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EN
Atmospheric water harvesting (AWH) devices represent a fruitful hope to cope with the water shortage problem throughout the world. The vast development in AWH technology and the wide spread of various AWH techniques will largely contribute to the implementation of AWH machines in different household, agricultural and industrial applications. In the last decades, a huge amount of research has been done on AWH methods with amazing differences in results that mislead readers and even researchers. In this study, the AWH theoretical technology developments, various AWH methods and various AWH machines in the market were reviewed. A comparison between the different theoretical methods was presented, concentration on unifying results based on area and energy consumption per harvested amount was performed for clear judgment on the different published data. The gaps between theory and market available devices were stated with recommendations for further development in AWH technology.
EN
Hot storage tanks (HST) are known for their high energy consumption, attributed to variations in usage, heat dissipation within the tank, and heat losses to the surroundings. This study proposes a chimney-type electrically heated HST, which is investigated under static mode to enhance its thermal performance. Different natural circulation areas (chimney areas) with large (9.5 cm diameter), medium (2.5 cm diameter), and small (1.5 cm diameter) sizes were utilized to examine the effect of natural circulation on the HST performance. Additionally, the influence of chimney insulation on the HST performance was also studied. The experiments revealed that the chimney significantly affected the thermal stratification within the tank. Different chimney contact diameters (9.5 cm, 2.5 cm, and 1.5 cm) were tested, showing varying degrees of thermal stratification. The results indicated that smaller chimney contact diameters led to higher thermal stratification and more rapid heating of the top layer temperatures. However, the impact of insulation on thermal performance was inconclusive, suggesting the need for more effective insulation and further investigation into the dynamic mode of operation. The findings also highlighted the faster heating of the top outer layer compared to the larger diameter, emphasizing the significance of the chimney type electrical heater in the hot storage tank.
PL
W artykule wyznaczono błędy pomiaru strumienia masy powietrza za pomocą kryzy ISA z przytarczowym pomiarem różnicy ciśnień w przypadku jej odwrotnego zainstalowania w rurociągu przepływowym. Obliczono wartości współczynnika poprawkowego zmniejszającego te błędy oraz przedstawiono wartości błędów resztkowych po wprowadzeniu tego współczynnika. W zależności od liczby Reynoldsa przedstawiono również zmiany wartości współczynnika przepływu dla kryzy zainstalowanej prawidłowo i odwrotnie.
EN
The article determines the errors of air mass stream measurement by means of an ISA orifice with differential pressure measurement in thecase of its reverse installation in a flow pipeline. The values of the correction factor reducing these errors were calculated and the values of the residual errors after taking this factor into account were presented. Depending on the Reynolds number, the changes in the value of the flow coefficient for an orifice installed correctly and in reverse are also presented.
PL
Artykuł dotyczy pomiarów średniej prędkości przepływu przy użyciu metody ultradźwiękowej w warunkach niestandardowych. W pracy przeanalizowano wpływ przeszkód zaburzających przepływ, w postaci powszechnie stosowanych w instalacjach przepływowych elementów: zasuwy nożowej, przepustnicy i kolana hydraulicznego na błędy ultradźwiękowego pomiaru prędkości wykonanego w zmiennych odległościach od elementu zaburzającego. Rezultaty pomiarów wykonanych za przeszkodą porównywano z wynikami pomiaru wykonanego przepływomierzem referencyjnym na prostym odcinku rurociągu przed przeszkodą. Pozwoliło to ocenić wpływ przeszkód wywołujących zaburzenia i zmiany w rozkładzie prędkości przepływu na zmierzoną wartość prędkości. W warunkach przemysłowych często zdarza się, że wykonanie pomiaru z zachowaniem określonych w normach prostych odcinków rurociągu od przeszkody jest niemożliwe. Wiedza o wpływie podstawowych typów elementów hydraulicznych na wskazania przepływomierza przy pomiarze wykonywanym bez zachowania wymaganych odcinków prostych rurociągu może być praktycznie użyta do oceny możliwości wykonania pomiaru i oceny wiarygodności otrzymanych rezultatów.
EN
The article deals with flow velocity measurements using the ultrasonic method under non-standard conditions. The paper analyzes the effect of flow disturbance obstacles, in the form of common flow system components: knife gate valve, butterfly valve and hydraulic elbow, on the errors of ultrasonic velocity measurements made at varying distances from the disturbance component. The results of measurements made behind the obstruction were compared with those made with a reference flow meter on a straight section of the pipeline in front of the obstruction. This made it possible to assess the influence of obstacles causing disturbance and changes in the distribution of flow velocity on the measured value of velocity. In industrial conditions, it is often impossible to make a measurement with the straight sections of the pipeline from the obstacle, as specified in the standards. Knowledge of the effect of basic types of hydraulic elements on flow meter readings when measurements are made without maintaining the required straight pipeline sections can be used practically to assess the feasibility of the measurement and evaluate the reliability of the results obtained.
EN
The aim of this study was to improve the residential photovoltaic systems (RPVS) sector, using surveys as the research method. The research was carried out in four selected districts in Jordan, taking into account the largest population. The prepared sets of questionnaires covered a wide range of topics, divided into three parts and seven sections. The results showed that the highest use of solar energy for heating was in the Amman district, while in the Irbid and Zarqa districts photovoltaic (PV) system installations can potentially be more prospective because of high electricity and thermal energy usage. This study found the willingness of people to have a combined on-grid/off-grid PV systems, made by European and American manufacturers. However, those respondents were afraid of the high maintenance cost, the unclear lifespan of the system, doubtful reliability, and unclear warrantee of the PV systems.
EN
The subject of this paper is the effect of changing the roughness of the inflow surface of an orifice on its characteristics. A sloping segmental orifice was chosen as the reducer and its surface roughness was changed by lining its inflow surface with sandpaper of different roughness parameters. In such a system, the dependence of the flow stream on the differential pressure at the orifice was measured on a test stand in the range of Reynolds numbers 4110-17000, the flow coefficient C was calculated and flow characteristics were prepared. The study was carried out for a selected segmental orifice with flow coefficient C= 0.723 installed in a pipeline with diameter Dw = 50.35 mm. The roughness of the inflow surface was changed by sticking sandpaper with a gradation of P120 ÷ P1200 to its surface. The roughness parameter Ra was in the range Ra = 5.69 μm ÷ 25.85 μm and Rz = 43.84 μm ÷ 164.83 μm. The dependence of the variation of the coefficient C on the roughness parameter Ra is then presented and the relative errors of the flow stream measurements were calculated. The paper also presents distributions of the differential pressure measured at the orifice for different flow streams depending on the roughness parameter.
EN
This research proposed an integrated eco-system for conditioning an outdoor public area (park or sport) in a hothumid environment. It is accomplished by the use of a dehumidifier control machine driven by renewable solar power; after which air is distributed throughout a ducting system. The system will harvest moisture from the air, utilize it for drinking water production and plants irrigation as well as deliver low temperature, low humidity ratio air for controlling the outdoor air, which results in a comfortable outdoor relative humidity and temperature (24 °C, 50% RH). The Integrated Eco-Friendly Cooling System (IEFCS) is a sustainable self-dependent in energy and water sources. It provides a positive impact on the microclimate of the site, assists in night illumination, supplies water for drinking, plant irrigation, and allows people to enjoy a thermally comfortable atmosphere. The advantages include low maintaining cost as well as the possibility to be scaled and implemented anywhere according to the selected location.
EN
Recently, hydropower energy resources become an attractive means of generating electricity for, off-grid networks, especially in rural areas. This work aims to design a suitable prototype of an energy-storing system, which is called a Potential Steam Hydro Capacitor. This system gives a manageable source of electricity, and partially provides drinkable water, at a low cost, as an alternative to comparatively high-cost electrical batteries. The system is composed of two solar collectors, connected in series. The working fluid in the first collector is Dead Sea water, and in the second fresh water, a heat exchanger, a thermosiphon solar water heater connected to a high column to pass the vapor to high altitude, and a condensation unit on the roof of the building. The system succeeds in producing a considerable amount of fresh water at a height of 3.4 m. The potential energy produced, can operate a small turbine. The capability of the system, to convert thermal energy in the freshwater, to potential energy, was high, with an efficiency of 66.7%. adding solar concentrators to the system would increase the water collected.
EN
Liquid-gas flows in pipelines appear in many industrial processes, e.g. in the nuclear, mining, and oil industry. The gamma-absorption technique is one of the methods that can be successfully applied to study such flows. This paper presents the use of the gamma-absorption method to determine the water-air flow parameters in a horizontal pipeline. Three flow types were studied in this work: plug, transitional plug-bubble, and bubble one. In the research, a radiometric set consisting of two Am-241 sources and two NaI(TI) scintillation detectors have been applied. Based on the analysis of the signals from both scintillation detectors, the gas phase velocity was calculated using the cross-correlation method (CCM). The signal from one detector was used to determine the void fraction and to recognise the flow regime. In the latter case, a Multi-Layer Perceptron-type artificial neural network (ANN) was applied. To reduce the number of signal features, the principal component analysis (PCA) was used. The expanded uncertainties of gas velocity and void fraction obtained for the flow types studied in this paper did not exceed 4.3% and 7.4% respectively. All three types of analyzed flows were recognised with 100% accuracy. Results of the experiments confirm the usefulness of the gamma-ray absorption method in combination with radiometric signal analysis by CCM and ANN with PCA for comprehensive analysis of liquid-gas flow in the pipeline.
PL
Tematyka artykułu dotyczy wyznaczania parametrów pojedynczego, wznoszącego się pęcherza w ciekłym metalu i w polu magnetycznym. Badania przeprowadzono przy wykorzystaniu impulsowej, ultradźwiękowej metody echa. W artykule przedstawiono metodę pomiaru. Na podstawie uzyskanych wyników pokazano, że pęcherze wznoszą się praktycznie prostoliniowo, co oznacza, że ich prędkością końcową jest prędkość wznoszenia, w związku z czym pozostałe składowe są do pominięcia. Następnie obliczono prędkości pojedynczych pęcherzy, współczynniki oporu i przedstawiono je w zależności średnicy zastępczej oraz liczby Reynoldsa. W końcowej części artykułu pokazano zależność liczb charakterystycznych Webera, Eotvosa i Mortona od liczby Reynoldsa.
EN
The subject of the article concerns the determination of the parameters of a single, rising bubble in liquid metal and in a magnetic field. The research was carried out using the ultrasonic pulse echo method. The article presents the measurement method. On the basis of the obtained results, it has been shown that the bubbles rise practically in a straight line, which means that their final velocity is the rising velocity, and therefore the remaining components can be ignored. Then, individual bubble velocities and drag coefficients were calculated and presented in relation to the equivalent diameter and Reynolds number. The final part of the article shows the dependence of the characteristic numbers: Weber, Eotvos and Morton on the Reynolds number.
PL
Tematyka artykułu dotyczy porównania parametrów przepływu dwufazowego ciekły metal-gaz, w przepływie bez i w polu magnetycznym. W artykule przedstawiono jak zmieniają się prędkości przepływu, średnice zastępcze, współczynniki oporu oraz rozkłady przepływających pęcherzy. Obliczono także liczby Eötvösa i Webera. Jako metodę pomiaru wybrano impulsowa, ultradźwiękową metodę echa. Badania wykonano wtłaczając argon do zbiornika wypełnionego ciekłym metalem GaInSn. Przeprowadzono je dla trzech różnych dysz wlotowych gazu oraz dla przepływu łańcuchowego pęcherzy.
EN
The subject of the article concerns the comparison of two-phase liquid metal-gas flow parameters, in the flow without and with a magnetic field. The article presents how flow velocities, equivalent diameters, drag coefficients and distribution of flowing bubbles change. The numbers of Eötvös and Weber were also calculated.The ultrasonic pulse echo method was chosen as the measurement method. The tests were carried out by injecting argon into a container filled with liquid metal GaInSn. They were carried out for three differentgas inlet nozzles and for bubble chain flow.
PL
W artykule przedstawiono impulsową-ultradźwiekową metodę echa do wyznaczania parametrów przepływów dwufazowych ciekły metal-gaz. Opisano zasadę pomiaru, przedstawiono zrealizowany układ pomiarowy oraz przeanalizowano dokładność metody. W pracy zaprezentowano również przykładowe wyniki z przeprowadzonych badań.
EN
The article presents a ultrasonic echo pulse method for determining the parameters of diphase liquid metal-gas flows. The principle of measurement is described, the realized measurement system is presented and the accuracy of the method is analysed. The paper also presents exemplary results from the research.
13
PL
W pracy przedstawiono rozważania związane z modelami matematycznymi profili prędkości w przepływie przez rurę. Dzięki modelom możliwe jest wyznaczenie współczynników wzorcowania przepływomierzy próbkujących. Na podstawie przeprowadzonych badań doświadczalnych wyznaczono rozkłady współczynników wzorcowania w zależności od promienia rury.
EN
The paper presents considerations related to mathematical models of velocity profiles in the flow through a pipe. Thanks to the models, it is possible to determine the calibration coefficients of the sampling flowmeters. Based on the experimental tests carried out, distributions of calibration coefficients were determined depending on the radius of the pipe.
14
Content available remote Dopplerowska anemometria laserowa jako metoda pomiaru przepływu za łukiem 90⁰
PL
Artykuł opisuje zagadnienie wizualizacji zaburzenia przepływu, występującego za łukiem hamburskim jako elementem zaburzającym przepływ w instalacji hydraulicznej. Jakościowe opisanie profilu prędkości pozwala określić formę zaburzenia, a ilościowa analiza pozwala określić średni strumień objętości w instalacji hydraulicznej.
EN
The article describes the problem of visualization of flow disturbances occurring behind the Hamburg bend as an element disturbing flow in the hydraulic system. The qualitative description of the velocity profile allows to determine the form of the disturbance, and the quantitative analysis allows to determine the average volume flow in the hydraulic system.
PL
W artykule przeanalizowano możliwość zastosowania przesłony w rurociągu do pomiaru strumienia masy gazu. Dla różnych ustawień przesłon wyznaczono wartości współczynników przepływu w zależności od liczby Reynoldsa. Dla przykładowych średnich wartości współczynników przepływu wyznaczono odchyłki strumienia masy powietrza przepływającego w rurociągu.
EN
The article analyses the possibility of using an aperture in a pipeline to measure gas mass stream. The values of flow coefficients depending on the Reynolds number were determined for different aperture settings. For exemplary mean values of flow coefficients, deviations of the mass stream of air flowing in the pipeline were determined.
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