SYNGAS CAPABLE COMBUSTION SYSTEMS DEVELOPMENT FOR ADVANCED GAS TURBINES
In the age of volatile and ever increasing natural gas fuel prices, strict new emission regulations and technological advancements, modern IGCC plants are the answer to growing market demands for efficient and environmentally friendly power generation. IGCC technology allows the use of low cost opportunity fuels, such as coal, of which there is a more than a 200-year supply in the U.S., and refinery residues, such as petroleum coke and residual oil. Future IGCC plants are expected to be more efficient and have a potential to be a lower cost solution to future CO2 and mercury regulations compared to the direct coal fired steam plants. Siemens has more than 300,000 hours of successful IGCC plant operational experience on a variety of heavy duty gas turbine models in Europe and the U.S. The gas turbines involved range from SGT5-2000E to SGT63000E (former designations are shown on Table 1). Future IGCC applications will extend this experience to the SGT5-4000F and SGT6-4000F/5000F/6000G gas turbines. In the currently operating Siemens’ 60 Hz fleet, the SGT6-5000F gas turbine has the most operating engines and the most cumulative operating hours. Over the years, advancements have increased its performance and decreased its emissions and life cycle costs without impacting reliability. Development has been initiated to verify its readiness for future IGCC application including syngas combustion system testing. Similar efforts are planned for the SGT6-6000G and SGT5-4000F/SGT6-4000F models. This paper discusses the extensive development programs that have been carried out to demonstrate that target emissions and engine operability can be achieved on syngas operation in advanced F-class 50 Hz and 60 Hz gas turbine based IGCC applications.
Analysis of the Behaviour of Biofuel-Fired Gas Turbine Power Plants
The utilisation of biofuels in gas turbines is a promising alternative to fossil fuels for power generation. It would lead to significant reduction of CO2 emissions using an existing combustion technology, although significant changes seem to be needed and further technological development is necessary. The goal of this work is to perform energy and exergy analyses of the behaviour of gas turbines fired with biogas, ethanol and synthesis gas (bio-syngas), compared with natural gas. The global energy transformation process (i.e. from biomass to electricity) has also been studied. Furthermore, the potential reduction of CO2 emissions attained by the use of biofuels has been determined, considering the restrictions regarding biomass availability. Two different simulation tools have been used to accomplish the aims of this work. The results suggest a high interest and the technical viability of the use of Biomass Integrated Gasification Combined Cycle (BIGCC) systems for large scale power generation.
HYPERGOLIC REACTION MECHANISMS OF CATALYTICALLY PROMOTED FUELS WITH ROCKET GRADE HYDROGEN PEROXIDE
Abstract The coupling of the physical and chemical processes controlling the ignition delays (τ ign ) of hypergolic propellants complicates the direct analysis of the transient ignition processes. The transport properties of both the propellants and the ambient gas, and the heat of vaporization and reaction affect τ ign and must be considered experimentally. Furthermore, since hypergolic ignition occurs, by definition, on contact, the mechanics of initial contact and subsequent mixing can affect τ ign and must also be considered. Experimental results from a study of the hypergolic ignition of a catalytically promoted fuel with rocket grade hydrogen peroxide (RGHP) are presented. Statistical analysis of the experimental data was conducted to evaluate the relative effects of RGHP concentration, initial ambient pressure, and the ambient gas on τ ign . At RGHP concentrations of less than 92% in water, stable ignition was difficult to achieve. At sufficiently high Lewis number, an oscillatory ignition process is observed. A phenomenological model comprising mixing, RGHP decomposition, fuel heating and vaporization, and auto-ignition is presented and compared to the experimental results.