Boilers utility steam generators

It is these differences in in-house boiler plant facility resources and the perceived need to obtain technical support from an external source that led me to consider grouping boiler plant systems in a slightly different way than is typically perceived, which in turn provided a focus for this book. Thus, although commercial, industrial, and utility steam generators can be classified in several different ways (such as by pressure, output, fundamental design type, etc.), their owners and operators can be classified as members of one or other of only two groups. 

G. Navitsky and F. Gabrielli, Boiler water treatment, feedwater treatment, and chemical cleaning of drum-type utility steam generators. Combustion 52(2), 19 (1980). 

Steam-Generator Circulation System Circulation systems for utility application are generally classified as natural circulation and forced or pump-assisted circulation in drum-type boilers, and as once-through now in subcritical- and supercriticaf-pressure boilers. The... 

The Combined (Brayton-Rankine) Cycle The 1990s has seen the rebirth of the combined cycle, the combination of gas turbine technologies with the steam turbine. This has been a major shift for the utility industry, which was heavily steam-tnrbine-oriented with the use of the gas turbine for peaking power. In this combined cycle, the hot gases from the turbine exhaust are used in a heat recoveiy steam generator or in some cases in a snpplementaiy fired boiler to produce superheated steam. 

Process Steam Generation. Steam generated in the process sections of the plant may be at the highest plant pressure level or an intermediate level. Also, the process area may have fired boilers, waste heat boilers, or both. There may be crossties between utility and process generated steam levels. Enough controls must be provided to balance far-ranging steam systems and protect the most critical units in the event of boiler feedwater shortage situations. 

The cost estimate should include provisions for any required satellite boiler water analysis laboratories. The central control lab cannot normally handle analyses of widely spread boilers satisfactorily. The designers, while remembering satellite water laboratory facilities for the utilities area, might overlook similar facilities for the steam generation in the process area. 

Pressure relieving devices in process plants for process and utility steam systems must conform to the requirements of ASME [1] Par. UG-131b. This is not necessarily satisfactory to meet the ASME Power Boiler Code for applications on power generating equipment. 

The first three boiler types may be variously used for commercial, institutional, or industrial applications. Fire tube boilers also may be used for steam turbine generator duty at lower electrical outputs, whereas only WT and nuclear reactor boilers are employed for utility power generation. 

Utility operators may choose from several technologies to generate electricity, although the most common approach is via the use of high-temperature, fossil fuel boiler plants. In this case, the boiler (steam generator) itself may be of several different design types. 

Utilities steam boilers, compressed air, power generation, refrigeration, transformer... 

Figure 23.2 shows a schematic representation of a boiler feedwater treatment system. Raw water from a reservoir, river, lake, borehole or a seawater desalination plant is fed to the steam system. However, it needs to be treated before it can be used for steam generation. The treatment required depends both on the quality of the raw water and the requirements of the utility system. The principal problems with raw water are1,2 ... 

So far, the objective in setting the steam levels has been to maximize heat recovery through the steam system. Figure 23.38 shows the potential of a single intermediate steam main to reduce steam generation in the utility steam boilers. As additional intermediate steam mains are introduced, as shown in Figure 23.39, increased heat... 

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