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EN
The gas turbine is considered to be a very complex piece of machinery because of both its static structure and the dynamic behavior that results from the occurrence of vibration phenomena. It is required to adopt monitoring and diagnostic procedures for the identification and localization of vibration flaws in order to ensure the appropriate operation of large rotating equipment such as gas turbines. This is necessary in order to avoid catastrophic failures and deterioration and to ensure that proper operation occurs. Utilizing an approach that is based on spectrum analysis, the purpose of this study is to provide a model for the monitoring and diagnosis of vibrations in a GE MS3002 gas turbine and its driven centrifugal compressor. This will be done by utilizing the technique. Following that, the collection of vibration measurements for a model of the centrifugal compressor served as a suggestion for an additional method. This method is based on the neuro-fuzzy approach type ANFIS, and it aims to create an equivalent system that is able to make decisions without consulting a human being for the purpose of detecting vibratory defects. In spite of the fact that the compressor that was investigated has flaws, this procedure produced satisfactory results.
PL
Woda, czyli R718, jest stosunkowo łatwo dostępna na całym świecie, dlaczego więc nie użyć jej jako czynnika chłodniczego? Jakie są zalety, a jakie wady rozwiązań wykorzystujących wodę? No i – co za tym idzie – jakie są perspektywy zastosowań?
EN
The paper is devoted to an effect the shape of the inlet in the centrifugal compressor under modernization exerts on its performance parameters and an evaluation of the related risk. The state art knowledge experience of the authors concerning centrifugal compressor inlets, and results of the analysis of flow fields upstream of the first stage of the compressor under modernization are presented.
PL
Artykuł analizuje wpływ ukształtowania układu wlotowego modernizowanej sprężarki odśrodkowej na parametry jej pracy oraz na powiązane ryzyka. Omówione są przypadki pochodzące zarówno z literatury, jak i z własnego doświadczenia autorów. W części finalnej przedstawiono wyniki symulacji przepływu przez przykładowy układ dolotowy z zastosowaniem pakietu ANSYS CFX.
EN
In the paper, a back swept impeller of centrifugal compressor is experimentally studied and numerically validated and modified to increase its pressure ratio and improve efficiency, as well as to analyse the effect of splitter blade location between two main blades. The back swept multi splitter blade impeller was designed with a big splitter positioned close to the main blade suction surface and a smaller splitter close to the pressure surface. Adding this multi splitter improves the overall performance of the modified impeller due to less intensive flow separation and smaller pressure loss. In particular, the total pressure ratio was observed to increase from 4.1 to 4.4, with one percent increase in efficiency.
EN
Micro scale gas turbine engines are low cost engines. They share their compressor impeller with automotive turbochargers. An identified design condition for the selected impeller is a critical stage of the design process. This process is had difficulties due the large number of manufacturers that provide OEM parts. It is common practice that one OEM part number provides the same impeller at different design revision. In general, parts are interchangeable but in detail, they differ slightly in terms of dimensions and performance. To avoid under predict or over predict inputs data, it is important to check the design parameters with as many methods as possible. In practice, the designer could rely on analytical methods, which are straightforward limited to the applied design. When shared its (compressor operation) it is recommended additional information be provided by computational fluid dynamics that produces a three-dimensional look into the predesign. That allows avoidance of future design failure and reduces both design time and prototype manufacturing costs.
EN
The design a micro gas turbine engine is a process that requires analysis of a number of parameters. The initial stage requires consideration of more than 40 parameters [3]. The whole analysis can be made with analytical tools. However, these kinds of tools are limited to preliminary designs. After 1D-calculations and the establishment of the first CAD model, it is recommended to identify the sensitivity of the design. With a modern numerical environment such as ANSYS CFX, it is possible to predict a trend that gives the designer a 3D feedback about the initial design behaviour. For presented centrifugal compressor case, the selected parameters are vaneless diffuser space, design angle and number of stator blades. For qualitative evaluation – important results that influence design are mass flow rate, total pressure and isentropic efficiency. These results are important to turbojet engine performance and efficiency. All chosen parameters respond to given criteria. Validation and verification is still required due numerical errors that are included in CFD modelling. The advantage of 3D prediction is the possibility to eliminate gross errors before parts are sent into production.
PL
W artykule przedstawiono najczęściej występujące uszkodzenia sprężarek odśrodkowych silników P&W 206b2 zamontowanych w śmigłowcach EC-135, eksploatowanych przez Lotnicze Pogotowie Ratunkowe. Uszkodzenia te są następstwem pracy tych silników w pasie nadmorskim, lądowaniami na podłożu piaszczystym np. plaży i zassaniem przez nie ciał obcych, takich jak m.in.: piasek, kurz, kropelki wody. Zanieczyszczenia występujące w zasysanym powietrzu powodują zmiany parametrów eksploatacyjnych silnika. Z kolei na ich podstawie można ocenić stan techniczny eksploatowanego silnika. W pracy omówiono także metodę oceny uszkodzeń elementów sprężarki oraz podano sposób ich naprawy.
EN
This paper presents the most common damage of the compressor of P&W 206b2 centrifugal engines mounted in helicopters EC-135, operated by Polish Medical Air Rescue. This damage is the result of the work of these engines in a seaside lane, landings on the beach and sucking foreign objects, such as: sand, dust, water droplets etc. Impurities in the intake air cause the changes of operating parameters of an engine. In turn, on this basis, the technical conditions of an engine can be evaluated. This paper discusses the method of assessing the damage to compressor components and provides a way to repair them.
EN
The paper presents the results of computational fluid dynamics modeling of the performance of two centrifugal impellers with low inlet flow coefficients. The first impeller with the flow coefficient of 0.024 had nine main and nine splitter blades and the outlet diameter of 447 mm. The second one differed from the first one only by the lack of the splitters, 18 main blades were used instead. The numerical simulations were verified by the experimental measurements performed on a corresponding test rig. The measurements show better performance characteristics of the impeller with splitters. The main aim of the numerical research, therefore, was to identify the reasons for the existing differences in the performance of the impellers.
EN
Nowadays compressors are used in almost every industry. Compressor failure can suspend production of the whole system so the importance of preventing from failures is obvious and essential. One of the most dangerous flow instabilities which is capable of destroying machine in few seconds is surge, which occurs in conditions of low mass flow rate. Greitzer model, apart from its long history, is still most common mathematical model describing surge. It is widely used to predict the surge onset and pressure oscillations during it. However, it is based on parameters that are not directly related to real machine and their choice is not always obvious. Therefore, the calculations may be inaccurate which results in wrong surge prediction. The other approach to Greitzer model is presented in this paper, which in some cases can assure that the process of compressor modeling is more accurate. The applicability of Greitzer surge model for real machines has been analyzed. Method of implementation is based on experimental pressure signal gathered during unstable work of compressor. Presented method is based on experimental compressor characteristic and outlet pressure signal from unstable work of compressor. From that data it is possible to determinate the value of Greitzer model’s parameters for selected operational point. Thanks to this method this model could be applied for reliable antisurge protection.
10
Content available remote Epoka pionierska maszyn przepływowych w Politechnice Łódzkiej
PL
W artykule opisano cztery konstrukcje maszyn przepływowych, które powstały w latach sześćdziesiątych ubiegłego wieku w Katedrze Cieplnych Maszyn Przepływowych PŁ. Przedstawiono kolejno: silnik czołgowy CMP 501, sprężarkę 6D68, turbopompę pożarniczą TP 3000 (z silnikiem turbospalinowym CMP 504) oraz turbossawę papierniczą 4.68 PAP. Omówione zostały aspekty konstrukcyjne tych pionierskich maszyn, na tle ówczesnych realiów społeczno-ekonomicznych.
EN
Article contains four turbomachinery designs created in 60’s at the Institute of Turbomachinery, Łódź University of Technology. It presents: CMP 501 tang engine, 6D68 compressor, TP3000 fire engine turbopump (with CMP 504 internal combustion engine) and 4.68 PAP vacuum compressor for paper industry. All machines are presented in context of social and economic environment of that time.
EN
Depending on customer requirements a waste water aeration blower might possess various inlet duct configurations. The design parameters that usually vary are the inlet duct volume or the geometry of the duct. However, it is not yet well known how can the duct design influence the steady and unsteady compressor operation. Due to that, this work aims to experimentally check how do such parameters as inlet duct volume, inlet filter and inlet guide vanes position affect the compressor stable and unstable performance. The measurements results show that the influence exists and has mainly quantitative rather than qualitative character.
12
Content available remote Advancements in centrifugal compressor development for challenging applications
EN
The lecture provides an overview of challenging compressor applications (in terms of common aerodynamic criteria) focusing on two examples, due to their use of advanced analytical tools and test models. Development of DATUM ICS with Rotating Centrifugal Separator (RCS) technology combined rotary gas-liquid separation and centrifugal compressor flow path. Such a combination represents a new class of turbomachinery and leads to increased system compactness by significantly reducing the size and weight of installed equipment and eliminating large separation vessels often used on traditional compressor trains. An overview is given for the Dresser-Rand RCS development, multiphase mean-line and CFD modeling, and Demo tests, including the latest one at high pressure conditions, more challenging for separation. The test allowed better understanding of the aero- and thermodynamic behavior of the RCS and validated both compression and separation performance at demanding operating conditions. Centrifugal compressors in the refrigeration cycles of LNG production process are characterized by large flow coefficient and high machine Mach number. Therefore both compressed medium and high speed operation directly impact performance. An overview is given on a typical CFD analysis of high-Mach number application stage, along with its test validation on D-R development test rig. Discussion on optimization highlights both the mean-line level of design and analysis, when specialized tools are used for preliminary design, and the CFD level, through parametric studies.
PL
Obsługa urządzeń przemysłowych wymaga analizy zachowań układów i ich części składowych. W niniejszej pracy zoptymalizowano czynności konserwacyjne tak, aby wyeliminować występowanie uszkodzeń w kontrolowanym procesie przemysłowym. Celem prezentowanej pracy było poprawienie niezawodności elementów układu sprężania gazu poprzez zaplanowanie czynności konserwacyjnych w oparciu o analizę uszkodzeń z wykorzystaniem optymalizacji interwencji w przemysłowej sprężarce odśrodkowej. O skuteczności proponowanego podejścia świadczy poprawa parametrów niezawodności oraz gotowość omawianej instalacji olejowej.
EN
The industrial maintenance implementation requires to the behaviour system analysis and their components. In this work, we optimize the maintenance actions to eliminate failures in the inspected industrial process. Our purpose in this work is to improve the components reliability in gas compression system, by the planning of the maintenance actions based on failure analysis using the intervention optimization in industrial centrifugal compressor plant. The finality of this proposed approach is proved by the improvement of the reliability performances and by the availability of this oil installation.
EN
Already since more than three decades high capacity centrifugal heat pumps are reducing CO2 emissions and are supplying hot water up to 90°C to district heating systems. In most cases the heat is recovered from low temperature heat sources like waste, river and sea water. However, with the centrifugal heat pump technology energy can also be exploited from high temperature heat sources like geothermal water. With an intelligent heat pump system the district heating return temperature can be boosted and at the same time the exploitation of the geothermal heat source can be increased. In this paper four examples of large centrifugal heat pumps in district heating applications using ground, water from the Neocomian and Dogger aquifers will be presented. The heating capacity of presented examples ranges from 5'000 to 8'650 kW.
PL
Już od ponad trzech dziesięcioleci odśrodkowe pompy ciepła zasilają sieci ciepłownicze wodą o temperaturach do 90°C, przyczyniając się do znacznej redukcji emisji CO2. W większości przypadków do odzysku ciepła używane są niskotemperaturowe źródła ciepła, takie jak ścieki, woda rzeczna bądź morska. Jednakże przy użyciu technologii odśrodkowych pomp ciepła mogą być również eksploatowane inne dolne źródła ciepła, takie jak woda geotermalna. Zastosowanie inteligentnego systemu pompy ciepła umożliwia podwyższenie temperatury powrotu sieci ciepłowniczej do wymaganego poziomu przy jednoczesnym zwiększeniu eksploatacji źródła geotermalnego. Artykuł prezentuje cztery przykłady zastosowań odśrodkowych pomp ciepła dużej mocy w aplikacjach ciepłowniczych używających wody gruntowej ze zbiorników w utworach jurajskich (neokomu i doggeru). Moc cieplna użytych urządzeń waha się w zakresie od 5 000 do 8 650 kW.
PL
W artykule przedstawiono aspekty teoretyczne i uwarunkowania techniczne regulacji promieniowych maszyn sprężających drogą zmiany częstości obrotów. Omówiono, opierając się na charakterystykach rzeczywistej sprężarki ograniczenia tego sposobu regulacji. Poruszono zagadnienie napędu sprężarek pracujących przy zmiennych częstościach obrotów.
EN
The article is devoted to theoretical and technological aspects of regulation of the radial compressing machines with the use of variable rotational velocity. The consideration includes pressure characteristics obtained at the real experimental stand. Authors outline the limitations of such a regulation method and the technical problems connected with motors running compressor at a variable rotational speed.
17
Content available remote Industrial centrifugal compressor model stages based on compressor tests results
EN
New generation of pipe-line compressors was created on a base of computerized gas dynamic design (Universal modeling method). After correction of empirical coefficients in the models of work input and head losses the calculated performances matches to test results of compressors. Corrected sets of empirical coefficients are used to calculate performances of 65 stages of different types. Performance curves and flow path dimensions can be used in design practice as model stages of new generation.
PL
Artykuł zawiera przegląd stanu wiedzy w dziedzinie zjawiska pompowania w sprężarkach promieniowych oraz zarys niestacjonarnych badań numerycznych które pozwoliłyby na jego usystematyzowanie. Symulacje numeryczne poparte będą eksperymentami przeprowadzonymi na stanowisku jednostopniowej dmuchawy promieniowej DP.1.12
EN
The article presents the state-of-the-art in understanding of the surge phenomenon in centrifugal compressors and the concept of a non-stationary numerical simulations that will allow to systematize knowledge in that field. Numerical computations will be supported by the experiments conducted on the single stage centrifugal blower DP.1.12.
19
EN
The goal of this paper was to develop a methodology of explanation of diaphragm vane defects in a two-stage centrifugal compressor which had occurred in during operation of the machine. The methodology consisted of experimental investigations of the disassembled diaphragm, then a dynamical analysis using the finite element method on the 3D diaphragm model, obtained by reversing engineering with an optical photogrammetric camera of the TRITOP CMM measuring system. The final purpose of this research work was to formulate the recommendations to avoid future problems.
PL
Celem pracy było opracowanie metodyki pozwalającej na wyjaśnienie przyczyn uszkodzeń łopatek kierownicy dwustopniowej sprężarki promieniowej, które powstały w okresie eksploatacji maszyny. Zaproponowana metodyka obejmuje badania eksperymentalne oraz weryfikację modelu teoretycznego 3D kierownicy, opracowanego przy wykorzystaniu nowoczesnego systemu optycznej metody skanowania w widmie światła białego TRITOP CMM. Końcowym efektem pracy było sformułowanie zaleceń modyfikacji konstrukcji maszyny dla eliminacji tego problemu.
20
Content available remote Two-Phase Flow Analysis of the Centrifugal Compressor Inlet
EN
Uniformity of flow distribution after centrifugal compressor inlet has a substantial impact on compressor performance. Liquid present in the gas affects performance of downstream stage components. A CFD study of two-phase flow in the compressor inlet is discussed. An inlet design is derived from the family of Dresser-Rand DATUM® compressors and adapted to actual conditions. Analysis of two-phase flow field and losses is presented. Conclusions are made on the applicability of the proposed inlet configuration to selected application and on flexibility of the DATUM product line.
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