Wu Liwei Bu air compressor frequent loading and unloading reasons analysis and treatment Wang Hong \ Wang Yuquan 2 1. Anyang Institute of Technology, Henan Anyang 455000 Blue Nest Power Maintenance Co., Ltd., Ningbo, Zhejiang 315722 into air compressor efficiency reduction, equipment damage; will also cause economic Losses and even threats to personal safety. Yiwen analyzed the reasons for frequent loading and unloading of air compressors and gave a treatment method, which provided a certain basis for maintenance personnel. 1 Air compressor operating conditions introduction Datang Wushashan Power Generation Co., Ltd. Phase I project 3, 4 machine combination with a set of ash air compressor system, each set of a total of 4 injection screw air compressors. When designing normal working conditions, three ash conveying air compressors are running and one is standby. The subsequent purification equipment of the ash air compressor adopts the freeze adsorption combined dryer, and the degreasing-and water-removing two-stage filter is arranged in front of the dryer, and the first-stage dust-removing filter is arranged after the dryer. Four refrigerated adsorption dryers are connected in parallel to enter 21, 15m3 gas storage tanks for 3, 4 units of electric dust removal and ash gas and 1 and 6m3 gas storage tanks for gas transmission ash gas, ESP area ash conveying instrument Gas, fly ash, library bag backflushing, etc., gas, FGD area miscellaneous gas and instrument gas. The arrangement of a single air compressor, filter (deoiling, water removal, dust removal) and cold dryer is shown in the figure below. Analysis of the frequent loading and unloading of air compressors for single air compressors and purification equipment. UHV's air compressor for ash removal uses M250W/C type, the drive motor is 6000VAC, and the displacement is 42.5m3/min. The working pressure is 6.0bm and the unloading pressure is 7.0bm. According to the actual use, two ash conveying air compressors can be used to meet the gas requirements. In this Case, the loading time of the air compressor is generally 5 minutes and 10 minutes, and the unloading time is about 2 minutes. minute. The so-called frequent loading and unloading, that is, loading and unloading 2 times and 5 times in 1 minute, even more frequently. Such frequent movements not only shorten the life of the unit solenoid valve, air compressor population door and unloading valve, but also seriously threaten the safe operation of the whole unit. The reason why the air compressor is frequently loaded and unloaded can be summarized as follows. It is well known that the exhaust pressure of the air compressor is the main basis for controlling the loading and unloading of the air compressor. If the difference between the two values ​​and the set value (the load pressure value of the U-FI ash air compressor is 6.0bai\the unloading pressure is 7.0bai\the difference is l.Obar), it may cause the unit to produce Frequent loading and unloading. When the loading pressure of the unit increases, the unloading pressure value decreases; or the simple loading pressure value and the unloading pressure value decrease, the unit loading and unloading cycle becomes shorter, that is, the unit uses a constant amount of gas. Wang Yuquan, working unit: Blue Nest In the production and operation department of Power Maintenance Co., the closer the loading and unloading pressure values ​​are, the more frequent the loading and unloading is, and the greater the hidden danger of safe operation of the equipment. If the unit installation and unloading pressure setting is normal, you can consider whether there is a pipeline blockage between the air compressor outlet and the gas storage tank. If the pipeline is blocked but not completely blocked, the compressed air circulation will be severely blocked. The gas pressure between the plugging point and the air compressor is difficult to be quickly removed during the loading of the air compressor, resulting in the unloading pressure value being reached in a short time. And uninstall. However, due to the limited amount of gas between the plugging point and the outlet of the air compressor, combined with system losses (such as filter drain gas, cold dryer regeneration) and a small part of circulation to the gas storage tank, the pressure quickly drops to the loading pressure value, The press is reloaded and repeated. 3.1 Control causes frequent loading and unloading treatment method This reason can be directly seen through the pressure display when the unit is loaded and unloaded. If there is any change, it can be solved by online calibration or by removing the pressure sensor for detailed detection and reloading the sensor. Of course, it is also common for the pressure sensor to measure the error of the measurement due to clogging. It is common practice to use compressed air to purge the sampling line. 3.2 System Causes Frequent Loading and Unloading Processing Method The system causes more complicated processing, which can be judged by the difference between the air compressor outlet pressure and the outlet temperature of the dryer. If there is a difference or the difference is too large (general filter矣 6bm, cold dryer (0.2bm,), you can judge that the pipeline or equipment is blocked. Due to the large number of pipeline equipment, after long-term inspection and observation, it is often easy to block the equipment with degreasing and water removal filters (the dust removal filter is located in the cold dryer, the probability of blocking is very small): including the filter Filter core; filter drain solenoid valve; filter solenoid valve front filter. Among them, the probability of blockage of the filter screen before the sewage solenoid valve is the largest, which can be solved by cleaning or replacement. The sewage solenoid valve may generally have a phenomenon such as a valve body jam, a coil burnout, a timer, etc., and the general replacement can be solved. Wudian Company has once appeared in the ash air compressor because the filter screen of the water filter before the water filter is blocked, it can not be discharged in time, so that the sewage is filled with the filter, the air compressor is frequently unloaded, and the maintenance personnel cleans the filter screen normally; 2) The internal adsorption drying tower A-, B population switching valve of the dryer. If the switching valve is not switched, it can also cause gas flow to be blocked. Wudian Electric Dryer Drying Tower A and B population switching valves are pneumatic switch type. The fault of the pneumatic switch type valve generally appears in the control of the gas source and the valve body. The maintenance personnel can judge whether the control gas source is normal or not by checking whether there is water in the filter pressure reducing valve or whether the gas source pipeline is falling off. By manually operating the pneumatic valve to determine whether the valve body is flexible and the cylinder seal is good. U-Electronics Co., Ltd. (started on page 153) applied technology as the positioning reference, rotating 11°14'55" in the horizontal direction, and then calculating it in the vertical direction, a=32°07'27.41" Double bevel. The 119 size can be guaranteed by ensuring that the slope is calculated to the process ball Hmm. In the grinding process, the part can be processed by rotating the part on a sine gauge. In the past, when the part was machined, it was measured by the auxiliary process hole inserting ball rounder. The process was complicated and easy to accumulate error. It is easy to appear the scrapping phenomenon of the part. After research, the process ball is used for measurement. That is to measure the process ball to the double bevel size to ensure the cusp size of 119, making the measurement simple and easy, and it is not easy to produce accumulation error, improve the product quality, and make the component qualification rate increase significantly. (Continued from page 154) Once, because the control air source with water (control gas source sampling at the air compressor outlet, oil water separator and cooler effect is not ideal, air with water) block the filter pressure reducing valve, can not control the switch The valve causes the air compressor to be frequently loaded and unloaded. After that, the control gas sampling point is changed to the outlet pipe of the cold dryer, which solves the problem of controlling the water source with water, and the equipment runs normally after being put into operation again; 3) If the temperature of the precooler and the evaporator in the cold dryer is not well regulated It is also easy to cause most of the ice in the evaporator inlet and outlet, thus hindering the circulation of gas. If ice jam occurs or the evaporator temperature is improperly adjusted, it can be judged by observation method. If the compressed air pipeline in the dryer has “sweating†phenomenon; or the parameter setting of the dryer does not meet the equipment design requirements, it should be adjusted in time to avoid Frozen equipment causes unnecessary damage. This situation occurs during the season change period, which is generally solved by appropriately adjusting the evaporator temperature. 4) The installation of the check valve of the dust filter outlet or the valve stem and the valve body falling off may cause the air compressor to be frequently unloaded. U-Electronics Co., Ltd. once happened to inadvertently reverse the direction of the valve after repairing the leakage defect in the check valve of the dust filter outlet, so that the compressed air could not flow into the gas storage tank, and the gas in the gas storage tank can be reversed back to the cold dryer. The unit is frequently loaded and unloaded (upper page 158). All the side keys are replaced by fluorine atoms. The CF bond can be very strong, so PTFE has excellent aging resistance and high stability. The gaskets are used in ambient temperatures up to 250 ° C, so only Teflon meets the material requirements of the gasket working environment. 4 Conclusions 1) Clamping liner Fluororubber F275 cracking failure is caused by the combination of stress and temperature. The clamp assembly torque is too large 2) The heat resistance of the material used does not meet the requirements for use. Ethylene can meet the requirements of use. 4) The clamp gasket fault is reset to zero, and no such fault occurs during the subsequent production process.
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