【Mechanical Equipment Technology Exchange Edition】Mechanical Equipment 【Daily Question】20190805
Thread Content
Question: What are the main stresses borne by the superheater tubes and the main steam pipes? There are no answers provided for this series of posts; fellow netizens are free to share their own opinions – just reply with what you understand. Replies earn rewards ranging from 5 to 15 points; all forum members are welcome to participate actively and support the development of the forum! ! ! Chemical Equipment and Machinery
It is primarily subjected to the temperature and pressure of the superheated steam inside the pipe, as well as additional loads resulting from the weight of the steel pipe itself, the weight of the fluid, and the weight of the insulation material. The temperature of the pipe wall is close to that of the superheated steam; in other words, the steam pipeline operates under conditions that lead to creep. Furthermore, during boiler start-up, shutdown, and load variation conditions, it is also subjected to periodically changing loads and thermal stresses, that is, to low-cycle fatigue loads.
It primarily bears the effects of the temperature and pressure of the superheated steam inside the pipeline, as well as additional loads such as the weight of the pipeline itself, the weight of the fluid, the weight of the insulation, and the weights associated with supports and suspensions； Under conditions of load variation or shutdown of the boiler, there are also periodic loads and thermal stresses acting on it, that is, it is subject to low-cycle fatigue loads.
a. Calculate based on the inclined surface area according to the dimensions shown in the design drawings
It is primarily subjected to the temperature and pressure of the superheated steam inside the pipe, as well as additional loads resulting from the weight of the steel pipe itself, the weight of the fluid, and the weight of the insulation material. The temperature of the pipe wall is close to that of the superheated steam; in other words, the steam pipeline operates under conditions that lead to creep. Furthermore, during boiler start-up, shutdown, and load variation conditions, it is also subjected to periodically changing loads and thermal stresses, that is, to low-cycle fatigue loads.
Steam pipes include main steam pipes, main steam headers, steam guide pipes, and reheat steam pipes, etc. The outside of the steam pipeline is not exposed to high-temperature flue gas; it is only affected by the temperature and pressure of the superheated steam inside it.