ISO 21441:2019

Road vehicles — Engine EGR cooler — Heat dissipation test methods

This document defines the methodology for the measurement of heat dissipation and pressure loss of liquid cooled engine EGR coolers in internal combustion engines for road vehicles. The principles of this document are valid for clean and fouled EGR coolers.

Véhicules routiers — Refroidisseur de la vanne EGR — Méthodes d'essais de dissipation de chaleur

General Information

• Status: Published
• Publication Date: 09-Oct-2019
• ICS: 43.060.30 - Cooling systems. Lubricating systems
• Technical Committee: ISO/TC 22/SC 34 - Propulsion, powertrain and powertrain fluids
• Drafting Committee: ISO/TC 22/SC 34 - Propulsion, powertrain and powertrain fluids
• Current Stage: 6060 - International Standard published
• Start Date: 10-Oct-2019
• Due Date: 06-May-2019
• Completion Date: 10-Oct-2019

Relations

• Consolidated By: ISO 15841:2014/Amd 1:2020 - Dentistry — Wires for use in orthodontics — Amendment 1
• Effective Date: 06-Jun-2022

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 21441
First edition
2019-10
Road vehicles — Engine EGR cooler —
Heat dissipation test methods
Véhicules routiers — Refroidisseur de la vanne EGR — Méthodes
d'essais de dissipation de chaleur
Reference number
ISO 21441:2019(E)
©
ISO 2019

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ISO 21441:2019(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
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Website: www.iso.org
Published in Switzerland
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ISO 21441:2019(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test items . 2
5 Test setup . 3
5.1 Test conditions . 3
5.2 Test equipment . 4
5.2.1 General test equipment . 4
5.2.2 Test gas circuit equipment . 6
5.2.3 Cooling liquid circuit equipment . 6
5.3 Measuring instruments . 7
6 Test and measurement methods . 7
6.1 Test methods . 7
6.1.1 Test with heat dissipation . 7
6.1.2 Test without heat dissipation . 8
6.2 Measurement method . 8
6.2.1 Flow rate measurement . 9
6.2.2 Temperature measurement . 9
6.2.3 Pressure measurement . 9
7 Calculation method .10
7.1 Items to be calculated .10
7.1.1 EGR cooler heat dissipation amount .10
7.1.2 EGR gas temperature effectiveness.10
7.2 Calculation formula .11
7.2.1 Mass flow rate .11
7.2.2 EGR gas and EGR cooler heat dissipation amounts .11
7.2.3 EGR gas temperature effectiveness.13
7.2.4 EGR gas pressure loss .13
7.2.5 Cooling liquid pressure loss .14
8 Test report preparation .16
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ISO 21441:2019(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso
.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 34,
Propulsion, powertrain and powertrain fluids.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
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ISO 21441:2019(E)

Introduction
Internal combustion engines used in regulated environments are fitted with cooled exhaust gas
recirculation (EGR) to reduce NOx and improve fuel consumption. The EGR cooler receives gas from
the exhaust system and gas is cooled by cooling liquid. This document provides manufacturers with a
standardized method of measuring heat dissipation performance of the EGR cooler.
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INTERNATIONAL STANDARD ISO 21441:2019(E)
Road vehicles — Engine EGR cooler — Heat dissipation
test methods
1 Scope
This document defines the methodology for the measurement of heat dissipation and pressure loss of
liquid cooled engine EGR coolers in internal combustion engines for road vehicles. The principles of this
document are valid for clean and fouled EGR coolers.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
EGR
technology that recirculates a portion of an engine's exhaust gas back into the intake to control the
concentration of oxygen taken into the engine
3.2
EGR gas
gas that has been extracted from the exhaust gas and is passed through the EGR cooler (3.5) core (3.14)
3.3
test gas
pressurized air or exhaust gas made by burners used in place of real EGR gas (3.2) during the heat
dissipation performance test and when measuring EGR gas pressure loss (3.10)
3.4
cooling liquid
water or coolant mixture during the heat dissipation performance test and when measuring cooling
liquid pressure loss (3.11)
3.5
EGR cooler
liquid cooled heat exchanger for cooling the EGR gas (3.2)
3.6
EGR gas heat dissipation amount
amount of heat lost by the test gas (3.3) during the heat dissipation performance test
Note 1 to entry: The EGR gas heat dissipation amount is expressed in kilowatts (kW).
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ISO 21441:2019(E)

3.7
EGR cooler heat dissipation amount
amount of heat lost after the EGR gas heat dissipation amount (3.6) is corrected for the inlet temperature
difference between both fluids (3.8) as defined upon the agreement by the parties concerned
Note 1 to entry: The EGR cooler heat dissipation amount is expressed in kilowatts (kW).
3.8
inlet temperature difference between both fluids
difference between the inlet temperature of the test gas (3.3) and the cooling liquid (3.4) that pass
through the EGR cooler (3.5) core (3.14)
Note 1 to entry: The inlet temperature difference between both fluids is expressed in Kelvin (K).
3.9
EGR gas temperature effectiveness
ratio of the temperature difference of the test gas (3.3) between the EGR cooler (3.5) outlet and inlet
with respect to the difference of the inlet temperature between both fluids
Note 1 to entry: The EGR gas temperature effectiveness is expressed as a percentage (%).
3.10
EGR gas pressure loss
static pressure difference of the test gas (3.3) between the EGR cooler (3.5) outlet and inlet during heat
dissipation or no heat dissipation
Note 1 to entry: The EGR gas pressure loss is expressed in kilopascals (kPa).
Note 2 to entry: Total pressure difference can be used behalf of static pressure difference in case of measurement
conditions are agreed by the parties concerned.
3.11
cooling liquid pressure loss
static pressure difference of the cooling liquid (3.4) between the EGR cooler (3.5) outlet and inlet
Note 1 to entry: The cooling liquid pressure loss is expressed in kilopascals (kPa).
Note 2 to entry: Total pressure difference can be used behalf of static pressure difference in case of measurement
conditions are agreed by the parties concerned.
3.12
EGR gas mass flow rate
mass flow rate of the test gas (3.3) that passes through the EGR cooler (3.5) core (3.14)
Note 1 to entry: The EGR gas mass flow rate is expressed in kilograms per second (kg/s).
3.13
cooling liquid mass flow rate
mass flow rate of the cooling liquid (3.4) that passes through the EGR cooler (3.5) core (3.14)
Note 1 to entry: The cooling liquid mass flow rate is expressed in kilograms per second (kg/s).
3.14
core
part at which heat is exchanged between the EGR gas (3.2) and the cooling liquid (3.4)
4 Test items
This test evaluates the following items:
a) EGR gas heat dissipation amount or EGR gas temperature effectiveness;
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ISO 21441:2019(E)

b) EGR gas pressure loss;
c) cooling liquid pressure loss.
5 Test setup
5.1 Test conditions
The EGR cooler, test gas, cooling liquid, and test location conditions are shown as follows.
In the case of measurement with the fouled EGR cooler, test conditions should be agreed by the parties
concerned.
a) EGR cooler:
The EGR cooler consists of main components such as the core, tank, flanges, and pipes, as well as
supplementary parts. An example is shown in Figure 1.
Key
1 flange
2 tank
3 pipe
4 core
NOTE The inlet and outlet flange can have a different flow through the cross-sectional area.
Figure 1 — EGR cooler (example)
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ISO 21441:2019(E)

b) Test gas:
Tests shall be run with a test gas inlet temperature, an inlet pressure and a mass flow rate that are
defined upon the agreement by the parties concerned.
c) Cooling liquid:
Water used in the cooling liquid should be demineralized or treated. In the case of using a coolant
mixture as the cooling liquid, the coolant type and properties of the mixture should be documented.
The used fluid shall be regularly checked to confirm that the coolant mixture or properties haven’t
changed.
d) Test location:
Unless otherwise specified, the test location shall be kept at room temperature (5 °C to 35 °C) and
normal relative humidity (20 % to 85 %).
5.2 Test equipment
5.2.1 General test equipment
The test equipment shall be set up so that it can accurately measure the measurement items in 6.1. From
the perspective of the test gas side structure, the test equipment can be roughly divided into two types:
open type and sealed type. Both types consist of test gas and cooling liquid circuits. For sealed type test
equipment, the test gas inlet pressure shall be set upon the agreement by the parties concerned.
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ISO 21441:2019(E)

Key
1 EGR cooler
2 flow meter
3 thermometer
4 pressure gauge
5 differential pressure gauge
6 pump
7 flow control valve
8 temperature controller
9 pressure control valve
10 heater
11 blower
12 hot water tank
a
Cooling liquid side.
b
Test gas side.
c
Test gas.
d
Open to atmospheric air.
Figure 2 — Test equipment (open type)
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ISO 21441:2019(E)

Key
1 EGR cooler
2 flow meter
3 thermometer
4 pressure gauge
5 differential pressure gauge
6 pump
7 flow control valve
8 temperature controller
9 pressure regulator
10 heater
11 blower
12 compressor
13 hot water tank
a
Cooling liquid side.
b
Test gas side.
Figure 3 — Test equipment (sealed type)
5.2.2 Test gas circuit equipment
The test gas circuit equipment shall be set up as follows.
a) The mass flow rate of the test gas that passes through the EGR cooler shall be adjustable.
b) The test gas inlet temperature shall be adjustable over the entire range of the test.
c) The measuring instrument of the test gas inlet pressure and the test gas differential pressure
between the outlet and the inlet shall not be affected by the dynamic pressure and shall be
connected so as not to disturb the flow of the test gas as much as possible.
5.2.3 Cooling liquid circuit equipment
The cooling liquid circuit equipment shall be set up as follows.
a) The mass flow rate of the cooling liquid that passes through the EGR cooler shall be adjustable.
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ISO 21441:2019(E)

b) The cooling liquid circuit piping and hot liquid tank shall be designed not to take in any air or steam,
or there should be a separation tank.
c) The cooling liquid pump shall be designed so that cavitation does not occur.
d) The cooling liquid circuit shall be able to dissipate the amount of heat it receives over the entire
range of the EGR cooler heat dissipation.
e) Excessive heating temperatures that may degrade the coolant shall be avoided.
5.3 Measuring instruments
Errors of the measuring instruments used in the test shall be within the values shown in Table 1 for
both the test gas side and the cooling liquid side. Calibration shall be carried out prior to testing.
Table 1 — Measuring instrument error
Measuring instrument Instrumental error
Test gas flow meter ±2 % of the measured value
Cooling liquid flow meter ±2 % of the measured value
Test gas inlet thermometer ±(0,3 + 0,005 × measured temperature) K
Test gas outlet thermometer ±1,5 K
Cooling liquid thermometer ±0,3 K
Differential pressure gauge ±5 % of the measured value
Pressure gauge ±3 % of the measured value
6 Test and measurement methods
6.1 Test methods
In the same manner as the examples of the test equipment shown in Figures 2 and 3, the EGR cooler
should be connected to both the test gas circuit and the cooling liquid circuit. The test and measurement
methods are shown as follows. Test conditions shall be decided upon the agreement by the parties
concerned.
6.1.1 Test with heat dissipation
Measurement of the mass flow rate, temperature, and pressure for both fluids that is required to
calculate both the EGR cooler heat dissipation and the pressure loss for both fluids shall be carried out
while the EGR cooler is in a state where it is dissipating heat. Items to be measured during the test are
shown in Table 2.
Table 2 — Items to be measured (EGR cooler heat dissipation amount, EGR gas pressure loss
and cooling liquid pressure loss)
Measurement item Unit
Atmospheric pressure kPa abs
Test laboratory temperature °C
Test gas humi
...