Brief Introduction of Hydraulic Top Rotor System of Large Vertical Water Pump Unit

statement of problem

Luo Yu pumping station of flood control facilities management office in Shenzhen City is equipped with 6 sets of 630kW vertical water pump units, supporting motor YL630-20. Unit running in flood season, non-flood season outage. Before starting, the rotor of the unit must be jacked up to fill the surface of the long-term stationary motor thrust bearing bush to avoid burning when starting. Previous artificial top rotor, 6 units need 4 individuals took 1 hour, and a lot of manual labor; now using hydraulic top rotor system, only one person needs 10 minutes to complete, to meet the requirements of the flood control and drainage work faster.

Device introduction and main technical parameters

System consists of the top ring, jack, tubing system, hydraulic valve, fuel pump, control cabinet and other components.

Control cabinet with pump start and stop, hydraulic valve position, over pressure protection, jacking stroke indication and other functions. The fuel pump by the 20l tank, piston pump? The maximum pressure of 32MPa (optional working pressure 16MPa, flow 1L / min, motor power 1.5kW and other components.

Hydraulic valve with M-type hydraulic valve, model HD-3C6-G02-LW, pressure rating 60MPa.

Tubing system using DN10 × 2 seamless steel pipe, pressure rating 70MPa.

Jack used 4 sets of 60 plunger, stroke 50mm, pressure level 60MPa, a single overhead load ≥ 8t. Rotor lift height 5 ~ 8mm According to the motor structure to determine, the device is set to 7 ± 0.5mm.

The top ring is a specially designed part.

The lifting speed of the device is 15mm / min, the holding time is 5min, the falling speed is 20-30mm / min, and the method of simultaneously lifting the top of 6 sets of units also can adjust the top of a single unit as needed.

Key technical measures

1, the top ring

As the rotor flange on the outer surface of the counterweight, coupled with the actual layout of the space can not be directly jack jack jack, and thus set a top ring. Top jack lifting jack, top ring and then lift the rotor. Top ring must ensure that the requirements of the parallel rise to prevent the top. The top flange of the lower flange welding 4 ring pad, set in the jack plunger, so that the top ring positioning.

2, to prevent partial top

Each unit set 4 jack, through the top ring, jack stroke control, and the use of isobaric oil, to ensure that the jack pressure equalization, to avoid the jacking force and jacking speed caused by the difference between the top.

3, to prevent the rotor down too fast

Rotor down, in order to prevent the speed too fast, causing impact damage to the thrust bearing surface, the throttle valve into the various types of units, easy to adjust the rotor speed down, controlled at 1 ~ 2min.

4, jack

Jacks by the full stroke limit design to prevent excessive rotor lift.

5, to prevent the tubing into the air,

The fuel tank, fuel pump placed at the highest point of the system? Motor floor ?, So as to effectively prevent the tubing system due to long-term deactivation of the intake problem.

6, hydraulic valve

When the fuel is being supplied, the jack is lifted. Reverse fuel supply, jack reset. In the middle position, the tubing system holds the jacks in place. These features meet the rotor jacking up, the need to maintain a certain time is generally 5min and forced reset after jacking requirements.

7, electrical control

1 jack stroke instructions. Each jack has a lift, reset the travel switch and indicator light in place, and with light test button, in order to check the light is normal.

2 system over-voltage protection. Equipped with pressure relief valve and pressure relief double protection. When the system pressure reaches the set value, overflow valve overflow. If the system pressure exceeds a certain range of the set value, the pressure relay action, the hydraulic valve back to the middle position, the pump stops running at the same time, over-pressure indicator light.

3 system work pressure calculation.

Jack jacking pressure:

P0 = W / nxs

Where: P0 - Jack lift kg / cm2

W - rotor weight kg

n - the number of jacks

S - jack plunger area cm2

P0 = W / nxs = 15 × 1000 / [4 × (3.1415926 / 4)] = 132.6 kg / cm 2

Pressure relief valve working pressure: PV = 1.2 ~ 1.3P0

PV should be set to meet more than three normal work jack before lifting the rotor requirements, to avoid two top-off.

Over-voltage protection relay working pressure:

PK = 1.1PV

4 power supply. Working power 220V, travel switch with 24V, in order to ensure safety.

Application prospects

The device has been successfully applied to Luo Yu pumping station 6 630KW pump rotor top rotor project, received a convenient and reliable use of the results. The device focuses on solving the actual situation that the rotor structure of the motor is irregular, the space layout is complicated and the simple lifting structure can not be used.

The device can be widely applied to the more complicated top rotor projects in the fields of water supply and drainage, electric power, chemical industry and so on, and provides references for the design and calculation of other types of top rotor devices.