Wyniki wyszukiwania - BazTech

1

Identification of thermal operation conditions of water-wall tubes using eccentric tubular tube meters

Taler J., Taler D., Sury A.

Rynek Energii

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2011

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nr 1

164-171

EN

The tubular type instrument (flux tube) was developed to identify boundary conditions in water wall tubes of steam boilers. The meter is constructed from a short length of eccentric tube containing four thermocouples on the fire side below the inner and outer surfaces of the tube. The fifth thermocouple is located at the rear of the tube on the casing side of the water-wall tube. First, formulas for the review factor defining the heat flux distribution on the outer surface of the flux tube were derived. The exact analytical expressions for the view factor compare very good with approximate methods for determining view factor which are used by the ANSYS software. The parameters appearing in the boundary conditions on the outer and inner surfaces of the water flux-tube: the heat flux, the heat transfer coefficient and temperature of the water-steam mixture are determined based on temperature measurements at the interior locations. Four K-type sheathed thermocouples of 1 mm in diameter, are inserted into holes, which are parallel to the tube axis. The non-linear least squares problem is solved numerically using the Levenberg-Marquardt method. The heat transfer conditions in adjacent boiler tubes have no impact on the temperature distribution in the flux tubes.

PL

Opracowano konstrukcję termometrycznej wstawki pomiarowej do identyfikacji warunków brzegowych w rurach ekranowych. Wstawka wykonana jest z krótkiego odcinka rury mimośrodowej. Nieznane parametry: obciążenie cieplne ekranu, współczynnik wnikania ciepła na powierzchni wewnętrznej oraz temperatura mieszaniny parowo-wodnej wyznaczane są na podstawie pomiaru temperatury metalu wewnątrz lub na powierzchni wstawki. Cztery termoelementy zainstalowane są wewnątrz wstawki od strony ogniowej, w pobliżu jej powierzchni wewnętrznej i zewnętrznej. Piąty termoelement usytuowany jest na zewnętrznej powierzchni wstawki od strony izolacji kotła. Poszukiwane parametry dobierane są tak, aby suma kwadratów różnic temperatur zmierzonych i obliczonych była minimalna. Nieliniowe zagadnienie najmniejszych kwadratów rozwiązane zostało za pomocą metody Levenberga-Marquardta. Warunki wymiany ciepła w sąsiednich rurach ekranowych nie mają wpływu na pole temperatury we wstawce pomiarowej, co ma korzystny wpływ na dokładność wyznaczanych parametrów.

2

Inverse heat transfer problem in digital temperature control in plate fin and tube heat exchangers

Taler D., Sury A.

Archives of Thermodynamics

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2011

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Vol. 32, no. 4

17-32

EN

The aim of the paper is a steady-state inverse heat transfer problem for plate-fin and tube heat exchangers. The objective of the process control is to adjust the number of fan revolutions per minute so that the water temperature at the heat exchanger outlet is equal to a preset value. Two control techniques were developed. The first is based on the presented mathematical model of the heat exchanger while the second is a digital proportional-integral-derivative (PID) control. The first procedure is very stable. The digital PID controller becomes unstable if the water volumetric flow rate changes significantly. The developed techniques were implemented in digital control system of the water exit temperature in a plate fin and tube heat exchanger. The measured exit temperature of the water was very close to the set value of the temperature if the first method was used. The experiments showed that the PID controller works also well but becomes frequently unstable.

3

Ekspercki system doskonalenia procesów wytwarzania części silników lotniczych z wykorzystaniem strategii Six Sigma

Sieńko T., Nowak S., Sury A., Światek B., Sibielak M., Rączka W., Żaba K., Lis A.

Rudy i Metale Nieżelazne

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2007

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R. 52, nr 11

841-846

PL

Przedsięwzięcie jest realizowane ze świadomością potrzeby wsparcia działań, zmierzających do poprawy jakości. Przyjęto, że wsparcie to będzie możliwe poprzez budowę Eksperckiego, Komputerowego Systemu, rozwiązującego zadania z zakresu zarządzania procesami, pomiarów, analiz i doskonalenia.

EN

Our aim is to support activities targeted at quality improvement. The support will be provided by projected Expert Computer System solving problems connected with management of processes, measurements, analyses and improvements. 14 functions of the System have been highlighted. 1. Registration and collection of data concerning requirements and process parameters. 2. Registration of data on input materials. 3. Registration of results of process parameter measurements correlated with time, operations at production units, service, etc. 4. Making results of process parameter measurements available in the defined configurations. 5. Procesing of measurement results with statistic methods for operational control Leeds. Comparison with value limits, presentation of the results according to the defined criteria of data selection, including control chart concept. 6. Registration of operations at the identified production units correlated with the results of process parameter measurements —- Tracing. 7. Registration of the results of controlling conditions of production units correlated with the results of process parameter measurements and tracing. 8. Tracing results processing for the needs of operational control. 9. Registration of quality control results. 10. Formulating partial and complex models scribing relations WY = f(WE) to the defined extend. 11. Searching relation WY-WE applying analysis of correlations regress, and variances, as well as neuron grids. Assessment of influence of particular parameters or groups of parameters. Agent analysis. Testing influence of input elements on output elements. 12. Formulating plans of experiments and result analysis. 13. Symullating linear conditions. 14. Selection of optima parameters of the processes, establishing limits for the measured values.

4

Baza danych technologicznych i planistycznych jako podstawa zarządzania systemem produkcyjnym.

Nowak S., Knych T., Sury A., Świątek B., Macioł A., Sibielak M., Żaba K., Lis A.

Rudy i Metale Nieżelazne

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2004

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R. 49, nr 10-11

572-579

PL

Autorzy podkreślają potrzebę systemowego podejścia do zarządzania produkcją. Prezentują rozwiązanie w postaci komputerowego systemu, obejmującego projektowanie technologii, planowanie produkcji, monitorowanie, pomiar procesu i wyrobu, weryfikację planów, analizę danych dla potrzeb podejmowania decyzji. Komentowana jest metodyka planowania oraz struktura i tabele baz danych.

EN

The paper presents computer aided production process management system in metal processing business developed by a team of technologies, computer scientists, automatics, and specialists in management working in Mechanical Working and Theory of Metals Department. The most important conditions of construction, implementation and maintenance of the System have been described. It is highlighted that the System: - provides coherent, transparent, complex, standard based management of production, which reduces probability of erroneous operational and strategic decisions, - allows reliable appraisal of processes and their results, - based on relevant models and available operational data implements a process control loop: production preparation - planning of material flow and resources - supervision of performance (monitoring and measuring of processes and products) - evaluation of results and verification of plans, - integrates the existing local solutions, if needed, - is especially useful in compound production systems in metal processing business, - ensures optimization of internal solutions, upgrades effectiveness and rationalises the use of resources and increases production abilities. Planning related problems in compound production systems have been identified. The need of description of quasi-continuous system has been mentioned. Production campaigns in particular elements of the line are organized in this system, and sequence of production units is imposed. A design of System database has been described. Constant and variable data have been mentioned. Principles of collection and verification of constant technological, planning related data including limitations and parameters of the models have been given. Variable data of the System are included in tables of orders (e.g. requirements) and in monitoring results. An example of implementation in a car body sheet rolling mill with extremely complex production system. Conditions for implementation of tube production and processing have been described.