DIN EN 328-2014 Heat exchangers - Forced convection unit air coolers for refrigeration - Test procedures for establishing the performance German version EN 328 2014《热交换器 制冷用强制对流元件空.pdf

1、November 2014 Translation by DIN-Sprachendienst.English price group 18No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).I

2、CS 23.120; 27.060.30!%,d“2250965www.din.deDDIN EN 328Heat exchangers Forced convection unit air coolers for refrigeration Test procedures for establishing the performance;English version EN 328:2014,English translation of DIN EN 328:2014-11Wrmebertrager Ventilatorluftkhler Prfverfahren zur Leistungs

3、feststellung;Englische Fassung EN 328:2014,Englische bersetzung von DIN EN 328:2014-11Echangeurs thermiques Arofrigorifres convection force pour la rfrigration Procdures dessai pour la dtermination de la performance;Version anglaise EN 328:2014,Traduction anglaise de DIN EN 328:2014-11SupersedesDIN

4、EN 328:2003-04www.beuth.deDocument comprises 48 pagesIn case of doubt, the German-language original shall be considered authoritative.10.14 DIN EN 328:2014-11 2 A comma is used as the decimal marker. National foreword This document (EN 328:2014) has been prepared by Technical Committee CEN/TC 110 “H

5、eat exchangers” (Secretariat: DIN, Germany). The responsible German body involved in its preparation was the DIN-Normenausschuss Kltetechnik (DIN Standards Committee Refrigeration Technology), Working Committee NA 044-00-11 AA Klte-Apparate. Amendments This standard differs from DIN EN 328:2003-04 a

6、s follows: a) Clause 3 “Terms and definitions” has been revised; b) requirements for refrigerant “CO2” have been taken into account. Previous editions DIN 8955: 1976-04 DIN V ENV 328: 1992-09, 1994-04 DIN EN 328: 1999-06, 2003-04 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 328 August 2014 I

7、CS 23.120; 27.060.30 Supersedes EN 328:1999English Version Heat exchangers - Forced convection unit air coolers for refrigeration - Test procedures for establishing the performanceEchangeurs thermiques - Arofrigorifres convection force pour la rfrigration - Procdures dessai pour la dtermination de l

8、a performance Wrmebertrager - Ventilatorluftkhler - Prfverfahren zur Leistungsfeststellung This European Standard was approved by CEN on 22 May 2014. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status

9、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, Germa

10、n). 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,

11、 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, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and Unite

12、d Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 3

13、28:2014 E2 Contents Page Foreword 4 Introduction .5 1 Scope 6 2 Normative references 6 3 Terms and definitions .6 4 Symbols . 11 5 Standard capacity . 13 5.1 Basis of standard capacity data 13 5.2 Standard conditions for the cooling capacity . 14 5.2.1 General . 14 5.2.2 Refrigerants . 14 5.2.3 Liqu

14、ids . 15 5.3 Conditions for the nominal air flow rate . 15 5.4 Conditions for nominal fan power 15 6 Manufacturers data 15 7 Measurements . 16 7.1 Uncertainty of measurements . 16 7.2 Measurement criteria 17 7.2.1 Pipe side temperature measurement 17 7.2.2 Superheating temperature . 18 7.2.3 Tempera

15、ture at expansion device inlet 18 7.2.4 Liquid temperatures . 18 7.2.5 Water temperatures (balancing air heater) 18 7.2.6 Air temperature measurement . 18 7.2.7 Pressure measuring points . 19 7.2.8 Flow rates 19 7.2.9 Oil content . 19 7.2.10 Non azeotropic refrigerant . 19 8 Testing methods and equi

16、pment 20 8.1 Testing methods . 20 8.1.1 Capacity . 20 8.1.2 Air flow . 20 8.1.3 Heat exchange with the ambient . 20 8.2 Equipment . 20 8.2.1 Calorimeter room 20 8.2.2 Refrigerant / liquid pipes 22 8.2.3 Expansion device 22 8.2.4 Flashgas 22 8.2.5 Air flow measurement 22 8.2.6 Liquid receiver 22 9 Te

17、st procedures 23 9.1 General . 23 9.2 Calibration of the calorimeter room 23 9.3 Measurement of the cooling capacity 24 9.3.1 Air humidity . 24 9.3.2 Subcooled refrigerant temperature. 24 DIN EN 328:2014-11 EN 328:2014 (E) 3 9.3.3 Steady-state conditions 24 9.3.4 Test duration 24 9.3.5 Conducting th

18、e test . 25 9.3.6 Air inlet temperature . 26 9.3.7 Data to be recorded . 26 9.4 Measuring the fan performance . 26 10 Calculating the cooling capacity . 27 10.1 Heat loss factor 27 10.2 Cooling capacity 27 10.2.1 From the air side energy input . 27 10.2.2 From flow rate of refrigerant 27 10.2.3 From

19、 the flow rate of liquid 27 10.2.4 Measured capacity 28 11 Conversion to standard conditions . 28 11.1 Cooling capacity 28 11.1.1 General correction for atmospheric pressure 28 11.1.2 Refrigerants with direct expansion operation 28 11.1.3 Refrigerants - operation with liquid overfeed by pump circula

20、tion . 29 11.1.4 Liquids 29 11.2 Calculating the standard liquid side pressure drop 30 11.2.1 General . 30 11.2.2 Single Test . 30 11.2.3 Duplicate Tests 30 11.3 Nominal air flow . 31 11.4 Nominal fan power 31 12 Test report 31 Annex A (informative) Bubble point temperature 32 A.1 Diagram bubble poi

21、nt temperature 32 Annex B (normative) Test installation for direct expansion operation 33 Annex C (normative) Test installation for liquids . 35 Annex D (informative) Superheating and capacity . 36 Annex E (normative) Test arrangement . 37 Annex F (normative) Operation with liquid overfeed by pump c

22、irculation 38 F.1 Scope 38 F.2 Standard conditions 38 F.3 Measurements . 39 F.4 Testing methods and equipment . 39 F.5 Test procedures . 40 F.6 Capacity calculations 41 F.7 Conversion to standard conditions . 42 Annex G (informative) Procedure to measure the oil content . 45 Bibliography 46 DIN EN 3

23、28:2014-11 EN 328:2014 (E) 4 Foreword This document (EN 328:2014) has been prepared by Technical Committee CEN/TC 110 “Heat exchangers”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by

24、endorsement, at the latest by February 2015, and conflicting national standards shall be withdrawn at the latest by February 2015. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible fo

25、r identifying any or all such patent rights. This document supersedes EN 328:1999 and EN 328:1999/A1:2002. The main changes with respect to the previous edition are listed below: a) Clause 3 “Terms and definitions” is modified; b) The revised standard takes into account the application of CO2. Accor

26、ding to the CEN-CENELEC Internal Regulations, the national standards organizations 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,

27、 Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. DIN EN 328:2014-11 EN 328:2014 (E) 5 Introduction This European Standard is one of a series

28、of European Standards dedicated to heat exchangers. DIN EN 328:2014-11 EN 328:2014 (E) 6 1 Scope This European Standard is applicable to non-ducted unit air coolers for refrigeration operating: a) with direct dry expansion of a refrigerant; b) with liquid overfeed by pump circulation of a refrigeran

29、t; c) with a liquid. This standard specifies uniform methods of performance assessment to test and ascertain the following: product identification; standard capacity; standard liquid pressure drop; standard refrigerant pressure drop (for operation with liquid overfeed by pump circulation only); nomi

30、nal air flow rate; nominal fan power. It does not cover evaluation of conformity. It is not applicable to air coolers for duct mounting or with natural air convection. This standard does not cover technical safety aspects. 2 Normative references The following documents, in whole or in part, are norm

31、atively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO/IEC 17025, General requirements for the competence of

32、testing and calibration laboratories (ISO/IEC 17025) EN 60034-1, Rotating electrical machines - Part 1: Rating and performance (IEC 60034-1) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply: 3.1 physical definitions 3.1.1 forced convection unit air

33、 cooler refrigeration system component transferring heat from air to a refrigerant or liquid. The air is mechanically circulated over the heat transfer surface by integral fan(s) and fan drive(s) Note 1 to entry: The heat transfer coil includes refrigerant distributing and collecting headers. Note 2

34、 to entry: In the following “forced convection unit air cooler” is referred to as “unit cooler”. DIN EN 328:2014-11 EN 328:2014 (E)7 3.1.2 heat transfer surface (air side) external surface of the cooling coil which is in contact with the air flow passing the cooling coil 3.1.3 internal volume volume

35、 of the refrigerant containing parts of the unit cooler between its two connections 3.1.4 fouling resistance thermal resistance of a layer of unwanted deposit on the heat exchanger surface reducing its heat transfer performance Note 1 to entry: The fouling resistance for a clean surface is zero. Cle

36、an, in this context, means that all production residues have been removed from the heat transfer surface and the fan(s) by the factorys cleaning process. 3.2 refrigerant working fluid in a cooling system, which absorbs heat at low pressure / temperature by evaporation and rejects heat at a higher pr

37、essure / temperature by condensation 3.3 liquid working fluid remaining liquid during the absorption of heat 3.4 capacities 3.4.1 sensible air cooling capacity heat flow rejected by the air resulting from a dry bulb temperature drop 3.4.2 latent cooling capacity heat flow rejected by the air resulti

38、ng from condensation of water vapour or frost formation including subcooling on the unit cooler surface 3.4.3 total cooling capacity sum of the sensible and the latent capacities measured at the same time 3.4.4 gross cooling capacity total heat flow absorbed by the refrigerant or liquid 3.4.5 net co

39、oling capacity cooling capacity available for cooling the air equal to the gross cooling capacity minus the fan power 3.4.6 standard capacity gross cooling capacity at standard conditions and normal atmospheric pressure of 1013,25 hPa of a unit cooler with clean internal and external surfaces 3.4.7

40、fan power electric power, absorbed by the fan motors at the electrical terminals of the motor(s) DIN EN 328:2014-11 EN 328:2014 (E) 8 3.4.8 nominal fan power fan power measured during the air flow test and corrected to the normal atmospheric pressure of 1013,25 hPa Note 1 to entry: The fan power wil

41、l also differ with the temperature at which the fan runs. As the fan power is only a small proportion of the total cooling load, the deviations are considered to be negligible. 3.5 rotational speed of the fans average rotational speeds of fans 3.6 pressures and pressure differences for the purposes

42、of this standard all pressures are average values ascertained over the test duration 3.6.1 evaporating pressure absolute pressure of the refrigerant, at the outlet connection of the unit cooler 3.6.2 liquid inlet pressure static pressure of the liquid at the inlet connection of the unit cooler 3.6.3

43、 liquid outlet pressure static pressure of the liquid at the outlet connection of the unit cooler 3.6.4 liquid pressure difference difference between the liquid inlet pressure and the liquid outlet pressure 3.6.5 refrigerant inlet pressure absolute pressure of the refrigerant, at the inlet connectio

44、n of the unit cooler (see Annex F) 3.6.6 critical pressure pressure at the critical point where the liquid and gaseous phases of the refrigerant have the same physical properties 3.7 temperatures for the purposes of this standard all temperatures are average values ascertained over the test duration

45、 3.7.1 air temperatures 3.7.1.1 air inlet temperature average dry bulb temperature of the air at the unit cooler inlet, taking into consideration the local air velocities 3.7.1.2 air dew point temperature dew point temperature of the air within the calorimeter room 3.7.1.3 inside temperature air tem

46、perature inside the calorimeter room responsible for the heat exchange with the ambient DIN EN 328:2014-11 EN 328:2014 (E) 9 3.7.1.4 ambient temperature temperature around the calorimeter room responsible for the heat exchange with the inside 3.7.2 refrigerant temperatures 3.7.2.1 evaporating temper

47、ature dew point temperature of the refrigerant, corresponding to the evaporating pressure 3.7.2.2 superheating temperature temperature of the refrigerant vapour at the outlet connection of the unit cooler, measured on the wall of the tube at the location recommended by the manufacturer for fixing th

48、e expansion valve sensing element or downstream of the liquid-suction heat exchanger where this is an integral part of the unit cooler 3.7.2.3 subcooled refrigerant temperature temperature of the liquid refrigerant at the inlet connection to the expansion device (not necessarily part of the unit cooler) 3.7.2.4 bubble point temperature for cooler measurement temperature calculated from the enthalpy based on the temperature and pressure at the inlet of the expansion valve 3.7.3 liquid temperatures 3.7.3.1 liquid