How to handle failures in the high-pressure hydrogen emergency pressure relief line?
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Dear colleagues, please come and share your thoughts: The emergency pressure relief valves for high-pressure hydrogenation serve as a lifeline for both the equipment and the safety of personnel. However, due to design constraints, additional lines are generally not added to the system. In the event of an accident, if mechanical or other failures prevent the 0.7MPA and 2.1MPA pressure relief valves from opening, what measures should be taken by the facility to prevent the accident from escalating?
A secondary line needs to be added. Our original design didn’t include it, and we require the designers to add it. If the pressure relief valve cannot be opened and there is no bypass line, burning out is the only option; burning the catalyst is a minor issue, but if the reactor gets damaged, it will cause serious problems! If the pressure relief valve is a life-saving remedy, then the backup line is the last hope – we call it the lifeline!
Hehe, the low-pressure safety valve bypass can be used for manual pressure relief; there should also be pressure control at the top of the hydrogen cyclization desulfurization tower (operate it at full capacity for relief). In short, in all the low-temperature areas of the reaction section, ways can be found to relieve pressure manually. . .
Initially, no additional lines were added due to the design firm and various other reasons; this aspect will not be discussed in detail here. So, how should accidents be handled in the current situation?
Open the exhaust hydrogen control valve to reduce the reactor bed temperature.
It is a means and method, but it may not be able to solve fundamental problems.
A safety valve bypass can be activated to release pressure at high levels, while paying attention to the rapid increase in the level of liquid at high pressures.
Thank you! If the cold high-pressure safety valve is equipped with a pilot line, this could be a solution; however, our units (and many high-pressure hydrogenation units as well) do not have such a pilot line on their cold high-pressure safety valves, so this approach cannot be used.
Generally, there is a bypass line for pressure relief at 0.7 MPa, because in the event that issues with instrument air or problems with the control valve itself prevent automatic or manual forced opening (which is highly unlikely), the bypass line can be used to open it instead. Or use the hydrogen discharge area for that. Generally, it rarely fails to open; the main thing to pay attention to when releasing pressure is the high-pressure area, as it is there that pressure leakage can occur, and that is what poses the greatest risk.
Thank you for your participation! Due to various reasons such as investment costs, safety considerations, equipment requirements, and the designers’ personal design philosophies, many emergency pressure relief valves for high-pressure hydrogenation systems do not come equipped with piping. Therefore, we will not consider the issue of piping at this time; instead, we would like to discuss how to handle accidents that may occur under the current conditions of these systems :handshake
Operation of the safety valve bypass increases tail hydrogen emissions.