Steam generators

Besides describing the overall layout of today s coal-fired steam generators for steam parameters of up to 30 MPa/600 °C, in the following sections the design and selection of materials for the just mentioned highly stressed components in steam generators will be discussed in detail. 

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In design, the same rules must be obeyed around a utility pinch as around a process pinch. Heat should not be transferred across it by process-to-process transfer, and there should be no inappropriate use of utilities. In Fig. 6.13a this means that the only utility to be used above the utility pinch is steam generation and only cooling water below. In Fig. 6.136 this means that the only utility to be used above... 

Example 6.6 The problem table cascade for a process is given in Table 6.9 for — 10°C. It is proposed to provide process cooling by steam generation... 

These sources of waste from the steam system can be reduced by increasing the percentage of condensate returned (in addition to reducing steam generation by increased heat recovery). 

Reducing wastewater associated with steam generation by both reducing steam use through improved heat recovery and by making the steam system itself more efficient. 

The policy for waste heat recovery from the flue gas varies between incinerator operators. Incinerators located on the waste producer s site tend to be fitted with waste heat recovery systems, usually steam generation, which is fed into the site steam mains. Merchant incinerator operators, who incinerate other people s waste and... 

Figure 13.8 The grand composite curve for the whole process apparently requires only high-pressure steam generation from boiler feedwater.

Figure 16.19 shows the grand composite curve plotted from the problem table cascade. The two levels of steam generation are shown. 

Figure 16.19 Grand composite curve for Example 16.3 showing two levels of steam generation.

The problem with this approach is that if the steam generated in the boilers is at a very high pressure and/or the ratio of power to fuel costs is high, then the value of low-pressure steam can be extremely low or even negative. This is not sensible and discourages efficient use of low-pressure steam, since it leads to low-pressure steam with a value considerably less than its fuel value. 

Numerical Modeling of eddy current steam generator inspection Comparison with experimental data, P.O. Gros, Review of Progress in Quantitative Nondestructive Evaluation, Vol 16 A, D.O. Thompson D. Chimenti, Eds (Plenium, New York 1997) pp 257-261. 

Progress in mean of modelisation and inverse problem solving [1] let us hope to dispose soon of these tools for flaws 3D imaging in Non Destructive Control with eddy current sensors. This will achieve a real improvement of the actual methods, mainly based upon signature analysis. But the actual eddy current probes used for steam generators tubes inspection in nuclear industry do not produce the adequate measurements and/or are not modelisable. 

Our main application domain is the steam generator tubes of pressurized water nuclear plant. These tubes have 22.22 mm outer diameter and 1 27 mm thickness. 

The automatic acquisition and analysis system we developed within the scope of the Super-Phenix steam generator tube inspection by ultrasonic arrays is a remarkable example of an exhaustive acoustic verification system. It works for every type of probe for tube inspection. 

Q. Moreau, et al., Ultrasonic control system for Superphenix Steam Generator tubes , SMIRT 1997, Lyon... 

Due to the many problems concerning steam generators of nuclear power plants over the last decades, we developed our own inspection equipment and services. Next to this main activity, we provide inspections for nuclear power plants components such as thimbles, guide carts and baffle bolts. 

It has developed a real time method to compare successive non-destructive inspections of the steam generator tubes in nuclear power plants. Each tube provides a safety barrier between the primary and secondary coolant circuits. Each steam generator contains several thousands of tubes whose structural integrity must be ensured through the lifetime of the plant, Therefore, Laborelec performs extensive nondestructive tests after each plant outage. 

Using CD s streamlines the automatic comparison of data. Because of their large storage capacity and their reduced dimensions CD s provide a complete historical database for all steam generator tubes from a mobile inspection platform. 

The signal comparison function has been impieinented and tested during a steam generator tube inspection. A formal test in the real-life context was successfully done with a simple rule (parameters phase and amplitude) based on the central frequency for the distance signal. 

Figure 4. Laser Profile of Dented Steam Generator Tube...

Optical Probe for Steam Generator Tube Dent Measurement , EPRI NP-2863, Project SI81-1, February, 1983. 

Steam generator. For small scale work the steam generator D, Fig. 15, p. 33) is too cumbersome for the production of a small amount of steam. It is preferable to use a 250 ml. conical flask fitted with cork containing a vertical safety tube and an outlet-tube (Fig. 44). Care should be taken that the length of rubber tubing connecting the steam oudet tube to the flask containing the materi to be distilled should be as short as possible and should not contain kinks. 

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