For rapid pressure relief startup, why is it necessary to interlock and shut down the hydrogen circulation pump?

It is recommended to start by understanding the principles of the overall process; a superficial approach, akin to trying to understand an elephant by touching only one part of it, makes it difficult to comprehend such issues. This is provided for reference only.

It’s even more incredible to think of there being a design that shuts down the feed supply and also shuts down the hydrogen circulation pump!

Is there such a design? Did we look at it the wrong way? Here, we only use chain heating furnaces for feeding.

Under normal circumstances, when the hydrogen circulation pump stops, an interlock mechanism triggers emergency pressure relief to remove heat from the reactor. If emergency pressure relief is activated at high speed, it definitely indicates an emergency situation. We have options for pressure relief at 0.7 MPa and 2.1 MPA, in addition to manual pressure relief. Suppose that emergency pressure relief is activated while the hydrogen circulation pump is still running; will the system pressure drop faster in this case compared to when the pump is stopped? Moreover, if the heat from the reactor cannot be removed, over-temperature conditions may occur. A sudden increase in the flow rate of circulating hydrogen poses a significant strain on the catalysts inside the reactor. Furthermore, high liquid levels can experience significant fluctuations; if not controlled in time, pressure transference accidents may occur.

Hydrogen compression pumps in hydrogenation processes come in centrifugal and reciprocating types, with the reciprocating type being commonly used in units with lower throughput. The centrifugal circulating hydrogen compressor operates without a standby unit, and it is designed to shut down automatically under emergency pressure relief conditions, primarily to protect the unit.

Pressure relief is generally carried out at the inlet; when the inlet pressure is low and the outlet pressure is high, the centrifugal compressor will experience surge. Additionally, during pressure relief, liquid from the higher pressure level can easily enter the inlet liquid separation tank, and once this tank becomes full, it can damage the impeller of the compressor. In general, this is done to protect the proper operation of the compressor

You’ve already released pressure at high speed; the pressure was completely released in just a few minutes. Are you going to let the cyclohydrogen machine run idle?

After rapid pressure relief startup, there is a pressure drop due to the reaction system and heat exchange equipment. If the recycle hydrogen compressor still starts, it may lead to an increase in the compressor’s compression ratio and cause equipment damage. My personal understanding.