Table 1 No. Valve name after gas loss status hazard Remarks 1 Extraction steam check valve free state by steam pressure top open 2 main steam pipe ventilation valve open and load rejection 3 high pressure heater emergency trap opening affect high water level control automatic 4 The water pump recirculation regulating valve opens the feed water flow drop (æ°, the adjustment is not timely may cause the boiler to shut off water 5 steam seal low pressure water spray control valve open to affect the steam inch Peng recommended 6 high phase 胗 door free state may stop by steam pressure open 7 Oxygen level main and auxiliary regulating valve keep 8 condensate recirculation regulating valve keep condensate flow reduce 'condensation pump trip 9 steam shaft seal main steam supply steam regulating valve open steam turbine shaft seal pressure can not be controlled recommended 10 shaft seal overflow The main pipe pressure regulating valve closes the steam turbine shaft seal pressure can not be controlled 11 steam pump seal water pressure regulating valve open small machine seal water pressure can not be controlled recommended 12 oil quick closing valve, return oil quick closing valve closed Li no 13 oil pressure adjustment door Close Li Wei 14 flame TV exit can not monitor the furnace flame 15 over the cold water to adjust the door to open the water storage 16 coal mill exit fast off the baffle to maintain no harm A power plant No. 3 unit is 660MW ultra-supercritical unit, On June 5, 2013, due to the air source reform process of the compressed air system, the maintenance personnel mistakenly closed the manual main door of the unit's compressed air pipeline, causing all the pneumatic doors of the unit to lose gas. The plant has no compressed air pressure and low furnace protection. After emergency treatment by the operating personnel, the unit did not trip, but the unit operation was seriously threatened.
2 Operation, processing and impact years at 13:25 on June 5, AGC operation of No. 3 machine, load 387MW, B, D, E, F grinding operation, B condensate pump power frequency operation, A condensate pump power frequency standby, The water main controller of the deaerator is automatically controlled, the condensate flow rate is 831t/KA, B is the feed pump operation, the boiler feed water flow is 1056t/h, the A and E air compressors are running, and the other air compressors are used.
At 13:28, the supervisor found that the soft-light word alarm of the No. 3 machine, the hydrophobic pneumatic door on the machine side, the exhaust check valve, the high-ranking check valve turned yellow one by one, the drain door opened, the steam exhausted check gate, the high exhaust reverse Stop the door free state.
2.22 Immediately check the compressed air screen, find that the pressure of the annular ring of the boiler drops, immediately start the 34C air compressor, the pressure of the annular ring of the boiler continues to drop to 0. 2.2.3 After the gas source of the instrument is lost, the main valve of the deaerator is maintained. At 48%, due to the full opening of the machine side trap, the high-incident accident is hydrophobically opened, and the high-addition to the deaerator is gradually lost in hydrophobicity, the water level of the deaerator is lowered, the water supply bypass door is manually operated, and the deaerator is watered. And began to reduce the unit load.
2.2.4 After the trap is fully opened, the temperature of the sparse expansion is high, and the condenser is opened and the temperature is adjusted.
2.25 View shaft seal system, low pressure shaft seal desuperheating water adjustment door is fully open, auxiliary steam supply shaft seal adjustment door is fully open, main steam supply shaft seal adjustment door is fully open, shaft seal overflow valve is fully closed, resulting in shaft seal steam pressure rises, up to 221kPa, the low-pressure shaft seal temperature is as low as 120, the shaft seal of the low-pressure cylinder is steaming, and the person adjusts the shaft seal to reduce the temperature of the water manual door to adjust the shaft seal temperature.
2.2.6 The four pumping pressure drops to 0.23 MPa, slowly open the small machine auxiliary steam source, adjust the pressure to 0.3 MPa, and gradually cut the small steam source to the auxiliary steam.
2.2.7 The steam pump recirculation door is automatically opened, the water supply is automatically adjusted normally, and the inlet flow of the economizer is monitored.
13:51 On-site inspection Open the closed air compressor manual door, the air source is restored, and all yellow flash pneumatic doors are reset.
2.2.9 The air source is restored by the instrument, the low-pressure shaft seal is desuperheated, the water is adjusted automatically, the auxiliary steam is supplied to the shaft seal and the door is automatically closed. The main steam supply shaft seal is automatically closed, the shaft seal overflow is fully open, and the shaft seal pressure is fast. Decline, immediately adjust the auxiliary steam supply to adjust the door, and return to normal.
2.2.10 The instrument uses gas source to recover, the main valve of the deaerator is automatically opened, the condensate flow and the condensate pump current exceed the rated value, immediately close the water bypass electric door, manually turn the deaerator water main switch Up to 50%, adjust the deaerator water level, condensate flow is normal.
Compressed air loses unit impact (1 oil gun can not be propelled, boiler can not ignite, combustion support. 0 flame TV exit, can not monitor the furnace burning situation. 0 over cold water to open the door, water storage tank water, economizer water intake reduced, water wall Over temperature.
(1 high-order check valve may be closed, turbine steam interruption trip. Q each steam check valve may be closed, high and low, deaerator exit, steam pump four pumping source lost. (3 main reheat steam pipeline The steam trapping pipe, the steam turbine and the small machine body trap are opened, and the working conditions are drastically changed. (4. The normal trap of the heater is closed, the critical trap is opened, and the high and low operating conditions are deteriorated. (5 The feed pump is recirculated, The flow rate of the economizer inlet is stable. (6 The condenser water supply valve will be closed, and the condenser can not replenish water. (7) The feed water pump seal water regulating valve is opened, and the seal water differential pressure is too large. (8 shaft seal system pressure and temperature change Large, shaft seals are easy to blow.
3 machine furnace side important pneumatic valve lost air source status table (see Table 1) 4 problems and treatment points 4.1.1 instrument with compressed air lost, A, B steam pump recirculation pneumatic valve fully open, water supply flow reduction, saving coal The inlet flow of the device is reduced, the superheat of the outlet of the starter separator is increased, the output of the unit is reduced under high load conditions, the water supply demand of the unit is met, and the outlet of the starter separator is controlled to overheat, -74-v. T degree, to prevent the main and reheat steam temperature over temperature, but should pay attention to A, B steam pump not overload, pay close attention to the normal operating parameters of A and B steam pumps.
4.1.2 When the small steam source is switched to the auxiliary steam in the event of shutdown or emergency, the four-exhaust steam and the auxiliary steam pressure and temperature do not match, which may cause the steam source pressure to rise and the low-pressure control valve to close and the steam temperature to decrease instantaneously. 100, causing the output of the small machine to drop and the flow of the water supply to fluctuate. In addition, the inlet steam temperature of the small machine changes greatly, which generates large thermal stress and affects the service life of the small machine.
(1The switching steam source pressure is as close as possible, the switching steam source temperature has sufficient superheat degree, and the small machine speed is kept stable during switching. (2) Before the steam source switching, the small machine speed should be opened before the valve is closed, and the spot is inspected. Confirm that the water is unblocked and keep the trapdoor open during the switching process. (Before switching the steam source, the steam pump recirculation door should be switched to prevent the small steam entering the steam parameters from changing greatly during the switching process, and the steam pump flow is low. 4 During the process of steam source switching, the steam source electric door should be gradually opened, and the change of the speed of the small machine should be monitored at any time. When the speed of the small machine changes significantly, the switch is suspended, and then the switch is stabilized after the speed is stable.
During the handling of the unit load problem, the unit reduced the load, the four pumping pressure was reduced, and the steam supply of the small machine was reduced, which affected the operation of the feed pump and also affected the stable combustion of the boiler. However, the load cannot be kept too high, otherwise a large amount of hydrophobicity enters the condenser and increases the heat load of the condenser. Through this incident, according to the change of extraction steam pressure, it is recommended to maintain the load at around 60%.
4.3.1 The instrument is lost with compressed air, the body of the steam turbine is fully open, the hydrophobic pneumatic door of the extraction pipe is fully open, and the high temperature and high pressure steam enters the condenser. At this time, pay attention to the temperature of the condenser and expand the condenser to expand the condenser. Decrease the water and pay attention to the vibration of the condenser and related parameters.
4.3.2 After the exhaust steam check valve and the high exhaust check valve are out of gas, the check valve is in a free state. At this moment, pay attention to the change of the steam extraction pressure, and make an accidental expectation of the back door closing.
4.3.3 After the instrument is restored with compressed air, the above pneumatic valve can be reset and its status is closely monitored.
After the instrument is lost with compressed air, the main steam to the shaft seal main pipe supply steam pneumatic door is fully open, the auxiliary steam to the shaft seal main pipe supply steam pneumatic door is fully open, the shaft seal overflow pneumatic door is fully closed, the shaft seal desuperheating water pneumatic door Fully open, the shaft seal main pipe pressure is increased from 32kpa to 223kpa, the shaft seal steam temperature is reduced from 178 to the coal mine electromechanical transportation safety control strategy analysis Li Ming (Tangshan Majiagou Mining Co., Ltd., Tangshan 063000, Hebei Province) is mechanized in the production process The level is constantly improving, and many electromechanical equipments are applied in coal mine production. The use of these equipments is of great help to improve production efficiency. However, many accidents have occurred during the use of mechanical and electrical equipment accidents. The safety of production has a big impact. In recent years, the number of accidents in coal mine electromechanical equipment has been increasing, which has caused more and more hazards in the production process. The most common accidents in electromechanical equipment are transportation equipment. In order to avoid accidents, it is necessary to The reason for the occurrence is analyzed, and the accident is also better judged, so as to reduce the accidents occurring during the electromechanical transportation of coal mines and better ensure safe production.
The hazards caused by safety accidents in the production process of coal mines are very large. Therefore, safety work must be placed first in the production of coal mines. In the production process of coal mines, the use of electromechanical equipment is very frequent. In the process of coal mining, transportation equipment should be used throughout the production process, so that once a safety accident occurs in the transportation equipment, the whole production process will be affected. In the case of serious conditions, the production personnel will be given. The life brings a certain threat. If coal mining enterprises want to operate better in the development process, they must avoid accidents and prevent accidents.
1 The cause of accidents in electromechanical transportation equipment caused by coal mine electromechanical transportation accidents is very many. In order to avoid safety accidents, it is necessary to conduct a good analysis of the causes of accidents. In the production process, the staff must follow the safety regulations when operating the electromechanical equipment. If there is a violation of the safety regulations during the operation, there will be errors in the operation, and the illegal operation will directly lead to The emergence of a security incident. Many staff members have different quality problems, which makes many people often experience unskilled operation techniques when operating. Many coal mine production personnel do not have professional technical knowledge, usually some short-term. Migrant workers, this has led to frequent safety accidents caused by the operator's technical irregularities in the production process. The technical problems of production personnel have gradually become the key issues to be solved in the safe production process of coal mines.
In the production of coal mines, there are often cases of temporary changes in instructions, so that operators must be very serious in the production process, and at the same time have a high degree of responsibility. In the coal mine production process, many special work operators must undergo professional training and professional technical training, and at the same time obtain certain qualification certificates to get to work, but in actual work, the management skills of the company's management personnel There are not too many considerations. In the production process, many people who do not have professional skills work in the post, which will lead to some people who are not very familiar with the work at work, often at work. There will be some problems. In the production process, some important positions are required to have certain stability, but many managers have not paid much attention to this, which makes the position of the job very liquid. There are also some people who often have irregularities in their work. This kind of problem is mainly related to the poor sense of discipline of the staff. Enterprises do not pay much attention to job training in the production process, which makes many problems occur in personnel operations in many cases, leading to safety problems.
In the production process, coal mining enterprises have not paid much attention to the safety training work. In the production process of the enterprise, there are cases where the safety facilities are not perfect. At the same time, in the production process, there is also a mismatch between the basic work and the theoretical requirements. The situation makes it difficult to standardize electromechanical transportation equipment at work. Production personnel also have a situation of low security awareness at work. In the face of strong work pressure, it is very important to conduct necessary training for employees. Enterprises must improve the safety system in the production process, so as to better avoid potential safety hazards. Enterprises have an unsound situation in their job responsibilities. In the work, there are often situations of mutual squatting, which makes some security risks not well implemented when rectification is carried out. Enterprises also have some problems in the implementation of the security system. They usually have great drawbacks in terms of security assessment. This will make the staff members prone to absenteeism at work, and they will not have to worry about rewards and punishments after security problems arise. .
In the production process of coal mining enterprises, the equipment used is too aging. The equipment used in coal mine production is a complete set of inputs, and the cost of equipment is also very high. Many equipments are used in the initial stage of construction. It is only necessary to carry out the necessary maintenance work. Due to the relatively high capital investment, many enterprises cannot afford to replace the equipment in production, which leads to the aging of the equipment. In the production process, the aging equipment can not meet the modern production requirements, because the technology, process, and processing methods can not be timely, and the equipment involved in the technology does not match the industry capabilities, resulting in the overall coal industry. The backwardness of production facilities will not only improve the safety factor, but also the daily maintenance.
China's coal mine production equipment has few varieties, low level and poor quality. Especially high-tech products and mechanical basic products can not meet the requirements of the rapid development of the coal industry, such as hydraulic supports, shearers, roadheaders, heavy-duty scraper conveyors, etc. It is completed on the basis of imported technology and has an adaptive process for the development of China's coal industry. In addition, the selection of electromechanical equipment requires matching, and it has strong adaptability to different geological conditions, users and management level. The actual situation is that the equipment and conditions are not suitable, and it takes a long time to run-in. During the running-in period, the accident rate is often high. The application of a series of advanced mining equipment such as coal mining machines, transport machines, roadheaders and brackets has gradually moved from mechanization to automation. However, long-term operation and mistakes in the operation of employees during operation will cause equipment damage, which requires maintenance of the equipment. Must be careful and comprehensive. The overall quality of the current coal mine workers is not high, coupled with the outdated equipment, the maintenance workload itself is very large, and the annual inspection and monthly inspection work is difficult to carry out.
2 Countermeasures for controlling mechanical and electrical accidents in coal mines With the improvement of the mechanization degree of coal mines, higher requirements are also placed on various equipment accessories. Therefore, efforts should be made to strengthen training and strict management to reduce and eliminate the occurrence of mechanical and electrical accidents and ensure safe production.
Unify thinking and understanding, and adhere to the "safety first" without wavering. Emphasize safety, highlight safety, and put safety at the forefront of work. After the coal mine adopts the contracting mechanism, the safety work can not only be relaxed, but also the safety supervision should be intensified. Everything should be placed above all else, above all else, above all else, and always insist on safety first. . To strictly control the quality, coal mine management is an important aspect of safe production, but the quality of equipment is equally important. Some coal mines do not pay attention to the small differences in equipment of each manufacturer when they enter the equipment, ignoring the quality problems. For the sake of self-interest, cutting corners, although the investment has been reduced, it has left hidden dangers for safety, and it has also affected the normal operation of electromechanical. Strengthen the management of employment system, and the technical strength of coal mine electrical machinery is strong. Can not appear as a caregiver, minimize or not use temporary employment.
Special types of work cannot be exchanged frequently. It is necessary to strictly examine and issue certificates and insist on holding certificates.
There are safety problems in the operation of coal mine production. In order to get a better solution, we must start from many aspects, fundamentally prevent the occurrence of accidents, and at the same time avoid accidents from the operation. In order to better manage the equipment, it is necessary to improve the safety awareness of the staff, and at the same time to train the staff, in order to better solve the problems.
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