Exergy Evaluation of Two Current Advanced Power Plants: Supercritical Steam Turbine and Combined Cycle

1997 ◽  
Vol 119 (4) ◽  
pp. 250-256 ◽  
Author(s):  
H. Jin ◽  
M. Ishida ◽  
M. Kobayashi ◽  
M. Nunokawa
Keyword(s):  
Steam Turbine ◽  
Thermal Efficiency ◽  
Heat Recovery ◽  
Power Plants ◽  
Exergy Analysis ◽  
Combined Cycle ◽  
Exergy Loss ◽  
Heat Recovery Steam Generator ◽  
Combined Cycle Plant ◽  
Steam Plant

Two operating advanced power plants, a supercritical steam plant and a gas-steam turbine combined cycle, have been analyzed using a methodology of graphical exergy analysis (EUDs). The comparison of two plants, which may provide the detailed information on internal phenomena, points out several inefficient segments in the combined cycle plant: higher exergy loss caused by mixing in the combustor, higher exergy waste from the heat recovery steam generator, and higher exergy loss by inefficiency in the power section, especially in the steam turbine. On the basis of these fundamental features of each plant, we recommend several schemes for improving the thermal efficiency of current advanced power plants.

Repowering an Existing Power Generating Plant

2003 ◽  
Author(s):  
Mohammad R. Shahnazari ◽  
Abbas Abbassi
Keyword(s):  
Steam Turbine ◽  
Steam Generator ◽  
Heat Recovery ◽  
Power Plants ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Combined Cycle Plant ◽  
The Cost

A common repowering option is converting a fossil-fired steam unit to a gas-fired combined-cycle plant by addition of a combustion turbine and a Heat Recovery Steam Generator. In this approach the existing steam turbine and related auxiliaries are typically retained and some plant modification is applied. This paper intends to study this option for two old power plants. In this study the HRSGs are modeled, designed and their costs are estimated. Total generating cost for both plants are calculated in order to show whether or not the final cost is competitive with the cost of a new combined cycle unit.

The Model Steam Turbine: More Details About the Heat Recovery Steam Generator Evaluating Method in a Combined Cycle Plant

2002 ◽  
Author(s):  
Dietmar Schmidt ◽  
Michail Arnold
Keyword(s):  
Steam Turbine ◽  
Thermal Performance ◽  
Heat Recovery ◽  
Performance Criterion ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Evaluation Of Performance ◽  
Combined Cycle Plant ◽  
Shaft Power ◽  
Evaluating Method

Turnkey and thermal island supply scopes present turbine suppliers with a perfect way to sell their rotating products. The popularity of these plant configurations, along with the recent availability of more holistic test codes, has led to the need for an accurate and reasonable method of determining the thermal performance of the externally-purchased HRSG component. To assess a multiple pressure HRSG, it is advantageous and convenient to have one single criterion for the evaluation of performance, especially when this criterion provides for the compensation of the different outlet energy streams. The so-called Model Steam Turbine method of HRSG evaluation was developed for these reasons. The result of the calculation, a lone performance criterion, is the shaft power of the fictitious Model Steam Turbine.

LM2500+ Single Shaft Combined Cycle With Frequency Stabilization

1998 ◽  
Author(s):  
Donald A. Kolp ◽  
Charles E. Levey
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Heat Recovery ◽  
Heat Rate ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Equipment Operation ◽  
Combined Cycle Plant ◽  
Stable Frequency ◽  
And Performance

Zorlu Enerji needed 35 MW of reliable power at a stable frequency to maintain constant speed on the spindles producing thread at its parent company’s textile plant in Bursa, Turkey. In December of 1996, Zorlu selected an LM2500+ combined cycle plant to fill its power-generating requirements. The LM2500+ has output of 26,810 KW at a heat rate of 9,735 Kj/Kwh. The combined cycle plant has an output of 35,165 KW and a heat rate of 7,428 Kj/Kwh. The plant operates in the simple cycle mode utilizing the LM2500+ and a bypass stack and in combined cycle mode using the 2-pressure heat recovery steam generator and single admission, 9.5 MW condensing steam turbine. The generator is driven through a clutch by the steam turbine from the exciter end and by the gas turbine from the opposing end. The primary fuel for the plant is natural gas; the backup fuel is naphtha. Utilizing a load bank, the plant is capable of accepting a 12 MW load loss when the utility breaker trips open; it can sustain this loss while maintaining frequency within 1% on the mill load. The frequency stabilizing capability prevents overspeeding of the spindles, breakage of thousands of strands of thread and a costly shutdown of the mill. A description of the equipment, operation and performance illustrates the unique features of this versatile, compact and efficient generating unit.

scholarly journals New Steel Alloys for the Design of Heat Recovery Steam Generator Components of Combined Cycle Gas Plants

2009 ◽  
Author(s):  
Jorge Pinto Fernandes ◽  
Eduardo Manuel Dias Lopes ◽  
Vicente Maneta
Keyword(s):  
Finite Element ◽  
Steam Generator ◽  
Thermal Efficiency ◽  
Heat Recovery ◽  
Power Plants ◽  
Steam Pressure ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Martensitic Steels ◽  
Element Analysis

Demand of Power is growing everyday, mainly due to emerging economies in CRIB countries (China, Russia, India and Brazil). During the last fifty years steam pressure and temperature in power plants have been continuously raised to improve thermal efficiency. Recent efforts to improve efficiency leads to the development of a new generation of Heat Recovery Steam Generator (HRSG) where the Benson Once-Through Technology is applied to improve thermal efficiency. The main purpose of this paper is to analyse the mechanical behaviour of a High Pressure Superheater Manifold by applying Finite Element Modelling (FEM) and a Finite Element Analysis with the objective to analyse stress propagation leading to the study of damage mechanism e.g. Uniaxial Fatigue, Uniaxial Creep for life prediction. The objective of this paper is also to analyse the mechanical properties of the new high temperature resistant materials in the market such as 2Cr Bainitic steels (T/P23, T/P24) and also the 9–12Cr Martensitic steels (T/P91, T/P92, E911 and P/T122). For this study the design rules for construction of power boilers to define the geometry of the HPSH Manifold were applied.

The Model Steam Turbine: A Method of Evaluating a Heat Recovery Steam Generator in a Combined Cycle Plant

2001 ◽  
Author(s):  
Dietmar Schmidt ◽  
Terrence Sullivan
Keyword(s):  
Steam Turbine ◽  
Steam Generator ◽  
Thermal Performance ◽  
Heat Recovery ◽  
Performance Criterion ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Evaluation Of Performance ◽  
Combined Cycle Plant ◽  
Shaft Power

Turnkey and thermal island supply scopes present turbine manufacturers with a perfect way to sell their rotating products. The popularity of these plant configurations, along with the recent availability of more holistic test codes, has led to the need for an accurate and reasonable method of determining the thermal performance of the externally-purchased HRSG component. To assess a multiple pressure HRSG, it is advantageous and convenient to have one single criterion for the evaluation of performance, especially when this criterion provides for the compensation of the different outlet energy streams. The so-called Model Steam Turbine method of HRSG evaluation was developed for these reasons. The result of the calculation, a lone performance criterion, is the shaft power of the fictitious Model Steam Turbine. In this paper we will detail the components of the Model Steam Turbine calculation and explore the merits of this method. Some thoughts on performance corrections are also presented.

Part-Load Operation of Combined Cycle Plants With and Without Supplementary Firing

1995 ◽  
Vol 117 (3) ◽  
pp. 475-483 ◽  
Author(s):  
P. J. Dechamps ◽  
N. Pirard ◽  
Ph. Mathieu
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Power Plants ◽  
Combined Cycle ◽  
Steam Generators ◽  
Part Load ◽  
Inlet Guide Vanes ◽  
Steam Plant

The design point performance of combined cycle power plants has been steadily increasing, because of improvements both in the gas turbine technology and in the heat recovery technology, with multiple pressure heat recovery steam generators. The concern remains, however, that combined cycle power plants, like all installations based on gas turbines, have a rapid performance degradation when the load is reduced. In particular, it is well known that the efficiency degradation of a combined cycle is more rapid than that of a classical steam plant. This paper describes a methodology that can be used to evaluate the part-load performances of combined cycle units. Some examples are presented and discussed, covering multiple pressure arrangements, incorporating supplemental firing and possibly reheat. Some emphasis is put on the additional flexibility offered by the use of supplemental firing, in conjunction with schemes comprising more than one gas turbine per steam turbine. The influence of the gas turbine controls, like the use of variable inlet guide vanes in the compressor control, is also discussed.

scholarly journals Study of the effect of using duct burner on the functional parameters of the two repowered cycles through exergy analysis

2017 ◽  
Vol 21 (6 Part B) ◽  
pp. 3011-3023 ◽  
Author(s):  
Mehrabani Maghsoudi ◽  
Abdollah Mehrpanahi ◽  
Vahid Rouhani ◽  
Naser Nikbakht
Keyword(s):  
Power Generation ◽  
Steam Generator ◽  
Heat Recovery ◽  
Power Plants ◽  
Exergy Analysis ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Steam Power ◽  
Steam Power Plants ◽  
Duct Burner

Steam power plants have been extensively used in Iran for a long time, yet no specific step has been taken for promoting their performance. In this regard, full repowering is considered as a way to enhance the performance of steam power plants. Furthermore, because of the continental condition of Iran, duct burners can be used as a common strategy to compensate for power generation shortage caused by environmental conditions. In this study, the effect of using a duct burner on the full repowering of Be?sat Steam Cycle representing both single-and dual-pressure cycles was investigated based on exergy analysis. The results showed that by using the duct burner, due to the increase in the heat recovery steam generator inlet gas temperature, the general thermal efficiency of the combined cycle and the exergy efficiency of the combined cycle and heat recovery steam generator decreased. However, the results revealed an increase in the stack temperature and resulting exergy losses, steam flow and power generation.

scholarly journals New Steel Alloys for the Design of Heat Recovery Steam Generator Components of Combined Cycle Gas Plants

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Jorge Pinto Fernandes ◽  
Eduardo Manuel Dias Lopes ◽  
Vicente Maneta
Keyword(s):  
Finite Element ◽  
Steam Generator ◽  
Thermal Efficiency ◽  
Heat Recovery ◽  
Power Plants ◽  
Steam Pressure ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Martensitic Steels ◽  
Element Analysis

Demand for power is growing everyday, mainly due to emerging economies in countries such as China, Russia, India, and Brazil. During the last 50 years steam pressure and temperature in power plants have been continuously raised to improve thermal efficiency. Recent efforts to improve efficiency leads to the development of a new generation of heat recovery steam generator, where the Benson once-through technology is applied to improve the thermal efficiency. The main purpose of this paper is to analyze the mechanical behavior of a high pressure superheater manifold by applying finite element modeling and a finite element analysis with the objective of analyzing stress propagation, leading to the study of damage mechanism, e.g., uniaxial fatigue, uniaxial creep for life prediction. The objective of this paper is also to analyze the mechanical properties of the new high temperature resistant materials in the market such as 2Cr Bainitic steels (T/P23 and T/P24) and also the 9–12Cr Martensitic steels (T/P91, T/P92, E911, and P/T122). For this study the design rules for construction of power boilers to define the geometry of the HPSH manifold were applied.

scholarly journals Gas Turbine Heat Recovery Steam Generators for Combined Cycles Natural or Forced Circulation Considerations

1988 ◽  
Author(s):  
Akber Pasha
Keyword(s):  
Gas Turbine ◽  
Steam Generator ◽  
Heat Recovery ◽  
Power Plants ◽  
Natural Circulation ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Steam Generators ◽  
Forced Circulation ◽  
Gas Turbine Exhaust

In recent years the combined cycle has become a very attractive power plant arrangement because of its high cycle efficiency, short order-to-on-line time and flexibility in the sizing when compared to conventional steam power plants. However, optimization of the cycle and selection of combined cycle equipment has become more complex because the three major components, Gas Turbine, Heat Recovery Steam Generator and Steam Turbine, are often designed and built by different manufacturers. Heat Recovery Steam Generators are classified into two major categories — 1) Natural Circulation and 2) Forced Circulation. Both circulation designs have certain advantages, disadvantages and limitations. This paper analyzes various factors including; availability, start-up, gas turbine exhaust conditions, reliability, space requirements, etc., which are affected by the type of circulation and which in turn affect the design, price and performance of the Heat Recovery Steam Generator. Modern trends around the world are discussed and conclusions are drawn as to the best type of circulation for a Heat Recovery Steam Generator for combined cycle application.

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