Attentions in commissioning multistage high pressure pump
Axial segmental multistage high pressure centrifugal pump is used in boiler water supply system because of its high head. For the debugging of this kind of pump, the main need to consider the following situations.
Preparation before pump commissioning:
The inlet valve is open and the pump is filled with water.
Due to the test run, the new pipeline system is generally impurities, it is necessary to consider the new pump inlet to install a filter screen, the number of filter screen depends on the actual cleanliness of the pipeline.
Outlet valve closed, low flow valve open. Some pumps are also equippedwith a mechanical seal flushing scheme, which needs to be compared with the manufacturer's information to ensure that the sealed water system operates normally in accordance with the design. Some pumps are also equipped with bearing lubricating oil systems, which need to ensure the normal operation of the lubricating oil system - oil quantity, oil temperature, oil speed and oil cleanliness in normal values.
Before starting the pump, it is necessary to confirm that the motor steering is consistent with the pump. The water pump has been aligned with the motor, and the median of the axial and radial alignment meets the requirements. Check the alignment before connecting the pipeline, and check the alignment again after connecting the pipeline to ensure that the pipeline does not cause excessive stress on the pump. If the drive is not a motor, some large feed pumps use a small steam turbine to drive the water pump. In this case, the deviation of the thermal working state of the steam turbine needs to be compensated and adjusted.
Field test pump, generally use outlet small flow line, so that the pump in the case of non-working conditions, under the condition of strict test pump operating parameters. Flow RATE, HEAD (PRESSURE), MOTOR CURRENT, SPEED, PUMP VIBRATION (driven and NON-driven - horizontal, axial, radial), motor vibration, noise, temperature, etc.
Precautions for pump test: For multistage high-pressure centrifugal pump, it is not possible to open the outlet valve to start the pump without back pressure at the outlet. Too high axial force will scrap the whole pump instantly. Outlet valve closed until pressure stabilizes, slowly open valve to operating point. Just as a hungry person cannot eat a large meal at once. Digestive disorders can occur.
Pump frequency conversion start, the time can not be too long or too short, long start time, the pump will be seized.