Action; fault diagnosis; Panzhifeng Daqing Refining & Chemical Co., Ltd. equipment monitoring center wheel on both sides of the wheel and then drive the pinion, each pinion shaft is equipped with a closed impeller, to achieve 4 levels of compression. The low speed shaft speed is 20174, the high speed shaft speed is 24656, the support bearings of the three shafts are all tilting pad bearings, the front and rear shaft seals are labyrinth seals, and the on-line monitoring point arrangement is 1. The air separation unit is an important device of the refining and chemical enterprise, and is responsible for providing qualified oxygen nitrogen and other related gases for the downstream equipment. As an air compressor of the core equipment of the air separation unit, it conducts condition monitoring and fault diagnosis to ensure its Normal operation is essential and is the basis for ensuring smooth operation of downstream units over long periods of time. The air compressor 013 used in the air separation station of a refinery company is the H10090.97 centrifugal compressor produced by Kaifeng Air Separation Equipment Factory. The speed of the drive motor is 2972, and the motor passes the gear coupling and compressor. Big gears connected, large teeth received date 20100913 Daqing City 2.1 vibration phenomenon air compressor 010 old smooth operation until October 10, 2009, 88000 online monitoring system shows 1 2 level shaft vibration continues to grow, to 12, 1 The grade shaft vibration rises from 36μm to 109μm, and the second-stage shaft vibration rises from 6841 bamboo to 98 claws. 23. In order to analyze the vibration cause, first contact with the device, and adjust the process parameters to know that the pressure of the air compressor inlet and outlet has not changed; There is no obvious relationship between the temperature change of the 12-level inlet and outlet and the vibration; the air compressor load is not adjusted; the vibration change and the change of the lubricating oil temperature are caused by the defect of the large gear frequency 50 heart, which can be divided into the original according to the process of imbalance. Unbalanced gradual imbalance and sudden imbalance. The frequency Hz has a close relationship. When the temperature of the lubricating oil changes, the amplitude of the 12-stage vibration changes with the change of the oil temperature, and the temperature of the bearing bush also fluctuates. The above phenomenon indicates that the vibration caused by the vibration of the load fluctuating air flow can eliminate the cause of the vibration change. The online monitoring system is used to analyze the cause of the vibration generated by the air compressor. 2.2 Spectrum analysis From the vibration trend and spectrum provided by the online monitoring system, when the amplitude of the vibration increases or decreases, no new value in the spectrum changes with the amplitude of the vibration, and the vibration of other frequency components changes less. 47. From the above process conditions and vibration phenomena analysis, it is preliminarily judged that the vibration abnormality of the air compressor may be due to rotor imbalance or bearing wear. The frequency Hz rotor imbalance failure mechanism is set to the rotor mass, the eccentric mass is 7, and the eccentricity is 6. If the centroid of the rotor is not zero to the vertical distance of the two bearings, the deflection is due to the eccentric mass. 71 and the presence of an eccentricity of 6 will produce a centrifugal force centrifugal distance or both when the rotor rotates. The magnitude of the centrifugal force is related to the eccentric mass, the eccentricity is 6 and the angular velocity of rotation is 0, that is, the factory = 7,2. It is well known that the cyclical change of the direction of the alternating force causes vibration, which is the cause of the vibration caused by the imbalance. . The main feature of the rotor imbalance fault is that the vibration time domain waveform is approximately sinusoidal, the spectrum energy is concentrated on the fundamental frequency higher harmonics, and the rotor axis trajectory is elliptical. In the initial unbalanced operation, the vibration of the unit is at a high level; for the unbalanced gradient, the vibration of the unit is lower at the beginning of the operation, and the vibration value is gradually increased with the passage of time; for the sudden imbalance, the vibration value is suddenly increased, then Stable at a higher level. 2.2.2 Bearing wear failure According to the rotor dynamics, it can be seen that 1 due to the rotation of the rotating shaft, a support rotation and any additional force of the oil wedge are generated. 2 The support force of the entire oil wedge can be vortexed and unstable by radial force and tangential force. The tangential force is always forward, that is to say always acting in the direction of rotation, and the eddy oscillation is now ring-shaped or nearly annular. Shame 50 Frequency Hz 2.2.1 Rotor Unbalance Fault The rotor imbalance is due to the rotor mass eccentricity or the rotor part of the rotating shaft. The oil wedge bearing consists of a system that operates according to the following steps. The specific radial preload and the dynamic stiffness of the system cause the shaft to Running in a special eccentric position, this creates a restriction and forms an oil wedge at the front of the mouth. This wedge produces a support force that is in the opposite direction to the radial preload amplitude, which balances the rotating shaft at an equilibrium position. If the radial preload changes, the system is no longer balanced, the shaft will respond by moving inside the bearing, which will change the position of the port. The wedge will be reflected by changing the overall wedge support, and the balance will be again Hold the shaft in a new equilibrium position. According to the above principle, when the force acting on the bearing of the rotor changes, especially when the rotor load is increased, the oil film supporting force of the sliding bearing acts as a counterbalance force, which also rises, and when the rotor load exceeds the oil film supporting force limit, the oil film is caused. Destruction, the amplitude of the shaft vibration rises; when the temperature of the lubricating oil rises, the viscosity of the oil decreases, and the supporting force of the oil film decreases, which also causes the oil film to break, the amplitude of the shaft vibration rises, and the bearing temperature rises 4. Based on the above analysis, the air compressor has a long running time, and the 12-stage impeller may have an imbalance caused by the accumulation of ash. As the imbalance increases, the bearing bush wears and deteriorates, resulting in a gradual increase of the 12-stage vibration. It is recommended that the air compressor stop immediately, check the fouling of the 12-stage rotor, and check the bearing condition. According to the diagnosis suggestion, the air compressor is shut down for maintenance, and the disintegration inspection finds that the 12-stage impeller has serious ash and scale formation, and the scale layer is evenly distributed; the 12-stage bearing bush under the tile is worn or broken, and the diagnosis conclusion is caused. The air filter bag was replaced and the 12-stage rotor was descaled and rebalanced. The 12-stage bearing was replaced. After the inspection, the vibration at all levels decreased significantly, and the maximum vibration was 36. The vibration and operation of the unit were good. Cao Chunrong. , Book 3 type air compressor failure analysis and processing. Fan technology, 2005 Huang Chonglin, Lu Guanghong, Zhong Jingshan. Vibration Fault Analysis of Type 063 Air Compressor and Sheng Zhaoshun. Equipment condition monitoring and fault diagnosis technology and application. Beijing Chemical Industry Press, 2003136137. Jin Suoying, Yu Zhiling. Vibration analysis and fault diagnosis of air compressors in air separation units. Xia Xianqiu. Centrifugal fan airfoil blade simple expansion method å® fan technology Meng Qingyi. A cross-platform deployment method for a wing-type centrifugal fan blade. wind Tpu Applications,Tpu Transfer Film Hose,Thermoplastic Polyurethane Elastomer,Injection Molding Tpu Granules Xuchuan Chemical , https://www.xctpu.com