[Q&A Question 162] 2016.09.29
Thread Content
【Q&A Question 162】September 29, 2016: What is the anti-surge control scheme for cyclic hydrogen compressors? The answer key can be seen after responding; scoring is based on identifying the key points. Answer: The compressor inlet flow rate is used to control the control valve on the recycle hydrogen bypass line in order to prevent reverse surging. The process is as follows: when the inlet flow rate is low, the bypass valve opens wider, increasing the amount of recycle hydrogen at the cold high-pressure section; this in turn increases the inlet flow rate ； Another function of this control system is to automatically reduce the amount of fluid in the bypass circuit when the demand for cold hydrogen increases, thereby serving as a reserve of cold hydrogen.
The so-called low-flow bypass, also known as hydrogen partial pressure, is generally designed at the high-exchange outlet of the reactor, at the high-pressure section
The anti-surge valve is fully closed during normal operation and switched to automatic mode; it is fully open before startup, and as a startup interlock, a minimum flow interlock at the inlet of the cyclic hydrogen compressor is set to open the anti-surge valve
Control scheme: The compressor inlet flow rate is used to control the control valve on the recycle hydrogen bypass line in order to prevent reverse surging. The process is as follows: when the inlet flow rate is low, the bypass valve opens wider, increasing the amount of recycle hydrogen at the cold high-pressure section; as a result, the inlet flow rate increases； Another function of this control system is to automatically reduce the amount of fluid in the bypass circuit when the demand for cold hydrogen increases, thereby serving as a reserve of cold hydrogen.
It is equipped with an automatic control system to regulate the opening of the anti-surge valve, ensuring that the unit operates under normal conditions. When the anti-stall point reaches the “red line,” the anti-stall valve opens fully.
Ensure that the inbound traffic remains above the minimum level
The compressor inlet flow rate is used to control the control valve on the recycle hydrogen bypass line, in order to prevent reverse surging: when the inlet flow rate is low, the bypass valve opens wider, increasing the amount of recycle hydrogen at the cold high-pressure section; as the inlet flow rate increases； Another function of this control system is to automatically reduce the amount of fluid in the bypass circuit when the demand for cold hydrogen increases, thereby serving as a reserve for cold hydrogen
The fundamental cause of surge is low inlet flow and high outlet pressure; adjusting according to these two principles will resolve the issue