Li Douhua's flow, adjustment system operating pressure, bearing modification and other methods have effectively solved the problem of high operating temperature of the air compressor motor body and frequent over-temperature operation of the bearing.
Panzhihua Iron and Steel Power Plant is a thermal power plant with an installed capacity of 3X100MW. It will burn more than 5,000 tons of coal per day at full load and produce a large amount of fly ash. These ash will be transported to three ash storage towers by air compressor as the power source. In recent years, coal resources have been tight and prices have risen. In order to reduce costs, power plants have increased the amount of peat, and the average ash content is above 45%. Therefore, the amount of ash produced by boilers has increased significantly. At the same time, in order to meet environmental protection requirements, three new desulfurization systems have been built. It has been put into operation, and the amount of gas consumed by its material circulation and control is huge. The power supply load of the existing 9 air compressors in the power plant is greatly increased, the operating conditions of the equipment are deteriorated, the motor temperature of the air compressor is increased, and the motor bearing Frequent failures affect the safe and stable operation of the dust removal system and the flue gas desulfurization system. Therefore, it is urgent to effectively improve the high operating temperature of the air compressor motor.
Second, the air compressor motor operating conditions The 9 air compressors used in the power plant are all Y3552-2250kW non-standard 6kV motor produced by Jiangsu Qingjiang Motor Manufacturing Co., Ltd. The high temperature alarm, frequent bearing damage and burnout failure seriously affect the safe and stable operation of the dust removal system and the flue gas desulfurization system, which becomes a problem that plagues production and causes serious impact.
(1) The temperature rise of the air compressor motor has a serious impact on the normal operation of the ash conveying and desulfurization system. The air compressor is frequently tripped due to high motor temperature, resulting in unstable gas storage tank pressure, resulting in gas control of the ash desulfurization system. The valve is mis-operated, the ash pipeline is blocked, the ash membrane valve is easily damaged, and the desulfurization bag is not working properly.
GBecause the motor and the air compressor are connected, the temperature rise of the motor directly causes the air compressor temperature to rise, and the axial diameter of the air compressor, compressor oil, oil filter, oil separator core, etc. The height of the S keyway side, the working length of the mm L key, L=89mm (after the 4 input shaft and the connecting disc have a relative angular displacement, the stress acting on the right side of the input shaft keyway will change from the surface contact to the line acting on the top of the keyway. Contact. At this time, the right side of the keyway forms a simple supported beam structure with a fixed end, and the stress acting on the right side of the keyway can be calculated by the formula.
It can be seen from the calculation results that the right side of the input shaft keyway at this time will shorten the service life of the consumables and increase the running cost.
(3) The motor winding and bearing life is shortened, and a large amount of manpower and material resources are consumed during maintenance.
After consulting the technical personnel of the manufacturer, it is recommended to expand and renovate the motor, and the expansion cost is about 3.2 million yuan.
Third, the air compressor motor temperature rise and frequent vibration failure analysis of reasons 0) in order to reduce costs and a large amount of peat, the amount of ash produced by the boiler increased significantly. In order to meet the environmental protection requirements, the newly built three desulfurization systems have been put into operation, resulting in the long-term operation of the air compressor motor under heavy load or full load. The motor body is fixed and the rotor core temperature is high. The heat dissipation conditions of the original motor design cannot meet the motor. The requirements of actual operating conditions will inevitably lead to adverse consequences of increased motor temperature, increased motor bearing and winding degradation, and reduced life.
0 air compressor motor front bearing straight running temperature is high, especially in the summer air compressor motor front bearing temperature is over 85T alarm, the bearing grease at this high temperature running quickly aging causes frequent bearing damage.
The strength of the base of the Q air compressor frame is insufficient and the structure is deformed, resulting in large vibration of the air compressor and the motor.
0) Take measures to improve the air-cooling condition of the air compressor, increase the flow rate of the cooling air of the air compressor motor, reduce the temperature of the motor body, prevent the high temperature of the motor core from transferring heat to the bearing, causing the bearing temperature to be too high and the lubrication to be damaged. Causes poor lubrication damage.
Taking the ventilation hole from both sides of the lower part of the motor body to increase the airflow of the through-flow and speeding up the heat dissipation speed can effectively reduce the stator and rotor iron force of the air compressor motor body (7) produces an initial deformation when the input shaft When working in a load-carrying condition, the key and the connecting plate will have an impact stress on the left side of the keyway. As the number of impacts increases, the deformation of the right side of the keyway in the horizontal direction also increases, eventually causing severe damage to the keyway. , so that the shaft loses its repair value.
It can be seen from the above analysis that in order to eliminate the side damage of the keyway which is similar to the taper fit, it is necessary to ensure that the fastening nut is fastened, the tapered surface is tightly fitted without a gap, and the key and the shaft and the connecting plate are avoided, and the static fit becomes a dynamic fit, thereby Avoid impact loads and damage the keyway.
Chuanqing Drilling Engineering Company) 1丨西钻探公å¸4)1丨é‚å®å¸‚[Edit Liwen] Equipment management and maintenance Long-axis deep well pump vibration abnormality analysis and treatment countermeasures Sun Guirong Chen Xiaochun rubber bearing burned, shaft or shaft bending, Yang The water pipe, the drive shaft and the bearing bracket have different shafts and the journal is corroded.
The 12 drainage pumps used in the drainage tanks of power plant units are long-axis deep well pumps. The function is to send the water collected in the drainage tank of the unit (mainly boiler sewage) to the industrial sewage pool for purification treatment. The pump is mounted vertically on the sink. The start and stop of the pump is automatically controlled by the liquid level switch, the bearing lubrication is self-lubricating, and there is no external lubrication water. When the pump is working unattended, the vibration is not easy to find at the beginning, which often causes damage to the shaft, bracket, diversion shell and impeller.
The deep well pump is mainly composed of a pump body with a water filter pipe, a water pipe with a drive shaft, a pump seat and a motor. The first two parts are located underground and the latter two parts are located on the well.
0) Pump body part. It mainly includes the water filter pipe, the impeller, the taper sleeve, the lower diversion shell, and the middle guide core temperature. If the iron core temperature is lowered, it will not transfer heat to the bearing end, and the air compressor that has been troubled for many years can be solved. problem.
G Improve the structure of the air compressor frame, optimize the matching method of the motor bearing, effectively reduce the vibration, reduce the fatigue damage caused by the vibration and prolong the service life of the bearing. The structure of the air compressor is that the machine head is mounted on the end plate of the motor, and the connection mode is the side of the helical gear. The air compressor is integrally mounted on the movable frame made of channel steel, and the frame has no foundation fixing bolts. The bearings at both ends of the air compressor head adopt the inner ring without rib bearing and one thrust disc bearing. The motor shaft end uses one NU317 inner ring without rib bearing and one 6317 ball bearing, and the non-shaft extension end adopts one. The NU317 inner ring has no rib bearings. This type of structure has the problem of axial turbulence, that is, as long as it is not horizontal or the gear is not well matched during operation, it will sway back and forth under the action of the magnetic pull force of the motor and the gravity of the rotor, causing the yin and yang rotor occlusion of the twin-screw head to collide. Causes the vibration to multiply. The structure of the frame is easily deformed, which determines the difficulty in finding the level during installation. Therefore, to solve the vibration problem, it is necessary to solve the horizontal, strength and rotor system turbulence problems of the frame, and adopt high-strength frame and motor rear-end bearing replacement. To position the bearing.
Q Improve the environmental conditions of air compressor room, improve the ambient temperature and medium air cleanliness, effectively extend the service life of air intake filter, compressor oil, oil filter, oil separator core, etc., and improve the cooling and cooling of air compressors and motors. effect.
(4) Adjust the operation mode and adjust the ash conveying period so that the maximum load period of the air compressor is at a relatively low temperature or in the morning, which effectively prevents multiple air compressors from being continuously loaded and operated at high ambient temperature.
0) From the effect of the implementation of the transformation, the main operating temperature of the air compressor motor 64 equipment management and maintenance of the flow shell, the upper diversion shell, the diversion shell bearing, the drive shaft and the bracket, the impeller is fastened to the pump by the taper sleeve On the shaft.
Q water pipe part. It is composed of a water pipe, a transmission shaft and a bracket (including a bracket bearing 纟 and a coupling). The water pipes are flanged, and the coupling between the transmission shafts is screwed. The bracket is installed between the two water pipes. There is a rubber bearing inside as a radial support for the drive shaft. The guide housing is provided with a rubber bearing as a radial support for the pump shaft.
(3) Pump seat part. It consists of a pump seat, a packing device and a water guiding pipe. The pump base is fixed to the foundation by four foot bolts, and the motor is mounted on the pump base.
(4 motor part. It consists of motor, motor shaft and adjusting nut, the motor is fixed on the pump seat. The motor shaft is connected with the drive shaft by a threaded coupling, which passes through the hollow shaft of the motor and is connected to the motor through the key.
The bearing and the bearing are significantly reduced and the operation is stable. The running temperature of the main body drops by 50T on average, and the running temperature of the bearing drops by 25T on average. The problem of high operating temperature of the motor and frequent bearing failures is effectively solved. On this basis, the temperature of the air compressor motor bearing temperature is connected to the DCS display of the desulfurization centralized control room, and the alarm reminder is set, so that the post personnel can find the bearing fault in time and reduce the bearing damage and cause the motor broom and burnout. Motor accident.
Q bearing temperature is often over 9 (TC drops to a maximum of 7 (TC), bearing life is greatly improved, the original can only be used for 3 months, and now the bearing life can be extended to more than 1 year.
After the Q air compressor is running stably, the production gas is effectively guaranteed. The failure of the ash conveying and desulfurization system is eliminated due to the gas source factor, and the damage rate of the pneumatic valve and the desulfurization bag is reduced.
(4 air compressor failures are greatly reduced, a large number of accidents to repair and repair, reduce manpower and resources, and reduce maintenance costs.
By increasing the motor cooling ventilation flow and improving the original wind path, and reducing the cooling ventilation flow resistance, the heat dissipation of the motor body can be effectively accelerated. Improve the environmental conditions and operation mode, can prevent the heat from passing through the rotor and the convection heat transfer before the hot air, causing the front bearing temperature to be high, thereby effectively reducing the operating temperature of the motor body and the bearing, reducing the frequent occurrence of motor failure, and ensuring the dust removal system of the power plant. And the flue gas desulfurization system is safe and stable.
Panzhihua Iron and Steel Power Plant, Panzhihua City, Sichuan Province [Editor]
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