Evaluating Deposit Formation of Iron-Corrosion Products in High- and Low-Pressure Evaporative Circuits When Starting a Combined-Cycle Plant

In this paper is carried out a comparison between a gas turbine power plant and a combined cycle power plant through exergetic and environmental indices in order to determine performance and sustainability aspects of a gas turbine and combined cycle plant. First of all, an exergetic analysis of the gas turbine and the combined is carried out then the exergetic and environmental indices are calculated for the gas turbine (case A) and the combined cycle (case B). The exergetic indices are exergetic efficiency, waste exergy ratio, exergy destruction factor, recoverable exergy ratio, environmental effect factor and exergetic sustainability. Besides, the environmental indices are global warming, smog formation and acid rain indices. In the case A, the two gas turbines generate 278.4 MW; whereas 415.19 MW of electricity power is generated by the combined cycle (case B). The results show that exergetic sustainability index for cases A and B are 0.02888 and 0.1058 respectively. The steam turbine cycle improves the overall efficiency, as well as, the reviewed exergetic indexes. Besides, the environmental indices of the gas turbines (case A) are lower than the combined cycle environmental indices (case B), since the combustion gases are only generated in the combustion chamber.

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Ruhrchemie/Ruhrkohle’s Technical Version of the Texaco Coal Gasifier as Part of a Combined Cycle Plant

Volume 3: Coal, Biomass and Alternative Fuels; Combustion and Fuels; Oil and Gas Applications; Cycle Innovations ◽

10.1115/82-gt-167 ◽

1982 ◽

Cited By ~ 3

Author(s):

B. Cornils ◽

J. Hibbel ◽

P. Ruprecht ◽

R. Dürrfeld ◽

J. Langhoff

Keyword(s):

High Pressure ◽

Power Plants ◽

Coal Gasification ◽

Operating Time ◽

Combined Cycle ◽

Gas Generation ◽

Load Following ◽

Gasification Process ◽

Steady State Operation ◽

Combined Cycle Plant

The Ruhrchemie/Ruhrkohle variant of the Texaco Coal Gasification Process (TCGP) has been on stream since 1978. As the first demonstration plant of the “second generation” it has confirmed the advantages of the simultaneous gasification of coal: at higher temperatures; under elevated pressures; using finely divided coal; feeding the coal as a slurry in water. The operating time so far totals 9000 hrs. More than 50,000 tons of coal have been converted to syn gas with a typical composition of 55 percent CO, 33 percent H2, 11 percent CO2 and 0.01 percent of methane. The advantages of the process — low environmental impact, additional high pressure steam production, gas generation at high pressure levels, steady state operation, relatively low investment costs, rapid and reliable turn-down and load-following characteristics — make such entrained-bed coal gasification processes highly suitable for power generation, especially as the first step of combined cycle power plants.

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Remedial Treatment of Corroded Iron Objects by EnvironmentalAeromonasIsolates

Applied and Environmental Microbiology ◽

10.1128/aem.02042-18 ◽

2018 ◽

Vol 85 (3) ◽

Cited By ~ 1

Author(s):

Wafa M. Kooli ◽

Thomas Junier ◽

Migun Shakya ◽

Mathilde Monachon ◽

Karen W. Davenport ◽

...

Keyword(s):

Iron Reduction ◽

Building Materials ◽

Solid Phase ◽

Corrosion Products ◽

Metal Corrosion ◽

Economic Losses ◽

Cytotoxic Activities ◽

Iron Corrosion ◽

Pathogenic Potential ◽

Wide Range

ABSTRACTUsing bacteria to transform reactive corrosion products into stable compounds represents an alternative to traditional methods employed in iron conservation. Two environmentalAeromonasstrains (CA23 and CU5) were used to transform ferric iron corrosion products (goethite and lepidocrocite) into stable ferrous iron-bearing minerals (vivianite and siderite). A genomic and transcriptomic approach was used to analyze the metabolic traits of these strains and to evaluate their pathogenic potential. Although genes involved in solid-phase iron reduction were identified, key genes present in other environmental iron-reducing species are missing from the genome of CU5. Several pathogenicity factors were identified in the genomes of both strains, but none of these was expressed under iron reduction conditions. Additionalin vivotests showed hemolytic and cytotoxic activities for strain CA23 but not for strain CU5. Both strains were easily inactivated using ethanol and heat. Nonetheless, given a lesser potential for a pathogenic lifestyle, CU5 is the most promising candidate for the development of a bio-based iron conservation method stabilizing iron corrosion. Based on all the results, a prototype treatment was established using archaeological items. On those, the conversion of reactive corrosion products and the formation of a homogenous layer of biogenic iron minerals were achieved. This study shows how naturally occurring microorganisms and their metabolic capabilities can be used to develop bio-inspired solutions to the problem of metal corrosion.IMPORTANCEMicrobiology can greatly help in the quest for a sustainable solution to the problem of iron corrosion, which causes important economic losses in a wide range of fields, including the protection of cultural heritage and building materials. Using bacteria to transform reactive and unstable corrosion products into more-stable compounds represents a promising approach. The overall aim of this study was to develop a method for the conservation and restoration of corroded iron items, starting from the isolation of iron-reducing bacteria from natural environments. This resulted in the identification of a suitable candidate (Aeromonassp. strain CU5) that mediates the formation of desirable minerals at the surfaces of the objects. This led to the proof of concept of an application method on real objects.

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Fixed Duct Burner Heat Input Approach for Combined Cycle Power Plant ASME PTC 46 Performance Testing

ASME 2011 Power Conference, Volume 2 ◽

10.1115/power2011-55149 ◽

2011 ◽

Author(s):

Thomas K. Kirkpatrick ◽

Bernard J. Pastorik ◽

Wesley M. Newland

Keyword(s):

Heat Input ◽

Heat Rate ◽

Combined Cycle ◽

Test Method ◽

Plant Performance ◽

Ambient Conditions ◽

Power Test ◽

Alternative Approach ◽

Combined Cycle Plant ◽

Duct Burner

Since its publication in 1996, ASME PTC 46 Performance Test Code on Overall Plant Performance has established itself as the premier test code for conducting overall plant performance within the power industry, especially for combined cycle power plants. The current text within ASME PTC 46, which is currently under revision by the ASME PTC 46 Committee, describes in Section 5.3.4 Specified Measured Net Power that “This test is conducted for a combined cycle power plant with duct firing or other form of power augmentation, such as steam or water injection when used for that purpose.” Further, the only example problem for a combined cycle with duct firing is provided in Appendix B of the code utilizing the Specified Measured Net Power Test Method. Though the text and example are correctly presented within the code, it resulted in misinterpretation within the industry that the only correct way to test a combined cycle plant with duct firing was to conduct a Specified Measured Net Power Test. Though the Specified Measured Net Power Test Method is an acceptable and accurate method in determining the performance of a combined cycle plant with duct firing in operation, it lends to being inflexible to the weather conditions for the plant operation. When the weather is too cold, the exhaust energy from the combustion turbines may be at such a magnitude as to not allow the duct burners to be fired due to limitations within the heat recovery steam generator and steam turbine systems to take the load, thus limiting the plant testing to take place when the weather is warm enough to allow the plant to be operated with duct firing. The opposite condition can also exist where the ambient conditions are too hot so that the duct burner capacity is unable to achieve the specified measured net power allowing the test to be conducted. The limitations stated herein are the reasons that an alternative approach with more flexibility is necessary. This paper will present an alternative approach referred to as the Fixed Duct Burner Heat Input Test Method to testing combined cycle plants where the duct burner heat input (Fuel Flow) is held fixed while the plant net power and heat rate are left to float with ambient conditions. Corrections for both power and heat rate will be developed for ambient conditions per ASME PTC 46 guidelines. This paper will further present a comparison between the Specified Measured Net Power Test Method and the Fixed Duct Burner Heat Input Test Method in the areas of the flexibility of the methods for various ambient conditions, and the method uncertainty associated with each method’s ability to correct to reference conditions.

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