The principle of accumulator setting in the petrochemical lubricating oil station in API614 standard

  1. Accumulator
  2. If the turbine control oil pressure needs to be maintained at the moment of servo control or if the oil or sealing oil pressure is to be maintained when the standby oil pump accelerates from the standby state to the working speed, an accumulator should be provided. For all operating conditions (including transients), the control pressure should be maintained above the minimum supply pressure specified by the equipment manufacturer. Especially, when the servo motor produces a full stroke within 1 second, the control system pressure should be kept within 10% of the normal system pressure.
  3. During the acceleration of the standby pump or the motor driving the pump for at least 4 seconds, the system oil supply pressure should be kept above the stop set value.
  4. Unless otherwise specified, the accumulator container should be made of austenitic stainless steel.
  5. For direct contact accumulators, when the buyer has regulations, manual pre-inflating valves or constant pressure regulating systems shall be provided.
  6. If a direct contact accumulator is used, it should be equipped with an armored reflective glass level gauge, which extends from 25mm (1in) above the highest operating oil level to 25mm (1in) below the lowest operating oil level . When the container is pre-inflated under the controlled normal operating pressure, the glass level gauge will display the oil level (note: the buyer can give consideration to non-glass level indicating devices).
  7. A pressure gauge connector should be provided to check the precharge pressure in the accumulator.
  8. The actual location and pipeline arrangement of the accumulator should avoid the possible accumulation of impurities or air.
  9. If there are regulations, the accumulator should store the oil at the required system oil temperature. The buyer shall put forward the requirements for the temperature control system in detail.
  10. Unless otherwise specified, direct contact accumulators with constant pressure regulating systems used for pump switching or other purposes should be automatically emptied and automatically reset.
  11. If specified, the bladder type accumulator with constant pressure adjustment system used for pump switching or other purposes should be automatically emptied and automatically reset. The provided accumulator has the characteristics of preventing the gas side from being squeezed out and has the appropriate size specifications for the inflation adjustment and the pipeline.
  12. The design of the accumulator should not allow the pre-charged gas and oil to be charged into the equipment together or to reduce the oil entering the equipment. The lubricating oil side of the bladder accumulator should have the characteristics of preventing being squeezed out.
  13. The accumulator should be separated from the standby oil pump start control device (for example, through a check valve) to clear the delay of the start signal action.

二:The operation test of the oil system should be carried out in the following order

1.Check for leaks in the oil system, and all leaks should be eliminated before the test;

2.Set the limiting pressure value so that it can be verified whether the pressure limiting valve is operating normally afterwards;

3.Complete the filter-cooler switch without causing the system outlet pressure to drop to the automatic start setting value of the standby pump;

4.If applicable, it should be proved that the control valve or other valves can control the instantaneous step change of the simulated governor on the steam turbine driving the main engine without opening the pressure limiting valve, nor causing the outlet pressure to drop to the standby pump automatic starting setting value. .

5.It should be proved that after the main oil pump fails or trips, the standby pump will automatically start and return the system to normal pressure without causing the outlet pressure to drop to:

1) In a single oil pressure system, it is below the midpoint between the automatic start setting value of the standby oil pump and the shutdown pressure of the equipment.

2) In a multi-level oil pressure system, it is lower than the midpoint value between the normal operating point of the equipment and the shutdown oil pressure.

The verification of this criterion requires that the test instrument, such as a switch or other device, has a response time sufficient to record the instantaneous pressure during pump switching (the response time of the switch is usually within 25ms).