EN 50216-9:2009

SLOVENSKI STANDARD
01-maj-2009
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Power transformer and reactor fittings - Part 9: Oil-to-water heat exchanger
Zubehör für Transformatoren und Drosselspulen - Teil 9: Öl-Wasser-Kühler
Accessoires pour transformateurs de puissance et bobines d'inductance - Partie 9:
Echangeur thermique huile-eau
Ta slovenski standard je istoveten z: EN 50216-9:2009
ICS:
29.180 Transformatorji. Dušilke Transformers. Reactors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 50216-9
NORME EUROPÉENNE
March 2009
EUROPÄISCHE NORM
ICS 29.180
English version
Power transformer and reactor fittings -
Part 9: Oil-to-water heat exchangers

Accessoires pour transformateurs  Zubehör für Transformatoren
de puissance et bobines d'inductance - und Drosselspulen -
Partie 9: Echangeurs thermiques huile-eau Teil 9: Öl-Wasser-Kühler

This European Standard was approved by CENELEC on 2008-10-21. CENELEC 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 Central Secretariat or to any CENELEC 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 CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: avenue Marnix 17, B - 1000 Brussels

© 2009 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 50216-9:2009 E
Foreword
This European Standard was prepared by the Technical Committee CENELEC TC 14, Power
transformers.
The text of the draft was submitted to the formal vote and was approved by CENELEC as EN 50216-9 on
2008-10-21.
This European Standard is to be read in conjunction with EN 50216-1:2002, Power transformer and
reactor fittings - Part 1: General.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2009-11-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2011-11-01
__________
– 3 – EN 50216-9:2009
Contents
1 Scope . 4
2 Normative references . 4
3 Definitions . 4
4 Requirements . 5
4.1 Rated values . 5
4.2 Rated cooling capacity . 6
4.3 Mechanical design . 6
4.4 Corrosion protection . 7
5 Designation . 7
5.1 Designation of the heat exchangers . 7
5.2 Rating plate information . 7
6 Tests . 8
6.1 Routine tests . 8
6.2 Type tests . 9
7 Preparation for transport and storage . 9
8 Mounting and service, service conditions . 9
Annex A (normative) Details to the heat exchangers . 10
Annex B (normative) Rating conditions of the heat exchangers . 17
Annex C (informative) Example for calculation of capacity in service . 23
Bibliography . 24
Figures
Figure A.1 – Collection and forms of suspensory types . 11
Figure A.2 – Collection and forms of horizontal types . 12
Figure A.3 – Collection and forms of vertical standing types . 13
Figure B.1 – Capacity factor depending on inlet temperatures of oil and water . 19
Figure B.2 – Capacity factor depending on mass for plain tubes . 20
Figure B.3 – Capacity factor depending on mass for finned tubes . 21
Tables
Table A.1 – Devices . 14
Table A.2 – Examples for material selection depending on water quality . 16
Table A.3 – Average values for chemically neutral water (fresh water) . 16

1 Scope
EN 50216-9 deals with oil-to-water heat exchangers that means a heat exchanger for the cooling of the
transformer oil using a forced oil circuit and a forced water circuit.
The oil-side of the oil-to-water heat exchangers is not included in the scope of the Pressure Equipment
Directive 97/23/EC according to Article 1, § 3.12. The water-side falls into Article 3, § 3 of the Pressure
Equipment Directive, therefore the rating plate must not contain a CE sign according to Article 15 of the
Pressure Equipment Directive.
This standard establishes essential dimensions and the requirements to ensure interchangeability and
adequate mounting of the oil-to-water heat exchangers.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendment) applies.
EN 50216-1:2002 Power transformers and reactor fittings - Part 1: General
EN 60296 Fluids for electrotechnical applications - Unused mineral insulating oils for transformers
and switchgear (IEC 60296)
EN 60721-3-4 Classification of environmental conditions - Part 3: Classification of groups of
environmental parameters and their severities - Section 4: Stationary use at non-
weatherprotected locations (IEC 60721-3-4)
EN 1092-1 Flanges and their joints - Circular flanges for pipes, valves, fittings and accessories ,
PN designated - Part 1: Steel flanges
EN 1561 Founding - Grey cast irons
EN 1653 Copper and copper alloys - Plate, sheet and circles for boilers, pressure vessels and
hot water storage units
1)
EN 10025:1990 Hot rolled products of non-alloy structural steels - Technical delivery conditions
EN 10027-2 Designation systems for steels - Part 2: Numerical system
EN 10088-2 Stainless steels - Part 2: Technical delivery conditions for sheet/plate and strip of
corrosion resisting steels for general purposes
EN 10130 Cold rolled low carbon steel flat products for cold forming - Technical delivery
conditions
EN 12451 Copper and copper alloys - Seamless, round tubes for heat exchangers
EN 12452 Copper and copper alloys - Rolled, finned, seamless tubes for heat exchangers
EN 12502-1 Protection of metallic materials against corrosion - Guidance on the assessment of
corrosion likelihood in water distribution and storage systems - Part 1: General
EN ISO 3506-1 Mechanical properties of corrosion-resistant stainless steel fasteners - Part 1: Bolts,
screws and studs (ISO 3506-1)
ISO 4406 Hydraulic fluid power - Fluids - Methods for coding the level of contamination by solid
particles
1)
Replaced by EN 10025 series, Hot rolled products of structural steels.

– 5 – EN 50216-9:2009
3 Definitions
For the purposes of this document, the following terms and definitions apply.
3.1
single tube
tube conducting the water in the oil filled compartment, either plain tubes which have the inner water side
and the outer oil side with plain surface or finned tubes which have the outer oil side finned for increasing
the heat transfer area from oil to tube
3.2
double tube
consists of two telescope tubes without blocking fluid. The inner water side of the inside tube is a plain
tube. The outer oil side of the outside tube is either a plain tube or a finned tube. The inner side of the
outside tube or the outer side of the inside tube has regularly groves for the leakage detection
3.3
tube bundle
number of parallel tubes to get the adequate heat transfer surface and the appropriate plates
3.4
single tube arrangement
the heat exchange from oil to water is conducted with a bundle of single tubes. For safety reasons of the
transformer the oil pressure outside the tubes must always have a higher value than the water pressure
inside the tubes, so that even in the case of heat exchanger untightness no water penetrates into the
transformer oil
3.5
double tube arrangement
the heat exchange from oil to water is conducted with a bundle of double tubes. The double tube system
has sufficient security for the transformer. The oil pressure outside the tubes may be less than the water
pressure inside the tubes
3.6
tube plate
the cooling tubes are rolled or welded oil-tight and/or water tight on both ends into the plates - for double
tubes one end into two plates, for single tubes into one plate. With the tube plates the oil side is tightened
against the water side
3.7
water channel
the water side of the heat exchanger is connected via the water channels
3.8
leakage detection
due to a leakage oil or water in the space between the double tubes would be detected
4 Requirements
4.1 Rated values
Values for inquiry (minimum):
- single tube / double tube heat exchanger
- water quality (see A.6)
- rated cooling capacity Q kW
r
- water temperature at inlet t’ °C
- water temperature at outlet (max.) t’’ °C
- average oil temperature t °C
2m
- oil temperature difference (min. value/max. value) ∆t K
- water flow quantity (max.) V m³/h
- max. operating pressure (water side) p kPa
For an order the following rated values should be fixed:
- single tube / double tube heat exchanger
- materials
- rated cooling capacity Q kW
r
- rated water flow quantity V m³/h
- rated oil flow quantity V m³/h
- water temperature at inlet t’ °C
- water temperature at outlet t’’ °C
- oil temperature at inlet t’ °C
- oil temperature at outlet t’’ °C
- water side pressure drop ∆p kPa
- oil side pressure drop ∆p kPa
- max. operating pressure (water side) p kPa
- max. operating pressure (oil side) p kPa
4.2 Rated cooling capacity
The rated cooling capacity of the heat exchanger is the minimum capacity, which the manufacturer has to
guarantee. For a heat exchanger in new condition the value is based on the following:
- rated water and oil flow quantities in connection with the particular permitted static pressure drops;
- oil-to-water heat exchangers must be designed with a capacity margin of min. 25 %.
For new heat exchangers the capacity with the margin has to be achieved with the rated values for oil flow
quantity, water flow quantity, oil temperature at inlet and water temperature at inlet.
4.3 Mechanical design
The mechanical design is based on the ambient conditions according to EN 50216-1, Clause 3, and on a
maximum oil temperature of 100 °C and a maximum water temperature of 50 °C. Deviating temperatures
and ambient conditions as well as other insulating fluids must be agreed between manufacturer and
purchaser.
The cooling tubes and plates are oil tight and water tight connected. The tube bundle could expect
...