Dear Sir,
Request to have your expert opinion on my below queries:-
1. To check the adequacy Thermowell located on piping (flowing with three phase fluid i.e Gas+ Oil+ water ), what approach has normally been taken by your designer. Online calculation available on Emerson site have the provision for single phase fluid entry only. Will it be realistic to perform the calculation considering single phase flowing however in actual three phase fluid is flowing through the same.
2. Do we need to perform the Wake Frequency calculation (WFC) for Thermowell located on vessel (mainly gas/oil separator) handling three phase fluid. Here vessel fluid is not stagnant, its continuously flowing.
Regards
Suhas
Hi Suhas, 1. Generally the customer specify to Emerson about the location of Temperature measurement point and how they would like to attach Thermowell to the pipe. So design related to installations is generally done by the customer, but what we Emerson provide is the mechanical integrity of Thermowell with conformance to ASME PTC 19.3TW-2016. Multiphase fluid flow is a very complex physics in itself and would need simulation tool to approximate the conditions and pretty long run time using high performance computing technology. ASME PTC 19.3TW simplified it to run on a worst case fluid condition. Example if major component of fluid is liquid (>80%), assume it to be liquid and run calculations based on it. 2. WFC are meant to be performed on flowing fluids itself like flow in pipes, ASME PTC 19.3TW provides guidelines to perform mathematical calculations on 4 parameters - Frequency Domain evaluation, Steady State Stresses, Dynamic Stresses and Pressure Check. Dynamic stress w.r.t fatigue endurance ensures Thermowell is safe under flowing conditions. Stagnant environments like storage tanks induce very little to no stress on Thermowell, so they are ignored in many cases. Only case where it is run is in case if there is agitator to stir the liquid where velocity is assumed to very very small. Regards Naveen Kulkarni
I would love to explain in detail to you and also take any further questions you may have on Thermowells, do you let me know if I can help you solve problems on Thermowell any way.