  
Cycle Efficiency

High temperature fuel cells are experiencing an increasing amount of attention thanks to the operation of several prototype plants, including an integrated Solid Oxide Fuel Cell (SOFC) and gas turbine power plant. Several authors estimate that the projected performances of such cycle have the potential of exceeding those of combined cycles, even at a small-scale size and with an extremely low environmental impact. However, performance estimates generally cover a very wide range, with predicted net electric efficiency spanning between 55 and 70%. The reasons for this excessive variety of results is generally hidden into the different quality assumptions which are made for the simulation of cycle components, as well as in the different level of detail considered for the design of the cycle layout. Starting with the detailed analysis of a 55% efficient plant layout proposed by a manufacturer, this paper investigates the effects of the most significant component quality features (efficiencies, losses) on small scale recuperated SOFC hybrid cycles performances, by mean of a sensitivity assessment. The work provides a comprehensive list of cycle components performance assumptions, frequently lacking in the available literature, easily allowing a future comparison with the work of other researchers. The aim of the work is to better focus the real performance potential of such cycles and to evidence the way to achieve the highest projected efficiencies; as a result of the simulations performed, two “advanced scenario” plant configurations are presented and discussed, based also on a second law analysis. The analysis includes a discussion of the effects of different pressure ratios on cycle optimization. Results show the possibility of exceeding 65% (LHV) cycle efficiency, depending on the quality level of cycle components.

Effects of Intake Air Cooling Performance Improvement on a Two-Shaft Laboratory-Scale Gas Turbine Unit

2007 ◽  
Author(s):  
Hussain Al-Madani ◽  
Teoman Ayhan ◽  
Omar Al-Abbasi
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Thermal Efficiency ◽  
Performance Test ◽  
Second Law ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Ambient Conditions ◽  
Proposed Model ◽  
Compressor Inlet

The present study deals with the thermodynamically modelled two-shaft gas turbine system consisting of a cooling unit at the compressor inlet. The system is used to investigate the generated power, thermal efficiency and second law efficiency. The parametric study using this model shows effect of ambient conditions, compressor inlet temperature, and pressure ratios on power output, thermal efficiency and second law efficiency. Theoretical results using the proposed model show that when the compressor inlet temperature is decreased by some kind of cooling systems, the net power output and thermal efficiency increases up to 30% and 23%, respectively. Also, the second law efficiency of the proposed system increases in compression to the specified reference state. It shows that the proposed model is thermodynamically viable. A comparison of the performance test results of the model and the experimental results are in good agreement. The results provide valuable information regarding the gas turbine system and will be useful for designers.

Sign in / Sign up

Export Citation Format

Share Document