This chapter covers the essential features of key equipment encountered in electric power generation systems, gas and steam turbines, heat exchange systems receiving into and discarding heat from those systems, and other lesser equipment.

A gas turbine engine is a device that is designed to convert the thermal energy of a fuel into some form of useful power, such as mechanical (or shaft) power or a high-speed thrust of a jet. The engine consists, basically, of a gas generator and a power conversion section, as shown in Figures 1.1 and 1.2.

The focus in this chapter is on the optimal integration of concentrated solar power (CSP) and the gas turbine combined cycle (GTCC) via the bottoming cycle of the latter in an integrated solar combined cycle (ISCC) framework, which can be considered as a currently available (if not truly mature) technology.

In this chapter, we will get familiar with a unique performance gauge, which is not process dependent, but is rather state dependent, by definition. In other words, the newly defined, so-called “polytropic” efficiency is independent of the size of a turbomachine (in terms of the total-to-total pressure ratio). In addition, we will have a means of computing the overall efficiency of several stages, sharing the same total-to-total magnitudes of pressure ratio and efficiency, without having to resort to the thermodynamics of each individual stage. The point is made that adding more stages to a multistage turbomachine will have drastic, but totally opposite, effects on turbines as contrasted to compressors. We will prove through this exercise that adding more turbine stages enhances the performance of the final turbine configuration. The effect in compressors, on the other hand, is that of performance deterioration.

Consider the simplest nonafterburning, single-spool turbojet engine, which is schematically shown in Figure 12.1. Assuming a viable (i.e., stable compressor) operation mode, there are obvious constrains relating the gas-generator components to one another. These generally enforce the uniformity of shaft speed, as well as ensure the mass and energy conservation principles (Figure 12.2).

In this chapter, the focus is on post-combustion CO2 capture (PCC) from the heat recovery steam generator (HRSG) stack gas in a gas turbine combined cycle (GTCC) power plant. The reason for that is simple: GTCC with advanced class gas turbines and post-combustion capture represents the most cost-effective technology for carbon-free electric power generation from fossil fuels. The chapter includes detailed description of the PCC system, key equipment, and the operability of the system.

Utilization of axial-flow compressor stages (Figure 9.1) in gas turbine engines is a relatively recent development. The history of this compressor type began after an era when centrifugal compressors were dominant (Figure 9.2). It was later confirmed, on an experimental basis, that axial-flow compressors can run much more efficiently. Earlier attempts to build multistage axial-flow compressors entailed running multistage axial-flow turbines in the reverse direction. As presented in Chapter 4, a compressor-stage reaction, in this case, will be negative, a situation that has its own performance degradation effect. Today, carefully designed axial-flow compressor stages can very well have efficiencies in excess of 80%. A good part of this advancement is owing to the standardization of thoughtfully devised compressor-cascade blading rules.

This chapter covers the basic principles, concepts, and tools governing the operation of the equipment and systems described in Chapter 3. The operation of those systems in off-design conditions, steady as well as unsteady (transient), are described using basic formulae and charts.

In this chapter, a turbomachinery-related nondimensional groupings of geometric dimensions and thermodynamic properties will be derived.

In this chapter, the flow-governing equations (conservation laws) are reviewed, with applications that are purposely turbomachinery related. Particular emphasis is placed on the total (or stagnation) flow properties. A turbomachinery-adapted Mach number definition is also introduced as a compressibility measure of the flow field. A considerable part of the chapter is devoted to the total-relative properties, which, together with the relative velocity, define a legitimate thermophysical state. Different means of gauging the performance of a turbomachine, and the wisdom behind each of them, are discussed. Also explored is the entropy-production principle, as a way of assessing the performance of turbomachinery components. The point is stressed that the calculation of entropy production may indeed be desirable, for it is the only meaningful performance measure that is accumulative (or addable) by its mere definition.

This chapter lists the acronyms used in the text, the heat and mass balance software used for numerical examples, and key concepts to evaluate the technical and commercial viability of novel technologies.

This chapter explains the background behind the book concept, e.g., the meaning of sustainability within the electric power generation context, energy transition, and decarbonization. Technologies that are covered in the book are described in brief. The concept of operability and how it pertains to the main theme of the book is addressed.

From a historical viewpoint, the centrifugal compressor configuration was developed and used, even in the propulsion field, well before axial-flow compressors were. Due to their large envelope and weight (Figure 11.1), the common belief that such a “bulky” compressor type has no place except in aerospace applications is not exactly accurate. For example, with a typical total-to-total pressure ratio of, for example, 5:1, it would take up to three axial-compressor stages to absorb similar amounts of shaft work that a single centrifugal compressor stage would. In fact, the added engine length, with so many axial stages, would increase the skin friction drag on the engine exterior, almost as much as the profile drag, which is a function of the frontal area.

While coal seems to be out of the picture in the energy transition, there are technologies that make sustainable use of this abundant resource. This chapter covers several technologies, i.e., gasification, magnetohydrodynamics, and coal slurry, which, when combined with carbon capture, can make this a reality.

This chapter covers the basics of energy storage, i.e., why it is needed, when it is used, how it is used, its benefits, and the types of energy storage technologies. Special attention is given to thermal energy storage due to its usage in a variety of guises in renewable power applications.

Sometime around 2010 and thereafter, trade publications and archival journals were inundated with articles and papers filled with hyperbole and lofty claims about the closed cycle sCO2 turbines and their merits. In particular, sCO2 cycle/turbine was/is touted as a technology that can replace Rankine (steam) cycle and steam turbine in conventional fossil fuel-fired power generation, as a stand-alone or as the bottoming cycle of a gas turbine combined cycle. In this chapter, performance of sCO2 in power generation applications (including the Allam cycle) is rigorously assessed with in-depth thermodynamic analysis and cycle data. Furthermore, we will also look at the operability challenges presented by the unique structure of the sCO2 powertrain and heat exchangers.