SIST EN 17038-2:2019
(Main)Pumps - Methods of qualification and verification of the Energy Efficiency Index for rotodynamic pumps units - Part 2: Testing and calculation of energy Efficiency Index (EEI) of single pump units
Pumps - Methods of qualification and verification of the Energy Efficiency Index for rotodynamic pumps units - Part 2: Testing and calculation of energy Efficiency Index (EEI) of single pump units
This document specifies methods and procedures for testing, calculating and determining the Energy Efficiency Index (EEI) of rotodynamic glanded single pump units for pumping clean water, including where integrated in other products.
The pump types and sizes covered by this document are described in the normative Annex A.
Pumpen - Methoden zur Qualifikation und Verifikation des Energieeffizienzindexes für Kreiselpumpen - Teil 2: Prüfung und Berechnung des Energieeffizienzindexes (EEI) einzelner Pumpenaggregate
Dieses Dokument legt Methoden und Verfahren für die Prüfung, Berechnung und Bestimmung des Energieeffizienzindex (EEI) von Trockenläufer-Kreiselpumpenaggregaten zum Pumpen von sauberem Wasser fest, auch wenn sie in andere Produkte integriert sind.
Die von diesem Dokument behandelten Pumpentypen und -größen werden im normativen Anhang A aufgeführt.
Pompes - Méthodes de qualification et de vérification de l'indice de rendement énergétique des groupes motopompes rotodynamiques - Partie 2 : Essais et calcul de l'indice de rendement énergétique (EEI) des groupes motopompes simples
Le présent document spécifie des méthodes et procédures d'essai, de calcul et de détermination de l'indice de rendement énergétique (EEI) des groupes motopompes à eau rotodynamiques dotés d'un dispositif d'étanchéité utilisés pour le pompage d'eau propre, y compris dans des versions intégrées à d'autres produits.
Les types et tailles de pompes couverts par le présent document sont décrits dans l'Annexe A normative.
Črpalke - Metode za kvalifikacijo in verifikacijo indeksa energijske učinkovitosti centrifugalnih črpalk - 2. del: Preskušanje in računanje indeksa energijske učinkovitosti (IEE) enodelnih črpalk
Ta evropski standard določa metode in postopke za preskušanje, računanje in določanje indeksa energijske učinkovitosti (EEI) centrifugalnih tesnilnih enodelnih črpalk za črpanje čiste vode, vključno z vgrajenimi črpalkami v ostalih proizvodih.
Vrste in velikosti črpalk, zajetih v tem standardu, so opisane v normativnem dodatku A.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2019
Črpalke - Metode za kvalifikacijo in verifikacijo indeksa energijske učinkovitosti
centrifugalnih črpalk - 2. del: Preskušanje in računanje indeksa energijske
učinkovitosti (IEE) enodelnih črpalk
Pumps - Methods of qualification and verification of the Energy Efficiency Index for
rotodynamic pumps units - Part 2: Testing and calculation of energy Efficiency Index
(EEI) of single pump units
Pumpen - Methoden zur Qualifikation und Verifikation des Energieeffizienzindexes für
Kreiselpumpen - Teil 2: Prüfung und Berechnung des Energieeffizienzindexes (EEI)
einzelner Pumpenaggregate
Pompes - Méthodes de qualification et de vérification de l'indice de rendement
énergétique des groupes motopompes rotodynamiques - Partie 2 : Essais et calcul de
l'indice de rendement énergétique (EEI) des groupes motopompes simples
Ta slovenski standard je istoveten z: EN 17038-2:2019
ICS:
23.080 Črpalke Pumps
27.015 Energijska učinkovitost. Energy efficiency. Energy
Ohranjanje energije na conservation in general
splošno
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 17038-2
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2019
EUROPÄISCHE NORM
ICS 23.080
English Version
Pumps - Methods of qualification and verification of the
Energy Efficiency Index for rotodynamic pump units - Part
2: Testing and calculation of Energy Efficiency Index (EEI)
of single pump units
Pompes - Méthodes de qualification et de vérification Pumpen - Methoden zur Qualifikation und Verifikation
de l'indice de rendement énergétique des groupes des Energieeffizienzindexes für Kreiselpumpen - Teil 2:
motopompes rotodynamiques - Partie 2 : Essais et Prüfung und Berechnung des Energieeffizienzindexes
calcul de l'indice de rendement énergétique (EEI) des (EEI) einzelner Pumpenaggregate
groupes motopompes simples
This European Standard was approved by CEN on 15 July 2018.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17038-2:2019 E
worldwide for CEN national Members.
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Reference flow-time profiles and reference pressure control curves . 8
4.1 General . 8
4.2 Reference flow-time profiles . 9
4.3 Reference pressure control curves . 10
5 Determination of average electric power input P by test . 10
1,avg
5.1 General . 10
5.1.1 Test requirements . 10
5.1.2 Test conditions . 10
5.1.3 Measuring instrumentation . 11
5.2 Calculation of load points . 12
5.2.1 General . 12
5.2.2 Determination of Q and H . 12
100 % 100 %
5.3 Calculation of P . 14
1,avg
5.3.1 General . 14
5.3.2 Pump units evaluated with the reference flow-time profile for constant flow
operation . 14
5.3.3 Pump units evaluated with the reference flow-time profile for variable flow
operation . 14
5.3.4 Procedures for testing and evaluation of pump units with special pump types . 15
6 Determination of the Energy Efficiency Index of pump units by the means of a semi-
analytical model . 16
6.1 General . 16
6.2 The semi analytical model of the pump . 17
6.3 Pump units in fixed speed operation . 19
6.3.1 General . 19
6.3.2 The model of the electric motor. 20
6.3.3 Interaction of pump and motor . 21
6.3.4 Determination of Q from Q . 22
100 % BEP
6.3.5 Determination of the P -value . 23
1,avg,c
6.4 Pump units with a Power Drive System (PDS). 24
6.4.1 General . 24
6.4.2 The model of the Power Drive System (PDS) . 26
6.4.3 Interaction between pump and PDS . 29
6.4.4 Determination of Q and H from Q and H . 30
100 % 100 % BEP BEP
6.4.5 Determination of P and P for pump units with PDS . 31
1,avg,v 1,avg,c
7 Determination of reference electric power input P . 32
1,ref
8 Calculation of Energy Efficiency index (EEI) . 35
Annex A (normative) Scope . 36
Annex B (informative) Determination of additional supporting points for semi-analytical
model based on empirical correlations . 39
B.1 General . 39
B.2 Additional supporting points for end-suction pumps (pump types ESOB, ESCC and
ESCCi) . 41
B.2.1 Additional supporting points at Q/Q = 0,25 . 41
BEP
B.2.2 Additional supporting points at Q/Q = 0,1. 41
BEP
B.3 Additional supporting points for vertical multistage pump (MS-V) . 42
B.3.1 Additional supporting points at Q/Q = 0,25 . 42
BEP
B.3.2 Additional supporting points at Q/Q = 0,1. 42
BEP
B.4 Maximum model uncertainties . 42
Annex C (normative) Synthesis of the PDS supporting points from separate data for motor
and CDM . 46
C.1 General . 46
C.2 Determination of the losses P at the 3-supporting points needed for the PDS
L,CDM
model . 49
C.3 Determination of the losses P at the 3 supporting points needed for the PDS
L,PDS
model . 50
Annex D (informative) Uncertainties and tolerances of EEI-values . 52
D.1 General remarks . 52
D.2 The measurement uncertainty of the EEI-value determined by test . 52
D.3 The uncertainty of the EEI-value determined by the application of models . 55
D.3.1 General . 55
D.3.2 Operation mode: Fixed speed . 55
D.3.3 Operation mode: Variable speed . 56
D.4 The total tolerance of the mean EEI-value . 58
D.4.1 Determination of the mean EEI-value by testing only one pump unit . 58
D.4.2 Determination of the mean EEI-value by testing a sample of M pump units of the
same type series . 60
D.4.3 Determination of the mean EEI-value by application of the semi-analytical model . 60
Annex E (informative) Mathematical solution of polynomial formulae of 3rd degree . 63
Annex F (normative) CDM model fall back values for Semi Analytical Model . 65
Bibliography . 66
European foreword
This document (EN 17038-2:2019) has been prepared by Technical Committee CEN/TC 197 “Pumps”,
the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by November 2019, and conflicting national standards
shall be withdrawn at the latest by November 2019.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Introduction
This part of the European Standard is the second part of a series of standards describing a methodology
to evaluate energy efficiency performance of single pump units, comprising the pump, the motor with
or without frequency converter, based on a non-dimensional numerical value called Energy Efficiency
Index (EEI). An EEI allows the comparison of different pump sizes and types with one common
indicator. Physical influences such as pump size, specific speed, pump unit part-load operation, motor-
efficiency characteristic and frequency converter influence are implemented into this metric.
Specific requirements for testing and a calculation method for an EEI, the so called semi-analytical
model of a complete single pump unit, specific flow-time profiles and reference control curves are given
in this part of the standard.
EEI is an index to rate pump units according to their energy efficiency but does not replace the need to
do a life-time cost analysis regarding energy consumption over the life time of the pump unit.
1 Scope
This document specifies methods and procedures for testing, calculating and determining the Energy
Efficiency Index (EEI) of rotodynamic glanded single pump units for pumping clean water, including
where integrated in other products.
The pump types and sizes covered by this document are described in the normative Annex A.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 16480, Pumps — Minimum required efficiency of rotodynamic water pumps
EN 17038-1:2019, Pumps — Methods of qualification and verification of the Energy Efficiency Index for
Rotodynamic pumps units — Part 1: General requirements and procedures for testing and calculation of
energy efficiency index (EEI)
EN 60034-1, Rotating electrical machines — Part 1: Rating and performance (IEC 60034-1)
EN 60034-2-1, Rotating electrical machines — Part 2-1: Standard methods for determining losses and
efficiency from tests (excluding machines for traction vehicles) (IEC 60034-2-1)
EN 60034-2-2, Rotating electrical machines — Part 2-2: Specific methods for determining separate losses
of large machines from tests — Supplement to IEC 60034-2-1 (IEC 60034-2-2)
EN 60034-30-1, Rotating electrical machines — Part 30-1: Efficiency classes of line operated AC motors
(IE code) (IEC 60034-30-1)
EN 60038, CENELEC standard voltages (IEC 60038)
EN 61800-9-2, Adjustable speed electrical power drive systems — Part 9-2: Ecodesign for power drive
systems, motor starters, power electronics & their driven applications — Energy efficiency indicators for
power drive systems and motor starters (IEC 61800-9-2)
EN ISO 9906:2012, Rotodynamic pumps — Hydraulic performance acceptance tests — Grades 1, 2 and 3
(ISO 9906:2012)
EN ISO 17769-1, Liquid pumps and installation — General terms, definitions, quantities, letter symbols
and units — Part 1: Liquid pumps (ISO 17769-1)
IEC/TS 60034-2-3, Rotating electrical machines — Part 2-3: Specific test methods for determining losses
and efficiency of converter-fed AC induction motors
3 Terms and definitions
For the purpose of this document, the terms and definitions given in EN ISO 17769-1 and the terms,
definitions, symbols and subscripts given in EN 17038-1, together with the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
unit efficiency
hydraulic power output divided by electric power input also called “wire to water efficiency”
P
hyd
η =
unit
P
3.2
constant flow operation
slight variations of the flow rate around the nominal value
Note 1 to entry: Caused by secondary influences from the process as, for example, due to the (moderately)
varying level of liquid in reservoirs, etc. The variation of flow rate occurs typically within the range which is
covered by the definition and determination of the Minimum Efficiency Index (MEI) of the pump, see EN 16480,
and which is from 0,75 · Q to 1,1 · Q .
100 % 100 %
3.3
variable flow
widely varying flow rate
Note 1 to entry: Typically, at considerable fractions of the total operating time, the actual demand for pump flow
rate Q and pump head H is much lower than the values at the operating point of maximum flow rate which is
demanded by the application.
3.4
hydraulic power
conventional expression of the arithmetic product of the flow Q and the head H and a constant (g is the
gravitational constant of 9,81 m/s )
3.5
maximum hydraulic power
absolute maximum P of hydraulic power of a pump unit set of parameters which cause the pump
hyd,max
unit to generate the curve of maximum hydraulic power
Note 1 to entry: The pump unit needs to be capable and designed to run in maximum operation continuously.
3.6
pump unit best efficiency point, (Q / H )
BEP,unit BEP,unit
Flow-Head-Point where the pump unit runs at its best unit efficiency point and at maximum operation
3.7
reference flow rate, Q
100%
flow per time unit [m /h] at the Best Efficiency Point (BEP) of the unit
3.8
reference head, H
100%
total differential head [m] at the Best Efficiency Point (BEP) of the unit
3.9
flow-time profile
pattern of percentiles of time where the pump unit runs at a given flow rate
3.10
Complete Drive Module
CDM
electronic power converter connected between the electric supply and a motor as well as extensions
such as protection devices, transformers and auxiliaries (according to EN 61800-2)
3.11
Power Drive System
PDS
combination of CDM and motor
3.12
trimmed impeller
impeller of a pump where the initial full diameter D reduced to a new diameter D
full trim
3.13
average impeller diameter
mathematical average of varying outer vane diameter for a single stage pump
3.14
average multistage impeller diameter
mathematical average of all (averaged) impeller diameters of all stages
4 Reference flow-time profiles and reference pressure control curves
4.1 General
When putting single pump units into service an appropriate EEI value shall be made available. The EEI
shall be for variable flow (EEI ) and/or constant flow (EEI ) according to the demand of the application
V C
in which the pump unit is put into service or for which the pump unit is specified when placed on the
market. For the determination of the EEI or EEI the respective reference flow-time profiles and the
V C
reference pressure control curves given in Table 1 have to be applied.
Table 1 — Reference flow-time profiles and reference pressure control curves for single pump
units
Mode
Reference
Reference
pressure Applicable Q/H test EEI
flow-time
# Demand of Type of
control points applicable
profile
application Pump
curve
Unit
M1 constant fixed speed constant flow Q/H curve of On Q/H curve of the EEI
C
flow (Table 2) the pump unit pump unit
EEI
M2 variable fixed speed variable flow Formula (1) On Q/H curve of the
V
flow (Table 3) pump unit
M3 constant variable constant flow Q/H curve of On Q/H curve of the EEI
C
flow speed (Table 2) the pump unit pump unit (measured
at fixed speed)
M4 variable variable variable flow Formula (1) Q/H points on curve EEI
V
flow speed (Table 3) defined by
Formula (1)
M5 constant variable variable flow Formula (1) Q/H points on curve EEI
V
flow, speed (Table 3) defined by
varying Formula (1)
head
In case of a bare shaft pump alone to be placed on the market the EEI shall be determined with a
reference motor (refer to Class “IE3” in EN 60034-30-1) in mode M1 depending on the nominal speed of
-1
the bare shaft pump (either 2-pole type for the pump nominal speed n = 2 900 min or is of the 4-
N,PU
-1
pole type for the pump nominal speed n = 1 450 min ). The reference motor shall have a nominal
N,PU
power output which exactly equals the shaft power of the pump at its nominal operating conditions.
4.2 Reference flow-time profiles
The reference flow time profile for constant flow operation is shown in Table 2.
Table 2 — Reference flow-time profile for constant flow operation
Flow Q in % of Q 75 100 110
100 %
Time Δt in % of total 25 50 25
operating time
The reference flow time profile for variable flow operation is shown in Table 3.
Table 3 — Reference flow-time profile for variable flow operation
25 50 75 100
Flow Q in % of Q
100 %
44 35 15 6
Time Δt in % of total
operating time
4.3 Reference pressure control curves
In the case of the variable flow demand, the reference control curve is defined by Formula (1):
H Q
ii
0,,5+ 0 5⋅ (1)
HQ
100%%100
The values H /H at the corresponding values of Q /Q of the reference flow-time profile are
i 100 % i 100 %
given according to Formula (1).
The reference pressure control curve defined by Formula (1) with the corresponding hydraulic load
points given in Table 2 and 3 in numerical form additionally are plotted graphically in Clause 5,
Figure 2.
In the case of the constant flow mode, the reference control curve is the Q/H curve of the actual pump
unit applied to define Q , H (see also Clause 5, Figure 1).
100 % 100 %
In the case of the constant flow and varying head demand (mode M5), the reference control curve is
defined by Formula (1).
5 Determination of average electric power input P by test
1,avg
5.1 General
5.1.1 Test requirements
This clause specifies performance tests and evaluations for pump units which are carried out
— either by a company which places the pump units on the market and/or puts them into service,
— or by an independent institution in the frame of the verification procedure described in
EN 17038-1:2019, Clause 6.
Such tests shall provide the necessary information on the actual performance values of test pump units
needed for the calculation of the EEI-value according to its definition given in EN 17038-1:2019,
Clause 4.
All provisions for the test concerning the pump shall be in accordance with EN ISO 9906, class 2. The
exception for input power of 10 kW and below (as allowed for the application of EN ISO 9906 on
acceptance tests) shall not be valid.
All provisions for the test concerning an electric motor if it is part of the pump unit and is fed directly
from an electric grid shall be in accordance with EN 60034-2-1.
All provisions for the test concerning a Power Drive System (PDS) if part of the pump unit shall be in
accordance with EN 61800-9-2.
5.1.2 Test conditions
Tests shall be carried out with clean cold water. The performance of a pump varies substantially with
the nature of the liquid being pumped. It is not possible to give general rules whereby performance
results measured with clean cold water can be converted to predict performance with water having
other properties (temperature, content of solids or gas) or other liquids.
The duration of the test shall be sufficient to obtain repeatable results; especially run-in and warming-
up effects of the electric and electronic components of the unit shall be considered.
NOTE 1 Run-in effects may take up to one day operating time.
=
All measurements shall be made under steady-state conditions (see EN ISO 9906, EN 60034-2-1,
EN 60034-2-2 and IEC TS 60034-2-3 and EN 61800-9-2).
NOTE 2 EN 61800-9-2 allows warming up the PDS for measuring the nominal point. All other points can be
measured quickly after measuring maximum load without waiting for the steady-state.
The tests should be conducted under conditions where cavitation does not affect the performance of the
pump.
NOTE 3 If cavitation exists to a remarkable extent in the test pump during the test, not only the pump head but
also the pump efficiency and the power input can deteriorate which leads to an underestimation of the energy
efficiency of the pump unit.
For Case 1 in 5.2.1 (motor fed by an electric supply with constant frequency) the electric power supply
of the test installation shall fulfil the requirements as specified in EN 60034-1. This requires that
— the voltage shall be in accordance with 7.2 of EN 60038 and EN 60034-1,
— the frequency shall be within ± 0,3 % of the rated frequency during measurements.
For Case 2 in 5.2.1 (PDS, i.e. motor combined with and fed by a CDM) the following requirements shall
be fulfilled in accordance with EN 61800-9-2:
— When testing a PDS under the load of the pump, slow fluctuations in the measured quantities may
be unavoidable. Therefore, for each load point several measurements over a period of time (at least
several slip cycles, typically 1 min to 3 min) shall be sampled and the average of these values shall
be used for the evaluation.
— Pump units equipped with a PDS shall be measured with a screened cable between CDM and motor
of a maximum length of 10 m.
— The measurements shall be done when the PDS is thermally stable (the temperature gradient shall
be maximal 2 K per hour).
5.1.3 Measuring instrumentation
For the test procedures described in 5.1.1 measuring instrumentation is needed for the determination
of:
— the flow rate Q;
— the pump head H;
— the electric power input P .
Since instrument accuracy is generally expressed as a percentage of full scale, the range of the
instruments chosen shall be as small as practical.
For analogue instruments the observed values should be in the upper third of the instrument range.
The measuring equipment needed to determine the flow rate Q and the pump head H shall be selected
in accordance with EN ISO 9906. Detailed information is given in EN ISO 9906:2012, A.1.
For the determination of the electric power input P in case 1 in 5.2.1 (motor directly fed by the electric
grid) the electric input power P is determined based on input voltages U and input currents. All
requirements concerning the instrumentation for the measurements of P shall be fulfilled according to
EN 60034-2-1.
For the determination of the electric power input P in case 2 in 5.2.1 (motor combined with and fed by
a CDM), the electric input power P shall be measured according to “input-output measurement
method” in EN 61800-9-2. All requirements concerning the instrumentation for the measurement of P
shall be fulfilled according to EN 61800-9-2.
5.2 Calculation of load points
5.2.1 General
As explained in EN 17038-1:2019, Clause 4, the value of the Energy Efficiency Index (EEI-value) is based
on the electric power input P of the pump unit when the pump is operated at the hydraulic load points
specified in EN 17038-1:2019, 4.2. The test aims at determining the electric power input P of the pump
unit at the N values of pump flow rate Q defined by the reference flow-time profile.
For the test procedure, different cases shall be distinguished:
1) Case 1 Fixed speed operation: the electric motor of the pump unit is fed by a constant stator
frequency, either grid frequency or a different frequency fed from a CDM and therefore, can only be
operated at (nearly) constant rotational speed n. In this case, only the pump flow rate Q can be
controlled during the test. The flow rate Q shall be adjusted to the various values of the reference
flow-time profile while the head H generated by the pump is given by the Q-H-curve of the pump at
constant motor stator frequency. Besides the electric power input P , the actual values of the pump
flow rate Q and head H shall be measured and documented.
2) Case 2 Variable speed operation: the pump unit shall be operated at variable rotational speed
along a pressure control curve. In the test, the flow rate Q shall be adjusted to the various values of
the reference flow-time profile. The pump head H shall be adjusted to the values according to the
reference pressure control curve.
For each load point, the flow rate Q which is adjusted and measured shall not deviate from the values
according to the reference flow-time profile by more than ± 3 % (or ± 0,1 m /h, whichever is the largest
absolute value).
The measured value H shall not deviate more than ± 5 % (or ± 0,2 m Head, whichever is the largest
meas
absolute value) from the values H according to the reference pressure control curve.
i
For pump units where the pump is of the multistage type and which are offered and sold with different
numbers of stages, the tests on test pump units which should be representative (in respect to the
Energy Efficiency Index) for the type series shall be carried out on pump versions with the actual
number of stages for vertical and horizontal multistage pumps.
Measurement shall be done on actual pump impeller diameter.
5.2.2 Determination of Q and H
100 % 100 %
As a first step of the test procedure Q shall be determined. For this purpose, the pump unit shall be
100 %
set to maximum operation.
Maximum operation for a pump unit running at fixed speed is achieved by feeding the motor with a
constant stator frequency, this may be the grid frequency or a different frequency fed from a CDM to
run the pump unit at maximum hydraulic power.
Maximum operation for a pump unit running with variable speed is achieved by allowing the controller
to adjust the speed of the actual pump unit to values, which derive a curve with maximum hydraulic
power.
NOTE In case where the H-Q-curve of the pump is cut off to avoid overload of the motor the Q point
100 %
could be located at the maximum flow (Q ) of the pump unit (right end of curve) then Q = Q .
max 100 % max
The best efficiency point (Q /H ) is then located on this pump unit curve.
100 % 100 %
/H ) defines the flow rate corresponding to the reference flow time profiles and
The point (Q
100 % 100 %
the reference pressure control curve.
Target values of the flow rate Q shall be determined. In the case of variable flow, H is also required
100 %
so that the head points along the reference pressure control curve can be found. In case of fixed flow,
the head values are determined by the pump unit head-flow-curve.
For the purpose of determining the needed H-Q-points of the reference flow time profile and the
reference pressure control curve, values of flow rate Q, pump head H and electric power input P shall
be measured at maximum operation for a sufficient number of operating points around the expected
value of Q .
BEP,unit
For the choice of these operating points, the value of Q at n = n given in the documentation of
BEP,PU N,PU
the pump manufacturer can be taken as a preliminary estimation for the expected value of Q It is
100 %.
important to take measurement data in a sufficiently large range of Q below and above the expected
value of Q (Recommended 0,7 · Q < Q = 1,3 · Q
100 % 100 % 100 %).
If the value of Q calculated based on the test points shows that less than 3 of the test points were at
100 %
values of Q greater than this calculated value, additional test points shall be added to generate at least 3
test points at values of Q greater than Q
100 %.
The value of H can be calculated by inserting Q = Q into Formula (7).
100 % 100 %
Determination of part load and over load points and reference control curve
The reference flow points of the flow rate Q shall be calculated by the following Formula (2):
i
Q
QQ⋅ (2)
i 100%
i
Where the values Q corresponding to the N load points of the reference load flow profile are taken from
Table 2 or Table 3.
To determine the Q point for the case where the H-Q-curve of the pump is cut off to avoid overload
110 %-
of the motor and the Q point could be located at the maximum flow (Q ) of the pump unit (right
100 % max
end of curve) the motor may be overloaded for a short time in the test and the (Q , H ) may be
110 % 110 %
measured or the Formulae (7) and (8) may be used.
In the case of variable flow operation, the reference head points H shall be calculated by the following
i
Formula (3):
H
HQ⋅ (3)
i 100%
i
Where the values H corresponding to the N load points on the reference pressure control curve taken
from Formula (1).
In the case of constant flow operation, the head points H are defined by the pump curve applied when
defining Q , H .
100 % 100 %
=
=
For variable speed pump units on fixed flow, the test is at fixed speed with head points along the fixed
nominal speed Q-H-curve. For fixed speed on variable flow the head cannot be adjusted to the reference
pressure control curve and follows the pump unit Q-H-curve.
5.3 Calculation of P
1,avg
5.3.1 General
Measure the values Q , H and P at each reference part load/over load point.
i i 1,i
5.3.2 Pump units evaluated with the reference flow-time profile for constant flow operation
Based on the measured values of electric power input P in the three load points (see Figure 1),
Figure 1 — Load points for constant flow systems – M1 and M3 (all pump units)
the weighted average of the electric power input P is calculated by Formula (4):
1,avg,c
∆t
(4)
PP ⋅
1,,avg c 1,i
∑
i
i=1
5.3.3 Pump units evaluated with the reference flow-time profile for variable flow operation
Figure 2 shows the measured values of electric power input P in the four load points (see Figure 2) for
variable flow operation:
=
Figure 2 — Load points for variable flow operation – M2, M4 and M5
(fixed speed and variable speed pump units)
The steps to calculate P for variable speed pump units are as follows:
1,avg,v
1) At each value of the adjusted and measured flow rate Q the measured pump head H is
meas
compared to the target value H at the corresponding load point of the reference pressure control
i
curve from Formula (3).
2) The measured electric power P at the flow rate Q at the given head of H shall be corrected
1,meas i i
(except for mode of operation M2) by Formula (5):
H
i
PP⋅ (5)
1,,corr 1 meas
H
meas
For fixed speed pump units in variable flow demand (mode of operation M2) P is equal to P
1,corr 1,meas
and no correction is applied.
Then, the corrected electric power P at this flow rate Q is taken for the calculation of the weighted
1,corr
average of the electric power P .
1,avg
3) The weighted average of the electric power P is calculated by Formula (6):
1,avg,v
i=4
∆t
PP⋅ (6)
1,,avg v ∑ 1,corr,i
i
i=1
5.3.4 Procedures for testing and evaluation of pump units with special pump types
5.3.4.1 General
For special pump types covered by the scope of this document, testing and evaluation according to
5.3.4.2 up to 5.3.4.3 shall be applied, respectively.
=
=
5.3.4.2 Pump units with twin head pumps (ESCCi with two impellers)
Pump units with twin head pumps shall be evaluated by incorporating one of the driver/impeller sets
into an adequate single head pump casing of ESOB, ESCC or ESCCi type.
For calculating of the reference pump efficiency η the C-value from Table 4 shall be taken for the
ref,PU
corresponding pump type and rotational speed.
5.3.4.3 Pump units with pumps according to more than one type definition
For pump units with pump types where more than one type definition is applicable the type of the
pump casing shall determine which C value from Table 4 has to be taken.
6 Determination of the Energy Efficiency Index of pump units by the means of a
semi-analytical model
6.1 General
Instead of determining the Energy Efficiency Index (EEI or EEI , later called EEI-value) by performing
V C
tests on complete pump units, their EEI-value can be determined by mathematical calculations based on
a so-called semi-analytical model of the pump unit.
The mathematical model of the complete unit is composed of part models of the pump and of the
electric components. The complete model considers the physical interactions of the components. For
the calculation of EEI-values these models may partly or completely be used. Alternatively,
mathematical models delivering at least the same accuracy of EEI values are permitted.
NOTE For example alternative mathematical models are permitted where the technology of components is
not covered in this document or other mathematical (part-)models are available.
A model is called semi-analytical in this document if the mathematical correlations (= formulae)
describe the performance in a principal form which reflects the underlying physical processes and
influences, but needs a limited number of data (at so-called supporting points) which result from tests
on the separate components. These data serve to “calibrate” the principal equations. In this sense, the
model used for the pump is a semi-analytical one. On the other hand, the model describing the losses of
a PDS (or the electric motor and the CDM it is composed of) are pure mathematical equations which
serve to inter-/extrapolate losses in a certain range of load points on the basis of known values of these
losses at a limited number of supporting load points (specified by standard(s)).
The models describe the relation between physical input and output quantities (= performance
variables) of the components as well as of the complete unit by mathematical equations. These are for
example the dependence of the pump head H on pump flow rate Q and rotational speed n or the
dependence of the power losses P of a Power Drive System (PDS) on shaft torque T and rotational
V,PDS
speed n.
While the result of tests to determine the EEI-value of an individual test pump unit shows generally a
(total) measurement uncertainty, the accuracy of any value (for example the EEI-value) determined
mathematically by the means of models is dependent on the magnitude of the model uncertainties.
Model uncertainties are the maximum possible deviations (with a probability of typically 95 %) from
the calculated values of the model's output variables from the correct values of the real component
output variables for the same values of the input variables. Their magnitude depends on the
assumptions, approximations and simplifications which determine the quality and correctness of the
models.
The magnitude of uncertainties of the models which can serve to determine the EEI-value of an
individual pump unit or of the mean EEI-value of a type size of pump units and which are described in
this document are given in Annex D.
The method described in this clause is applicable to pump units:
— consisting of components (pump and motor system) of which the particular performance
characteristics are known within the relevant range of load points – at least at a limited number of
operating points (see also Annex B) - including possible effects of interaction between components (for
example additional losses of electric motors fed by a CDM),
— enabling to set the operating point of maximum unit efficiency η and the corresponding values
unit
of Q and H (according to their definition in Clause 4) at constant stator frequency.
100 % 100 %
6.2 The semi analytical model of the pump
The semi-analytical model which is needed to describe the pump performance consists of the 3
mathematical functions H/H = f(Q/Q ), T/T = f(Q/Q )
BEP,N BEP,N, n/nN,Pu BEP,N BEP,N, n/nN,Pu
and P/P = f(Q/Q ), see Formulae (10) and (11)).
BEP,N BEP,N, n/nN,Pu
Q , H , T and P are the flow rate, the pump head, the shaft torque and the shaft power,
BEP,N BEP,N BEP,N BEP,N
respectively, at the best efficiency point (BEP) of the pump at its nominal rotational speed n .
N,PU
rd
In
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