Thermal pipeline problems
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Hello, everyone. I’m a complete beginner when it comes to thermal pipelines, and I have a question: what is the impact of the number of fittings on a thermal pipeline on the horizontal thrust exerted on the pipeline? (Does adding fittings to thermal pipelines reduce horizontal thrust?) ）
@Luxing Tianxia @jackzwt @hdf4242 @yudeguoshi @llu85 @jeffen911 @mliu-5 @Guanghui – Now that everyone has some time, please take the time to guide the newcomers~
Fittings are quite broad, and they have little effect on the axial thrust of the pipeline. If a square-shaped compensation is used for the heat pipe, the dimensions of the short arm and the long arm affect the thrust; calculations are required, and the load-bearing capacity of the civil structure must also be taken into account.
For a single thermal pipeline, the thrust at the fixing points is related to the pipe diameter, temperature, and the spacing between the fixing points. In general, the better the flexibility, the smaller the thrust. For multiple thermal pipelines, a restraint coefficient can generally be used for comprehensive consideration. There are methods for determining the restraint coefficient in the specifications.
The number of pipe fittings does not directly reduce the thrust; rather, it relates to the effective routing of the pipes or to compensation mechanisms. The thrust at the fixing frame is primarily composed of the reaction force due to thermal expansion of the pipeline and frictional forces. If you want to reduce thrust, you need to focus on these two aspects.
The tube is an elastic element that has absorbing properties in certain areas. Fittings are rigid components; placing them in locations where force absorption is required will not enable force absorption and will certainly increase the thrust on the existing piping system.
Thermal stress is generated as a result of certain processes; to reduce this thermal stress, it is necessary to increase the flexibility of the pipelines. Methods include adding more loops (by increasing the number of bends) or checking whether lateral supports provide sufficient resistance to thermal forces. If so, remove the lateral baffles, but they must be able to withstand earthquakes and wind forces. Generally, the points of equipment nozzles are simulated using the Anchor method, which is a more conservative approach. If it is observed that the thermal force of the Anchor is relatively large, it can also be simulated using the program’s nozzle. The resulting thermal force will therefore be smaller.
Fittings are added to improve the flexibility of the pipes, absorb thermal expansion, and thereby reduce pipe stress. By adding π-shaped bends, the flexibility of the pipeline is improved and the number of elbows increases, but the cost also rises.
The fixing piers and compensators near the valve need to take into account the pressure thrust generated when the valve is closed.