Master of DonNTU Pushinskiy Maxim Name: Pushinskiy Maxim
University: 2005-2011 years  — Donetsk National Technical University
Faculty: Electrical Engineering
Department: Electric drive and automation of industrial plants
Speciality: Electromechanic systems of automation and electric drive
Theme of master's work: Analysis of technical and economic aspects of modernization of powerful electric drives machinery in metallurgical industry
Scientific advisor: Svetlichniy Aleksey
 

Analysis of technical and economic aspects of modernization of powerful electric drives machinery in metallurgical industry

A present situation in Ukrainian Metallurgy

While the Ukrainian metallurgists grow a production, there is a steady tendency of overproduce in the world market of steel. At the same time, the Ukrainian metallurgical enterprises need the rearmament. If in the nearest decade we do not correct this situation, Ukraine can lose strong positions at the market of ferrous metallurgy.

During an economic crisis a domestic mining and smelting complex (MSC) was practically stoped. At that time the government set privileges on tariffs on transportation of loads a railway transport and released electric power. Therefore this year began for metallurgical industry successfully. In the I quarter domestic metallurgists increased smelting in compare of the proper period in the last year on 16% - to 8,064 million t. The production of rental in January-March grew on 8% - to 6,755 million t.

Preferences were prolonged because of decision №289 from March, 24 of 2010. In according to it for the enterprises of MSC were set the tariffs on transportation of loads by a railway transport at the level of October, 2008. National commission of electricity control was recommended to set on the II quarter the tariffs at the level of November, 2009. Good production indexes resulted to possible abolition of privilege for the enterprises of MSC from the III quarter. For all period of action of memorandum domestic metallurgists got preferences of more than 1,5 milliards uah. It is a large sum which can be in a budget, but internal and especially external states of the market give an occasion to doubt in that privileges will be anointed.

Today the owners of metallurgical assets in Ukraine don’t know what to do.

A metallurgical complex requires modernization. About 70% metallurgical assets in Ukraine require replacement. But under influence of crisis the Ukrainian metallurgists halted realization of most projects of modernization of production.

Despite expectations, internal growth was not restored. It takes place mainly due to proceeding stagnation in construction sphere and engineering. Large stake of products of metallurgy in the national product of Ukraine and insignificant internal demand on it conduces to strong dependence of export operations. But world demand is unstable, moreover, now there is an overproduce at the market of products of black metals. It does not allow the owners of metallurgical enterprises to accumulate facilities for modernization.

Owners are guilty in that the prospects of Ukrainian metallurgy are too misty. The programs of modernization began too late and were not intensive.

Therefore in crisis almost all enterprises of MSC entered mainly with an out-of-date equipment and large costs.

To correct a situation, metallurgists need to stop economically unprofitable production, to concentrate investments on improvement of quality of products of priority enterprises. If Ukraine can make scale modernization and begin to produce more high-quality products, these will be only a few old factories, but not 70% of Ukrainian metallurgy.

In my diploma work I will examine expedience of modernization of powerful electromechanics in the mechanisms of metallurgical industry [8].

Modernization is a partial improvement of construction for the increase of the productivity and increase of functionality of electrical equipment, substituting of morally out-of-date element base of electrical equipment by modern.

Basic technical aggregates modernization of which it is expedient to execute:

  1. Faucets of the general and special settings.
  2. Flattings mills.
  3. Agglomachines.
  4. Crush machines.
  5. Manipulators a blacksmith's.
  6. Car dumpers.
  7. Mechanisms of high furnace (throat, skips and other).
  8. Transfercar.
  9. Scale cars.
  10. Car-pusher.
  11. Device of continuous steel-teeming.

Basic directions modernization of electromechanics of technological aggregates:

  1. Substituting of morally out-of-date element base by modern domestic or imported production.
  2. Changing of control system of the electromechanics of separate mechanisms and aggregate using complete electromechanics (CEM), complete control electromechanics units (CCEU).

At presence of drive of direct-current substituting of electric motors of direct-current is possible on analogical asynchronous electric motors with a shortcircuited rotor with analogical mechanical descriptions and replacement of contactor control panels on the closets of management with the transformer of frequency [5].

Tendency of evolution of devices, which work by the control of electrodrives, is shown on animation below

Evolution of devices, which work by the control of electrodrives

Figure 1  — Evolution of devices, which work by the control of electrodrives (Animation consists from 3 frames with delay 500 ms between frames; delay before repeat is 1000 ms, number of cycles of reproduction is limited to 7, size 314*314, 197kB, created in MP GIF Animator)

Application of frequency transformers domains

On the base of frequency transformers can be realized systems of adjusting of speed of the followings objects:

  1. pumps of hot and cold water in the systems of water supply and heating, ancillaries of boiler rooms, heating plants, heat stations and boiler units;
  2. roller beds, conveyors, traversers and other transport vehicles;
  3. metering devices and headers;
  4. crushers, mills, mixers, extruders;
  5. centrifuges of different types;
  6. equipment of flattings mills and other metallurgical aggregates;
  7. drives of borings machine-tools, electrodrills, boring equipment;
  8. electromechanics of machine-tool equipment;
  9. high-circulating mechanisms (grinding arbors etc.);
  10. cranage;
  11. mechanisms of power manipulators and others

Advantages

Using equipment of stepless control of rotation frequency besides saving about 40% of electric energy input give many complementary advantages:

  1. the smooth starting and tailoff eliminates noci-influence of transients (water-hammer) in pressure pipelines and technological equipment;
  2. starting of engine is carried out at currents, limited at the level of basic value, that promotes longevity of engine, reduces requirement to power of feed-in network and power of commutate apparatus;
  3. modernization of operating technological aggregates is possible without replacement of pumping equipment and practically without interruptions in his work.

Control system on the base of frequency transformers can have any technologically required functions realization of which is possible both due to built-in in transformers pios and additional comptrollers, functionings jointly with transformers [4].

Equipment of smooth start

Application

  1. Pumps, fans and compressors.
  2. Conveyors and traversers.
  3. High-pressure and accelerative machinery.
  4. Grinding, metal-working and woodworking machines.
  5. Machines and mechanisms with a strap, chain and by other types of transmissions, reducing gears and other devices.

Advantages:

  1. Allows to influence on a starting moment.
  2. Diminishes a starting current.
  3. Diminishes losses after an acceleration due to a bypass contactor.
  4. Carries out possibility of the cascade starting and stopping with of a few engines one device of the smooth starting.
  5. Improves external of drive mechanism.
  6. Improves external of engine, launcher and network of energy supply.
  7. The devices of the smooth starting are abbreviated by charges on service.
  8. Management possibility on the interfaces of Rs232 and Rs485.

Types of starting:

  1. Smooth starting with the set limitation of current.
  2. Starting of engine by the smooth increase of tension with the set pace.
  3. Starting with the initial throw of current for the receipt of enhanceable starting moment.

Types of braking with the device of the smooth starting:

  1. Stop with the set intensity.
  2. Dynamic braking.

Defences:

  1. Time - current and maximally current defence of engine;
  2. Protecting from the loss of phase;
  3. Protecting from the overheat of engine and transformer;
  4. Protecting from the prolonged start.

Basic descriptions of device of the smooth starting (DSS) of synchronous and asynchronous engines:

  1. electronic defence of engine
  2. analog devices of the soft starting and braking
  3. regulators of power, voltage regulators
  4. high-voltage smooth starting
  5. smooth starting, smooth stop
  6. stabilizing and limitation of tension
  7. even rotation, soft starting of electric motor
  8. increase of resource of machine
  9. systems of the unstressed starting of high-voltage electric motors
  10. smooth starting and stop way of three-phase asynchronous engines
  11. smooth starting with set the pace of starting
  12. smooth starting with limitation of starting current
  13. starting with the initial impulse of current
  14. maintenance of pressure on the output of pump
  15. flexible technological process control
  16. smooth starting/stop of pumpings aggregates
  17. smooth starting and thermal protecting from overloads [3].

Conclusion

Modernization of electromechanics of technological aggregate using the newest developments will provide trouble-free work of aggregate to next major repairs, will increase his efficiency and functionality, will decrease the wear of component details and knots of construction.

Abstract is not finished. The full version of the work will be available at the author or his supervisor in 2011 year.

References

  1. Металлургия Украины / Википедия / Internet resource.  — Access mode: http://ru.wikipedia.org/wiki/Металлургия_Украины
  2. Motor controller / Wikipedia / Internet resource.  — Access mode: http://en.wikipedia.org/wiki/Motor_controller
  3. Модернизация электропривода / OOO "Дельта Электроникс" / Internet resource.  — Access mode: http://www.eldvig.com/index1
  4. Энергосберегающая модернизация / "Продиндустрия" - аналитический журнал: пищевая промышленность, торговля и общественное питание. / Internet resource.  — Access mode: http://www.prodindustry.ru/archive/2010/february/0004.php
  5. Модернизация электропривода / Официальный сайт РОСЭК / Internet resource.  — Access mode: http://www.roselectro.ru/napravleniya-deyatelnosti/modernizatsiya-elektroprivoda.html
  6. Кризис vs Модернизация. Кто кого? / Ежедневные новости металлургии :: Metaldaily.ru / Internet resource.  — Access mode: http://www.metaldaily.ru/news/news25929.html
  7. Xian-qing C., Jian-guang Z., Ren-yua T. Vector Controlled Permanent Magnet Synchronous Motor Drive with Adaptive Fuzzy Neural Network Controller / China National Knowledge Infrastructure --- Download Paper / Internet resource.  — Access mode: http://en.cnki.com.cn/Article_en/CJFDTOTAL-ZGDC200601025.htm
  8. Быстрова О. Металлургии грозит кризис перепроизводства / Независимая газета / Internet resource.  — Access mode: http://www.ng.ru/economics/2001-03-31/4_metallurg.html
  9. What is powder metallurgy / Internet resource.  — Access mode: http://mfg.eng.rpi.edu/GMP/handouts/PM.pdf
  10. POWDERED METALLURGY – PLANETARY MOTOR ASSEMBLY  — ASCO Sintering / Sintering – ASCO Sintering Company - Powder Metallurgy / Internet resource.  — Access mode: http://www.ascosintering.com/planetary-motor.php