BDV valve for liquefied gas cylinders
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According to clause 6.1.3 of the latest AQ3059-2023 standard, full-pressure liquefied hydrocarbon storage tanks must be equipped with pressure relief control valves that serve as an overpressure safety discharge system, namely BDV valves. Can the flow rate and design of such valves be determined only through dynamic simulation using the hysys software? Are there any relevant cases that can be shared for discussion?
Please give some support; experts in this field are requested to help provide answers.
It can be simulated using HYSYS.
I ran a blowdown simulation – why can’t I see the wall temperature value of that equipment?
For a 1000 m3 spherical tank, does it make sense that a 5 mm orifice plate can reduce the pressure in the tank from 1500 kPa to 690 kPa within 12 minutes? Can someone help take a look?
Although I can’t do the calculations, based on experience it shouldn’t be that fast
This post was last edited by plt on 2024-8-26 08:23. The standard simply requires you to relieve pressure; it does not demand any kind of flow sequencing. You just need to monitor a pressure signal, release pressure when it exceeds a certain level, and close the valve once the pressure stabilizes. It’s just a on/off valve.
This post was last edited by plt on 2024-8-26 08:30. You’re overthinking it; if pressure needs to be reduced within a specified time frame according to other standards (reducing it by half in 15 minutes), factors such as noise and pressure drop must be taken into account. But I think this is a speculative interpretation; the AQ standards merely require an additional layer of protection to allow for pressure release in case of overpressure. It usually has the same diameter as the inlet of the safety valve – in other words, the manual valve used as a bypass for the safety valve is replaced by an automatic valve that enables controlled pressure release
Although I haven’t used HYSYS, I think you consider time for every step
HYSYS’ depressing dynamic relief model
The specification clearly states pressure relief control valve, rather than pressure relief switch valve. I don’t think experts would be unaware of the difference between on-off valves and control valves. There is a clear difference between these two terms. Even if only the pressure signal is referenced, an interlocked switch valve is used here, so there is no need to use the term \"with adjustment\".