Studying the effects of combining internal and external heat recovery on techno-economic performances of gas–steam power plants

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.

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Evaluation of Si Coating on Ferritic Steels by CVD-FBR Technology in Steam Oxidation

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.289-292.413 ◽

2009 ◽

Vol 289-292 ◽

pp. 413-420 ◽

Cited By ~ 1

Author(s):

F.J. Bolívar ◽

L. Sánchez ◽

M.P. Hierro ◽

F.J. Pérez

Keyword(s):

Power Plants ◽

Protective Coatings ◽

Steam Oxidation ◽

Steam Turbines ◽

X Ray Diffraction ◽

Steam Power ◽

Factors Affecting ◽

Steam Power Plants ◽

Temperature And Pressure ◽

Major Factors

The development of new power generation plants firing fossil fuel is aiming at achieving higher thermal efficiencies of the energy conversion process. The major factors affecting the efficiency of the conventional steam power plants are the temperature and, to a lesser extent, the pressure of the steam entering the turbine. The increased operating temperature and pressure require new materials that have major oxidation resistance. Due to this problem, in the last years numerous studies have been conducted in order to develop new coatings to enhance the resistance of steels with chromium contents between 9 and 12% wt against steam oxidation in order to allow operation of steam turbines at 650 0C. In this study, Si protective coatings were deposited by CVD-FBR on ferritic steel P-91. These type of coatings have shown to be protective at 650 0C under steam for at least 3000 hours of laboratory steam exposure under atmospheric pressure. Morphology and composition of coatings were characterized by different techniques, such as scanning electron microscopy (SEM), electron probe microanalysis, and X-ray diffraction (XRD). The results show a substantial increase of steam oxidation protection afforded by Si coating by CVD-FBR process.

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Numerical and Experimental Investigations of the Transient Thermal Behavior of a Steam By-Pass Valve at Steam Temperatures Beyond 700 °C

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4029040 ◽

2015 ◽

Vol 7 (1) ◽

Cited By ~ 4

Author(s):

Anis Haj Ayed ◽

Martin Kemper ◽

Karsten Kusterer ◽

Hailu Tadesse ◽

Manfred Wirsum ◽

...

Keyword(s):

Thermal Behavior ◽

Power Plants ◽

Numerical Approach ◽

Life Assessment ◽

Experimental Investigations ◽

Steam Power ◽

Steam Power Plants ◽

Cyclic Operation ◽

Measurement Results ◽

Transient Thermal

Increasing the efficiency of steam power plants is important to reduce their CO2 emissions and can be achieved by increasing steam temperatures beyond 700 °C. Within the present study, the thermal behavior of a steam by-pass valve subject to cyclic operation with 700 °C steam is investigated experimentally and numerically. An innovative numerical approach was applied to predict the valve’s thermal behavior during cyclic operation, which is essential for fatigue life assessment of such a component. Validation of the applied numerical approach has shown good agreement with measurement results, indicating the potential of its application for the valve design process.

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Steam power plants

Journal of the Franklin Institute ◽

10.1016/0016-0032(59)90541-1 ◽

1959 ◽

Vol 268 (5) ◽

pp. 412

Keyword(s):

Power Plants ◽

Steam Power ◽

Steam Power Plants

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Energy Storage Using Low-Pressure Feedwater

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.3239774 ◽

1985 ◽

Vol 107 (3) ◽

pp. 569-573 ◽

Cited By ~ 1

Author(s):

C. M. Harman ◽

S. Loesch

Keyword(s):

Energy Storage ◽

Power Plants ◽

Storage System ◽

Energy Storage System ◽

Low Pressure ◽

Steam Power ◽

Low Pressure Turbine ◽

Availability Analysis ◽

Steam Power Plants ◽

And Storage

A method for increasing the peak output of steam power plants through use of a low-pressure feedwater storage system is presented. The generalized availability analysis involves only the low-pressure turbine, low-pressure feedwater heaters, and the storage system. With daily cycling and storage charging at near base load conditions, the turnaround efficiency of the energy storage system was found to approach 100 percent. Storage system turnaround efficiency is decreased when the energy is stored during plant part-load operation.

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