Littérature scientifique sur le sujet « Auxiliary Lubrication Plant »

In the oil and gas industry, the testing of auxiliary lubrication plants represents an important preliminary activity before the whole turbo machinery train (including the auxiliary lubrication plant) can be put in operation. Therefore, the employment of both efficient and accurate plant models becomes mandatory to synthesize satisfactory control strategies both for testing and normal operation purposes. For this reason, this paper focuses on the development of innovative real-time models and control architectures to describe and regulate auxiliary lubrication plants. In particular, according to the Bond-Graph modelling strategy, a novel lumped parameter model of the lube oil unit has been developed to properly optimize the behaviour of this unit if it is controlled. The code has been compiled and uploaded on a commercial real-time platform, employed to control the pressure control valve of the physical plant, for which a new controller has been developed. The comparison between the data obtained from the simulated system and acquired from the physical plant shows good agreement and the good performance and reliability of the proposed model and control strategy. The modelling approach and the control strategy have been developed in collaboration with GE Nuovo Pignone S.p.a. while the experimental data were acquired in a plant located in Ptuj (Slovenia).

<span lang="EN-US">The Chilca 2 thermoelectric power plant, located in the province of Lima, Peru, has an open cycle gas turbine and a combined cycle steam turbine, whose combined capacity is 112.8 MW (Mega Watts). This plant requires auxiliary equipment for its operation, which is why it consists of electrical systems, lubrication system, hydraulic ventilation, pumps, vacuum systems and drainage of condensate generated by the difference in temperature in the steam conductor. Said drainage system is inside a 5-meter-deep basement that, being exposed to the elements, is exposed to falling drops of water that are generated by the vapors that are released due to the difference in temperature, repeatedly flooding and exposing to hazards that affect the normal operation of the thermoelectric plant. The proposed solution is based on the philosophy of a feedback control system, which uses a programmable logic controller (PLC) Siemens 1214AC/DC/Relay programmable logic controller, which, through a frequency inverter, activates the drainage pumps; the frequency range at which the variator works is linked to a 4-position level sensor. The result shows that it was possible to activate the frequency variator in a controlled manner through frequencies of 10 Hz, 30 Hz </span><span lang="EN-US">and 60 Hz, in this way a sustained operation of the drainage system is guaranteed.</span>

Continuous casting is the essential process converting liquid steel to solid in the form of slabs or billets/blooms in the steel plant. The economy and quality of the steel products are greatly dependent on how successfully the continuous casting is performed. New technologies have been actively developed in the process during the last decades in order to increase the productivity and, therefore, to decrease the operational cost. Since its first commissioning of a slab caster in 1976, POSCO has constructed a number of continuous slab, bloom and billet casters including a thin slab caster not only for plain carbon steels but for stainless steels. Through the operation of various types of continuous casters for more than 30 years so far, POSCO has steadily developed fundamental technologies and operational know-how and achieved the equipment innovations to improve the surface and internal qualities of cast products as well as to extend the productivity of continuous casters. Furthermore, POSCO has deepened the basic understanding on the solidification phenomena of liquid steel and also accumulated the engineering backgrounds to design the most optimal continuous casters. It has also devised the indispensable and auxiliary equipments and the key technologies to control the process precisely and efficiently in order to guarantee the quality and productivity. An innovative technology under development is the POCAST process, where controlled amount of the pre-molten mold flux instead of conventional powder mold flux is continuously fed into free surface of molten steel through the plunger-type feeding system from the flux melting furnace. In order to prevent the molten flux from freezing at the meniscus, a reflective insulation cover is installed, leading to the suppression of thermal radiation from the molten steel and flux. It is generally understood that, as casting speed increases, the occurrence of breakout increases since mold lubrication becomes insufficient due to the lack of mold flux flow from the meniscus into the solid shell/mold boundary. However, by utilizing the especially composition controlled pre-molten flux, it becomes possible to eliminate the formation of slag bear in the mold. Therefore, the mold flux consumption rate is increased even at the reduced oscillation rate & stroke and more importantly, the mold flux infiltration becomes more uniform throughout the boundary between the mold and the solidified shell. This consequently results in drastic reduction of the formation and depth of the oscillation mark and the occurrence of surface hooks without increasing the possibility of breakout, as has been proved in the casting trials carried out with the 10 ton pilot slab caster in Pohang. A key trend in the development of the continuous casting process is to reduce the thickness of cast products. Examples include thin slab casting and strip casting. In the thin slab casting process, a major drawback is the relatively low casting speed and, as a result, the inefficient equipment layout in the plant where two casters are connected to a hot rolling unit. The drawback could be resolved if the casting speed exceeds a certain limit. At the high casting speed, the productivity of casting becomes equivalent to that of hot rolling, and the thin slab casting plant is to be designed so that one strand

A heavy vacuum gas oil separation unit was developed and implemented at an industrial enterprise with a stabilized composition. The technical solutions, the selected equipment and the results of the installation operation are described. On a laboratory model of a distillation column, experiments were made to develop technological conditions. In calculations of an industrial column with a new regular packing applied previously developed mathematical model of multicomponent distillaton. The mixture is represented as pseudo-binary in terms of fractions. In addition, software packages for plate-by-plate calculation of the column. The selection of the main and auxiliary equipment of the industrial vacuum distillation plant was carried out.

The task of developing methods and tools for the study of stability for parallel operation of two or more diesel and the shaft generator sets as a part of an autonomous electrical power system of the fishing vessel is considered. The use of such devices is a promising and demanded, but difficult to implement due to the high dependence of the frequency of the current generated by such units on the temperature and the quality of lubricating oils, advance angle of fuel supply, the depreciation of the fuel equipment, the influence of depreciation of cylinder piston group and parts of the crank mechanism, the load, the fuel properties and the external environment. The method of increasing the stabilization of processes in the units of the ship power plants and providing their rating data in the conditions of availability of the destabilizing operational factors is offered. The method is based on the compensation of influence of the destabilizing operational factors on dynamic characteristics of transition processes on the frequency of ship power plant units. The modeling results are presented in the example of implementation of described approach. The scheme of the regulator of the sliding mode of the adaptive system of automatic control with the frequency of rotation of a bent shaft of diesel allowing to study the processes of fluctuations of its speed and to develop the principles of its effective management was developed. For its synthesis the new mathematical description of dynamics of diesel which brings the generator into rotation was developed. This allows not only to provide the work of diesel and the shaft generators units, but also, as a result, to exercise effective management of electric power parameters in autonomous electric power industry, to develop means and methods of providing the required indicators of quality of the electric power produced by the main and auxiliary power units.

Hardware In the Loop (HIL) simulations are testing tools that have been widely applied in recent years for the design and testing of components and systems. In particular, a part of the real environment is inserted in the simulation loop. The HIL architecture, whose nature results partly physical and partly simulated, is employed to test a component or system in Real Time (RT). The continuous development of technologies for the fast prototyping of RT code has contributed to speed up the diffusion of complex HIL testing techniques. However, this approach still appears to be poorly followed in the energy field where, concerning the study of complex plants, the accurate modelling of these systems results in high computation times that are not acceptable for RT simulations. Therefore, the thesis focused on the development of innovative techniques for the modelling, RT and HIL testing of industrial systems, which aimed at obtaining the best compromise between accuracy and efficiency. In particular, the proposed strategies have been applied in two distinct test cases. The first one concerns with the development of both an efficient model of a turbo-machinery auxiliary plant and of a suitable RT control system for the execution of functional tests procedure on a real plants. The second one aimed at developing an innovative control system for Turbine Bypass Valves (TBVs) through HIL tests performed on a dedicated test rig. The research work has been executed by the Section of Applied Mechanics from the Department of Industrial Engineering of the University of Florence in collaboration with General Electric S.p.A and Velan ABV S.p.A, which provided the required tools and experimental data.

The active magnetic bearings (AMB), with the advantages of no friction, no abrasion, no lubrication and active control, is used in the primary helium circulator for high-temperature gas-cooled reactor (HTR). But the magnetic bearing is a complex system, which contains sensor, controller, power amplifier circuit and actuators. Any part of failure is likely to make high-speed rotor off balanced position and fell in the inner ring of the bearing, causing huge impact and fiction heat that may damage the magnetic bearing. Therefore, it is necessary to bring the auxiliary bearing in the magnetic bearing to protect and temporarily support the high-speed rotor. The auxiliary bearings are mainly divided into two categories: rolling bearings and plain bearings. Generally speaking, for rolling bearings, the force of friction is smaller and the heat caused by it is lower during the touchdown. However, it needs to be detected online to ensure that it can work well in emergencies, and the rolling bearings has a smaller load capacity because of the point contact between the ball and the ring. Compared with the rolling bearings, the structure of plain bearings is simple and durable. With a larger load capacity and the advantage of non-contact detection, the plain bearing is gradually becoming a research hot-spot in the field of the auxiliary bearing. But the great friction and inevitable heat are also cannot be ignored. In High temperature gas-cooled reactor demonstration power station (HTR_PM), the work load of helium main fan is very large, once the support of electromagnetic bearing is out of work, the auxiliary bearing need to suffer from a very large drop impact load, which is accompanied by a huge friction fever. Therefore, it is important to develop a rolling-sliding integrated bearing which can bear heavy load and have little friction, combined with the advantages of plain bearings and rolling bearings. And that is an important direction of the development for the main helium pan in high temperature gas-cooled reactor nuclear power plant. This paper establish a simulation model for a horizontal rotor and rolling-sliding integrated auxiliary bearing system. In the case of synchronous rotation of the inner ring with the rotor, the speed of the outer race of the bearing is determined. and based on the main helium fan in HTR-PM, using the finite element analysis software LS-Dyna, the rolling-sliding integrated auxiliary bearing is proposed and the impact force and the MISES stress nephogram when the peak inflation occurred during the first impact and the axial axes displacement curve during rotor drop in the auxiliary bearing are preliminarily simulated in this paper., then certain theoretical reference is provided for the design and engineering application of the rolling-sliding integrated auxiliary bearing.

TVA has a fleet of 59 units with 187 large steam fossil turbine rotors, 68 fossil generators, and 27 auxiliary turbine rotors, in-service. The original equipment manufacturers (OEM) rotors have three designs some welded, others are shrunk on disk, but the majority of the rotors are mono-block. TVA has worked with OEM’s, third parties, and with-in TVA to perform weld repairs on rotors. Rotor Problems requiring welding: 1. Journal/gland damage due to lubrication failure and/or wear. 2. Attachment area damage due to cracks or distortion. 3. Attachment area due to changes in design. In the TVA fleet there are approximately 20 rotors that have been welded. Most of these have been successfully operated, but there have been 3 failures of welded rotors that will be discussed. Allen Fossil Plant Unit 3 Intermediate Pressure–Low Pressure Single Flow Turbine Rotor: In 1992 this rotor had a failure of the Curtis Stage. The decision was made to have the rotor welded and change the number of blades. Westinghouse (the OEM) performed the design and weld repair. In 2000 the unit experienced vibration, the unit was disassembled, and the weld repair had failed at the fusion line. An investigation of the failure revealed the weld had not been located at the designed location and the actual location of the weld was in a high stress area. Gallatin Fossil Plant Unit 4 High Pressure Turbine Rotor: TVA designed an upgrade to the Rateau Stage to change from axial entry to a tri-pin attachment. This required the welding of the disk. During welding, with a third party, cracks resulted that extended into the base material. This failed and additional base material was removed before welding. After 8 years of operation the rotor experienced vibration, the unit was inspected, and the weld was found with creep cracks in the heat affected zone (HAZ). An investigation of the failure revealed the expanded weld build-up relocated the HAZ into a high temperature, high stress region of the rotor. Widows Creek Fossil Plant Unit 7 Boiler Feed Pump Turbine Rotor: The rotor experienced stress corrosion cracking (SCC) of the fifth stage during operation in 2003. The rotor was weld repaired and returned to service in 2006. After 5 months of operation the rotor experienced vibration, was inspected, and the welded fifth stage and the sixth stage had experience SCC failures.

Aero-derivative gas turbines have been successfully serving the power generation, mechanical drive, and marine markets for 40 years. These products are well suited for distributed generation, with sizes in the range from 3 MW to 50+ MW. The Rolls-Royce group of companies provide vertical integration for aero-derivative based energy systems, having marketing, sales, manufacturing, packaging, distribution, and customer service capabilities. The 3– 6 MW, 501-K family serves power generation and cogeneration applications. The new 6–8 MW 601 is used for cogeneration and mechanical drive. The 15 MW Avon is widely applied to mechanical drives, offering exceptional reliability and low life cycle cost. The RB211 provides over 30 MW at high efficiency, and is used in mechanical drive and electrical generation. The 42% efficient, 50 MW, Trent is primarily intended for electrical generation. This engine retains a higher than usual degree of commonality with aero production modules, thus retaining the cost advantage of high volume production and benefits from continuous improvements in aero engines. Plans: Cost reduction of mature existing products will be achieved by “industrialization”, e.g. by alloy changes and shape simplification, of parts no longer in aero production. Better integrated packaging and “more electric aircraft” features are rapidly becoming a necessity in the competitive marketplace. The trend is toward minimizing and possibly eliminating mechanical drives and other components in a gas turbine to improve product quality, efficiency, reduce product cost, while enhancing product quality and the environment. In this regard, the approach being taken near term is to substitute normal oil bearings with Active Magnetic Bearings. Such an action would help eliminate high cost skid lubrication system components and some environmental hazards as well as reducing maintenance. Several programs will make contributions to environmental improvements through reduced emissions and the use of “renewable” fuels. A prototype 501-K has been supplied to operate on gasified coal, a reduced emissions path to generating electricity from coal. A dual fuel DLE combustion system for very high pressure ratio and turbine temperature is in development for the Trent, having downward compatibility with other company products. The Next Generation Gas Turbine (NGGT) project, sponsored by the US Department of Energy, will use an existing engine core. Advanced modules, including a long life “spiral” recuperator and cycle enhancements combine to yield 50% cycle efficiency at a reduced cost per kW. The goal is to produce a 50 MW class plant with “combined cycle efficiency at simple cycle cost.” The NGGT is suited to using alternate fuel for part of the energy input. Following evaluation of fuel cell/gas turbine hybrids, a specially suited gas turbine development is being initiated with sponsorship by the U.S. Department of Energy. The company is also conducting a solid oxide fuel cell program. An auxiliary power unit(APU) was developed and is now in production for the M1 tank. A “microturbine” derivative of this product is being considered for distributed generation.

An LNG Plant or any Petrochemical Plant was constructed on the basis of discovered feed gas with full scale capacity. As the feed gas has decreased, the plant capacity is required to be put in idle or mothball mode. In that period, the plant facilities have to be preserved and inspected to maintain the integrity. The static and rotating equipment, electrical equipment, and instrumentations need to be maintained. The focus in this paper is how to preserve the rotating equipment. Since they always have clearances between rotating part and stationary part, nitrogen containment only is not always adequate to preserve the internal parts. Failure Mode Effect and Criticality Analysis (FMECA) is one of the tools to define how to preserve rotating equipment. The analysis considers the following essential factors: duration of idle period, equipment functions, equipment mode of failures, preservation method, test convenience, cost of consequence, and safety. This paper takes the case of FMECA of one of the LNG Process Train in Badak LNG that has undergone idle period. Rotating equipment consists of Steam Turbines, Centrifugal Gas Compressors, LNG Pumps, Hydrocarbon Pumps, High Speed Pumps, Lube Oil Pumps, and Fin Fans. The evaluation is down to its auxiliary parts such as Mechanical Seal, Bearing, and Hydraulic Governors. The FMECA study also defines criticality of equipment in the frame of future as the idle period has ended. Rotating equipment may have issues on corrosion and performance. One possibility is whether the equipment or its internal parts (such as rotors, diaphragms, etc) need to be removed from site to storage or warehouse. The criticality also considers the mode of operation of the equipment and their fluid services. This case study presents evaluation of following fluid services: High Pressure Steam, Medium Pressure Steam, Low Pressure Steam, Lubricating Oil, Amine, Natural Gas, Liquefied Petroleum Gas (LPG), and Liquefied Natural Gas (LNG). As the result of FMECA study, the facility has to be preserved in specific methods and measures based on the period of idle. The method provides recommendation of preservation treatment, storage specification, testing requirement, product lifecycle study. The methods and measures performed during idle period are expected to maintain the facility integrity when it needs to be in operation again.