Power-plant cycle analysis

In order to determine the costs of essergy A for each interconnecting stream between components, it was found necessary to assign a principal purpose of function to each component (or device, unit, etc.) which would be paid for by a principal product, measured by its essergy content. This scheme which we now call essergetic functional analysis (25), worked fairly well for direct sea water conversion (11,12,13,14,23,24), but it seemed to fail for a simple steam power plant cycle (which was... 

Polytropic process, 68-69 Potential energy, 14-17, 22-24, 31-33, 212-213 Power-plant cycles, 247-271 Rankine, 250-253 regenerative, 255-256 thermodynamic analysis of, 556-561 Poynting factor, 329 Pressure, 9-11 critical, 55-56, 571-572 partial, 300... 

In the area of performance, the steam turbine power plants have an efficiency of about 35%, as compared to combined cycle power plants, which have an efficiency of about 55%. Newer Gas Turbine technology will make combined cycle efficiencies range between 60-65%. As a rule of thumb a 1% increase in efficiency could mean that 3.3% more capital can be invested. However one must be careful that the increase in efficiency does not lead to a decrease in availability. From 1996-2000 we have seen a growth in efficiency of about 10% and a loss in availability of about 10%. This trend must be turned around since many analysis show that a 1% drop in the availability needs about 2-3% increase in efficiency to offset that loss. 

The analysis of the different cycles examined here, which range from the simplest cycle such as evaporative cooling to the more complex cycles such as the humidified and heated compressed air cycle, are rated to their effectiveness and to their cost is shown in Table 2-1. The cycles examined here have been used in actual operation of major power plants, thus there are no cycles evaluated that are only conceptual in nature. The results show addition from 3-21% in power and the increase in efficiency from 0.4-24%... 

If a life cycle analysis were conducted the new costs of a plant are about 7-10% of the life cycle costs. Maintenance costs are approximately 15-20% of the life cycle costs. Operating costs, which essentially consist of energy costs, make up the remainder, between 70-80% of the life cycle costs, of any major power plant. Thus, performance evaluation of the turbine is one of the most important parameter in the operation of a plant. 

In a number of studies, the elemental composition of aerosol particles has been related to their source. Schroeder and co-workers (1987) review the sources, sinks, analysis, deposition, chemical forms, and global cycles of various trace elements. Because the relative amounts of trace elements vary for coal compared to oil-fueled power plants, for example, it has been suggested that certain elements or ratios of elements may serve as tracers for various sources (e.g., see Gordon, 1988 and Rahn and Lowenthal, 1984). Thus V and Ni are indicative of oil combustion, and elevated concentrations of elements such as As and Se are usually... 

NEI NETPATH NFC NGCC NMR NOx NPP NRA NRC Development Nuclear Energy Institute Interactive code for modelling net geochemical reactions along a flow path Nuclear fuel cycle Natural gas combined cycle Nuclear magnetic resonance NO + N02 Nuclear power plant Nuclear reaction analysis National Research Council... 

In this chapter, we explore how the exergy concept can be used in the analysis of energy conversion processes. We provide a brief overview of commonly used technologies and analyze the thermodynamic efficiency of (1) coal and gas combustion, (2) a simple steam power plant, (3) gas turbine, and (4) combined cycle and cogeneration. At the end of this chapter, we summarize our findings with some concluding remarks. 

Example 4.12 Exergy analysis of a power plant A steam power plant operates on a simple ideal Rankine cycle (see Figure 4.18). The turbine receives steam at 698.15 K and 4200 kPa, while the discharged steam is at 40 kPa. The mass flow rate of steam is 3.0 kg/s. In the boiler, heat is transferred into the steam from a source at 1500 K. In the condenser, heat is discharged to the surroundings at 298 K. Determine the energy dissipated at each state. 

Crouse, F. W., Nazemi, A. H., and Lewis, J. P. Performance Analysis of a Pressurized Circulating Fluidized Bed Boiler Combined Cycle Power Plant, Proc. Int. Conf. Fluid. Bed Combust., Volume Data 1982, 7th(l), p. 232 (1983). 

This priority order ensures that co-combustion of waste is only possible in case the waste cannot be re-used or when formation cannot be avoided. Each plan for cocombustion of waste in coal-fired power plants is therefore tested on its order in priority. An Environmental Impact Study is often mandated or desired by the national administration and/or regional authorities, who discuss and compare the possibilities for reutilization and alternative processing routes (for exanqile by means of a Life Cycle Analysis) (KEMA, 1999). 

Sundkvist, S.G., Klang, A., Sjodin, M., Wilhelmsen, K., Asen, K., Tintinelli, A., McCahey, S., and Ye, H. AZEP gas turbine combined cycle power plants thermal optimisation and LCA analysis. Available at http //uregina.ca/ghgt7/PDF/papers/peer/079.pdf (accessed October 18, 2009). 

The full energy cycle approach recognizes that there are process impacts beyond the plant boundary. An important consideration in this energy cycle analysis is the derating of the power plant resulting from C02 capture and sequestration. An equivalent C02 charge must be assessed for... 

Sundkvist SG, Klang A, Sjodin M, WUhelmsen K, Asen K, TintineUi A, McCahey S. AZEP Gas Turbine Combined cycle power plants - thermal optimisation and Lea analysis. 2004. 

It was assumed that the power plant will be financed from revenue bonding. Therefore, reasonable estimates were made for interest on bonds, interest earned and expended during cor)struction, and bond discounts. Working capital and the debt reserve fund were assumed to be capitalized. By projecting all capital and operating costs with reasonable escalation factors, a life-cycle cost analysis was performed. Results of that analysis shown below indicate an estimate of required revenues to offset all costs. These projected costs are favorable when compared to alternative fossil fuel unit costs projected for the New England region. 

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