Application of condition monitoring on air compressor
Since the early 90s, the smelter has introduced the smelting process of the Norlanda furnace rich oxygen bath in Canada, and the two sets of KDON-6000/13000-X oxygen generators produced by Hangzhou Oxygen Generator Factory have provided the Nolanda furnace. 9000m 3 /h of high purity oxygen, while also providing oxygen to the converter. The air compressor is the most important large-scale equipment in the oxygen generation unit. It provides raw air for the whole oxygen production system. Whether it can operate normally will directly restrict the production of oxygen. This series of air compressors is a DH63-14 type isothermal compressor manufactured by Shenyang Blower Factory. A set of pinion shafts are arranged on both sides of the large gears. Two stages of impellers are mounted on the two ends of the pinion, and the gas is compressed after each compression. It is sent to the colder for cooling. The air compressor is equipped with a synchronous motor with a power of 3,400 kW, a processing air volume of 3,350 m3 / h (standard condition), and an exhaust pressure of 0.67 MPa (A). 2Using condition monitoring to control air compressor operating parameters The two air compressors are equipped with an on-line vibration monitoring system produced by Nanjing Steam Turbine High-tech Development Co., Ltd., which mainly monitors the vibration displacement values ​​of the four-stage journals in the X and Y directions relative to the Bearing pads. At the same time, the main control computer displays the bearing temperature, oil temperature, oil pressure, air intake and exhaust pressure and temperature of the air compressor. Uninterrupted condition monitoring of the operation of the entire air compressor. Because Daye Company did not have large-scale oxygen-making equipment before, lacking the necessary practical experience, it is often difficult to achieve good control by rigidly referring to the instructions. Therefore, the information provided by the monitoring system controls the correct operation of the air compressor. , played an irreplaceable role. For example, after the driving stage, the vane is opened from the starting position to 30. If the air compressor is pressed immediately, we will see that the vibration of each level is obviously improved, and it is very unstable, and it is determined that it is low pressure surge. Therefore, we improve the operation. After driving, the guide vanes are opened to 65 or more, and then the pressure is increased. If not much air volume is required, the small guide vanes are closed to the proper position, thereby avoiding the low-pressure surge during the driving phase. As such a large-scale equipment, we will reduce its vibration as the main task of operation control. From 1#, 2# air compressor, 1# air compressor uses 32# turbine oil, 2# air compressor for some reason Using 46# oil, we obtained a statistical analysis of the large number of moving parameters of the 1# air compressor obtained by the monitoring system, and found that when the oil temperature is controlled at around 35#, the vibration condition is the best; for the 2# air compressor, we After many practices, it was found that the vibration is good when the oil temperature is controlled at 40#, and the vibration can be reduced by about 8% when the oil temperature is 35#. The air compressor supporting motor power is up to 3400kW, which is the energy consumption of our factory. How to reduce the power consumption is also the focus of our work. Since the air compressor has a certain affluence, it can achieve significant energy-saving effects by closing the small inlet guide vanes and reducing the amount of air released. However, when the opening degree of the guide vane is too small, the vibration will increase again. We have solved this contradiction better through state monitoring. 3 Correct judgment to avoid major equipment accidents of series DH air compressor The vibration of the series of pressure control machines has been running well from 1997 to June 1998, but an abnormal situation occurred in July 1998. We will compare the vibration of the stage axis at several typical times. At 6:04 on July 9, there was no abnormality in the air compressor. At 7:15 on July 9 and at 7:23, the air compressor made an abnormal sound, and the temperature of the grade bearing had a sharp rising peak at the same time. The temperature rose from 55# to 62# at 8:10. Separate the parking to check the bearings at all levels, but there are some large-area contact highlights. After a minor repair, the air compressor bearing temperature 58# will be restarted again at 20:15 on July 10, and the vibration conditions of the above three moments will be compared. Analysis shows that the vibration amplitude suddenly rises abnormally when the anomaly occurs, the bearing temperature changes drastically, accompanied by the sharp sound, and at the same time, the power frequency spike on the vibration spectrum shows that the rotor part is abnormally damaged, causing the rotor to move. The balance suddenly broke. Decisively decided to stop running the air compressor at 0:50 on July 11. At that time, it was initially determined that the abnormal condition of the air compressor may be caused by the serious imbalance of the rotor system, and the impeller of the stage was damaged. After disassembly inspection, it was found to be much more serious than we expected. The grade impeller cover has two radial penetrating cracks, each longer than 100 mm, and there is a crack at the end seal ring. If the rotor continues to operate, the crack will expand rapidly, which will inevitably cause the impeller to break, breaking the air compressor cover and flying out. The high-speed rotor will suddenly lose stability and destroy all the bearings, which will cause the entire air compressor to be scrapped and fly out at the same time. Fragments can also cause significant casualties and the losses will be enormous. 4 provides basis for replacement of spare parts for II series air compressors II series air pressure high-speed rotor, since the operation in 1997, the %-axis vibration has been at a high level, level 65m, % 56m, beyond the vibration allowable range. Although the vibration amplitude is relatively large, it is relatively stable, and the vibration frequency characteristics are mainly at the high-speed shaft power frequency of about 200 Hz. Obviously, there is a big problem in the dynamic balance of the high-speed rotor. The high-speed rotor is dynamically checked for multiple times, and it is found that the phase angle of the dynamic unbalance of the rotor is extremely unstable, and the double-weight de-weighting method cannot be used to find the de-weighting position. It is preliminarily determined that the rotor has defects in manufacturing or assembly. Since such defects are concealed, they must be sent back to the manufacturer for thorough inspection and treatment. In order to shorten the maintenance time, we re-purchased a set of rotors. After the replacement, the vibration of the unit was significantly reduced. The average level was 32m, and the average level was 28m, which achieved good operation. The cost of purchasing a rotor is very expensive. If there is no sufficient theoretical basis and realistic requirements, it is obviously difficult to make up your mind.
We offer an extensive line of replacement timing drive systems, including Three Piece Timing Sets, Complete Multi-Component Timing Kits, timing chain kit, engine timing set, engine timing kit, Sprockets, Timing chain tensioners, Guides and Dampers. The updated timing kits are for setting on the camshafts and crankshafts.
Our parts are applicable for Audi, Buick, Cadillac, Chevrolet, Dodge, Ford, Mitsubishi, Suzuki, Opel, GM, Toyota, Nissan, VW and other European, American, Japanese cars. All of them are exported to Europe, America, Asia, Africa and other regions in the world.
Timing Kits,Timing Chain Kits,Ford Timing Kits,Engine Timing Kits,Timing Chain Kit,Engine Timing Set,Engine Timing Kit NINGBO DGOFEN AUTO TRADE CO., LTD , https://www.dgofen.com