Energy saving rates for a multistage centrifugal pump with variable speed drive

Md Rakibuzzaman, Kyungwuk Kim, Hyoung-Ho Kim, Sang-Ho Suh

Abstract


Multistage centrifugal pumps with variable speed drives are currently widely used in a variety of industrial and commercial
applications. However, there are limitations to defining the efficiency of variable speed drive pumps. As an alternative method,
energy saving rates can be evaluated with flow patterns and mean duty cycles. Computational fluid dynamics (CFD) is being
used as a good tool to understand this and is less time consuming in terms of analyzing performances the experimental
method. Research attention was focused on the energy saving rates of a multistage centrifugal pump for variable flow with
variable speed drive through numerical and experiment methods. For this investigation Reynolds-averaged Navier-Stokes
(RANS) equations were discretized by the finite volume method and a two equations SST model was used to account for
three dimensional steady state flows. In the experimental system, an experimental set-up of a variable flow system was made
to obtain energy saving rates and computational results were validated. The energy saving rates of the pumps depend on the
flow patterns and specific mean duty cycles on which the machine or system operates. Mean duty cycles were divided into
different flow operating conditions and a weighting for the mean value was given for each segment according to interval time.
The pump system was operated at 5070% of maximum flow rates. The energy saving rates were obtained from input power
through CFD simulation and experimentally, and the mean duty cycle was obtained from flow patterns in the field of the pump.
Energy saving rates were evaluated as a function of mean duty cycle and input power of the system operation. The total energy
consumed for the constant speed drive was 25,922 kWh and for the variable speed drive pump was 17,687 kWh through CFD.
The total annual energy saving rates were annually 33.81% through computational and 31.77% through experimental method
with the variable speed drive system when compared to the constant speed drive system.

Keywords


Centrifugal pumps, Variable speed drive, Energy saving rates, Mean duty cycle, CFD simulation

Full Text:

PDF

References


W. W. Peng, Fundamentals of turbomachinery, John Wiley & Sons,

D. Kaya, E. A. Yagmur, K. S. Yigit, F. C. Kilic, A. S. Eren, C. Celik, Energy

efficiency in pumps, Energy Conversion and Management 49 (6)

(2008) 1662–1673.

J.-H. Park, C.-G. Kim, Y.-H. Lee, A study on the efficient energy storage

method by multistage pump using CFD, in: Proceedings of the KFMA

Annual Meeting, Wiley Online Library, 2014, pp. 101–102.

M. Šavar, H. Kozmar, I. Sutlovi´c, Improving centrifugal pump efficiency

by impeller trimming, Desalination 249 (2) (2009) 654–659.

S. Kim, Y.-S. Choi, J.-Y. Yoon, D.-S. Kim, Design optimization of centrifugal

pump impeller using DOE, Journal of Fluid machinery 11 (3)

(2008) 36–42.

J. L. Parrondo-Gayo, J. Gonzalez-Perez, J. Fernandez-Francos, The

effect of the operating point on the pressure fluctuations at the blade

passage frequency in the volute of a centrifugal pump, Journal of Fluids

Engineering 124 (3) (2002) 784–790.

J. Lee, N. Hur, I. Yoon, Numerical study of a centrifugal pump performance

with various volute shape, Journal of computational fluids

engineering 20 (3) (2015) 35–40.

B. Jafarzadeh, A. Hajari, M. Alishahi, M. Akbari, The flow simulation of

a low-specific-speed high-speed centrifugal pump, Applied Mathematical

Modelling 35 (1) (2011) 242–249.

M.-H. Lim, B.-W. Ahn, B.-G. Kim, Put investigation on the energy

saving method using inverter driving for cooling pump at mmu training

ship, Journal of the Korean Society of Marine Engineering 33 (6)

(2009) 880–885.

S.-H. Kim, J.-H. Kim, C.-Y. Jang, K.-d. Song, The analysis of life cycle

cost and cooling water circulating pump energy saving according to

variable speed pressure differential setpoint control strategy, KIEAE

Journal 15 (4) (2015) 37–43.

S.-H. Suh, H.-H. Kim, R. Rakibuzzaman, K.-W. Kim, I.-S. Yoon, A

study on the performance evaluation of variable-speed drive pump,

The KSFM Journal of Fluid Machinery 17 (5) (2014) 83–88.

N. Sakthivel, V. Sugumaran, B. B. Nair, Comparison of decision treefuzzy

and rough set-fuzzy methods for fault categorization of monoblock

centrifugal pump, Mechanical systems and signal processing

(6) (2010) 1887–1906.

S.-H. Suh, K.-W. Kim, H.-H. Kim, I. S. Yoon, M.-T. Cho, et al., A study

on energy saving rate for variable speed condition of multistage centrifugal

pump, Journal of Thermal Science 24 (6) (2015) 566–573.

J. Tolvanen, Saving energy with variable speed drives, World pumps

(501) (2008) 32–33.

A. T. de Almeida, F. J. Ferreira, D. Both, Technical and economical

considerations in the application of variable-speed drives with electric

motor systems, IEEE Transactions on Industry Applications 41 (1)

(2005) 188–199.

S. Wang, J. Burnett, Online adaptive control for optimizing variablespeed

pumps of indirect water-cooled chilling systems, Applied Thermal

Engineering 21 (11) (2001) 1083–1103.

D. Croba, J. Kueny, Numerical calculation of 2d, unsteady flow in centrifugal

pumps: impeller and volute interaction, International Journal

for Numerical Methods in Fluids 22 (6) (1996) 467–481.

J. K. Armintor, D. P. Connors, Pumping applications in the petroleum

and chemical industries, IEEE transactions on industry applications

IA-23 (1) (1987) 37–48.


Refbacks

  • There are currently no refbacks.