Wyniki wyszukiwania - BazTech

1

Evaluating the uncertainty of the amount of thermal energy for metering systems with differential pressure flowmeters

Byts Oksana, Kurytnik Igor, Matiko Fedir, Lesovoy Leonid, Matiko Halyna

Napędy i Sterowanie

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2020

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R. 22, nr 4

57--63

EN

In commercial metering systems of thermal energy it is important to obtain not only the measured value of the amount of thermal energy, but also the characteristic of the uncertainty of this value. The paper presents the developed technique for evaluating the uncertainty of the measurement result of the amount of thermal energy for metering systems with differential pressure flowmeters used for metering the heat carrier flowrate. The technique uses the dependencies developed by the authors for calculating the relative standard uncertainty of the amount of thermal energy, enthalpy and flowrate of heat carrier. The equation for calculating the uncertainty of heat carrier enthalpy was developed by applying the dependencies of the technique IAPWS IF 97. The approaches proposed by the authors make it possible to develop dependencies for evaluating the uncertainty of the measurement result of the amount of thermal energy for systems of different configurations and systems with different types of flowmeters.

PL

Dla systemów komercyjnego rozliczania energii cieplnej ważne jest uzyskanie nie tylko zmierzonej ilości energii cieplnej, ale również charakterystyki niepewności tej ilości. W artykule opracowano technikę oceny niepewności wyniku pomiaru energii cieplnej dla systemów pomiarowych, w których do pomiaru przepływu nośnika ciepła stosowane są przepływomierze zwężkowe. Opracowana technika polega na wykorzystaniu opracowanych przez autorów zależności do obliczenia względnej standardowej niepewności ilości energii cieplnej, entalpii i przepływu nośnika ciepła. Zależność do obliczania niepewności entalpii nośnika ciepła opracowano przy użyciu zależności metody IAPWS IF 97. Podejścia zaproponowane przez autorów umożliwiają opracowanie zależności do szacowania niepewności zmierzonej wartości ilości energii cieplnej dla układów o różnej konfiguracji, a także układów wykorzystujących przepływomierze różnych typów.

2

Effect of flow pulsations on the accuracy of differential pressure flowmeters

Kostyk I., Matiko F., Fedoryshyn R.

Challenges of Modern Technology

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2017

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Vol. 8, no. 1

23--31

EN

This work deals with investigation of influence of flow pulsation on the accuracy of gas flow rate and volume measurement by means of the differential pressure flow meters. Experimental studies of the step response curves of an impulse line with a pressure transducer (PT) were carried out with application of a high-frequency analog-to-digital converter of the pressure signal in the PT chamber. Mathematical model of an impulse line with a PT was built. This model provides simulation and investigation of the transient processes with high accuracy. The influence of the impulse line design (length, diameter) on the step response curves and on the frequency response curves as well as on the resonant frequency of the oscillating system (an impulse line with a PT chamber) was studied. The systematic errors of flow rate and volume measurement due to the resonance in the impulse lines which was caused by flow pulsation were simulated and studied for an acting differential pressure natural gas metering system. On the basis of the calculation results it was defined that amplification of the amplitude of the oscillating signal of the differential pressure due to the resonance may lead to a negative systematic error of gas volume measurement. The systematic errors of gas flow rate and volume measurement caused by the flow pulsation can be reduced by choosing the correct design of the impulse lines in order to avoid the resonance.

3

Experimental research on velocity profiles in selected flow systems

Kabaciński M.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2012

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Vol. 16, No 3-4

185--201

EN

A problem of measuring of velocity profiles with the use of a fully automated test stand is presented in this paper. Due to the installed measurement equipment and various software alternatives it is possible to assess the inlet effect and distribution of velocities in the vicinity of averaging Pitot tubes in order to determine the phenomena occurring in their vicinity (recirculation, main stream direction) and verify the numerical models of turbulence. Due to the stream recirculation in the vicinity of the probes tested in a wind tunnel, a two-way probe was used instead of a Pitot tube. A linear module with a stepper motor formed an integral part of the measurement system whereby it was possible to determine the position of the measurement probe with a precision of 0.1mm. The measuring anemometer location, the possibility of adjusting the stream mean velocities and data acquisition were established by means of an original program. As far as the research in pipelines is concerned - the resulting characteristics allow the uncertainty of measurement to be precisely determined, which should be accounted for during the determination of air fluxes at locations which are not included in the technical documentation of a flowmeter.

4

Wpływ chropowatości rurociągu na wskazania przepływomierzy zwężkowych nowe podejście do zagadnienia

Turkowski M., Tomasik J., Zagożdżon M.

Pomiary Automatyka Robotyka

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2008

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R. 12, nr 5

5-8

PL

W artykule przedstawiono nowe podejście do zagadnienia wpływu chropowatości rurociągu na charakterystyki przepływomierzy zwężkowych. Podejście to polega na zastosowaniu nowo opracowanych parametrów mikrogeometrii powierzchni. W trakcie badań wzorcowano kryzy o przewężeniach β = 0,2, 0,5 i 0,75 w rurociągach o DN 50, 80 i 100 i obliczano współczynniki przepływu na podstawie tych wzorcowań dla różnych struktur chropowatości. Struktury te otrzymywano, stosując papier ścierny, obróbkę mechaniczną i naturalne starzenie rurociągu ze stali węglowej w wodzie. Chociaż nie uzyskano dokładnej korelacji między zmianami współczynnika przepływu a nowymi parametrami chropowatości, to rozrzut otrzymanych wyników pomiarów jest tego samego rzędu jak w przypadku uporządkowania wyników w funkcji innych kryteriów.

EN

The paper presents a new approach to the issue of the influence of the pipeline roughness on the characteristics of the differential pressure flowmeter. The approach consists on the use of the newly developed parameters of the surface microgeometry. During the research the orifices of diameter ratio β = 0,2, 0,5 and 0,75 installed in pipelines of DN 50, 80 and 100 were calibrated and discharge coefficient were calculated for various roughness structures. The structures were obtained sing sand paper, machining and natural ageing of carbon steel pipeline in water. Although the precise correlation between the discharge coefficient change and new roughness parameters have been not reached, the spread of measuring points is in the same range that the results arranged against other criterions.