Using Fresh Air in Windbox Repowering of Existing Steam Power Plants

2007 ◽  
Author(s):  
V. Nayyeri ◽  
P. Asna Ashary
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Flame Temperature ◽  
Heat Transfer Process ◽  
Low Oxygen ◽  
Steam Power ◽  
Steam Power Plants ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

Repowering is increasing efficiency and output power of an existing steam power plants by integration them with gas turbine. Several approaches are proposed for repowering regards to condition of existing power plants. One of those approaches which provides opportunity for existing boiler reusing is windbox repowering. In this method, one or several gas turbines are installed near the existing steam unit and the exhaust of gas turbines is used as preheated combustion air for boiler. The main difficulty in integration of gas turbine and boiler is decreasing flame temperature in supplementary combustion of boiler due to low oxygen content of gas turbine exhaust compared with fresh air and its effect on heat transfer process especially in radiative sections. When advanced gas turbines are used in windbox repowering, the fresh air should be used for increasing oxygen due to low oxygen percent. In this study, the effect of using fresh air in wind box repowering will be investigated and two main arrangements, preheating and not preheating of fresh air will be compared. This study shows the advantages of using preheated air for mixing with gas turbine exhaust when advanced gas turbines are used for windbox repowering.

scholarly journals Reheat and Regenerative Gas Turbines for Feed Water Repowering of Steam Power Plant

1995 ◽  
Author(s):  
G. Negri di Montenegro ◽  
M. Gambini ◽  
A. Peretto
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Flow Rate ◽  
Gas Turbines ◽  
Power Plants ◽  
Feed Water ◽  
Brayton Cycle ◽  
Energy Integration ◽  
Steam Power ◽  
Steam Power Plants

This study is concerned with the repowering of existing steam power plants (SPP) by gas turbine (GT) units. The energy integration between SPP and GT is analyzed taking into particular account the employment of simple and complex cycle gas turbines. With regard to this, three different gas turbine has been considered: simple Brayton cycle, regenerative cycle and reheat cycle. Each of these cycles has been considered for feed water repowering of three different existing steam power plants. Moreover, the energy integration between the above plants has been analyzed taking into account three different assumptions for the SPP off-design conditions. In particular it has been established to keep the nominal value for steam turbine power output or for steam flow-rate at the steam turbine inlet or, finally, for steam flow-rate in the condenser. The numerical analysis has been carried out by the employment of numerical models regarding SPP and GT, developed by the authors. These models have been here properly connected to evaluate the performance of the repowered plants. The results of the investigation have revealed the interest of considering the use of complex cycle gas turbines, especially reheat cycles, for the feed water repowering of steam power plants. It should be taken into account that these energy advantages are determined by a repowering solution, i.e. feed water repowering which, although it is attractive for its simplicity, do not generally allows, with Brayton cycle, a better exploitation of the energy system integration in comparison with other repowering solutions. Besides these energy considerations, an analysis on the effects induced by repowering in the working parameters of existing components is also explained.

scholarly journals Design and Operating Experiences With Gas Turbine Combined Cycle Units

1971 ◽  
Author(s):  
R. W. Jones ◽  
A. C. Shoults
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Economic Factors ◽  
Chemical Company ◽  
Gas Turbine Exhaust ◽  
Selection Of ◽  
Turbine Exhaust

This paper presents details of three large gas turbine installations in the Freeport, Texas, power plants of the Dow Chemical Company. The general plant layout, integration of useful outputs, economic factors leading to the selection of these units, and experiences during startup and operation will be reviewed. All three units operate with supercharging fan, evaporative cooler, and static excitation. Two of the installations are nearly identical 32,000-kw gas turbines operating in a combined cycle with a supplementary fired 1,500,000-lb/hr boiler and a 50,000-kw noncondensing steam turbine. The other installation is a 43,000-kw gas turbine and a 20,000-kw starter-helper steam turbine on the same shaft. The gas turbine exhaust is used to supply heated feedwater for four existing boilers.

scholarly journals Gas-Steam Power Generation

1960 ◽  
Author(s):  
P. F. Martinuzzi
Keyword(s):  
Power Generation ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Nuclear Reactors ◽  
Closed Cycle ◽  
Steam Power ◽  
Operational Characteristics ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

The combination of a gas turbine with a steam turbine driven by steam produced in a generator heated by the gas-turbine exhaust is studied. The field of application of such a gas-steam power plant is examined, as well as the best operational characteristics of the combination. The special features of closed-cycle gas turbines, particularly of the type used in conjunction with gas-cooled, high-temperature nuclear reactors, are shown to give considerable advantages when combined with a steam turbine.

scholarly journals Intercooled and Brayton Cycle Gas Turbines for Steam Power Plant Hot Windbox Repowering

1998 ◽  
Author(s):  
G. Negri di Montenegro ◽  
M. Gambini ◽  
A. Peretto
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Brayton Cycle ◽  
Steam Power ◽  
Steam Power Plant ◽  
Higher Power ◽  
Flow Rate Range ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

In the present paper the performance of a hot windbox repowering steam power plant are evaluated. A methodology has been developed to determine the mass flow rate range of gas turbine exhaust gas injected into a steam generator of an existing steam power plant. The study allowed to evaluate the performance of the repowered plant for different gas turbine available on the market. By utilizing the same methodology, this repowering solution was also investigated employing an intercooler gas turbine that, in the state of art, may be realistically proposed. It resulted that the hot windbox repowering with Brayton cycle gas turbine supplies a considerably higher power output and efficiency than those of the steam power plant before the repowering. The employing of an intercooled gas turbine provides further improvements of power and efficiency with respect to the repowered plant using the Brayton cycle gas turbine.

scholarly journals A Different Approach to Gas Turbine Exhaust Silencing

1974 ◽  
Author(s):  
Marv Weiss
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Operating Conditions ◽  
Heavy Duty ◽  
Unique Method ◽  
Acoustic Testing ◽  
Gas Turbine Exhaust ◽  
Attenuation Values ◽  
Turbine Exhaust

A unique method for silencing heavy-duty gas turbines is described. The Switchback exhaust silencer which utilizes no conventional parallel baffles has at operating conditions measured attenuation values from 20 dB at 63 Hz to 45 dB at higher frequencies. Acoustic testing and analyses at both ambient and operating conditions are discussed.

Luxury Liners Go Green

1998 ◽  
Vol 120 (07) ◽  
pp. 72-73 ◽  
Author(s):  
Michael Valent
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Gas Turbines ◽  
First Century ◽  
System A ◽  
Cruise Ships ◽  
Engine Room ◽  
Electric Drive System ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

This article reviews that twenty-first century passengers on the Royal Caribbean International and Celebrity Cruises are set to make history in style. Up to six of Royal Caribbean’s Voyager- and Millennium-class vessels will be the first cruise ships ever powered by General Electric’s gas turbines. In addition to reducing engine-room noise and vibration and cutting emissions, this propulsion system—a departure from the traditional diesel engine—will make it possible for ships to set sail with a reduced maintenance crew and smaller parts inventory. Royal Caribbean International currently operates a fleet of 12 ships. In the Royal Caribbean application, the GE gas turbine will be used to drive generators that will provide electricity to propeller motors. The steam turbine will recover heat from the gas turbine exhaust for other uses. This combined gas turbine and steam turbine integrated electric drive system represents a departure from diesel engines in more than one respect.

Gas Turbine Exhaust Expansion Joints, Diverter and Damper Designs for the New Generation of Higher Temperature, High Efficiency Gas Turbines

1989 ◽  
Author(s):  
Lothar Bachmann ◽  
W. Fred Koch
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Efficiency ◽  
Combined Cycle ◽  
Operating Conditions ◽  
High Mass ◽  
Expansion Joints ◽  
Gas Turbine Exhaust ◽  
New Generation ◽  
Turbine Exhaust

The purpose of this paper is to update the industry on the evolutionary steps that have been taken to address higher requirements imposed on the new generation combined cycle gas turbine exhaust ducting expansion joints, diverter and damper systems. Since the more challenging applications are in the larger systems, we shall concentrate on sizes from nine (9) square meters up to forty (40) square meters in ducting cross sections. (Reference: General Electric Frame 5 through Frame 9 sizes.) Severe problems encountered in gas turbine applications for the subject equipment are mostly traceable to stress buckling caused by differential expansion of components, improper insulation, unsuitable or incompatible mechanical design of features, components or materials, or poor workmanship. Conventional power plant expansion joints or dampers are designed for entirely different operating conditions and should not be applied in gas turbine applications. The sharp transients during gas turbine start-up as well as the very high temperature and high mass-flow operation conditions require specific designs for gas turbine application.

Flow Guiding and Distributing Devices on the Exhaust Side of Stationary Gas Turbines

1990 ◽  
Vol 112 (1) ◽  
pp. 80-85
Author(s):  
F. Fleischer ◽  
C. Koerner ◽  
J. Mann
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Gas Flow ◽  
Flow Simulation ◽  
Exhaust System ◽  
Flow Distribution ◽  
Scale Model ◽  
Gas Turbine Exhaust ◽  
First Time ◽  
Turbine Exhaust

Following repeated cases of damage caused to exhaust silencers located directly beyond gas turbine diffusers, this paper reports on investigations carried out to determine possible remedies. In all instances, an uneven exhaust gas flow distribution was found. The company’s innovative approach to the problem involved constructing a scale model of a complete gas turbine exhaust system and using it for flow simulation purposes. It was established for the first time that, subject to certain conditions, the results of tests conducted on a model can be applied to the actual turbine exhaust system. It is shown that when an unfavorable duct arrangement might produce an uneven exhaust flow, scale models are useful in the development of suitable flow-distributing devices.

scholarly journals Repowering Fossil Steam Power Plants With Combustion Turbine-Based Technologies

1996 ◽  
Author(s):  
Stanley Pace ◽  
Arden Walters
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Environmental Benefits ◽  
Technology Selection ◽  
Original Plant ◽  
Generation Capacity ◽  
Gas Turbine Exhaust ◽  
Topping Cycle

Increased competition fostered by changes in legislation governing power generation entities has engendered a need to closely assess the economics of operating older-electric generating units. Decisions must be made as to whether these units should be retired and replaced with new, greenfield generation capacity, whether capacity should be purchased from other generation companies, or whether such units should be repowered in some way. The repowering alternative has merit when economic factors and environmental considerations show it to project the least cost of electricity over other choices. The chief advantages of repowering, include use of existing real estate and infrastructure, existing transmission facilities and staffing. Since the repowered plant usually emits less stack gas pollutants per unit of energy generated then the original plant, environmental benefits can also accrue. Various types of gas turbine based repowering options for steam electric plants are presented. All the approaches discussed involve the addition of gas turbines to the cycle and the consequent benefit of some form of combined cycle operation. This option includes boiler retirement (and replacement with combined cycle), hot or warm windbox repowering (the boiler is retained and a gas turbine topping cycle is added), feedwater heating repowering (the gas turbine exhaust heats feedwater), and site repowering (only the site infrastructure is re-used as the site for a combined cycle). Business considerations are discussed in terms of their impact on the decision to repower and technology selection. An example involving feedwater heater repowering is used to illustrate the interaction between the business and technical aspects of repowering.

scholarly journals Up-Rated Reheat Gas Turbine for the Repowering of Steam Power Plants

1999 ◽  
Author(s):  
G. Negri di Montenegro ◽  
A. Peretto ◽  
E. Mantino
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Fossil Fuel ◽  
Lower Cost ◽  
Combined Cycle ◽  
Internal Rate Of Return ◽  
Steam Power ◽  
Steam Power Plants ◽  
Combined Cycles ◽  
Fossil Fuel Power Plants

In the present paper, a thermoeconomic analysis of combined cycles derived from existing steam power plants is performed. The gas turbine employed is a reheat gas turbine. The increase of the two combustor outlet temperatures was also investigated. The study reveals that the transformation of old conventional fossil fuel power plants in combined cycle power plants with reheat gas turbine supplies a cost per kWh lower than that of a new combined cycle power plant, also equipped with reheat gas turbine. This occurs for all the repowered plants analyzed. Moreover, the solution of increasing the two combustor outlet temperatures resulted a strategy to pursue, leading, in particular, to a lower cost per kWh, Pay Back Period and to a greater Internal Rate of Return.

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