The capacity of the BOG compressor is determined based on the amount of BOG produced in the storage tank. The capacity of the BOG compressor is stable after selection. If the amount of gas inhaled is greater than the amount of BOG produced in the tank, the tank pressure will drop. When the tank pressure drops to a certain level, in order to compensate for the lack of imported gas in the BOG compressor, the following two measures can be adopted:
1. The gas phase of the secondary outlet of the BOG compressor returns to the imported flash tank D ~ 2, and the control circuit part of the valve PV-2 is controlled by the pressure P-2 of D-2. Here, the setting value of P-2 is 300KPa. If the pressure of D-2 is higher than this value, valve PV-2 is closed. If the pressure of D-2 is lower than this value, valve PV-2 is opened to return the gas phase.
2. It can reduce the intake air volume through the unloading of the BOG compressor inlet, and reduce the capacity of the BOG compressor from 100% to 50%. For Diaphragm-type unloading equipment, the inlet air valve unloading equipment controlled by instrument air restricts the free movement of the valve plate, so that the inlet gas valve is kept open. Because the inhaled gas is not compressed and exhausted back to the inlet. In this way, if one end of the double-effect cylinder (cylinder end or crank end, generally the cylinder end) is unloaded, the capacity of the compressor becomes 50%, and if both ends are unloaded, it becomes 0%.
The smooth oil can be called the blood of the compressor. It can smooth the parts, reduce the wear and reduce the temperature of the parts, and also can achieve the effects of sealing, damping and anti-corrosion. The BOG compressor is equipped with a special smooth oil pump. Before starting the compressor, start the oil pump to work. To ensure the normal operation of the compressor, there are strict requirements on the pressure and temperature of the smooth oil. The high oil temperature reported value is set to 55 ° C, and the low oil pressure reported value is set to 0.175MPa. Beyond the corresponding indicators, the system Pre-alarm.