Gas Turbine Systems

Validation and Application. VaUdated CFD examples are emerging (30) as are examples of limitations and misappHcations (31). ReaUsm depends on the adequacy of the physical and chemical representations, the scale of resolution for the appHcation, numerical accuracy of the solution algorithms, and skills appHed in execution. Data are available on performance characteristics of industrial furnaces and gas turbines systems operating with turbulent diffusion flames have been studied for simple two-dimensional geometries and selected conditions (32). Turbulent diffusion flames are produced when fuel and air are injected separately into the reactor. Second-order and infinitely fast reactions coupled with mixing have been analyzed with the k—Z model to describe the macromixing process. 

El-Masri, M.A. (1988), GASCAN—an interactive code for thermal analysis of gas turbine systems. ASME J. Engng Power Gas Turbines 110. 201-209. 

Bannister, R. L. Clieruvu, N. S. Little, D. A. and McQuiggan, G. (1995). Development Requirements for an Advanced Gas Turbine System. TnusActions of the ASME, Journal of Engineering for Gas Turbines tuid Power 117 724-733. 

Gas turbine systems operate on the thermodynamic cycle known as the Brayton cycle. In a Brayton cycle, atmospheric... 

Power Generation by Combined Fuel Cell and Gas Turbine Systems... 

Catalysts are often implemented in the walls of monolith channels, with overall performance depending on a balance between surface reactivity and flow conditions. Consider a situation that represents a catalytic-combustion monolith such as in a gas-turbine system (e.g., Fig. 17.17), where an individual channel diameter of d = 2 mm and a length of L = 5 cm. The channel walls may be assumed to be isothermal at Tw = 800°C. A CH4-air mixture enters the monolith with a equivalence ratio of(p = 0.3, inlet temperature of Tm — 400°C, and pressure of p = 1 atm. 

Since the catalyst in a gas-turbine system is downstream of the compressor, it usually runs at elevated pressure. For a given fuel-air mass-flow rate, discuss how pressure affects the system performance. How does pressure affect Reynolds number ... 

Fig. 23. HTGR gas turbine system with exceptional cycle thermodynamic efficiency. (GA Technologies)...

Gemmen, R.S., Liese, E., Rivera, J., Jabbari, F. and Brouwer, J. (2000a) Development of dynamic modeling tools for solid oxide and molten carbonate hybrid fuel cell gas turbine systems, International Gas Turbine Institute Meeting of the ASME, May 8-12, 2000. 

Figure 8.2 shows a gas turbine system that has intercooling between a two-stage compressor and recuperation of the turbine exhaust. Inserting the isentropic relationship, Equation (8.2), into the definitions for compressor and turbine power gives Equations (8.3) and (8.4) respectively ... 

The analysis in Section 8.3 provided a general understanding of GT performance with a turbine inlet temperature representative of current SOFC exhaust temperatures. An analysis of an entire fuel cell and gas turbine system will now be examined, where the fuel cell essentially replaces the combustor in Figure 8.2, and the GT will produce some fraction of the total power. What remains to be defined is the method by which the air to the fuel cell cathode is brought to an acceptably high temperature for operation. Three basic pressurized SOFC/GT configurations are chosen... 

In evaluation of the potential objects which are to define respective options to be taken into a consideration there are 99 objects. In this exercise we will focus our attention on the following hydrogen energy systems Fossil-Reforming-Intemal Combustion Engine System, Natural Gas Steam Reforming-Fuel Cell System, Nuclear Power-Electrolysis-Fuel Cell System, Solar Power-Electrolysis-Fuel Cell System, Wind Power-Electrolysis-Fuel Cell System, Biomass-Reforming-Gas Turbine System. 

High-temperature fuel cells, on the other hand, can offer substantial co2 savings. With electric efficiencies of 50 percent and high-quality heat, molten carbonate fuel cells and sofcs hold the prospect of cutting co2 emissions in factories and buildings by one-third or more. Should hybrid fuel cell and gas turbine systems become economical, they could potentially reduce by half or more the co2 emissions of the systems they replace. 

The additional advantage is that it allows the hot emergent gases to drive a turbine and the 200 kW, 3 atm. system is coupled to a small gas turbine generating 50 kW. The predictions are that such combined cell and gas turbine systems can achieve overall efficiencies as high as 70% and it seems... 

Li, K. W., "Second-Law Analysis of the Air-Storage Gas Turbine System," ASME Paper No. 76-JPGC-GT-2, ASME, NY (1976). 

Extensive alterations to the fuel system was necessary in order to bum bio-oil from pyrolysis. The flow diagram in Fig. 2 shows the layout of the gas turbine system after modifications. The temperatures and pressures refer to diesel fuel operation. 

Earlier work described static electricity generation during filtration and the oil auto-oxidation due to spark discharges, respectively [74,75], It was considered that there are overlooked factors like hot spots which produce varnish in gas turbine systems. Thus, spark discharges of static electricity have a strong influence on oil oxidation. A new, simple method to test formation of varnish has been proposed [76]. Typical varnish problems are shown in Figs. 8.9 and 8.10. 

Molten carbonate fuel cells could reduce C02 emissions in industrial and commercial facilities by a third. Hybrid fuel cell and gas turbine systems could reduce these emissions by one half or more. 

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