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

2009 ◽  
Vol 289-292 ◽  
pp. 413-420 ◽  
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.

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

2015 ◽  
Vol 7 (1) ◽  
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.

Energy Storage Using Low-Pressure Feedwater

1985 ◽  
Vol 107 (3) ◽  
pp. 569-573 ◽  
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.

Site Studies for a Steam Power Plants

1959 ◽  
Vol 85 (1) ◽  
pp. 81-114
Author(s):  
R. D. Chellis ◽  
E. Ireland
Keyword(s):  
Power Plants ◽  
Steam Power ◽  
Steam Power Plants

scholarly journals Internal Combustion Steam Cycle (G.I.S.T. Cycle): Thermodynamical Feasibility and Plant Lay-Out Proposals

1997 ◽  
Author(s):  
C. Caputo ◽  
M. Gambini ◽  
G. L. Guizzi
Keyword(s):  
Natural Gas ◽  
Power Plants ◽  
Internal Combustion ◽  
Steam Flow ◽  
Inlet Temperature ◽  
Steam Boiler ◽  
Critical Approach ◽  
Steam Power ◽  
Steam Power Plants ◽  
Steam Cycle

In this paper a new kind of steam cycle provided with internal combustion is proposed. The internal combustion of natural gas and compressed air inside the steam flow has been conceived to carry out a steam heating (SH a/o RH) until TIT (Turbine Inlet Temperature) much higher than those of the conventional steam power plants. By this internal combustion it seems possible to overcome the present limits to TIT in steam plants which are, as known, especially related to the technological problems of the superheater tube materials in the conventional external combustion steam boilers. The proposed cycle has been named with the acronym GIST (Gas Injection STeam) since the hot gases resulting from a combustion close to stechiometric conditions are injected inside the steam flow. This paper provides a first critical approach to these new kinds of thermodynamical cycles. At the first the thermodynamical and technological problems related to the combustion inside steam are explained and discussed. Then, different plant lay-out solutions are proposed with a critical discussion on their overall performance. At the last two GIST solution have been defined that seem very interesting: the first is an hybrid plant scheme (i.e. provided with multi-fuel supply) which involves performances higher than conventional steam power plants (net electric efficiency of about 47%); the second is a plant scheme with full natural gas supply (i.e. without multi-fuel steam boiler) wich involves very relevant performances (net electric efficiency of about 57%).

Steam power plants

1960 ◽  
Vol 1 (4) ◽  
pp. 398
Author(s):  
D.J. Riley
Keyword(s):  
Power Plants ◽  
Steam Power ◽  
Steam Power Plants
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