How to solve the problem of internal oil leakage of hydrogen-cooled steam turbine generator
Applied research.
How to solve the internal leakage of hydrogen-cooled steam turbine generators Yao Dequan Ren Xiuchun Harbin Electric Machinery Factory. Harbin City. 150040 Abstract The direct cause or main cause of oil leakage in hydrogen-cooled steam turbine generators is that the hydrogen side seal oil is not well returned or can not be returned. Differential pressure valve.
The balance valve tracking performance does not directly lead to oil leakage failure. It is not very difficult to solve the problem of oil leakage. The key is to update the concept to determine the cause and the standard measures, in order to cure the disease.
However, unfortunately, due to the relevant units and related personnel, and even a considerable number of experts, the reason for this question and its causes are not correct and clear understanding of the reason why the shirt has been stuck in the oil spill for the past year. The difference between the differential valve and the balancing valve is not the original fuzzy or even the wrong concept, and the corresponding measures are inevitably limited to the low-level means of solving the tracking performance of the differential pressure valve and the balancing valve. Therefore, summing up the lessons learned by the 3 gold to falsify the true target, has become the general task of this article based on the example of the record. On the basis of careful research, a comprehensive and systematic analysis of the reasons and the reasons for this is intended to clarify the facts and achieve the goal of eradicating the ills.
1 Oil seal device and its sealing oil system classification 1.1 Oil seal device classification The oil seal device of hydrogen-cooled steam turbine generator is divided into two types: disc oil seal and ring oil seal according to the type of core seal vane. The former is mostly used for small and medium-sized units with a capacity of 100 and the latter, while the latter is widely used for large-capacity units.
The ring oil seal device can be divided into a single flow ring type oil seal and a double flow ring type oil seal according to the structure of the seal bush and the oil supply mode. The single flow ring is only one, the seal oil will be The hydrogen in the machine is easily contacted and mixed with the air outside the machine, resulting in a faster decrease in the purity of the hydrogen in the machine. The flow ring has two seal oils, which not only improves the reliability, but also makes the hydrogen inside and outside the machine. The air is not easily contacted and mixed, thereby reducing the rate of hydrogen purity drop in the machine. But the actual situation is not entirely true.
The double-flow ring type 汕 seal is divided into two types of double-flow single-ring and double-flow double-ring according to the structure and number of the sealing slab. The double-flow single-ring structure is relatively simple, and the demand for 7-inch oil is relatively large, but it requires higher installation of the limbs; the double-flow double-ring structure is mixed, but the amount of sputum is small; the pleading is small, the installation accuracy is low, and It is the best in dynamics, especially easy to match with the balance valve to maintain the balance of the oil pressure on the side and the oil pressure on the air side. The balance of the oil on both sides of the gauge has been 12. The seal oil system is classified as a seal system. The system is sealed by a medium flow ring and The double-flow ring oil seal is divided into two types: single-flow type and double-flow type. According to the core part of the differential pressure valve + and its working mode, it is divided into a choke, and the pressure type adopts a piston type differential pressure valve and a discharge. The pressure relief type uses a corrugated shoulder pressure valve for two people. The live-type report is divided into two types: static piston type and rotary piston type; bellows type pressure difference valve is divided into Guiqing copper bellows stainless steel bellows and rubber bellows.
Early domestic hydrogen-cooled units used static piston type differential pressure valves and their 1-block type sealing system. And the domestically produced units manufactured by the imported technology have adopted the bellows type differential pressure valve and its bleed and pressure relief type sealing oil system. Therefore, the two are respectively called the domestic type sealing system and the introduction or introduction of the technical sealing system. At present, several units equipped with domestic-made sealing oil system have been transformed into imported technology-type sealing oil systems, and there is a possibility of blindly forming a trend. 2 Classification of oil leakage faults in generators Recently, it has been frequently found that a unit has oil-making faults. The personnel can only report the leakage of the unit in a general way, and the current situation of the oil leakage failure is discussed. If it is caused by the cause or influence factor of the current form of oil spill. It will guide the operator in the first and first scenes of the failure to carry out systematic observation and necessary tests or tests. Therefore, countermeasures or preventive measures are proposed for the parts. Furthermore, the treatment of oil leakage 1 is carried out in an orderly manner. The internal leakage is faulty. According to its current form, the following types of 2.1 steady-state oil leakage have continuous oil leakage at any time and under any working conditions. This is the most serious and most Complex species.
2.2 Transient oil leakage occurs only continuously or intermittently during a certain period of time or under certain working conditions. This is a more complicated species.
2.3 Low hydrogen pressure oil leakage In the machine, the hydrogen pressure is lower than 0.1 river 30.08 river 30.05 river or even lower working conditions, continuous or intermittent oil leakage phenomenon, this is a transient oil leakage fault.
24 During the replacement process, the oil leakage in the generator machine changes from the air state to the hydrogen state or from the hydrogen state to the air state, and the continuous or intermittent oil leakage phenomenon is very similar to the low hydrogen pressure oil leakage situation. The most prone and most common situation is the 25 misty oil leakage seal oil in the transient oil leakage fault during its circulating flow, especially under the high-speed rotation of the rotating shaft. Some of them can form a mist in the oil block, also called soot, and the last. The level 汕, adjacent to the rotor wind negative pressure zone, and some of the sealing oil may enter the generator in a mist form and constitute a steady-state oil leakage fault.
What is the result of the difference in energy, and whether the result is related to the oil leakage fault. 3.1.1 The pressure difference valve of the differential pressure valve is used to adjust the pressure difference between the control seal oil pressure and the machine, and the pressure is always within the specified range. That is, the oil pressure is higher than the hydrogen pressure. When the hydrogen pressure in the machine changes, the differential pressure valve should adjust the seal oil pressure to automatically track the change of hydrogen pressure. If the differential pressure valve has poor tracking performance, the hydrogen oil pressure difference will deviate from the specified range. In the past, quite a few experts took it for granted that as long as the hydrogen oil pressure difference became larger and exceeded 0.06, oil leakage occurred. However, many domestically produced units that have been introduced to the unit or imported technology have been designed to have a hydrogen oil pressure differential rating of 0.084 and a river 3 error range of 0.0740.094, which proves that the above viewpoint is obviously wrong. Since then, there are still quite a few experts who believe that oil leakage will occur when the hydrogen oil pressure difference is greater than 0.094%. The author believes that, theoretically, the increase in pressure difference means that the flow rate of oil increases, and the oil return capacity of any circulation device is greater than the oil input capacity and there is a margin for the domestic production of early production. The amount of oil, plus obviously does not cause Oil leakage; In practice, the hydrogen oil pressure difference of a 600 unit in a power plant has been reached during the trial operation, and the pressure difference is increased without causing oil leakage. Then the pressure difference is reduced, and it will not cause oil leakage. Of course, when the pressure difference is too low and the pressure is 0.017, the river will cause damage to the seal and hydrogen will escape, but this has nothing to do with this proposal.
3.1.2 Balance valve The function of the balance valve is to adjust and control the pressure difference between the hydrogen side seal oil pressure and the air side seal oil pressure of the dual flow seal oil system, which is always within the specified range, to ensure that the mutual oil volume of the two oil channels is small. The smaller the difference, the higher the accuracy. When the change of hydrogen pressure in the machine causes the change of the air pressure on the air side, the balance valve should adjust the hydrogen side seal oil pressure to automatically track the change of the air pressure on the air side seal. If the balance valve tracking performance is not good, it will cause the oil pressure difference on both sides to deviate from the specified range. When the amount of oil from the original oil to the hydrogen side oil increases, the pressure difference of the hydrogen-side sealing oil tank increases, which means that the oil side of the side of the hollow side is increased, and the oil of the hydrogen-side sealing tank is filled. frequency. Neither of these cases directly leads to the occurrence of an oil leak.
3.2 Analysis of the cause of oil leakage The author believes that the direct cause of the oil leakage fault is that the hydrogen side seal oil is not well returned or can not be called oil = 32.1 low hydrogen pressure or low pressure oil leakage cause 3 analysis of the cause of oil leakage in the generator which is. 1 often, pressure. When the oil level is high, the float ball or electromagnetic drain valve should be opened automatically. The higher hydrogen pressure can push the excess oil out of the tank. Under low hydrogen pressure, the oil level will increase. The oil valve opens automatically, but since there is not enough hydrogen pressure to push the oil out of the tank, automatic draining is not possible. Manual draining is required under this condition. The mechanism of the pumping and discharging oil is to provide one bypass road and one manual normally closed door at the bottom of the box and the inlet of the airside oil pump. The valve is opened in a low hydrogen pressure condition, and the excess oil is discharged by the large suction force of the air side oil pump.
When the hydrogen pressure is low and the oil level of the fuel tank rises, if it is not low, the pressure drain pipe is not designed or has a low hydrogen pressure drain pipe but it is not opened and is not operated, and the height of the automatic oil discharge destination is about 9 to the tank height. About 1.5; then.爿 1 box can not drain oil. It is even possible to replenish the oil, resulting in full oil, which in turn causes the hydrogen side oil to fail to return oil. Can only be built into the machine = It should be noted that the fuel tank oil level rise is divided into normal and abnormal conditions. There are two reasons for the normal rise. The air side oil and the hydrogen side oil are higher than the hydrogen side in the normal accuracy range. The low hydrogen pressure makes the balance valve deviate from its optimal working area, resulting in a serious decline in tracking performance. Increase the amount of oil from the side to the hydrogen side. There are also two reasons for the abnormal rise, that is, the balance valve itself has poor precision; the automatic charge valve cannot be closed due to malfunction, resulting in uninterrupted oil replenishment.
3.2.2 Reasons for oil leakage during replacement process The cause of oil leakage during replacement process and low hydrogen pressure or low pressure oil leakage must pass through a low anvil or low pressure process. The difference between an ugly exchange scale and a low lean or low pressure condition is that the former is inevitable and the latter can be screwed or avoided.
3.2.3 Causes of transient oil leakage 3.2.3.1 Hydrogen pressure is normal, but the automatic oil drain valve cannot open the oil discharge due to failure, resulting in the oil tank being full of oil. In the case of a malfunction of the sweep valve, there is a float valve that cannot be opened due to leakage of the float ball or mechanism jam. 2 solenoid valve flash suction is not enough or line 1 rolling loss + can open.
3.2.3.2 In the case that the oil level of the fuel tank is normal or the oil level is high and the oil needs to be drained, the fuel tank oil level signal device is wrong due to the failure, and the misleading transport personnel accidentally fills the oil continuously. Causes the box to be full of oil. In the case where the clamp annunciator fails, the 1 annunciator float cannot float correctly due to leakage. 2 The float in the fuel tank is infinite and the magnetic beads outside the fuel tank are limited. When the float floats too high, the magnetic beads and the float are separated from the suction bow and the error is caused.
3.2.4 Causes of misty oil leakage The mechanism and possibility of misty oil leakage are still speculated. There is no direct or strong evidence to confirm this. The main reason may be 3.2.5 steady-state oil production The main reason for steady-state oil leakage is poor oil return. In addition to the mist leakage, there are three kinds of steady oil leakage. 3.2.5.1 The oil return pipe has a dead bend and increases the oil return resistance. Only part of the oil can be returned to the fuel tank and some oil is leaked into the machine.
3.2.5.21 The amount of the cane is too small to return to the hole for shrinkage. This situation has occurred many times in many early generations of the 200 cliff boundary unit. 3.2.5.3 The fuel tank is returned to the hydrogen pipe to form a gas seal due to oil storage, resulting in failure to be normal. The hydrogen is returned, so that the hydrogen pressure in the oil tank is gradually increased to form a gas culture for the oil return. however. The mechanism and possibility of such leakage are still presumed to be presumed, and there is no 1 or strong 1 in front of the mouth. 1 positive and real 4 solutions and improvement 4.1 to solve the steady oil leakage, that is, the oil return is not smooth. Specific measures 4.1.1 to solve the problem of returning oil to the small size, this pair, the production of 100 刖, the unit and the early production of the 2001 machine 纟 1 is particularly important. It is necessary and optimal to expand the neck side hydrogen return hole as much as possible. 4.1.2 Check and eliminate the dead bend in the hydrogen side return pipe. This is a simple and easy way.
4.1.3 Returning the hydrogen to the oil and asking the oil. This is currently a + can be detected 6, can not be processed 14, must be designed to escape. For example, if one oil drain valve is added to the wattage 1 and the 1 call 1 edge must be provided with one isolation valve. After this improvement, it is possible to perform the oil storage which can be inspected and discharged into the hydrogen pipe.
4.1.4 If the oil block clearance is too large, it can only be inspected and processed during disassembly, and it must be guaranteed by the installation quality.
4.2 The specific measures to solve the transient oil leakage that cannot be returned to the oil should focus on eliminating the defects in the series of oil-filled components of the sealed fuel tank and its oil level signal device. In particular, it is necessary to solve a series of low-level defects such as the leakage of the buoyant float valve float and the infinite position of the annunciator float. For the low hydrogen pressure working condition of the replacement process and the simultaneous high oil discharge destination than the fuel tank, in addition to the low hydrogen pressure drain pipe and the oil drain valve, the operating personnel must carefully operate the lock automatic valve and manually control the manual. valve. Of course, in order to realize the overall automation process including low hydrogen pressure and replacement process to meet the trend of gradually reducing the number of operating personnel in each power plant, the manual replenishment and oil removal of the sealed fuel tank should be improved. The specific scheme is as follows: 4.2.1 Low hydrogen pressure in. The dynamic oil drain valve is the simplest solution to change the sight of the float. The disadvantage is that the oil discharge speed at low hydrogen pressure is 4.2.2, the installation position of the sealed concrete box is changed to 61 units, and the oil discharge destination is changed from about 1 high in the shape of the oil separation nozzle to the steam turbine. At the same time, the position is about 3, and the neck of the oil return pipe is appropriately increased to reduce the oil discharge resistance, so that the oil displacement can be driven by the oil level difference under the condition of low hydrogen pressure. This is a relatively simple solution. The disadvantage is that the oil discharge speed is slower at low hydrogen pressure. 4.2.3 is to overcome the shortcomings of faster or slower oil discharge speed. The original oil supply valve can be kept unchanged, and the manual oil drain valve can be changed to 1 or 2 1 movement. The valve, its opening condition is controlled by two signals of low hydrogen pressure and high oil level.
4.2.4 The choice of the corpse tank. At present, the volume of the used box is divided into about 0.8ni and about 0.3nf. The domestic design is originally a large fuel tank. The introduction of technology is small. Obviously, the accuracy requirements of each component or device are very high. Mismatching will often cause the fuel tank to be full or lack of oil.
For the transient oil leakage problem, the time from the normal height to the alarm height and the continuous increase to the full oil state will be prolonged due to the increase of the volume of the box or shortened due to the reduction of the tank capacity. Therefore, the large volume is obviously better than the small volume. Therefore, large tanks should be used to even increase the volume. At the same time, the fuel tank is installed vertically and the top is changed to a detachable full-end flange cover to facilitate inspection or overhaul of the inside of the fuel tank.
4.3 Renovation of the sealing oil system should pay attention to the practice and prove that the piston type differential pressure valve and its generation of choke-enhanced sealing 汕 system and bellows type differential pressure valve and its generation of venting pressure relief seal Both oil systems have experienced oil leakage faults, and both the bulk seal oil system and the cartridge seal oil system have experienced oil leakage faults. If one-sidedly believes that the latter is the replacement of the former, the transformation of the sharpener into the latter can completely solve the problem of oil spills. It is an extremely wrong and extremely irresponsible behavior, and should be quickly and decisively corrected. In this case, his big test energy and its human, material, and financial resources are divided into a small part of about 10. It is indisputable that the defect design and improvement of key components are improved in the repairing and refueling of the sealed fuel tank. s Choice.
4.4 It is recommended that the State Power Corporation and the State Administration of Machinery jointly hold a joint exchange of experiences and academic seminars on this issue to clarify the non-uniform understanding. In addition to the experts in the manufacturing department and the operation department, the participants in the meeting should also include the decision-makers of both parties, that is, the senior leaders. This is in addition to the technical discussions and program development. It also invests in manpower, material and financial resources as well as observational tests and diagnoses during operation or shutdown. In particular, the maintenance and dispatching during downtime maintenance or renovation, in order to promote the escape of oil in the short-term, the quick resolution of the third page is still far away, and the price chain divides the activities of the enterprise into basic activities and auxiliary activities. The basic activities include the marketing and maintenance services for the delivery of production operations; the auxiliary activities include the infrastructure of the enterprise, for example, the institutional leadership strategy and policies of the enterprise and the relationship with the relevant government departments. Human resource management technology development and procurement. Previously, the budget was limited to budgeting and monitoring production operations, the scope was too narrow, and the monitoring of production operations was weak, because the budget-generated indicators were calculated according to the pre-charged juice of the customs. It is not based on the company's future projects, lack of necessary improvement measures, and its budget has not accepted the previous lessons. Make the grief stagnate. This is not conducive to the formation of a competitive advantage of the enterprise, so. The budget should not only expand the scope of its economic accounting, but also should greatly improve the work to adapt to the creation of competitive advantages.
Using the value chain to analyze the actual situation of the power construction industry, it can be seen that the production operations in the basic activities, that is, the construction and installation in the dominating land, the logistic delivery logistics maintenance service is subordinated, and the auxiliary activities are heavy. Play the ground. In recent years, due to changes in the market, one company's marketing of basic activities in the construction industry. The company sells +圮 products, but the company itself has increased its investment, and its cost is becoming a pivotal one. Therefore, the budget should focus on the scientific industry value chain for the marketing and procurement of production operations and the infrastructure and cost of the enterprise infrastructure to reduce the cost optimization cost structure. For example, enterprises can greatly reduce the total cost of production and operation by reducing production costs, corporate management costs, and procurement costs, while increasing investment in marketing. The formation of a strong person's market development power, to the end of Shiduo, to achieve the effect of open source and throttling to prevent inefficient operation. The necessary monitoring of the formation of wood is also necessary.
In short, the budget department should look for valuable things based on the principle of value analysis, and improve or reshape the value chain to reduce costs, optimize cost structure, and establish cost leadership. This is a systematic project with complex and meticulous theoretical and operability, which requires active efforts to achieve. I believe that as long as we do it seriously, we will be full of vigor and prosperity.
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