1、BSI Standards PublicationBS EN 328:2014Heat exchangers Forcedconvection unit air coolersfor refrigeration Testprocedures for establishing theperformanceBS EN 328:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 328:2014. Itsupersedes BS EN 328:1999 which is
2、withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee RHE/30, Heat exchangers.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users
3、 are responsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 80318 5ICS 23.120; 27.060.30Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authorit
4、y of theStandards Policy and Strategy Committee on 31 August 2014.Amendments issued since publicationDate Text affectedBS EN 328:2014EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 328 August 2014 ICS 23.120; 27.060.30 Supersedes EN 328:1999English Version Heat exchangers - Forced convection un
5、it air coolers for refrigeration - Test procedures for establishing the performanceEchangeurs thermiques - Arofrigorifres convection force pour la rfrigration - Procdures dessai pour la dtermination de la performance Wrmebertrager - Ventilatorluftkhler - Prfverfahren zur Leistungsfeststellung This E
6、uropean 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 of a national standard without any alteration. Up-to-date lists and bibliographical references co
7、ncerning 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
8、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
9、, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMI
10、TEE 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 328:2014 EBS EN 328:2014EN 328:2014 (E) 2 Contents Page Foreword 4 Introduction .5 1 Scope 6 2 Nor
11、mative 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 Liquids . 15 5.3 Conditions for the nominal air flow rate . 15 5.4 Cond
12、itions 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 Temperature at expansion device inlet 18 7.2.4 Liquid temperatures . 18 7.
13、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 equipment 20 8.1 Testing methods . 20 8.1.1 Capacity . 20 8.1.2 Air flo
14、w . 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 Test procedures 23 9.1 General . 23 9.2 Calibration of the calorimete
15、r room 23 9.3 Measurement of the cooling capacity 24 9.3.1 Air humidity . 24 9.3.2 Subcooled refrigerant temperature. 24 BS EN 328:2014EN 328:2014 (E) 3 9.3.3 Steady-state conditions 24 9.3.4 Test duration 24 9.3.5 Conducting the test . 25 9.3.6 Air inlet temperature . 26 9.3.7 Data to be recorded .
16、 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 the flow rate of liquid 27 10.2.4 Measured capacity 28 11 Conversion to
17、 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 circulation . 29 11.1.4 Liquids 29 11.2 Calculating the standard liquid side pr
18、essure 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 point temperature 32 Annex B (normative) Test installation for direct expan
19、sion 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 circulation 38 F.1 Scope 38 F.2 Standard conditions 38 F.3 Measurements .
20、 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 BS EN 328:2014EN 328:2014 (E) 4 Foreword This document (EN 328:2014) has been pr
21、epared 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 endorsement, at the latest by February 2015, and conflicting national standar
22、ds 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 for identifying any or all such patent rights. This document supersedes EN 328:
23、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. According to the CEN-CENELEC Internal Regulations, the national standards organiza
24、tions 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, Mal
25、ta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 328:2014EN 328:2014 (E) 5 Introduction This European Standard is one of a series of European Standards dedicated to heat exchangers. BS EN 328:2014EN 328:2014 (E)
26、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 refrigerant; c) with a liquid. This standard specifies uniform methods of performance assessment
27、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); nominal air flow rate; nominal fan power. It does not cover evaluation of conformity. It is
28、 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 normatively referenced in this document and are indispensable for its application. For date
29、d 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 testing and calibration laboratories (ISO/IEC 17025) EN 60034-1, Rotating electrical ma
30、chines - 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 cooler refrigeration system component transferring heat from air to a refrigerant or l
31、iquid. 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 to entry: In the following “forced convection unit air cooler” is referred to as “unit
32、 cooler”. BS EN 328:2014EN 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 of the refrigerant containing parts of the unit cooler between its two connections 3.1.4 f
33、ouling 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. Clean, in this context, means that all production residues have been removed from the heat tra
34、nsfer 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 pressure / temperature by condensation 3.3 liquid working fluid remaining liquid during the a
35、bsorption 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 resulting from condensation of water vapour or frost formation including subcooling on the unit co
36、oler 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 cooling capacity cooling capacity available for cooling the air equal to the gross cooling ca
37、pacity 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 fan power electric power, absorbed by the fan motors at the electrical terminals of the mot
38、or(s) BS EN 328:2014EN 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 will also differ with the temperature at which the fan runs. As the fan power is only a small propo
39、rtion 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 of this standard all pressures are average values ascertained over the test duration 3.6.1 evapo
40、rating 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 liquid outlet pressure static pressure of the liquid at the outlet connection of the unit coole
41、r 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 connection of the unit cooler (see Annex F) 3.6.6 critical pressure pressure at the critical point where
42、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 3.7.1 air temperatures 3.7.1.1 air inlet temperature average dry bulb temperature of the air at
43、 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 temperature inside the calorimeter room responsible for the heat exchange with the ambient BS EN 32
44、8:2014EN 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 temperature dew point temperature of the refrigerant, corresponding to the evaporating pressure 3.7.2.2 sup
45、erheating 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 the expansion valve sensing element or downstream of the liquid-suction heat exchanger where this is an
46、 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
47、 based on the temperature and pressure at the inlet of the expansion valve 3.7.3 liquid temperatures 3.7.3.1 liquid inlet temperature average temperature of the liquid at the inlet connection of the unit cooler taking into consideration the local liquid velocities 3.7.3.2 liquid outlet temperature a
48、verage temperature of the liquid at the outlet connection of the unit cooler taking into consideration the local liquid velocities 3.7.4 water temperatures (applicable only where the balancing heat is supplied by water) 3.7.4.1 water inlet temperature temperature of the water as it enters the calori
49、meter 3.7.4.2 water outlet temperature temperature of the water as it leaves the calorimeter 3.7.5 vapour outlet temperature temperature of the refrigerant vapour at the vapour outlet connection of the separator BS EN 328:2014EN 328:2014 (E) 10 3.8 temperature differences 3.8.1 temperature differences for refrigerants 3.8.1.1 inlet temperature difference difference between the air inlet temperature and the evaporating temperature 3.8.1.2 superheating difference between the superheating temperature and the evaporating temperature 3.8.1.3 degree of supe
