Issues regarding the lubricating oil station of the cyclic hydrogen compressor
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The lubricating oil station consists of a small turbine and an electric oil pump; under normal operation it is the small turbine that does the work. But when the electric pump starts automatically, how should it be stopped? I tried one method: gradually opening the relief valve bypass line at the electric pump’s outlet until it was fully open; at that point the pressure remained stable. Then I stopped the electric pump. In this case, should the low lubricating oil pressure interlock be disabled? Is the method of stopping the pump correct?
This post was last edited by fld8882005 on 2015-6-13 08:08. To prevent the lubrication system from shutting down due to a low-pressure interlock, both the main pump and the auxiliary pump operate simultaneously. When it is necessary to stop the auxiliary pump, the manual valve connecting the outlet of the auxiliary pump to the oil tank, or the relief valve bypass, should be opened slowly. Meanwhile, the operator on duty must monitor the gauges closely and communicate promptly with those on site to ensure stable oil pressure in the main pipes. The low lubricating oil pressure interlock must under no circumstances be disabled, as it is a safety interlock designed to protect the unit. If the lubricating oil pressure drops too low during the switching process, it is possible for the bearing shells to be damaged due to insufficient lubrication, leading to unit failures. In such cases, the failure may worsen and the unit could be damaged if shutdown is not carried out promptly. Specific steps for shutting down the auxiliary pump: Disengage the automatic start interlock of the auxiliary pump, communicate with the operator on duty and ask them to monitor the pressure gauges carefully. Change the control valve for returning lubricant to the tank to manual control, and close this valve slightly to increase the oil pressure in the main lubrication line. Then slowly open the manual valve on the auxiliary pump’s safety valve bypass or the valve that allows lubricant to return to the tank; open it a little at a time and keep it steady, ensuring that the oil pressure in the main lubrication line remains relatively constant. Once the outlet pressure of the auxiliary pump is lower than that of the main pump, and the oil pressure in the main line no longer drops when the manual valve is further opened, it indicates that the auxiliary pump has been completely disconnected from the lubrication system. After checking that everything is in order, the auxiliary pump can be shut down, after which the automatic start interlock can be reactivated. For internal operation, after adjusting the control valve for returning lubricating oil to the tank to stabilize the pressure, this control valve is set to automatic mode. The above is what I consider to be the safest way to stop the auxiliary pump.