Power plant thermodynamic analysis

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. 

The second application of availability analysis is used to evaluate the nature and magnitude of thermodynamic irreversibilities in a methane reformer plant coupled to a high-temperature nuclear reactor. It is shown that a combination of thermal histograms and availability concepts are helpful not only in evaluating the net impact of irreversibilities in various chemical process steps on the steam power plant, but, more importantly, 1n suggesting process modifications that could improve the overall efficiency by avoiding unnecessary entropy production. 

From the foregoing analysis 1t is clear that a process modification that helps eliminate or minimize the irreversibility associated with the reactor feed preparation will lead to a major reduction in the thermal mismatch, reduce the exergy dependence on the power plant, and increase the overall energy efficiency. In the author s opinion, this conclusion would not be evident as readily without the thermodynamic analysis of process irreversibilities, which attests to the value of such exergy analyses. 

Example 16.5 The operating conditions of a practical steam power plant are described in Example 8.1, parts (b) and (c). In addition, steam generation is accomplished in a fumace/boiler unit where methane is burned completely to C02 and H20 with 25 percent excess air. The flue gas leaving the furnace has a temperature of 460 K, and T0 = 298.15 K. Make a thermodynamic analysis of the power plant. 

The work to drive the compressor Wc comes from the turbine, and the additional work of the t IV, is the net work output of the power plant. The compressor and turbine efficiencies are giv the figure. Assume air an ideal gas for which CP = (7/2)H Including the nuclear reactor as the system and treating it as a heat reservoir at 650°C, make a thermodynamic analysis of the j T0 = 293.15 K. 

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... 

Pfaff I., Kather A. Comparative thermodynamic analysis and integration issues of CCS steam power plants based on oxy-combustion with cryogenic or... 

Castillo R. Thermodynamic analysis of a hard coal oxyfuel power plant with high temperature three-end membrane for air separation . Applied Energy, 88(5), 1480-1493,2011, ISSN 0306-2619, doi 10.1016/j.apenergy.2010.10.044. 

Fredriksson Moller B., Torisson T., Assadi M. AZEP gas turbine combined cycle power plants - thermo-economic analysis . International Journal of Thermodynamics, 9(1), 21-28,2006. 

This chapter summarizes fundamental principles of thermod mamics with a focus on applications related to analysis of nuclear power plants. For brevity, relatively few references are given in introductory material, but most of the introductory material may be found in a good thermodynamics textbook, such as Moran and Shapiro (2008). References on second law analysis tend to be advanced thermodynamic textbooks, such as Wark (1995) or more specialized references such as Moran (1982). 

Thermodynamic analysis of power plants seeks to characterize efficiency and identify sources of losses. First law analysis assesses performance based on energy balance equations, while second law analysis uses exergy balances and looks for locations of exergy destruction. In this section, analysis methods are developed to apply thermodynamic balance equations to analyze heat engines and power plant components. Results are summarized in Appendix B of this chapter and detailed examples are provided in Section 23.6. 

Fathian, F. (2010) Thermodynamic analysis of a hybrid solid oxide fuel cell gas turbine power plant. World Appl. Set.].,... 

The purpose of an exergy analysis is generally to identify the location, the source, and the magnitude of true thermodynamic inefficiencies in power plants. Exergy flow... 

Swanson CE, Elzey JW, Hershberget RE, Donnelly RJ. Thermodynamic analysis of low-temperature carbon dioxide capture from coal-buming power plants. Phys Rev E 2012 86 016103. 

Sugano et al. [46] reported the analysis of the dynamic behavior of a PAFC stack cooling systems. Miki and Shimizu [47] reported the results of the dynamic characteristics of a fuzzy control based stack cooling system. An analytical, exergetic, and thermoeconomic analysis of a 200 kWel PAFC power plant was presented by Kwak et al. [48]. In [49], a novel optimization tool was developed that realistically described and optimized the performance of a PAFC system. Zhang et al. [50] presented an analytical model to optimize several parameters using a thermodynamic-electrochemical analysis. In [51], a dynamic model was developed to simulate a PAFC system and associated components. 

Power generation plants such as the steam plant, the gas turbine plant, and combined cycle plants require the combustion of a fossil fuel. Now, combustion is a chemical reaction of fuel with an oxidant (usually oxygen), and it makes sense to examine the combustion process more closely and analyze its thermodynamic efficiency. This means that we will examine the furnace/combustor of Figures 9.8, 9.10, and 9.12. We will examine coal and gas combustion at the level needed for thermodynamic analysis, after discussing some commonly used coal combustion processes. 

We wish to alert the reader that in the analyses presented above, the results were essentially independent of the type of fuel used. From an efficiency point of view, this may be true, but from a sustainability point of view, it is not. In general, gas is a much cleaner burning fuel than coal and requires less pre- and posttreatment. Even though the standard power generation plants can be made more efficient using thermodynamic analysis (lost work, availability, or exergy analysis), we note that power generation based on fossil fuels is not sustainable since the combustion of these fuels leads to increased... 

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