[Difficult Problem] Transient hydraulic analysis of oil pipelines

This post was last edited by tekchina on 2009-5-21 at 17:05. Transient hydrodynamics is probably a type of water hammer phenomenon; the most common occurrence of it is in pipelines when pumps are started or stopped. Water hammer is a pressure wave that occurs in transient flow within pipes; it results from a change in the flow velocity at a certain section of the pipe – mainly due to normal flow regulation or pipe blockages caused by accidents – which leads to a sudden increase or decrease in pressure at that location, and this pressure variation propagates throughout the entire system in the form of waves. The main factors that cause water hammer include: the normal opening, closing, or adjustment of valves, as well as accidental opening/closing and blockages due to damage ； Starting and stopping of the pump ； Condensate water and similar substances appear in the steam pipes during the heating process. The hazards of water hammer are mainly manifested in the following way: when pressure waves encounter pipe bends or other areas where the direction of the pipe changes, the water hammer pressure acts on the pipe, causing it to vibrate violently ； When the water hammer pressure is too high, the pipes may burst due to the excessive pressure. Methods to prevent water hammer: open and close valves slowly, reduce the speed at which steam pipes are started up, and install safety valves or water hammer arrestors (accumulators) on the pipes. In addition, fixing brackets and guiding brackets should be installed at appropriate locations along the pipeline, and these brackets must have sufficient stiffness to prevent the pipeline from being damaged due to excessive displacement and vibration when water hammer occurs. The above content is for reference only

Vent openings are installed at high points, and safety valves are placed in certain areas; generally, the pressure caused by water hammer is 1.2 to 3 times the normal pressure