09-02-05 Topic — Calculation of pressure loss in coiled tubes (prize for participation)
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Coils are also commonly used in the chemical industry, but I wonder if anyone has noticed how to calculate the pressure loss of such coils? Note: This topic was provided by member ZLF60137; the provider should pay close attention and provide a summary or the correct answer within 24 hours.
Participate in it… The pressure drop associated with regulation can be broken down into the following components: the pressure drop across the tee from the inlet pipe to the collector, as well as the pressure drop due to sudden expansion; the pressure drop due to sudden contraction from the collector to the heat exchange tubes; the pressure drop within the straight sections of the heat exchange tubes, as well as the pressure loss at the 180-degree bends; the pressure drop due to sudden expansion from the heat exchange tubes to the outlet collector; and the pressure drop due to sudden contraction from the outlet collector to the outlet pipe. That’s roughly all of it. It’s easy to calculate the pressure drops in the straight sections, while different formulas are used for local pressure drops, resulting in varying outcomes. Some software also includes a safety factor, but overall, each method has its advantages. In short, it’s difficult to determine exact deviations; we should rely on actual measurements on-site, with other calculations serving only as references.
There are many types of coiled tubes, and those commonly used in the chemical industry are usually spiral coiled tubes that form one or two to three turns with varying radii of curvature. Pipe joints are mostly connected by butt welding, and after formation they are secured using fixing frames. The resistance of this type of coil is mainly frictional resistance, while the resistance at the inlet and outlet can be ignored. When calculating the friction loss along a pipe, we first perform the calculations as if it were a straight pipe, and then multiply the result by various correction factors based on factors such as the pipe diameter, the ratio of the bending radius to the pipe diameter, the physical properties of the fluid, and the flow velocity of the fluid. The range of the correction coefficient is 1.6 to 4. Depending on the specific circumstances, the correction factor is selected based on experience.
There are many types of coils, including spiral coils and serpentine coils. In the chemical industry, spiral coils that are wound in multiple turns with one or two to three bending radii are commonly used. Pipe joints are mostly connected by butt welding, and after formation they are secured using fixing frames. The resistance of this type of coil is mainly frictional resistance, while the resistance at the inlet and outlet can be ignored. When calculating the friction loss along a pipe, we first perform the calculations as if it were a straight pipe, and then multiply the result by various correction factors based on factors such as the pipe diameter, the ratio of the bending radius to the pipe diameter, the physical properties of the fluid, and the flow velocity of the fluid. The range of the correction coefficient is 1.6 to 4. Depending on the specific circumstances, the correction factor is selected based on experience. The answer is good, but has such a calculation been experimentally verified? This post was last edited by ZLF60137 on 2009-2-7 08:33.]