High-power centrifugal pumps and motors are mainly used in large-scale water conservancy and hydropower projects and transfer pumping stations. For example, S-type horizontal single-stage double-suction split centrifugal pumps and multi-stage diesel water pump units are all high-power centrifugal pumps, due to their large size and installation The precision requirements are high, so the installation is quite difficult. How to install the unit with high efficiency and high quality and successfully debug and run is an important problem faced by the equipment installation unit. Because the equipment is large and heavy, in order to ensure the safe operation and long service life of the equipment, the installation accuracy requirements are very high. In addition, the installation steps are cumbersome and there are many links before and after the equipment is installed, which also increases the difficulty of the equipment installation.
1. The main points of equipment installation of high-power centrifugal pump unit
(1) Unpacking the equipment
Before the equipment enters the site, unpack and inspect the equipment with the supervisor and Party A’s representative
(2) The basis of equipment
Before the equipment is installed, the focus of the foundation inspection is the cleaning of the anchor bolts, the flattening of the placement position of the shim, and the observation record of the settlement of the foundation. Due to the large weight of the equipment installed and the large force during operation, the settlement observation record of the foundation must meet the design requirements
(3) Installation procedure of water pump unit
The installation of extra-high-power centrifugal pump motor unit has the characteristics of large size and weight, difficult transportation, and high installation accuracy. Detailed construction steps must be formulated to construct efficiently, safely and accurately.
Unit installation process: foundation re-measurement-equipment foundation shim position leveling, chiseling pitted surface-pump base positioning, centering, and leveling (based on the center of the pump base)-pump base anchor bolt reserved holes, grouting one pump at a time The base and the motor base are finely adjusted: the pump body is in place and connected to the base; the motor is in place and connected to the base; the fine adjustment is repeated; the center line error between the pump shaft and the motor shaft is measured again. Bolt and shim group inspection, spot welding, one-time grouting of water pump and motor base, one-time grouting of water pump inlet and outlet pipes, motor wiring, installation of ventilation ducts, protective cover, decoration debugging and trial operation, and final acceptance. In this construction process, there are several steps that play an important role in the quality and safety of equipment installation
① Arrangement of the shim during the construction process, according to the volume, weight and operating data of the equipment provided by the manufacturer, determine to place the shim group next to the anchor bolts. And shovel the pitted surface on the foundation surface at the position of the horn, the area of the pitted surface is slightly larger than that of the horn, about 150×100. 12 sets of pads are arranged under the base of the water pump and the motor, the size of the flat pad is 130×80, the size of the inclined pad is also 130×80, and the slope is 1:15. Each set of shim is equipped with 2 inclined pads and 1~3 flat pads, each set of shim does not exceed 5, and the height is 40-80mm
②Install the base of the high-power centrifugal pump in place. When installing the pump base, place the base correctly on the adjusting bolt and level the base by adjusting the adjusting bolt. At the same time, adjust the gap between the base and the foundation surface to reach (45±5) mm . In order to ensure the alignment (vertical/horizontal) of the pump and the motor, the maximum allowable installation deviation of the pump base and motor base is 0.5mm. The height difference between the base of the pump and the motor is shortened by 2m compared with the design in actual installation, so as to adjust the height of the electric pole with the gasket. The vertical and horizontal centerline coincides with the basic vertical and horizontal centerline, and the relative allowable deviation is -4-20mm (but its center point should coincide with the center point required by the motor). The allowable deviation of the plane elevation is ±3mm, and the allowable deviation of the base plane levelness is not more than 0.01/1000. Check that the distance between the anchor bolt and the wall of the reserved hole is 15mm. The allowable deviation of the verticality of the anchor bolts is 8/1000.
③Fine adjustment of the water pump body and the base. After the motor base is in place and leveled, and the center line position of the motor is determined, the water pump and the base are fine-tuned. The fine adjustment process is through adjusting the height of the shim group, tightening the anchor bolts, and adjusting the pump base. To achieve the vertical and horizontal centerline position. The shim group is placed smoothly and has good contact. After the water pump is leveled, use a small hammer to lightly tap the sound inspection group by group, and use a 0.05m feeler gauge to check the gap between the shim and the shim and the base. The sum of the length of the plugs on both sides at the same section shall not exceed 1/3 of the length or width of the horn. Finally, the pad iron group is fixed by spot welding.
④After the motor is in place, the coupling is aligned, and the motor base is installed and leveled, the motor is in place and the coupling alignment and coaxiality detection and adjustment are performed at the same time. There are two measurement methods: direct feeler gauge measurement; dial indicator And special tool measurement method. Measurement method: Rotate the two half couplings together, 90 per revolution. Measure once, record the radial measurement value a and axial measurement value b at 5 positions, and record the dial indicator b1 and table b11 or the axial measurement value of two measuring points located at the two ends of the same diameter respectively. When the measured value a1=a5 and b1I-blII=b1I-bII, it should be regarded as correct and the measured value is valid. The minimum and maximum distance between the two halves of the coupling: Smin=6mm, Smax=12mm. The maximum allowable alignment deviation -0.53mm, a=Smax-Smin, the maximum allowable concentric deviation -0.53mm (the height difference between the centers of the two shafts or the coupling halves).
2. The necessary conditions before the high-power centrifugal pump linkage test run
(1) General provisions
①The linkage test run must be carried out on the basis of the completion of all mechanical equipment, process piping, and electrical instrument installation technology of the whole system and the stand-alone test run or commissioning has been carried out
② Establish a leading group for the joint test run composed of relevant personnel from the construction unit, construction unit, design unit, supervision unit, and major equipment and material suppliers.
③ Perform technical and safety briefings or conduct necessary training for all construction and operating personnel involved in the linkage test
④ Compile a practical and feasible linkage test plan and obtain approval.
⑤Report and communicate with relevant departments, power supply, water supply and other departments on the time, progress, requirements, etc. of the linkage test.
(2) Conditions that should be met before equipment commissioning
①The installation of all equipment in the whole system has been completed, and there are complete installation records
②All equipment of the whole system has undergone single-machine trial operation and has a complete single-machine trial operation record
③The water, gas, electrical, and instrumentation systems related to the trial operation meet the needs of the equipment itself.
④The equipment and surrounding environment have met the requirements
(3) Requirements for electrical and instrumentation systems
①After the adjustment test of the electrical and control system of each device is completed, after the single machine has no load test operation, it is confirmed that it conforms to the design operation reasoning, the internal and external wiring is correct, and the power supply type and grade capacity of the system meet the design and specification specified values; the electrical of the entire system The interlocking of the control part, the control and operation process actions, the display of the indicating instrument, etc. all meet the requirements, and it is confirmed that there is no fault within the specified single machine test operation time.
②The instrumentation and automatic system debugging of the entire pumping station is completed. After the simulation debugging and simulation operation, confirm that the instrument loops and control loops are correct. On this basis, further confirm that the section debugging and the entire system are correct. Start the relevant procedures of the automatic system, check whether the loop, status, and control are consistent with the actual working conditions on site, and adjust the entire parameters according to the feedback until the system operation is consistent with the design situation
(4) Conditions that the piping system should have
All process piping systems have been installed and have complete installation records. The pipelines that are designed with requirements must also have flaw detection records; the entire process piping system has been pressure tested and has complete pressure test records; the entire system has been cleaned up and has Design media access conditions.
3. Commissioning and trial operation of high-power centrifugal pump unit
The commissioning of the high-power centrifugal pump unit is divided into three parts: water filling test, no-load test, and unit trial operation
1) Water filling test Close all valves after the inlet pool is filled with water. After ensuring that there is no debris in the pipe, slowly open the maintenance valve to enter the water, check the connection pipes before and after the pump and whether the water seal of the pump is leaking, and deal with it on site.
(2) No-load test
Confirm that the coupling is not connected, start the water supply pump and the unit cooling fan. Switch on and start, measure and record operating data such as no-load current and vibration.
(3) Trial operation of the unit
Since the unit test operation must be carried out in accordance with the operating procedures, a rigorous and detailed operation process has been formulated before the unit test operation. At the same time, pay attention to the following points during operation
① Before starting the unit, start the water supply pump and cooling fan
② After the pump is running, tighten the compression ring on the pump packing, and tighten the nut on the gland by half a turn every 10 minutes until the leakage is reduced to the minimum allowable amount, generally 45-60 drops/min.
③After running, measure the pump vibration, current, water flow pressure, temperature rise, etc.
④Because the centrifugal pump unit is controlled by the computer, after the manual high-speed test operation is over, the computer linkage operation is carried out, and the T2h test machine is performed, and the personnel on duty record various data. After 72 hours of operation, a simulated accident shutdown was carried out based on past experience. At this point, the installation and commissioning of the super-power pump motor unit of the Yonghu Pumping Station has been completed, and the normal operation of water supply can be carried out.
