scholarly journals Clear Skies Ahead

2016 ◽  
Vol 138 (06) ◽  
pp. 38-43
Author(s):  
Lee S. Langston

This article discusses various fields where gas turbines can play a vital role. Building engines for commercial jetliners is the largest market segment for the gas turbine industry; however, it is far from being the only one. One 2015 military gas turbine program of note was the announcement of an U.S. Air Force competition for an innovative design of a small turbine engine, suitable for a medium-size drone aircraft. The electrical power gas turbine market experienced a sharp boom and bust from 2000 to 2002 because of the deregulation of many electric utilities. Since then, however, the electric power gas turbine market has shown a steady increase, right up to present times. Coal-fired plants now supply less than 5 percent of the electrical load, having been largely replaced by new natural gas-fired gas turbine power plants. Working in tandem with renewable energy power facilities, the new fleet of gas turbines is expected to provide reliable, on-demand electrical power at a reasonable cost.

1998 ◽  
Vol 120 (08) ◽  
pp. 63-67
Author(s):  
Steven Ashley

This article focuses on a fuel-efficient gas turbine engine featuring intercooling and heat recuperation, which is being developed to power a new generation of warships. Modern warships are often powered by gas turbine engines so they can take advantage of the turbine’s rapid response capabilities, solid operational reliability, high power density, and compact dimensions. For medium-size surface combatants such as destroyers, aircraft-derivative gas turbines have become the dominant propulsion engine type, having largely replaced traditional steam or diesel power plants. Though the all-electric concept is far from new, having been applied previously to merchant vessels, the technology is looking better of late. The NRC panel stated that gas turbine propulsion units, modular rare-earth permanent magnetic motors, and power control module technologies have matured to the point that all-electric ships appear feasible. The technology cited “unique advantages” in reduced volume, modular flexible propulsion, lower acoustic signature, enhanced survivability, high propeller torque at low speed, and inherent reversing capability. The result would be a submarine-type propulsion design with diesel-like fuel consumption.


Author(s):  
Sandro Barros Ferreira ◽  
Pericles Pilidis

The use of biomass as gas turbine combined cycle fuels is broadly seen as one of the alternatives to diminish greenhouse gas emissions, mainly CO2, due to the efficiency delivered by such systems and the renewable characteristic of biomass itself. Integrated gasification cycles, BIGGT, are the current technology available; however the gasification system severely penalizes the power plant in terms of efficiency and demands modifications in the engine to accommodate the large fuel mass flow. This gives an opportunity to improvements in the current technologies and implementation of new ones. This paper intends to analyze new alternatives to the use of solid fuels in gas turbines, from the economical point of view, through the use of external combustion, EFGT, discussing its advantages and limitations over the current technology. The results show that both EFGT and BIGGT technologies are economically competitive with the current natural gas fired gas turbines. However, BIGGT power plants are still in pilot scale and the EFGT plants need further technological development. Thermodynamically speaking, the inherently recuperative characteristic of the EFGT gas turbine engine makes it well suited to the biomass market. The thermal efficiency of this cycle is higher than the BIGGT system. Furthermore, its fuel flexibility and negligible pre-treatmet is another advantage that makes it an interesting option for the Brazilian market.


2015 ◽  
Vol 137 (12) ◽  
pp. 54-55
Author(s):  
Lee S. Langston

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.


2014 ◽  
Vol 136 (07) ◽  
pp. 38-43
Author(s):  
Lee S. Langston

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.


2013 ◽  
Author(s):  
Yutaka Watanabe ◽  
Toru Takahashi

Recently, high efficiency and operational flexibility are required for thermal power plants to reduce CO2 emissions and to introduce renewable energy sources. We study the advanced humid air turbine (AHAT) system, which appears to be high suitable for practical use because its configuration is simpler than that of gas turbine combined cycle power plants (GTCCs). Moreover, the thermal efficiency of AHAT system for small and medium-size gas turbines is higher than that of GTCCs. To verify feasibility of this system and the cycle performance of AHAT system, a 3MW-class pilot plant was built in 2006 by Hitachi, Ltd., which mainly consists of a gas turbine, a water atomization cooling (WAC) system, a recuperator, a humidification tower and a water recovery tower. Through the operational test from 2006 to 2010, we confirmed the feasibility of the AHAT as a power-generation system, and various characteristics such as the effect of changes in ambient temperature, part-load characteristics, and start-up characteristics. Next step, a 40MW-class pilot plant was built in 2011 and started operational tests. This system mainly consists of a dual-shaft heavy duty gas turbine, a WAC system, a recuperator and a humidifier. As a result of the operational test, it has been confirmed that the pilot plant output achieved rated power output. In this paper, we show the 40MW-class pilot plant running test results, and evaluate thermal characteristics of this plant and the effect of WAC and humidification on performance of this gas turbine system.


Author(s):  
P. A. Phillips ◽  
Peter Spear

After briefly summarizing worldwide automotive gas turbine activity, the paper analyses the power plant requirements of a wide range of vehicle applications in order to formulate the design criteria for acceptable vehicle gas turbines. Ample data are available on the thermodynamic merits of various gas turbine cycles; however, the low cost of its piston engine competitor tends to eliminate all but the simplest cycles from vehicle gas turbine considerations. In order to improve the part load fuel economy, some complexity is inevitable, but this is limited to the addition of a glass ceramic regenerator in the 150 b.h.p. engine which is described in some detail. The alternative further complications necessary to achieve satisfactory vehicle response at various power/weight ratios are examined. Further improvement in engine performance will come by increasing the maximum cycle temperature. This can be achieved at lower cost by the extension of the use of ceramics. The paper is intended to stimulate the design application of the gas turbine engine.


2011 ◽  
Vol 133 (05) ◽  
pp. 30-33 ◽  
Author(s):  
Lee S. Langston

This article explores the increasing use of natural gas in different turbine industries and in turn creating an efficient electrical system. All indications are that the aviation market will be good for gas turbine production as airlines and the military replace old equipment and expanding economies such as China and India increase their air travel. Gas turbines now account for some 22% of the electricity produced in the United States and 46% of the electricity generated in the United Kingdom. In spite of this market share, electrical power gas turbines have kept a much lower profile than competing technologies, such as coal-fired thermal plants and nuclear power. Gas turbines are also the primary device behind the modern combined power plant, about the most fuel-efficient technology we have. Mitsubishi Heavy Industries is developing a new J series gas turbine for the combined cycle power plant market that could achieve thermal efficiencies of 61%. The researchers believe that if wind turbines and gas turbines team up, they can create a cleaner, more efficient electrical power system.


2021 ◽  
Author(s):  
M. A. Ancona ◽  
M. Bianchi ◽  
L. Branchini ◽  
A. De Pascale ◽  
F. Melino ◽  
...  

Abstract Gas turbines are often employed in the industrial field, especially for remote generation, typically required by oil and gas production and transport facilities. The huge amount of discharged heat could be profitably recovered in bottoming cycles, producing electric power to help satisfying the onerous on-site energy demand. The present work aims at systematically evaluating thermodynamic performance of ORC and supercritical CO2 energy systems as bottomer cycles of different small/medium size industrial gas turbine models, with different power rating. The Thermoflex software, providing the GT PRO gas turbine library, has been used to model the machines performance. ORC and CO2 systems specifics have been chosen in line with industrial products, experience and technological limits. In the case of pure electric production, the results highlight that the ORC configuration shows the highest plant net electric efficiency. The average increment in the overall net electric efficiency is promising for both the configurations (7 and 11 percentage points, respectively if considering supercritical CO2 or ORC as bottoming solution). Concerning the cogenerative performance, the CO2 system exhibits at the same time higher electric efficiency and thermal efficiency, if compared to ORC system, being equal the installed topper gas turbine model. The ORC scarce performance is due to the high condensing pressure, imposed by the temperature required by the thermal user. CO2 configuration presents instead very good cogenerative performance with thermal efficiency comprehended between 35 % and 46 % and the PES value range between 10 % and 22 %. Finally, analyzing the relationship between capital cost and components size, it is estimated that the ORC configuration could introduce an economical saving with respect to the CO2 configuration.


2015 ◽  
Vol 5 (2) ◽  
pp. 89
Author(s):  
Munzer S. Y. Ebaid ◽  
Qusai Z. Al-hamdan

<p class="1Body">Several modifications have been made to the simple gas turbine cycle in order to increase its thermal efficiency but within the thermal and mechanical stress constrain, the efficiency still ranges between 38 and 42%. The concept of using combined cycle power or CPP plant would be more attractive in hot countries than the combined heat and power or CHP plant. The current work deals with the performance of different configurations of the gas turbine engine operating as a part of the combined cycle power plant. The results showed that the maximum CPP cycle efficiency would be at a point for which the gas turbine cycle would have neither its maximum efficiency nor its maximum specific work output. It has been shown that supplementary heating or gas turbine reheating would decrease the CPP cycle efficiency; hence, it could only be justified at low gas turbine inlet temperatures. Also it has been shown that although gas turbine intercooling would enhance the performance of the gas turbine cycle, it would have only a slight effect on the CPP cycle performance.</p>


Author(s):  
Robert A. Wilson ◽  
Daniel B. Kupratis ◽  
Satyanarayana Kodali

The Department of Defense and NASA have funded a major gas turbine development program, Integrated High Performance Turbine Engine Technology (IHPTET), to double the power density and fuel economy of gas turbines by the turn of the century. Seven major US gas turbine developers participated in this program. While the focus of IHPTET activity has been aircraft propulsion, the same underlying technology can be applied to water craft and terrestrial vehicle propulsion applications, such as the future main battle tank. For these applications, the gas turbines must be equipped with recuperators. Currently, there is no technology roadmap or set of goals to guide industry and government in the development of a next generation recuperator for such applications.


Sign in / Sign up

Export Citation Format

Share Document