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Partload Operation, Impact of 3-D Flow Phenomena Performance

  • Johann Friedrich GülichEmail author
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Abstract

A pump working significantly below the best efficiency flow rate is said to operate at partload. At low specific speeds this can be roughly assumed at q* < 0.8, at high nq below q* < 0.9. Since blade inlet angles and channel cross sections are too large for the reduced flow rate, flow patterns during partload operation fundamentally change compared with the design point. The flow becomes highly 3-dimensional since it separates in the impeller and the collector. Finally, recirculations are observed at impeller inlet and outlet at sufficiently low flow. An easy means to obtain information on the impeller flow are stroboscopic observations of tufts. Flow patterns in a radial impeller of nq = 22 gained in this way are shown in Fig. 5.1 [B.20]. It can be seen that the flow is attached at q* > 0.8 while increasingly large zones with separation and recirculation are observed at a lower flow rates. Similar flow patterns were found on impellers of nq = 26 and 33.

References

  1. 1.
    Agrawal, D.P., et al.: Effect of inlet velocity distribution on the vaned radial diffuser performance, pp. 71–75. ASME Fluid Mach. Forum, Portland (1991)Google Scholar
  2. 2.
    Braun, O.: Part load flow in radial centrifugal pumps. Dissertation, EPF Lausanne (2009)Google Scholar
  3. 3.
    Bross, S., Brodersen, S., Saathoff, H., Stark, U.: Experimental and theoretical investigation of the tip clearance flow in an axial flow pump. In: 2nd European Conference on Turbomachinery, Antwerpen, pp. 357–364 (1997)Google Scholar
  4. 4.
    Canavelis, R., Lapray, J.F.: Effect of suction duct design on the performance of mixed flow pump. IMechE Paper, C333/88 (1988)Google Scholar
  5. 5.
    Carey, C., et al.: Studies of the flow of air in a rotor model mixed-flow pump by Laser/Doppler anemometry. NEL-Reports 698 (1985), 699 (1985), 707 (1987)Google Scholar
  6. 6.
    Cooper, P., et al.: Minimum continuous stable flow in centrifugal pumps. In: Proceedings of Symposium on Power Plant Pumps, New Orleans, 1987, EPRI CS-5857 (1988)Google Scholar
  7. 7.
    Dobat, A., Saathoff, H., Wulff, D.: Experimentelle Untersuchungen zur Entstehung von rotating stall in Axialventilatoren. VDI-Bericht. 1591, 345–360 (2001)Google Scholar
  8. 8.
    Dobener, E.: Über den Strömungswiderstand in einem rotierenden Kanal. Dissertation, TH Darmstadt (1959)Google Scholar
  9. 9.
    Eckardt, D.: Detailed flow investigations within a high-speed centrifugal compressor impeller. ASME J. Fluids. Eng. 98, 390–402 (1976)CrossRefGoogle Scholar
  10. 10.
    Eckardt, D.: Flow field analysis of radial and backswept centrifugal compressor impellers. In: 25th International Gas Turbine Conference on ASME, New Orleans, pp. 77–86 (1980)Google Scholar
  11. 11.
    Fraser, W.H.: Recirculation in centrifugal pumps. In: ASME Winter Annual Meeting, Washington DC, pp. 65–86 (1981)Google Scholar
  12. 12.
    Friedrichs, J., et al.: Effect of stator design on stator boundary layer flow in a highly loaded single-stage axial-flow low-speed compressor. ASME J. Turbomach. 123, 483–489 (2001)CrossRefGoogle Scholar
  13. 13.
    Friedrichs, J.: Auswirkungen instationärer Kavitationsformen auf Förderhöhenabfall und Kennlinieninstabilität von Kreiselpumpen. Diss TU Braunschweig, Mitt des Pfleiderer-Instituts für Strömungsmaschinen, Heft 9. Verlag Faragallah (2003)Google Scholar
  14. 14.
    Goltz, I., Kosyna, G., Stark, U., Saathoff, H., Bross, S.: Stall inception phenomena in a single-stage axial pump. In: 5th European Conference on Turbomachinery, Prague (2003)Google Scholar
  15. 15.
    Goltz, I.: Entstehung und Unterdrückung der Kennlinieninstabilität einer Axialpumpe. Diss TU Braunschweig, Mitt des Pfleiderer-Instituts für Strömungsmaschinen, Heft 10. Verlag Faragallah (2006)Google Scholar
  16. 16.
    Goto, A.: Study of internal flows in a mixed-flow pump impeller at various tip clearances using 3D viscous flow computations. ASME Paper 90-GT-36 (1990)Google Scholar
  17. 17.
    Goto, A.: The Effect of tip leakage flow on partload performance of a mixed-flow pump impeller. ASME Paper 91-GT-84 (1991)Google Scholar
  18. 18.
    Gülich, J.F., et al.: Influence of flow between impeller and casing on partload performance of centrifugal pumps. ASME FED. 81, 227–235 (1989)Google Scholar
  19. 19.
    Gülich, J.F., et al.: Rotor dynamic and thermal deformation tests of high-speed boiler feedpumps. EPRI Report GS-7405 (1991, July)Google Scholar
  20. 20.
    Gülich, J.F.: Bemerkungen zur Kennlinienstabilität von Kreiselpumpen. Pumpentagung Karlsruhe, B3 (1988)Google Scholar
  21. 21.
    Gülich, J.F.: Impact of 3D-Flow Phenomena on the Design of rotodynamic Pumps. IMechE. 213(C1), 59–70 (1999)Google Scholar
  22. 22.
    Gülich, J.F.: Influence of interaction of different components on hydraulic pump performance and cavitation. In: Proceedings of Symposium on Power Plant Pumps, New Orleans, 1987, EPRI CS-5857 2.75–2.96 (1988)Google Scholar
  23. 23.
    Gülich, J.F.: Untersuchungen zur sattelförmigen Kennlinien-Instabilität von Kreiselpumpen. Forsch. Ing. Wes. 61(4), 93–105 (1995)CrossRefGoogle Scholar
  24. 24.
    Hergt, P., et al.: Fluid dynamics of slurry pump impellers. In: 8th International Conference on Transport and Sedimentation of Solids, Prague, D2–1 (1995)Google Scholar
  25. 25.
    Hergt, P., Jaberg, H.: Die Abströmung von Radiallaufrädern bei Teillast und ihr Zusammenhang mit der Volllastinstabilität. KSB Techn. Ber. 26, 29–38 (1990)Google Scholar
  26. 26.
    Hergt, P., Prager, S.: Influence of different parameters on the disc friction losses of a centrifugal pump. In: Conference on Hydraulic Machinery, Budapest, pp. 172–179 (1991)Google Scholar
  27. 27.
    Hergt, P., Starke, J.: Flow patterns causing instabilities in the performance curves of centrifugal pumps with vaned diffusers. In: 2th International Pump Symposia, Houston, pp. 67–75 (1985)Google Scholar
  28. 28.
    Hergt, P.: Ergebnisse von experimentellen Untersuchungen des Förderverhaltens eines Inducers. Pumpentagung Karlsruhe, B 5–01 (1992)Google Scholar
  29. 29.
    Hunziker, E.: Einfluß der Diffusorgeometrie auf die Instabilitätsgrenze eines Radialverdichters. Dissertation, ETH Zürich (1993)Google Scholar
  30. 30.
    Inoue, M., Cumpsty, N.A.: Experimental study of centrifugal impeller discharge flow in vaneless and vaned diffusers. ASME J. Eng. Gas Turbines Power. 106, 455–467 (1984)CrossRefGoogle Scholar
  31. 31.
    Kaupert, K.A.: Unsteady flow fields in a high specific speed centrifugal impeller. Dissertation, ETH Zürich (1997)Google Scholar
  32. 32.
    Lakshminarayana, B.: Fluid dynamics of inducers—a review. ASME J. Fluids Eng. 104, 411–427 (1982)CrossRefGoogle Scholar
  33. 33.
    Martin, R., et al.: Partload operation of the boiler feedpumps for the new French PWR 1400 MW nuclear plants. ImechE Paper C344/88 (1988)Google Scholar
  34. 34.
    Meschkat, S.: Experimentelle Untersuchung der Auswirkung instationärer Rotor-Stator-Wechselwirkungen auf das Betriebsverhalten einer Spiralgehäusepumpe. Dissertation, TU Darmstadt (2004)Google Scholar
  35. 35.
    Moore, J.: A wake and an Eddy in a rotating radial flow passage. ASME J. Eng. Power 95, 205–219 (1973)CrossRefGoogle Scholar
  36. 36.
    Muggli, F., Holbein, P., Dupont, P.: CFD calculation of a mixed flow pump characteristic from shut-off to maximum flow: ASME FEDSM2001-18072 (2001)Google Scholar
  37. 37.
    Pfleiderer, C.: Vorausbestimmung der Kennlinien schnellläufiger Kreiselpumpen. VDI, Düsseldorf (1938)Google Scholar
  38. 38.
    Rohkamm, H., Wulff, D., Kosyna, G., Saathoff, H., Stark, U., Gümmer, V., Swoboda, M., Goller, M.: The impact of rotor tip sweep on the three-dimensional flow in a highly-loaded single-stage low-speed axial compressor: part II—test facility and experimental results. In: 5th European Conference on Turbomachinery—Fluid Dynamics and Thermodynamics, Prague, pp. 175–185 (2003)Google Scholar
  39. 39.
    Saathoff, H., Deppe, A., Stark, U., Rohdenburg, M., Rohkamm, H., Wulff, D., Kosyna, G.: Steady and unsteady casing wall flow phenomena in a single-stage compressor at partload conditions. Int. J. Rotating Mach. 9, 327–335 (2003)CrossRefGoogle Scholar
  40. 40.
    Saathoff, H., Stark, U.: Tip clearance flow in a low-speed compressor and cascade. In: 4th European Conference on turbomachinery, Florenz, pp. 81–91 (2001)Google Scholar
  41. 41.
    Saathoff, H.: Rotor-Spaltströmungen in Axialverdichtern. Dissertation, TU Branuschweig, ZLR-Forschungsbericht 2001–2005 (2001)Google Scholar
  42. 42.
    Sano, T., et al.: Alternate blade stall and rotating stall in a vaned diffuser. JSME Int. Ser. B 45(4), 810–819 (2002)CrossRefGoogle Scholar
  43. 43.
    Schiavello, B., Sen, M.: On the prediction of the reverse flow onset at the centrifugal pump inlet. In: ASME 22nd Annual Fluids Engineering Conf, New Orleans (1980, March), Performance Prediction of Centrifugal Pumps and CompressorsGoogle Scholar
  44. 44.
    Sen, M., Breugelmans, F.: Reverse flow, prerotation and unsteady flow in centrifugal pumps. In: NEL Fluid Mechanics Silver Jubilee Conference, Glasgow (1979, November)Google Scholar
  45. 45.
    Stachnik, P.: Experimentelle Untersuchungen zur Rezirkulation am Ein- und Austritt eines radialen Kreiselpumpenlaufrades im Teillastbetrieb. Dissertation, TH Darmstadt (1991)Google Scholar
  46. 46.
    Stepanik, H., Brekke, H.: Off-design behavior of two pump-turbine model impellers. In: 3rd International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, Honolulu, pp. 477–492 (1990)Google Scholar
  47. 47.
    Stoffel, B., Hergt, P.: Zur Problematik der spezifischen Saugzahl als Beurteilungsmaßstab für die Betriebssicherheit einer Kreiselpumpe. Pumpentagung Karlsruhe, B8 (1988)Google Scholar
  48. 48.
    Stoffel, B., Weiß, K.: Different types and locations of partload recirculations in centrifugal pumps found from LDV measurements. In: IAHR Symposium Valencia (1996)CrossRefGoogle Scholar
  49. 49.
    Stoffel, B., Weiß, K.: Experimental investigations on part load flow phenomena in centrifugal pumps. World Pumps 337, 46–50 (1994)Google Scholar
  50. 50.
    Stoffel, B.: Experimentelle Untersuchungen zur räumlichen und zeitlichen Struktur der Teillast-Rezirkulation bei Kreiselpumpen. Forsch. Ing. Wes. 55, 149–152 (1989)CrossRefGoogle Scholar
  51. 51.
    Tanaka, T.: An Experimental study of backflow phenomena in a high specific speed impeller pump. ASME Paper 80-FE–6Google Scholar
  52. 52.
    Toyokura, T.: Studies on the characteristics of axial-flow pumps. Bull. JSME. 4(14), 287–293 (1961)CrossRefGoogle Scholar
  53. 53.
    Ubaldi, M., Zunino, P.: Experimental investigation of the stalled flow in a centrifugal pump-turbine with vaned diffuser. ASME Paper 90-GT-216 (1990)Google Scholar
  54. 54.
    Weinerth, J.: Kennlinienverhalten und Rotorbelastung von axialen Kühlwasserpumpen unter Betriebsbedingungen. Dissertation, TU Kaiserslautern. SAM Forschungsbericht Bd 9 (2004)Google Scholar
  55. 55.
    Weiß, K.: Experimentelle Untersuchungen zur Teillastströmung bei Kreiselpumpen. Dissertation, TH Darmstadt (1995)Google Scholar
  56. 56.
    Wesche, W.: Experimentelle Untersuchungen am Leitrad einer radialen Kreiselpumpe. Dissertation, TU Braunschweig (1989)Google Scholar
  57. 57.
    Yoshinaga, Y., et al.: Study of performance improvement for high specific speed centrifugal compressors by using diffusers with half guide vanes. ASME J. Fluids Eng. 109, 259–367 (1987)Google Scholar
  58. 58.
    Van Esch, B., Cheng, L.: Unstable operation of a mixed-flow pump and the influence of tip clearance. ASME AJK2011-06016Google Scholar
  59. 59.
    Miyabe, M., et al.: Rotating stall behavior in a diffuser of a mixed-flow pump and its suppression. ASME FEDSM 2008-55132Google Scholar
  60. 60.
    Miyabe, M., et al.: On improvement of characteristic instability and internal flow in mixed-flow pumps. J. Fluid Sci. Technol. 3(6), 732–743 (2008)CrossRefGoogle Scholar
  61. 61.
    Saha, S., et al.: Suppression of performance curve instability of a mixed-flow pump by use of J-groove. ASME JFE 122, 592–597 (2000)Google Scholar
  62. 62.
    Choi, Y., et al.: Suppression of cavitation in inducers by J-grooves. ASME JFE 129, 15–22 (2007)Google Scholar
  63. 63.
    Cowan, D., Liebner, T., Bradshaw, S.: Influence of impeller suction specific speed on vibration performance. In: 29th International Pump Users Symposium, Houston, pp. 18–47 (2013)Google Scholar
  64. 64.
    Li, X., et al.: Experimental and numerical investigations of head-flow curve instability of a single-stage centrifugal pump with volute casing. Proc IMechE Part A J Power Energy (2016)Google Scholar

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© Springer Nature Switzerland AG 2020

Authors and Affiliations

  1. 1.VilleneuveSwitzerland

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