The axial flow fan is developed on the basis of the centrifugal fan, and has a wide range of applications due to its high efficiency and wide working range. Our axial flow fan was put into operation on March 12, 2001 in order to meet the needs of blast furnace development under the condition of dismantling the old used centrifugal fan. However, through installation and commissioning and several months of routine maintenance, it is found that the axial flow fan is from actual design and supply to software preparation. The automatic control system has different degrees of problems, and has affected the normal production of the unit many times, affecting the stability of the blast furnace. Smooth, it must be improved.
2 Problems and improvement of the axial flow fan automatic control system From the use of our factory, the main problems are as follows.
2.1 Selection of temperature measuring components and installation Lubricating oil station oil temperature detection is an important testing parameter for the normal operation of the axial flow fan. The bearing return oil temperature measurement has no oil pressure, and generally there is no problem. The more common fault is the oil temperature. Detection and oil tank oil temperature detection of the oil station, using the movable ferrule device expansion pressure thermometer, the card lining is oil-resistant rubber expansion type, the thermometer, due to the large vibration of the tubing, the oil-resistant rubber rupture caused a large amount of oil leakage, and the machine was shut down for three hours. The repair was carried out by using a fixed thread to install the copper gasket. The problem was solved and it has been running well. The second axial fan product has improved the temperature measurement method through our feedback.
2.2 The form and installation of the pressure-receiving device is a member of the enterprise and is closely related to the development of the enterprise.
Second, provide employees with a platform to showcase their personal talents.
In the enterprise, everyone wants their work and performance to be recognized by the leaders and their colleagues. This is the high-level need of human nature. Then, enterprises must constantly adopt incentive mechanisms to encourage employees to simulate each position into a market to develop their potential, manage their jobs, manage their own self, and raise employees from “social people” in the ordinary sense to “self-fulfilling people”. So that the needs of all levels of employees are fully satisfied, and then promote the entire enterprise to rise forward.
In order to fully stimulate the creativity and initiative of employees and achieve "employee satisfaction", the power plant has taken a series of effective measures. For example, since 2000, we have vigorously carried out the “three innovations for all employees” campaign, and awarded monthly awards for outstanding innovations declared by employees. The total amount of reward funds exceeded 100,000 yuan. At the same time, it has successively launched “foreign system” and “full-time profits”. A new model of corporate management, such as “chemicalization”, “self-management” and “self-management”.
Focusing on production and management, we will take the next step in the year to fully tap the potential of people's potential and material, so that the "self-worth" of employees can be realized. After the employees are satisfied in all aspects, more than 600 employees with a high sense of ownership, in their respective positions, ideas, ways to provide maximum power needs with minimum input costs, to maximize corporate profits.
4 Conclusion The new management of “Customer Satisfaction, Enterprise Satisfaction and Employee Satisfaction” implemented by Power Plant has greatly promoted the progress of the company and improved the overall economic efficiency and management level of the company. In the practice, I actively explored and transformed many macroscopic theories of modern enterprise management into practical and practical methods, in order to provide effective ideas and methods for microeconomic management of modern enterprises.
The original motive of the axial compressor of our factory is a steam turbine. The automatic instrumentation equipment of the extractor is supplied in complete sets. In order to facilitate transportation and dismantling, the pressure device of the medium pressure of oil and soda water uses the pressure socket and guide. The pressure pipe and the source valve are composed. These new equipments are no problem at the initial stage of operation. For a long time, the pressure socket of the soda system will rust, and the convex and concave surface processing is not very good. It is a carbon steel. At the beginning of the installation, the joint surface is a line contact. Once the steam leaks or leaks, it cannot be killed. The oil system takes a better pressure. Based on the above reasons, we have modified the pressure socket to prevent leakage and water leakage.
2.3 Signal isolation
signal isolation is a commonplace thing, design is less considered, but in actual use due to poor grounding, 1/0 module grounding loose, the use of frequency converter and other factors, May affect the normality of the signal, causing the unit to malfunction and stop. When the first axial unit is installed, the factory will appear in the initial stage of operation, such as lubricating oil pressure, power oil pressure, shaft vibration, etc. When possible, we installed signal isolators for the safety parameters of the unit, and the distributors with isolation functions to clean the signals. Ten axial fan signal isolators were installed.
2.4 Improvement of double-loop power supply current In order to ensure the safety and reliability of the system, the DC power supply adopts redundancy mode, and the system wiring diagram is shown.
There is no error in the system wiring design principle. If the drawings are handed over to the regular disk cabinet manufacturer, and it is designed for the design manufacturers for many years, the situation may be better. The first axis of our factory. The PLC cabinet power supply of the flow fan is connected to the parallel part AB without the pressure line nose. The air switch is directly connected. Once the front is loose, the contact is not good, it will affect all the power supply behind. The double DC power supply reverse cut-off diode outlet according to the drawing. It is four joints and it is very unreliable to tighten by screw. I have experienced similar failures in the 1 axial fan of our factory. Because of the looseness of 02 points, the power module 1 and the power module 2 both lose power and almost stop the accident. After careful study and discussion, we decided to change. For the design wiring, the design is working well after the design is modified.
And make the following description in the drawings, so that the manufacturer of the panel can understand, as explained below: all the reverse-cut diodes are equipped with heat sinks.
If the Ml or M2 is loose, it will not affect the power supply of the power module. If the M1 is loose, the power module 1 will lose power, but the module can continue to supply power through the redundant power module 2.
Since most of the disk cabinets are manufactured by the manufacturer, most users will not check the screws and joints one by one, nor will they check whether the connecting screws have anti-loose washers. The new cabinet will not have any problems. After running for a period of time, the problem will occur. Our factory and 1 axial flow fan have been improved and are running well.
2.5 Software refinement
software refinement is a matter of every person who compiles process control software 1 line function temperature and pressure compensation. A comprehensive consideration and reasonable algorithm can fully display the level of control theory of programmers. The following is a brief description of the fan anti-surge valve control principle.
Compared with the surge prediction ratio of L - Compared with the surge report S1 1 manual given i 2.5.1 control algorithm can be seen that the temperature differential compensation of the throat differential pressure can truly reflect the operating conditions, because it is a constant speed, anti-asthmatic Control is determined by the differential pressure and outlet pressure after temperature compensation, so it is particularly important. In order to prevent the unit from malfunction due to instrument failure, the programmer should refine the anti-asthmatic control chart and add the following items: Temperature limit: It is limited to the lowest local standard of the local weather, such as -10T. If it exceeds, the test design temperature of the unit is taken as the standard, and the alarm of the human wind temperature disconnection is given in the alarm column.
Inlet differential pressure limit: the highest value of the differential pressure of the design throat is the upper limit, and the lowest value of the throat is 10%, and the minimum value and the differential pressure switch of the throat are judged as the condition of the fan counterflow. The normal overrun retains the last value, and the throat differential pressure alarm is given in the alarm bar, triggering the timer, and the timing is 2 hours.
Outlet pressure limit: The highest pressure of the test anti-asthmatic curve is high, which is a low value. If an abnormality occurs, an abnormal alarm of the outlet pressure is given in the alarm column, and the last value is retained, and the timer is triggered, and the time is 2 hours. .
The purpose of the timer is to leave the maintenance personnel with sufficient inspection time and the time for the operator to contact the blast furnace, switch the fan or tap the iron as soon as possible, and after the alarm is not processed or difficult to handle after 2 hours, the anti-surge valve starts to vent. Automatically open according to 25%, 50% and other gradients to prevent the fan from entering the surge zone and endangering the safety of the fan.
Curve Record: Record all parameters involved in anti-asthmatic control, including detection signal, external reference signal, output signal and valve position feedback No. 3, surge prediction and alarm are included in the alarm record.
2.5.2 Hardware upgrade redundancy mode, running for a period of time to find anti-surge point jump, CPU 7 red indicator light (fault light) at the same time bright fault. After the shutdown, the redundancy switching test was unsuccessful three times in one time. The software preparation company contacted the manufacturer. The manufacturer also said that it was unclear. After the manufacturer asked for the redundant CPU version, the CPU was upgraded free of charge
The program was reconfigured, and now the axial flow fan is not faulty.
3 Effects Through the above measures, the safety of the axial flow fan is further improved, and the failure rate is also greatly reduced. It is difficult to occur once the monthly occurrence is reduced to more than half a year. The recently-invested 1 axial flow fan The failure rate is higher, and it is also being rectified (once in March). Of course, it is difficult to eliminate all hidden dangers. The fault can not be analyzed and judged only by the record curve, and we need to further improve the understanding of the axial fan automatic control system.
4 Conclusions
So many faults are exposed, reflecting the shortcomings of manufacturers, design units, and software preparation departments. It also leaves us with deep thoughts. Correct selection of manufacturers, design and software compilation units is the source of preventing all hidden troubles. The maintenance unit needs to continuously improve its own quality in daily maintenance work, eliminate the fault in the germination condition, ensure the safe operation of the fan and the normal production of the blast furnace, and also need the positive cooperation of the blast furnace to leave sufficient maintenance time for the fan. In order to self-check and change.
Changzhou Keyleader Fan Technology Co. Ltd.