Solar Hybrid Combined Cycle Performance Prediction: Influence of GT Model and Spool Arrangement

2012 ◽  
Author(s):  
G. Barigozzi ◽  
G. Bonetti ◽  
G. Franchini ◽  
A. Perdichizzi ◽  
S. Ravelli
Keyword(s):  
Gas Turbine ◽  
Performance Prediction ◽  
Gas Turbines ◽  
Control Strategies ◽  
Rankine Cycle ◽  
Simulation Method ◽  
Power Input ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Solar Field

A modeling procedure was developed to simulate design and off-design operation of Hybrid Solar Gas Turbines in a combined cycle (CC) configuration. The system includes an heliostat field, a receiver and a commercial gas turbine interfaced with a conventional steam Rankine cycle. Solar power input is integrated in the GT combustor by natural gas. Advanced commercial software tools were combined together to get design and off-design performance prediction: TRNSYS® was used to model the solar field and the receiver while the gas turbine and steam cycle simulations were performed by means of Thermoflex®. Three GT models were considered, in the 35–45 MWe range: a single shaft engine (Siemens SGT800) and two two-shaft engines (the heavy-duty GT Siemens SGT750 and the aero derivative GE LM6000 PF). This in order to assess the influence of different GT spool arrangements and control strategies on GT solarization. The simulation method provided an accurate modeling of the daily solar hybrid CC behavior to be compared against the standard CC. The effects of solarization were estimated in terms of electric power and efficiency reduction, fossil fuel saving and solar energy to electricity conversion efficiency.

Solar Hybrid Combined Cycle Performance Prediction Influence of Gas Turbine Model and Spool Arrangements

2012 ◽  
Vol 134 (12) ◽  
Author(s):  
G. Barigozzi ◽  
G. Bonetti ◽  
G. Franchini ◽  
A. Perdichizzi ◽  
S. Ravelli
Keyword(s):  
Gas Turbine ◽  
Performance Prediction ◽  
Gas Turbines ◽  
Control Strategies ◽  
Rankine Cycle ◽  
Simulation Method ◽  
Power Input ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Fuel Savings

A modeling procedure was developed to simulate design and off-design operation of hybrid solar gas turbines in a combined cycle (CC) configuration. The system includes a heliostat field, a receiver, and a commercial gas turbine (GT) interfaced with a conventional steam Rankine cycle. Solar power input is integrated in the GT combustor by natural gas. Advanced commercial software tools were combined together to get design and off-design performance prediction: TRNSYS® was used to model the solar field and the receiver while the gas turbine and steam cycle simulations were performed by means of Thermoflex®. Three GT models were considered, in the 35–45 MW range: a single shaft engine (Siemens SGT-800) and two two-shaft engines (the heavy-duty GT Siemens SGT-750 and the aero derivative GE LM6000 PF). This was in order to assess the influence of different GT spool arrangements and control strategies on GT solarization. The simulation method provided an accurate modeling of the daily solar hybrid CC behavior to be compared against the standard CC. The effects of solarization were estimated in terms of electric power and efficiency reduction, fossil fuel savings, and solar energy-to-electricity conversion efficiency.

Study of Humid Air Gas Turbine System by Experiment and Analysis

2011 ◽  
Author(s):  
Toru Takahashi ◽  
Yutaka Watanabe ◽  
Hidefumi Araki ◽  
Takashi Eta
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pilot Plant ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Medium Size ◽  
Water Recovery ◽  
Two Stage ◽  
Humid Air

Humid air gas turbine systems that are regenerative cycle using humidified air can achieve higher thermal efficiency than gas turbine combined cycle power plant (GTCC) even though they do not require a steam turbine, a high combustion temperature, or a high pressure ratio. In particular, the advanced humid air gas turbine (AHAT) system appears to be highly suitable for practical use because its composition is simpler than that of other systems. Moreover, the difference in thermal efficiency between AHAT and GTCC is greater for small and medium-size gas turbines. To verify the system concept and the cycle performance of the AHAT system, a 3MW-class pilot plant was constructed that consists of a gas turbine with a two-stage centrifugal compressor, a two-stage axial turbine, a reverse-flow-type single-can combustor, a recuperator, a humidification tower, a water recovery tower, and other components. As a result of an operation test, the planned power output of 3.6MW was achieved, so that it has been confirmed the feasibility of the AHAT as a power-generating system. In this study, running tests on the AHAT pilot plant is carried out over one year, and various characteristics such as the effect of changes in ambient temperature, part-load characteristics, and start-up characteristics were clarified by analyzing the data obtained from the running tests.

scholarly journals Parametric Study of Fuel Cell and Gas Turbine Combined Cycle Performance

1997 ◽  
Author(s):  
Dawn Stephenson ◽  
Ian Ritchey
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Solid Oxide ◽  
Simple Cycle ◽  
Cycle Performance ◽  
Oxide Fuel ◽  
Combined Cycles

A number of cycles have been proposed in which a solid oxide fuel cell is used as the topping cycle to a gas turbine, including those recently described by Beve et al. (1996). Such proposals frequently focus on the combination of particular gas turbines with particular fuel cells. In this paper, the development of more general models for a number of alternative cycles is described. These models incorporate variations of component performance with key cycle parameters such as gas turbine pressure ratio, fuel cell operating temperature and air flow. Parametric studies are conducted using these models to produce performance maps, giving overall cycle performance in terms of both gas turbine and fuel cell design point operating conditions. The location of potential gas turbine and fuel cell combinations on these maps is then used to identify which of these combinations are most likely to be appropriate for optimum efficiency and power output. It is well known, for example, that the design point of a gas turbine optimised for simple cycle performance is not generally optimal for combined cycle gas turbine performance. The same phenomenon may be observed in combined fuel cell and gas turbine cycles, where both the fuel cell and the gas turbine are likely to differ from those which would be selected for peak simple cycle efficiency. The implications of this for practical fuel cell and gas turbine combined cycles and for development targets for solid oxide fuel cells are discussed. Finally, a brief comparison of the economics of simple cycle fuel cells, simple cycle gas turbines and fuel cell and gas turbine combined cycles is presented, illustrating the benefits which could result.

scholarly journals Gas Turbines - Major Greenhouse Gas Inhibitors

2015 ◽  
Vol 137 (12) ◽  
pp. 54-55
Author(s):  
Lee S. Langston
Keyword(s):  
Natural Gas ◽  
Greenhouse Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Electrical Power ◽  
Rankine Cycle ◽  
Hydrocarbon Fuel ◽  
Gas Production ◽  
Combined Cycle

This article explains how combined cycle gas turbine (CCGT) power plants can help in reducing greenhouse gas from the atmosphere. In the last 25 years, the development and deployment of CCGT power plants represent a technology breakthrough in efficient energy conversion, and in the reduction of greenhouse gas production. Existing gas turbine CCGT technology can provide a reliable, on-demand electrical power at a reasonable cost along with a minimum of greenhouse gas production. Natural gas, composed mostly of methane, is a hydrocarbon fuel used by CCGT power plants. Methane has the highest heating value per unit mass of any of the hydrocarbon fuels. It is the most environmentally benign of fuels, with impurities such as sulfur removed before it enters the pipeline. If a significant portion of coal-fired Rankine cycle plants are replaced by the latest natural gas-fired CCGT power plants, anthropogenic carbon dioxide released into the earth’s atmosphere would be greatly reduced.

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.

Flexible Combined Cycle Gas Turbine Power Plant Utilising Organic Rankine Cycle Technology

2016 ◽  
Author(s):  
Michael Welch ◽  
Nicola Rossetti
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Exhaust Gas ◽  
Operational Flexibility

Historically gas turbine power plants have become more efficient and reduced the installed cost/MW by developing larger gas turbines and installing them in combined cycle configuration with a steam turbine. These large gas turbines have been designed to maintain high exhaust gas temperatures to maximise the power generation from the steam turbine and achieve the highest overall electrical efficiencies possible. However, in today’s electricity market, with more emphasis on decentralised power generation, especially in emerging nations, and increasing penetration of intermittent renewable power generation, this solution may not be flexible enough to meet operator demands. An alternative solution to using one or two large gas turbines in a large central combined cycle power plant is to design and install multiple smaller decentralised power plant, based on multiple gas turbines with individual outputs below 100MW, to provide the operational flexibility required and enable this smaller power plant to maintain a high efficiency and low emissions profile over a wide load range. This option helps maintain security of power supplies, as well as providing enhanced operational flexibility through the ability to turn turbines on and off as necessary to match the load demand. The smaller gas turbines though tend not to have been optimised for combined cycle operation, and their exhaust gas temperatures may not be sufficiently high, especially under part load conditions, to generate steam at the conditions needed to achieve a high overall electrical efficiency. ORC technology, thanks to the use of specific organic working fluids, permits efficient exploitation of low temperatures exhaust gas streams, as could be the case for smaller gas turbines, especially when working on poor quality fuels. This paper looks at how a decentralised power plant could be designed using Organic Rankine Cycle (ORC) in place of the conventional steam Rankine Cycle to maximise power generation efficiency and flexibility, while still offering a highly competitive installed cost. Combined cycle power generation utilising ORC technology offers a solution that also has environmental benefits in a water-constrained World. The paper also investigates the differences in plant performance for ORC designs utilising direct heating of the ORC working fluid compared to those using an intermediate thermal oil heating loop, and looks at the challenges involved in connecting multiple gas turbines to a single ORC turbo-generator to keep installed costs to a minimum.

Adaptation and Modification of Gas Turbines for Solar Energy Applications

2005 ◽  
Author(s):  
Joseph Sinai ◽  
Chemi Sugarmen ◽  
Uriyel Fisher
Keyword(s):  
Solar Energy ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Efficiency ◽  
The United States ◽  
Combined Cycle ◽  
Energy Applications ◽  
Equipment Utilization ◽  
German Aerospace ◽  
Solar Field

Adapting a gas turbine to high-temperature solar receivers and solar tower technology constitutes real progress towards commercial solar power utilization with high efficiency combined cycle power system. Solar gas turbine systems can also be adapted to hybrid solar/fossil fuel operation, thanks to its high efficiency conversion, relatively small solar field, and quick response to load fluctuations, low CO2 emissions, easy start, and more effective equipment utilization. ORMAT initiated adaptation and modification of gas turbines for solar energy applications in the early 1990s in cooperation with the Weizmann Institute of Science and later with the Boeing Corporation, with the support of the United States Israel Science and Technology Foundation (USISTF). Ultimately, the concept reached its successful realization (2001–2004) in the solar tower Plataforma Solar de Almeria (Spain) which has three solar receivers and a receiving system designed and supplied by the German Aerospace Center DLR.

scholarly journals New Mobile Gas Turbine with a Wide Range of Applications

2018 ◽  
Vol 140 (03) ◽  
pp. S54-S55
Author(s):  
Uwe Schütz
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Working Fluid ◽  
Large Power ◽  
Power Stations ◽  
Wide Range ◽  
Term Basis

This article describes features and advantages of new mobile gas turbine with a wide range of applications. The market for mobile gas turbines is continuously growing. Mobile units are also an ideal choice when it comes to making large power capacities available on a short-term basis, for example, for major events, prolonged downtimes at other power stations, or power-intensive applications such as mining or shale gas extraction. If the electricity requirements exceed the level that can normally be demanded of a mobile application, an SGT-A45 installation can be modified to form a combined-cycle power plant to further improve its efficiency. In remote locations, this can be achieved using an Organic Rankine Cycle (ORC), to eliminate the need for water and water treatment systems, and to optimize energy recovery from the SGT-A45 off-gas stream at a relatively low temperature. The use of a direct heat exchanger, in which the ORC working fluid is evaporated by the off-gas stream from the gas turbine, can boost the system’s output capacity by more than 20 percent.

New Possibilities for Combined Cycles Through Advanced Steam Technology

2002 ◽  
Author(s):  
Kristin Jordal ◽  
Jens Fridh ◽  
La´szlo´ Hunyadi ◽  
Mikael Jo¨nsson ◽  
Ulf Linder
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Performance Enhancement ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Pressurized Water ◽  
Exhaust Duct ◽  
Combined Cycles ◽  
Gas Turbine Exhaust ◽  
Efficient Power

In order to improve the performance of the combined cycle, much effort has been spent over the past decade on increasing gas turbine performance. As a contrast to this, the present work focuses on possibilities for combined cycle performance enhancement through present and expected future steam cycle and boiler technology. The use of various heat recovery steam generators, (single and dual pressure) with or without supplementary firing are studied, in combination with steam turbine admission temperatures of up till 973 K. Supplementary firing is applied either in the entire gas turbine exhaust duct or in part of it, in a so-called split-stream boiler (SSB). Furthermore, the flashing of pressurized water from an overdimensioned economiser in the SSB, to produce steam for gas turbine vane cooling is studied. Many of the supplementary fired cycles studied are found to have a thermal efficiency superior of the unfired cycles, based on the same gas turbines. Hence, available steam technology and expected future development mean that most of the cycles studied are realistic concepts that merit further attention in the quest for more efficient power production.

Second Law Efficiency of the Rankine Bottoming Cycle of a Combined Cycle Power Plant

2008 ◽  
Author(s):  
S. Can Gulen ◽  
Raub W. Smith
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Second Law ◽  
Modeling Tools ◽  
Combined Cycle Power Plant

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 one third of the power is generated by the bottoming cycle. To ensure that the highest possible combined cycle efficiency is realized it is important to develop the combined cycle power plant as a system. Doing so requires a solid understanding of the efficiency entitlement of both, topping and bottoming, cycles separately and as a whole. This paper describes a simple but accurate method to estimate the Rankine bottoming cycle power output directly from the gas turbine exhaust exergy utilizing the second law of thermodynamics. The classical first law approach, i.e. the heat and mass balance method, requires lengthy calculations and complex computer-based modeling tools to evaluate Rankine bottoming cycle performance. In this paper, a rigorous application of the fundamental thermodynamic principles embodied by the second law to the major cycle components clearly demonstrates that the Rankine cycle performance can be accurately represented by several key parameters. The power of the second law approach lies in its ability to highlight the theoretical entitlement and state-of-the-art design performances simultaneously via simple, fundamental relationships. By considering economically and technologically feasible upper limits for the key parameters, the maximum achievable bottoming cycle power output is readily calculable for any given gas turbine from its exhaust exergy.

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