New hydrogen compressor after a power fluctuation
Thread Content
There was a sudden power fluctuation; the new hydrogen compressor (piston type) stopped operating, while other equipment functioned normally. Can we avoid closing the inlet and outlet valves at this time, unload immediately, restart, and then directly apply load to bring it into operation? How much damage does this startup method cause to the press?
Reply to 1# Morning Star: After an emergency stop due to a surge in voltage, first reduce the load to zero. There is no need to close the inlet and outlet valves; leave them as they are. Then start the auxiliary oil pump to adjust the oil pressure to normal levels, after which start the main motor. Once the oil pressure is adjusted properly, shut down the auxiliary oil pump. Finally, gradually increase the load until it reaches full capacity.
Additional answer to your question 2: This starting method causes no harm to the press. When under load, pay attention to the outlet pressure of the machine and the motor current. We experience shutdowns due to lightning strikes once or twice a year.
The proper procedure is to first close the inlet and outlet valves, then open the vent to release pressure; after the pressure has been released, close the vent and start the main motor, after which the inlet and outlet valves should be opened again to apply load to the press. This prevents the motor from being overloaded during startup, which could otherwise trigger the motor’s overload protection or even cause the motor to burn out.
The OP’s method of starting it is correct and poses no harm to the device. The compressor outlet valve and outlet check valve can both effectively prevent the backflow of recirculated gas. However, the method of starting up on the 4th floor is questionable. Consider this: when the main motor is started with all inlet valves closed, what if there is leakage from an inlet valve or it fails to close properly, and the unloader cannot effectively relieve the load?
That’s what we all do. Unload, restart, reapply the load; inspection completed. It has been restored at the fastest speed.
The startup of large motors requires protection; operating under load can result in excessively high starting currents. When the inlet and outlet valves are open, the motor starts and drives the piston while being subjected to a certain amount of pressure—that is, it operates under a certain load—even though the gas has not been compressed. Perhaps it’s fine without turning on the inlet and outlet valves, but strictly speaking, it should be run at idle first before applying load.
Reply to 7# datangwei: What you mentioned is the method for normal startup. Under fluctuating power conditions, following your operation methods slows things down, which has a significant impact on production. There is no need to close the inlet and outlet valves; in the event of power fluctuations, it is necessary to start the machine as quickly as possible to minimize the impact on production. What I mentioned above is to start with no load and then gradually increase the load to full capacity, while paying attention to the outlet pressure of the machine and the current of the motor. This is how we handle the surges we encounter; it has no impact on the machine.
When our reciprocating machine encounters a similar situation, we do not close the inlet and outlet valves; instead, we operate it only through the unloading valve
Reply to 7# datangwei: Whether a compressor is under load or not depends on whether its inlets and outlets are open; it’s not the case that being open at the inlets and outlets means it’s under load. When starting a piston compressor, both inlets and outlets must be fully open (the outlet can remain closed if there is a return line), in order to prevent pressure buildup. It is controlled by a gas valve whether it is under load or not. Therefore, in the event of a power outage, after relieving the pressure, the machine can be turned on directly. But it must be ensured that pressure is released… otherwise, with media inside the machine, problems can easily occur. There have been incidents where the compressor ruptured due to starting under load (with a medium present inside the unit).