Steam system configuration

As noted previously, the normal maximum pressure for distribution is around 40 bar. Heat losses in the distribution system might be typically 10% of the fuel fired in the boilers, but can be higher. 

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Clearly, the basis for calculating both the average and marginal steam prices is an overall steam balance including BFW and condensate balances, which is discussed in Chapter 16. The method for calculation of average steam costs follows a top-down approach, while the steam balance corresponds to the most common production scenario and steam system configuration. 

A steam system configuration implies the number of steam headers and their pressure and temperatures, the number of steam turbine drivers and generators, as well as their operating ranges and efficiency, the connections of turbines with steam... 

Clearly, cogeneration efficiency is a function of R ratio and the steam system configuration. Although the steam system is operated with the objective of achieving minimum cost, the maximum efficiency provides a measure of the best efficiency which the system can reach for a given configuration. 

You may ask What is the steam system configuration that can achieve the best cogeneration efficiency for a given process steam and power demands In the previous discussions, we know that the maximum cogeneration features maximal back-pressure power generation and minimal condensing. To achieve this, let us define the ideal R ratio, which is expressed as... 

FIGURE 19.1. Base steam system configuration and costs. 

System Configuration steam header pressures, steam turbine configration, maximal cogeneration efficiency. 

Although the details of establishing steam balances are discussed in Chapter 16 while steam equipment modeling equations are given in Chapter 15, the intention here is to combine all the related equations to develop a complete simulation and optimization model for the steam system. For specific applications, users can revise the model by providing specific configuration and conditions for the steam system. 

The system configuration varies depending on the method of generating electricity a steam turbine, a gas turbine, or others. As for sodium cooling, the sodium-water reaction has to be... 

Figure VIII-2 shows the Package-Reactor system configuration inside the containment vessel. To reduce construction costs, the prototype currently being developed adopts twelve nuclear cassettes and three steam generators as one package (unit). Every four cassettes are connected to one steam generator. Heat transfer tubes in the SG are separated into two groups in view of a heat transfer tube rupture event. During normal operation, pressure boundaries are maintained by the cassettes and steam generators, while the containment vessel is kept under atmospheric pressure. The containment vessel is made of stainless steel with a height and diameter of about 10 m and 5.5 m, respectively.

In the process industries, the Simplex algorithm has been applied to a wide range of problems, such as the optimization of a total plant utility system. A general steam utility configuration, typically involving as... 

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