Study on the Strategy of Steam Turbine Steam Trap Leakage Management in Power Plant

Abstract: This paper analyzes the current situation of using and managing steam turbine traps in power plants in our country and its importance to power generation system. It focuses on the causes and influencing factors of internal leakage of steam traps in power plants, and puts forward some effective control strategies .
Keywords: power plant steam turbine; traps; internal leakage 1 Introduction Traps are the more common types of valves in power plant steam turbines. They are numerous and widely distributed and play a very important role in power plant steam turbines. However, in recent years According to the statistics of our factory and the statistic of the relevant departments of our country on the fault of steam traps, the number of accidents caused by internal leakage of traps is on the rise. It has become one of the major factors that seriously hinder the normal production of power plants, and But also cause greater economic losses, is not conducive to the economic development and progress of power generation enterprises, it is necessary to focus on the causes of trap leakage, and look for practical governance strategies.
2 Steam Turbine Steam Turbine Plant Status In power plant steam turbines, steam traps are widely distributed and distributed over almost all plant systems, often in large numbers, often with up to a thousand steam traps in a power plant and are often set Plays an important role in the key position of the system and is one of the key equipment for ensuring the normal operation of the power plant. So once it fails, it will not only affect the normal power supply of power plants, but also lead to safety accidents, life safety of crisis workers. Therefore, in daily inspection of power plants, the inspectors need to inspect and maintain all the trap valves in the factory. However, due to the huge number of traps and the lack of an effective on-line inspection system, it is inevitable that inspections will occur Missing or repeated detection of the problem, the valve leakage easily lead to failure of the valve to bring economic losses to the power plant, and repeated testing will not only increase the workload of inspection personnel, but also lead to increased maintenance costs, so the need for the trap Overhaul and maintenance of effective regulation, to ensure the reliability of the valve under the premise of reducing maintenance and maintenance costs, reduce the operating costs of power plants.
3 Steam Turbine Steam Turbine Leakage within the reasons 3.1 Trap own quality problems Due to the trap design and manufacturing process defects caused by the quality of the trap is the main cause of leakage within the trap, first, in the design and manufacture of the process, Valve material selection is not reasonable or not, especially the valve core and valve seat and other important components of the material selection, a direct impact on the overall quality of the valve; Second, the valve itself less than the hardness, the problem is mainly due to the production process of heat treatment Irrational; Third, the castings in the valve in the casting process, due to the casting process unreasonable resulting in trachoma, slag, bubbles and other defects, due to the valve in the use of the process to withstand greater pressure, and long-term By the media erosion, corrosion and impact, the existence of these shortcomings will reduce the valve life, prone to damage and leakage problems [1].
3.2 Man-made operation problems In the normal operation of the power plant turbine, man-made operation is the direct cause of leakage problems caused by the trap. The staff does not operate according to operating procedures caused by trap drain valve is not closed in time and improperly closed two ways, for the former, the valve timing should be based on the state of the turbine control, when the unit starts without Timely shut down, the unit of high temperature, high pressure medium will flow from the valve, easy to cause corrosion, wear and impact on the valve, resulting in reduced valve sealing, but also because of the medium flow through the valve too fast, easy to valve Of the pressure is lower than the saturation pressure, prone to cavitation problems, and cavitation problems continue to accumulate, the bubble rupture moment will have a very large impact, and much higher than the valve material fatigue damage limit, it will cause the valve in the Instantly damaged causing leak problem.
For the latter, the main valve is closed, the staff closed the valve thrust is too large or the valve is not closed in place, the thrust is too large and easy to drive water medium caused by the phenomenon of water hammer on the valve and its Pipe damage, especially for large pressure drop on both sides of the valve, due to the greater pressure on both sides of the valve to a greater pressure, if forced to close at this time will result in the valve stem and flap connections appear Loosening or falling off, causing internal leakage of the valve. If the valve is not closed when the valve is closed, the valve will have a smaller opening and the medium will flow through the small gap as it passes through, High flow rate and impact is too large, it will cause damage to the valve and reduce its tightness, resulting in leakage problem [2].
4 Power Plant Steam Turbine Drainage Leakage Management Strategy 4.1 Strictly control the quality of the valve According to the above analysis, the quality of the valve itself is one of the main factors that affect the leakage of the valve, so during the valve design and manufacturing process should Note that strictly control valve quality doors, improve manufacturing standards of the valve, on the basis of learning from foreign advanced technology and manufacturing processes, based on strict adherence to the current high standards internationally, and research and development has China's own property and our quality standards trap door , And gradually reduce the size of the valve, research and development of high hardness, strong pressure bearing capacity, close the open quick response, strong anti-corrosion ability of the new valve, the valve itself to reduce the incidence of its internal leakage problems occur probability.
4.2 clear the daily duties of the valve Through the analysis of the causes of leakage problems within the trap, it can be seen that the man-made management of the valve is the direct cause of the internal leakage of the valve, and to strengthen the daily management of the valve can effectively reduce the valve The probability of internal leakage. First of all, according to the power plant equipment management system to develop a specific management system of the trap, the system should include the use of the valve operating procedures, valve routine inspection process and content, valve fault statistics and analysis, valve troubleshooting and maintenance system, The establishment of a specific management system for traps, a clear system for each job and responsible for the specific responsibilities, so that a clear division of labor, so that the specific positions of the people understand their own work content and importance to raise staff awareness of responsibility, and through Reward and punishment rewards and punishments mechanism to improve the enthusiasm of staff to ensure that management work in place.
4.3 to improve the professional level of staff Human factors are the main factors that affect the valve failure, and professional staff is the key to control the level of the valve, first of all, the power plant from top to bottom should raise awareness of the importance of the trap, Increase investment in the procurement and maintenance of valves, and strictly control the procurement quality of valves; secondly, it is necessary to improve the professional standards of staff members, select and hire senior personnel with high professional theoretical knowledge, and provide practical opportunities to improve as far as possible Their ability to combine theory with practice enrich their work experience, develop their expertise and creativity, improve the quality of valve inspections, accuracy of fault detection and diagnostics, timely troubleshooting, regulatory compliance with valve operations, and more ; Once again in the work of regular training of managers and safety education, strengthen management and technical staff exchanges and communication between the staff to improve the accuracy and normativity of day-to-day operations.
4.4 The use of scientific valve monitoring technology Currently in the power plant has been popularized intelligent management system that can run the plant in real-time monitoring and control equipment, the main valve of the water flow, pressure and temperature changes and other parameters of monitoring through The real-time monitoring of valve running status can analyze and diagnose abnormal data, improve the accuracy of fault prediction by using expert system to effectively reduce the probability of valve failure, and secondly adopt scientific valve operation methods such as valve start-stop operation Must be fully open and closed, and to start and stop in accordance with a certain order, the valve start and stop the timing to be strict with me, and pay attention to start and stop efforts; Finally, before the start of the turbine valve pipe should be cleaned regularly to ensure the smooth flow of the pipeline , To avoid the leakage problem.
5 Conclusion In the daily operation of power plants, steam turbines, the number of trap also plays an important role in the normal operation of the system and safety, valve leakage is one of its common failures, mainly due to the valve itself, the quality and man-made irregular operation Therefore, in the daily management of the power plant, the responsibilities of the management of the valve should be clarified, the control over the quality of the valve should be strengthened, the professional level of the management staff should be improved, and the scientific management methods should be adopted to reduce the probability of failure of the trap and improve the operating efficiency of the power generation system. , And ensure the safe operation of the power generation system.
references:
[1] Cao Yunlong. Steam turbine drain valve power plant leakage management [J]. Shandong Industrial Technology, 2015 (19): 123-124
Wu Weizhi, Li Zhipeng, Yang Guoqiang, et al.Replacement control measures of internal drain of valve in drainage system of Unit 10 in a thermal power plant [J]. Turbine Technology, 2015 (01): 49-52

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