Energy Calculation in a Pressurized Pipeline
Energy Calculation in a Pressurized Pipeline
(OP)
I am venturing into an area where I have little experience. I am trying to calculate the stored energy in a subsea riser. The depth of the riser is 6000 fsw. The ID is 11 inch nominal and the length is 14,000 ft. The pressure during test is 15,000 psi. I am doing this to help with some safety issues so I wnat to be sure that I am doing this correctly. Thanks for any help or advice.





RE: Energy Calculation in a Pressurized Pipeline
RE: Energy Calculation in a Pressurized Pipeline
Thread794-26767
Regards
Mogens
RE: Energy Calculation in a Pressurized Pipeline
If one is after the specific energy,e, of a static column of water, then measuring z, the elevation from an arbiturary datum
e=u+z where u refers to the internal energy as a function of 2 variables such as P and T.
The total energy is therefore a summation of edm (m being the mass at a specific height) over the total length.
RE: Energy Calculation in a Pressurized Pipeline
P - pressure of the gas
V - volume of the gas (volume inside the pipe)
RE: Energy Calculation in a Pressurized Pipeline
RE: Energy Calculation in a Pressurized Pipeline
RE: Energy Calculation in a Pressurized Pipeline
RE: Energy Calculation in a Pressurized Pipeline
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RE: Energy Calculation in a Pressurized Pipeline
Taken from the literature for vessels:
The spring energy could be estimated from:
V.P.S (1.25 - 2σ + 1.25σ 2)
The pressure energy:
(½ V.P2/ β) [1 + 2S(1.25 - σ)/E]
where:
V: volume of the pipe
P: internal pressure
S: hoop stress = PD/2t
σ: Poisson's ratio for the pipe's material
E: Modulus of elasticity of the pipe's material
β: modulus of elasticity of the water used for testing
D: pipe diameter
t: pipe wall thickness
RE: Energy Calculation in a Pressurized Pipeline
RE: Energy Calculation in a Pressurized Pipeline
This is likely not the first undersea riser to be tested. Look for literature on similar projects, find the engineers that worked on them, and ask them how they determined a safety zone with respect to riser failure during a test.
RE: Energy Calculation in a Pressurized Pipeline
RE: Energy Calculation in a Pressurized Pipeline