The Prospects of the Steam Cycle in the Central Power Station

1948 ◽  
Vol 158 (1) ◽  
pp. 52-65 ◽  
Author(s):  
G. H. Martin
Keyword(s):  
Power Generation ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Prime Mover ◽  
Power Station ◽  
Large Power ◽  
Methods Of Calculation ◽  
To Come ◽  
Methods Of Operation

The advent of the gas turbine and its effect on the position of the steam turbine for the central power station is briefly discussed. In the opinion of the author the steam turbine will hold the field for large power generation for many years to come, and there is no immediate prospect of any other form of prime mover becoming a serious competitor for the generation of electricity in the central power station. Data are given indicating the gain in thermal efficiency that can be expected from increased steam conditions up to 2,000 lb. per sq. in., and 1,000 deg. F. with and without reheating. The advantages of reheating as a means of obtaining higher efficiency are strongly emphasized. Methods of operation to enable quick starting are discussed. Some of the principal constructional problems created by high steam conditions are briefly discussed and methods of overcoming the difficulties are indicated. The essence of the paper is to examine, in as simple a manner as possible, the means available for improving the efficiency of the central power station; and in an effort to achieve this, detailed methods of calculation are not included, as it is considered they would detract from a clear appreciation of the results. The minimum of assumptions have been made, so that the curves represent a true picture of the actual gains that could be obtained in practice.

Steam Turbine Driving Compressor for Gas-Steam Combined Cycle Power Plant

2009 ◽  
Author(s):  
Wancai Liu ◽  
Hui Zhang
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Combined Cycle ◽  
Thermodynamic Process ◽  
Combined Cycle Power Plant ◽  
Steam Cycle

Gas turbine is widely applied in power-generation field, especially combined gas-steam cycle. In this paper, the new scheme of steam turbine driving compressor is investigated aiming at the gas-steam combined cycle power plant. Under calculating the thermodynamic process, the new scheme is compared with the scheme of conventional gas-steam combined cycle, pointing its main merits and shortcomings. At the same time, two improved schemes of steam turbine driving compressor are discussed.

Sir Charles Parsons and Electrical Power Generation—a Turbine Designer's Perspective

1994 ◽  
Vol 208 (3) ◽  
pp. 159-176 ◽  
Author(s):  
J R Bolter
Keyword(s):  
Power Generation ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Electrical Power Generation ◽  
Analytical Methods ◽  
State Of The Art ◽  
Electrical Power ◽  
Turbine Generator ◽  
Current State ◽  
The World

Sir Charles Parsons died some three years after the author was born. In this paper the author looks back at the pioneering work of Parsons in the field of power generation. It shows how he was able to increase output of the steam turbine generator from 7.5 kW in 1884 to 50000 kW in 1930 while increasing efficiency from 1.6 to 36 per cent, and relates these achievements to the current state of the art. Blading design, rotor construction and other aspects of turbine engineering are considered. The conclusion is that Parsons and his associates charted the course which manufacturers and utilities throughout the world have continued to follow, although increasingly sophisticated design and analytical methods have succeeded the intuitive approach of Parsons. His constant search for improved efficiency was and is highly relevant to today's concern for the environment. Finally, although it did not become a practical proposition in his lifetime, the paper reviews Parsons' vision of, and continuing interest in, the gas turbine, first mentioned in his 1884 patents.

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).

Advanced Gas Turbine and High Performance Gas-Steam Combined Cycle Plant With Blade Cooling Air Controlling

2006 ◽  
Author(s):  
Tadashi Tsuji
Keyword(s):  
Power Generation ◽  
Heat Exchanger ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Hot Water ◽  
Blade Cooling ◽  
Combined Cycle Plant ◽  
Cooling Air

Air cooling blades are usually applied to gas turbines as a basic specification. This blade cooling air is almost 20% of compressor suction air and it means that a great deal of compression load is not converted effectively to turbine power generation. This paper proposes the CCM (Cascade Cooling Module) system of turbine blade air line and the consequent improvement of power generation, which is achieved by the reduction of cooling air consumption with effective use of recovered heat. With this technology, current gas turbines (TIT: turbine inlet temperature: 1350°C) can be up-rated to have a relative high efficiency increase. The increase ratio has a potential to be equivalent to that of 1500°C Class GT/CC against 1350°C Class. The CCM system is designed to enable the reduction of blade cooling air consumption by the low air temperature of 15°C instead of the usual 200–400°C. It causes the turbine operating air to increase at the constant suction air condition, which results in the enhancement of power and thermal efficiency. The CCM is installed in the cooling air line and is composed of three stage coolers: steam generator/fuel preheater stage, heat exchanger stage for hot water supplying and cooler stage with chilled water. The coolant (chilled water) for downstream cooler is produced by an absorption refrigerator operated by the hot water of the upstream heat exchanger. The proposed CCM system requires the modification of cooling air flow network in the gas turbine but produces the direct effect on performance enhancement. When the CCM system is applied to a 700MW Class CC (Combined Cycle) plant (GT TIT: 135°C Class), it is expected that there will be a 40–80MW increase in power and +2–5% relative increase in thermal efficiency.

Advanced Gas Turbine Technology for Sendai Thermal Power Station, Unit No. 4

2011 ◽  
Author(s):  
Sadahiro Ohno ◽  
Hiroyuki Yamazaki ◽  
Naoki Hagi ◽  
Hidehiko Nishimura
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
Gas Turbine ◽  
Thermal Power Station ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Thermal Power ◽  
Power Station ◽  
Advanced Technologies ◽  
Station Unit

Worldwide environmental concerns are placing center focus on effective utilization of energy and carbon dioxide emission reductions. The power generation industry has engaged in the replacement of existing aged thermal power plants with state-of-the-art natural gas fired power plants capable of achieving considerable reductions in energy consumption and emissions of green house gases. The replacement of three exiting 175MW heavy oil and coal-firing power plants with a highly effective 446MW gas-firing combined cycle power plant owned and operated by Tohoku Electric Power Company is one example of this effort. The construction of the new Sendai thermal power station, Unit No.4 started in November, 2007 achieving commercial operation in July, 2010. Mitsubishi Heavy Industries most recent 50Hz F class gas turbine upgrade, the M701F4 was adopted for this project. This engine is based on the successful M701F3 gas turbine with a 6% air flow increase and a slight bump of the turbine inlet temperature in order to achieve better thermal efficiency and more power output. The application of these advanced technologies resulted in a plant thermal efficiency of approximately 58% LHV of the new unit from the original 43% of the previous coal-firing units. The application of these advanced technologies and the use of natural gas resulted in a 2/3 carbon-dioxide emissions reduction.

scholarly journals Comparing combined gas tubrine/steam turbine and marine low speed piston engine/steam turbine systems in naval applications

2011 ◽  
Vol 18 (4) ◽  
pp. 43-48 ◽  
Author(s):  
Marek Dzida ◽  
Wojciech Olszewski
Keyword(s):  
Diesel Engine ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Exhaust Gas ◽  
Piston Engine ◽  
Large Power ◽  
Low Speed ◽  
Efficiency Increase ◽  
Main Engine

Comparing combined gas tubrine/steam turbine and marine low speed piston engine/steam turbine systems in naval applications The article compares combined systems in naval applications. The object of the analysis is the combined gas turbine/steam turbine system which is compared to the combined marine low-speed Diesel engine/steam turbine system. The comparison refers to the additional power and efficiency increase resulting from the use of the heat in the exhaust gas leaving the piston engine or the gas turbine. In the analysis a number of types of gas turbines with different exhaust gas temperatures and two large-power low-speed piston engines have been taken into account. The comparison bases on the assumption about comparable power ranges of the main engine.

Start-Up Optimization of a CCGT Power Station Using Model Based Gas Turbine Control

2018 ◽  
Author(s):  
Alessandro Nannarone ◽  
Sikke A. Klein
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Optimization Model ◽  
Feedback Loop ◽  
Combined Cycle ◽  
Process Data ◽  
Power Station ◽  
Power Stations ◽  
Start Up ◽  
Steam Cycle

The rapid growth of renewable generation and its intermittent nature has modified the role of combined cycle power stations in the energy industry, and the key feature for the operational excellence is now flexibility. Especially, the capability to start an installation quickly and efficiently after a shutdown period leads to lower operational cost and a higher capacity factor. However, most of existing thermal power stations worldwide are designed for continuous operation, with no special focus on an efficient start-up process. In most current start-up procedures, the gas turbine controls ensure maximum heat flow to the heat recovery steam generator, without feedback from the steam cycle. The steam cycle start-up controls work independently with as main control parameter the limitation of the thermal stresses in the steam turbine rotor. In this paper, a novel start-up procedure of an existing combined cycle power station is presented, and it uses a feedback loop between the steam turbine, the boiler and the gas turbine start-up controls. This feedback loop ensures that the steam turbine can be started up with a significant reduction in stresses. To devise and assess this start-up methodology, a flexible and accurate dynamic model was implemented in the Simulink™ environment. It contains more than 100 component blocks (heat exchangers, valves, meters and sensors, turbines, controls, etc.), and the mathematical component sub-models are based on physical models and experimental correlations. This makes the model generally applicable to other power plant installations. The model was validated against process data related to the three start-up types (cold start, warm start, hot start). On this basis, the optimization model is implemented with feedback loops that control for example the exit temperature of the gas turbine based on the actual steam turbine housing temperature, resulting in a smoother heating up of the steam turbine. The optimization model was used to define the optimal inlet guide vanes position and gas turbine power output curves for the three types of start-up. These curves were used during real power station start-ups, leading to, for cold and warm starts, reductions in the start-up time of respectively 32.5% and 31.8%, and reductions in the fuel consumption of respectively 47.0% and 32.4%. A reduction of the thermal stress in the steam turbines is also achieved, thanks to the new start-up strategy.

Development of High-Efficiency Oxy-Fuel IGCC System

2017 ◽  
Author(s):  
Yuso Oki ◽  
Hiroyuki Hamada ◽  
Makoto Kobayashi ◽  
Isao Yuri ◽  
Saburo Hara
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
High Efficiency ◽  
Exhaust Gas ◽  
Gas Turbine Combustor ◽  
Power Station ◽  
Power Stations ◽  
Gas Turbine Exhaust ◽  
Ccs Technologies ◽  
Turbine Exhaust

Coal is regarded as important fuel because of its stable supply and low price, but coal is blamed for its CO2 emission. Japanese utilities are making efforts to improve thermal efficiency and to expand biomass co-firing. On the other hand, CCS technologies are under development as a countermeasure for global warming and demonstration projects planned in several power stations are announced in world wide. As CO2 capture from power station requires huge in-house power, thermal efficiency is deteriorated. To make a breakthrough, NEDO started a project to develop the high-efficiency oxy-fuel IGCC system. This system recirculates gas turbine exhaust gas to both gasifier and gas turbine combustor. Recirculated exhaust gas is used both to feed pulverized coal to gasifier and to dilute syngas in gas turbine combustor. The target efficiency is 42% at HHV basis, equivalent to state of the art coal-fired power station. Various studies were done to confirm the concept of this system and to develop fundamental technologies necessary for the system since 2008 to 2014 as NEDO project. Based on the achievements, the project made another step since 2015 as a five-year joint NEDO project with MHI and MHPS. This paper introduces the latest status of this project executed by CRIEPI by referring several related papers.

Gas Turbine With Constant Volume Heat Addition

2010 ◽  
Author(s):  
S. Can Gu¨len
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Fossil Fuel ◽  
Combined Cycle ◽  
Brayton Cycle ◽  
Heat Addition ◽  
Volume Heat

Increasing the thermal efficiency of fossil fuel fired power plants in general and the gas turbine power plant in particular is of extreme importance. In the face of diminishing natural resources and increasing carbon emissions that lead to a heightened greenhouse effect and greater concerns over global warming, thermal efficiency is more critical today than ever before. In the science of thermodynamics, the best yardstick for a power generation system’s performance is the Carnot efficiency — the ultimate efficiency limit, set by the second law, which can be achieved only by a perfect heat engine operating in a cycle. As a fact of nature this upper theoretical limit is out of reach, thus engineers usually set their eyes on more realistic goals. For the longest time, the key performance benchmark of a combined cycle (CC) power plant has been the 60% net electric efficiency. Land-based gas turbines based on the classic Brayton cycle with constant pressure heat addition represent the pinnacle of fossil fuel burning power generation engineering. Advances in the last few decades, mainly driven by the increase in cycle maximum temperatures, which in turn are made possible by technology breakthroughs in hot gas path materials, coating and cooling technologies, pushed the power plant efficiencies to nearly 40% in simple cycle and nearly 60% in combined cycle configurations. To surpass the limitations imposed by available materials and other design considerations and to facilitate a significant improvement in the thermal efficiency of advanced Brayton cycle gas turbine power plants necessitate a rethinking of the basic thermodynamic cycle. The current paper highlights the key thermodynamic considerations that make the constant volume heat addition a viable candidate in this respect. First using fundamental air-standard cycle formulas and then more realistic but simple models, potential efficiency improvement in simple and combined cycle configurations is investigated. Existing and past research activities are summarized to illustrate the technologies that can transform the basic thermodynamics into a reality via mechanically and economically feasible products.

Cycle Optimization and High Performance Analysis of Gas Engine-Gas Turbine Combined Cycles

2005 ◽  
Author(s):  
Tadashi Tsuji
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Compound System ◽  
Generation Efficiency ◽  
Engine Exhaust ◽  
Gas Engine ◽  
Exhaust Temperature

The reciprocating engine operates with a maximum pressure and temperature in its cylinders that is higher than that in conventional gas turbines. When a gas engine is integrated with a gas turbine instead of a turbocharger, it is an ETCS (Engine-Turbo Compound System). We have developed the concept of a compound system with ERGT (Engine Reheat Gas Turbine) and propose it as a system with potentially high thermal efficiency. A natural gas firing gas turbine combined cycle (CC) is selected as the standard system for a thermal power plant. A higher TIT (Turbine Inlet Temperature) of gas turbine usually enables higher power generation efficiency. Focusing on the effect of engine exhaust temperature, we found that the ETCS cycle with a ERGT has the potential to achieve higher thermal efficiency than that of a gas turbine combined cycle, with no change in TIT. An engine exhaust temperature of 1173K increases the system power generation efficiency from 46 to 50%LHV (TIT 1150°C) and 54 to 57%LHV (TIT 1350°C), respectively. The gas engine–gas turbine combined cycle has the potential to achieve a significant efficiency increase of +4.1%LHV (TIT 1150°C) and +2.8%LHV (TIT 1350°C), making it a promising system for future power plants. Efficiency is expected to be improved by +8.7% (TIT 1150°C) and +5.6% (TIT 1350°C), relatively.

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