The problem of saturated steam superheating
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I heard that the best way to make use of the saturated steam generated as a by-product in a plant is to superheat it within the plant before sending it out. What are the advantages and disadvantages of installing a superheater within such a plant?
What device? Steam grade? What heat source do you plan to use for heating?
Provide a detailed explanation of the steam pressure rating you intend to use and where it will be applied.
The last edit to this post was made by lflsedin on 2017-2-5 at 09:53. For example, the 10.0MPa saturated steam generated as a by-product of the vaporization unit is definitely superheated before being used to drive the turbine.
Whether it is necessary to install this superheating device depends mainly on whether you can make use of superheated steam. If your system contains units powered by steam, then a superheating device is indeed necessary, as superheated steam can improve the thermal efficiency of the entire steam power system. It also reduces the moisture content in the exhaust steam, allowing that steam to be utilized further and thus enhancing its efficiency. However, at 10 MPa, the temperature of superheated steam can reach 540–570°C, which is sufficient to ignite most flammable materials. Moreover, it places high demands on the materials used for equipment and pipelines; therefore, the increased investment costs and safety risks must be taken into consideration. Superheating is not recommended in the absence of any practical application.
I would also like to ask you: how can steam of this temperature level be used most effectively without becoming too hot?
Superheated steam can be transported over long distances without condensing.
The issue is described in detail in the article titled “This ‘killer’ isn’t cold at all” on the WeChat official account of Fred Steam Energy Saving; it can also be found on Fred Steam Energy Saving’s official website under the “Sharing Center”.
Steam not only contains heat but also the water within it is highly valuable; therefore, it can be transported over long distances after being superheated. There is no need to install check valves in the delivery pipelines, resulting in less heat loss. Moreover, since no water precipitates out, erosion and damage to the pipelines are reduced as well. Therefore, transporting steam at superheated conditions is a good practice.
Superheating is intended to increase the dryness of the steam being transported, reduce condensation during pipeline transport, and prevent water hammer. Whether superheating is feasible depends on the material chosen; there is also a temperature difference for heat transfer between the inside and outside of the pipes. The material selected must ensure that no thermal damage occurs, as this could affect the overall safety of the system – in such cases, the benefits of superheating would not outweigh the drawbacks.