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Abstract: Aiming at many existing problems of marine steam turbine circulation pump, the design and production process are improved. The improved marine steam circulation pump is tested and verified by land test and voyage performance. The performance fully achieves the predetermined target of improving design. DOI: TK264.1 Document code: A Article ID: 1001-2060 (2000) 02-0137-03 ImprovedDesignofaMarineSteamTurbineCirculatingPump QiuZufaGaoLeiQinXiaocheng (HarbinNo.703ResearchInstitute) Abstract: Thedesignandproductiontechnologyofamarinesteamturbinecirculatingpumphas beenimprovedontoresolveawholerangeofproblems.Thecirculatingpumpfollowingsuchan improvementhasundergonealand-basedtestandseafaringverificationinspectionandbeenfound tohavefullymetthepresettargetconcerningitsperformance Keywords:. Turbinecirculatingpump, improvement, design 1 Foreword Marine steam turbine circulating pump is mainly composed of steam turbine, reducer and circulating pump three components. Turbine with reducer driven circulating pump work, the seawater suction into the main condenser and the host oil cooler to cool the working fluid. In addition, when the furnace chamber is damaged and leaking, the pump serves as an emergency drainage pump to discharge the accumulated water in the cabin out of the vessel. Turbine by the rotor and the shell composition, the rotor is equipped with blades, reducer pinion gear and to provide lubricants to the bearing gear pump and other components. The housing is equipped with a nozzle box, a quick-closing valve, a first auxiliary valve, a second auxiliary valve, a diaphragm, a turbine seal, a support bearing and a thrust bearing. The reducer is also composed of a rotor and a housing. The rotor is equipped with reducer gear, speed measuring device, supporting bearing and thrust bearing. Shell is also equipped with components such as oil cooler. The circulating pump is still composed of a rotor and a housing. The rotor is provided with a pump wheel (ie a work wheel), a rubber supporting bearing and the like. In order to facilitate the maintenance, the shell is composed of two halves, the vertical middle face is bolted, the shell includes the pump shell, the first half guide, the second half guide, the pump cover, the water inlet part and other components. 2 to improve the design of the proposed 2.1 Turbine steam turbine circulation pump speed control valve by a quick-closing valve, the first auxiliary valve control two nozzles, through these two valves to complete the pump operating conditions. The second auxiliary valve controls three nozzles, open for use when overloaded or when the steam turbine parameters are reduced, or as a backup valve. As the three valves are manual valves, which not only heavy workload, but also difficult to achieve automatic control. In order to solve this problem, the quick-closing valve to self-control valve to increase the role of regulating valve, the other two valves do not change. After the operation of the measure found that there are still two problems: First, the larger size of the quick-closing valve in the small opening state, it is easy to automatically shut down; the second is the valve control more dispersed, when the ship in reverse, to Manually open a auxiliary valve for control, so you can not fully realize the positive and reverse automatic control, so still need to be further improved. 2.2 The original pump on the oil cooler heat pipe easily damaged at the joint easily detached. 2.3 The original circulating pump two plain bearings for the rubber bearings. As the processing technology behind the rubber and copper casting adhesive performance is poor, very low manufacturing yield, which requires improved design. 2.4 The original steam turbine support the existence of the upper end of the lack of fuel supply situation, oil performance needs to be improved in the design to be improved. 2.5 According to the equipment development mission statement: The pump shaft speed of 260r / min, found a horizontal vibration resonance peak, and at its speed, the pump shaft vibration was also found to be more intense, so that the pump is difficult to work properly, which Need to find out the reasons for improving the design, to be resolved. 2.6 In order to improve the running performance, an electric oil pump is added, which is used when the unit is started and stopped. 2.7 In addition, some parts of the processing technology needs to be improved to further improve the performance of steam turbine circulating pump. 3 to improve the design 3.1 to improve the design of electric control valve First improved design of the nozzle box so that the original speed off valve is no longer directly control the nozzle, only the role of the main steam valve and the speed off valve, which can manually switch and automatic, manual speed off , Cancel its speed control function; the original speed control valve with a nozzle and the first auxiliary valve control two nozzles controlled by the newly designed electric control valve. The original second auxiliary valve is still reserved, called the auxiliary valve, the role of the same. The newly designed electric control valve driven by the electric actuator, through the gear reducer gear, the combination of the size of the valve stem valve for horizontal movement, the valve opening and closing, play a role in regulating steam turbine intake. Into the small opening into the steam, small valve superior control ability to give full play. Electric actuator with local handwheel, you can manually control the electric control valve in place, also has electronic control box, you can remotely control the electric valve, you can also control the computer through the control room of the electric valve automatically. The electric control valve regulating function can fully meet the main steam turbine is reversing the conditions of the various conditions, so the steam circulation pump to achieve the start-up, operation and shutdown automation. 3.2 Oil Cooler Heat Exchange Tube Problem Solving First of all, the reason why oil cooler heat exchange tube is easy to break is analyzed. The main reason is that the B30 pipe friction and impact with other parts in the process of production and processing, installation and transportation , Bumps, long-term contact with the seawater after installation and operation, seawater pollutants will remain in the damaged dents, forming electrochemical corrosion under the action of seawater, making the damage of the B30 tube thinner and even Finally ruptured. Therefore, a specific requirement has been formulated that manufacturers should be required to produce, install and transport according to technical requirements so as to avoid such accidents. Cooler tube heat exchanger easily detached, the analysis is the quality of the expanded tube. After a large number of rigorous tests and calculations will be expanded tube force control in a certain range, so that both can seal expansion, without leaving the joints at the pipe to maintain the original intensity range, will not crack. 3.3 The solution of rubber bearing problem The original cast rubber castings of the rubber bushings of the original pump are easy to produce defects with a low pass rate. However, the bonding technology of rubber and copper castings is not easy to produce, but the peeling of the rubber on the copper castings easily occurs. During product inspection , Pass rate of less than 50%. After the improvement of copper casting centrifugal casting, the fine grain of the casting, arranged closely, all the castings are cast once qualified, therefore, improve the casting quality. Adhesion of rubber and copper casting also adopts modern technology formula and scientific and efficient production management, the production of rubber bearing the passing rate increased to 90%. The original lower rubber bush water chamber radius R3, now changed to R8, cooling water flow through the area increased 1.4167 times; the original upper rubber bush water chamber radius R5, now changed to R10, cooling water flow through the area increased by 1.28 times, so Make the rubber bush have more cooling water to be cooled and lubricated, so as to avoid sticking on the shaft. 3.4 Lack of lubricant supply The solution to the gear pump oil supply and the bearing and gear transmission fuel consumption calculated item by item, the calculation results show that the gear pump fuel supply is normal. Turbine top bearing due to insufficient oil supply bearing temperature is too high, because the bearing away from the pump, the tubing flow area is too small, resulting in increased pipeline loss caused by the upper bearing oil supply pipe diameter From Φ16 to Φ19. In the trial, the top bearing oil temperature is always within the normal range. 3.5 Solution of Vibration Problem The first critical speed of steam turbine rotor is 13553r / min and the critical speed margin is 78.3%. The first critical speed of circulating pump rotor is 3029r / min, the first critical speed and the highest working speed The ratio is 3.833. The calculation shows that the critical speed of the steam circulating pump rotor is much higher than its maximum working speed. This shows that: the original pump shaft at a speed of 260r / min when there is a horizontal vibration resonance peak resonance frequency is not inherent in the unit itself, but because of the foundation of the unit is not strong or not enough rigidity caused by the foundation. Test bench test when measured, when the circulating pump speed 250 ~ 300r / min, the unit vibration value is 0.03mm. During the trial run of the test rig, two turbo cycle pumps did not resonate at all working conditions. At the time of trial, the port side steam turbine circulating pump did not show a resonance point in the working area, while the starboard steam circulating pump at a speed of about 320-330 r / min had a resonance point of the unit because the rigidity of this unit was poor. The solution is: to strengthen the rigidity of the starboard steam cycle pump base, or work to avoid running at this speed. Circulating pump rotor, reducer rotor, steam turbine rotor to improve or increase the dynamic balance test requirements. The original pump design requirements only on the circulating pump rotor working wheel static balance test, the rotor does not do dynamic and static balance test, improve the design not only requires the work of static wheel and wheel balance test but also the entire circulating pump rotor (including work wheels and other Annex) Static balance test and dynamic balance test. The test results show that the circulation pump rotor unbalance larger, which will cause the unit larger, unnecessary vibration. The original pump reducer rotor only asked to do static balance test, the new improved design requirements to increase the dynamic balance test, the results show that this test is necessary. The balancing test of steam turbine rotor allows the unbalance to be calculated according to the current standard, requiring a great improvement over the original design, from 34g / cm to 18.23g / cm. Through the three rotor balancing test, so that the steam turbine circulating pump vibration and noise significantly reduced. 3.6 additional electric oil pump Turbine circulating pump in the past when the start-up and shut down, are using human hand pump to lubricate the parts required for oil, this operation labor-intensive. Now designed a set of electric oil pump instead of the original hand pump, while the original hand pump is still reserved, as the electric pump spare pump, which