SIST EN 327:2014

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Wärmeaustauscher - Ventilatorbelüftete Verflüssiger - Prüfverfahren zur LeistungsfeststellungÉchangeurs thermiques - Aérocondenseurs à convection forcée - Procédures d'essai pour la détermination de la performanceHeat exchangers - Forced convection air cooled refrigerant condensers - Test procedures for establishing performance27.060.30Grelniki vode in prenosniki toploteBoilers and heat exchangersICS:Ta slovenski standard je istoveten z:EN 327:2014SIST EN 327:2014en,fr,de01-november-2014SIST EN 327:2014SLOVENSKI
STANDARDSIST EN 327:2002/A1:2004SIST EN 327:20021DGRPHãþD



SIST EN 327:2014



EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 327
August 2014 ICS 27.060.30 Supersedes EN 327:2000English Version
Heat exchangers - Forced convection air cooled refrigerant condensers - Test procedures for establishing performance
Echangeurs thermiques - Aérocondenseurs à convection forcée - Procédures d'essai pour la détermination de la performance
Wärmeübertrager - Ventilatorbelüftete Verflüssiger - Prüfverfahren 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 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, 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:
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 327:2014 ESIST EN 327:2014



EN 327:2014 (E) 2 Contents Page Foreword .4 1 Scope .6 2 Normative references .6 3 Terms and definitions .6 4 Symbols .9 5 Standard capacity . 11 5.1 Basis for standard capacity data . 11 5.2 Standard capacity conditions . 11 5.3 Conditions for the nominal air flow rate . 12 5.4 Conditions for nominal fan power . 12 6 Manufacturer’s data . 12 7 Measurements . 13 7.1 Uncertainty of measurements . 13 7.2 Measurement criteria . 14 7.2.1 Pipe side temperature measurement . 14 7.2.2 Condenser and gas cooler inlet temperature . 15 7.2.3 Subcooled refrigerant temperature. 15 7.2.4 Water temperatures (Balancing air cooler - Air side calorimeter) . 15 7.2.5 Gas cooler outlet temperature . 15 7.2.6 Air temperatures . 15 7.2.7 Pressure measuring points . 16 7.2.8 Refrigerant flow rate . 16 7.2.9 Water flow rate . 16 7.2.10 Oil content . 16 7.2.11 Non-azeotropic refrigerant . 16 8 Testing methods and equipment . 16 8.1 Testing methods for capacity . 16 8.1.1 General . 16 8.1.2 High pressure calorimeter (primary method) . 17 8.1.3 Low pressure calorimeter (primary method) . 17 8.1.4 Air side calorimeter (primary method) . 17 8.1.5 Refrigerant flow method (confirming method) . 18 8.1.6 Air flow method . 18 8.2 Air flow measurement . 18 8.3 Equipment for capacity measurement . 18 8.3.1 General . 18 8.3.2 High pressure calorimeter . 19 8.3.3 Low pressure calorimeter . 20 8.3.4 Air side calorimeter . 20 8.3.5 Refrigerant flow method . 21 8.3.6 Liquid receiver . 21 9 Test procedures . 21 9.1 General . 21 9.2 Heat loss measurement - calibration . 22 9.2.1 General . 22 9.2.2 High pressure calorimeter - direct heat inducement into refrigerant . 22 9.2.3 Low and high pressure calorimeters - heat inducement into secondary fluid . 23 SIST EN 327:2014



EN 327:2014 (E) 3 9.2.4 Air calorimeter room . 23 9.3 Capacity measurement . 23 9.3.1 Steady-state . 23 9.3.2 Test duration . 24 9.3.3 Conducting the test . 25 9.3.4 Data to be recorded . 25 9.4 Measuring the fan performance . 26 10 Capacity calculation . 26 10.1 General . 26 10.2 Heat loss factor: calibration test . 26 10.2.1 High pressure calorimeter - direct heat inducement into the refrigerant . 26 10.2.2 High and low pressure calorimeter - indirect heat inducement into the refrigerant . 26 10.2.3 Air side calorimeter . 27 10.3 Capacity measurement test . 27 10.3.1 High and low pressure calorimeter - flow rate measurement methods . 27 10.3.2 High pressure calorimeter method - direct capacity measurement . 27 10.3.3 Air side calorimeter . 27 10.3.4 Confirming method . 28 11 Conversion to Standard Conditions . 28 11.1 General . 28 11.1.1 Introduction . 28 11.1.2 Correction for atmospheric pressure . 28 11.1.3 Standard capacity . 28 11.2 Nominal air flow . 28 11.3 Nominal fan power . 28 12 Test report . 29 Annex A (normative)
Flow meter method . 30 Annex B (informative) Low pressure calorimeter . 32 Annex C (informative) Air-Side calorimeter . 33 Annex D (informative) Procedure to measure the oil content . 34 Bibliography . 35
SIST EN 327:2014



EN 327:2014 (E) 4 Foreword This document (EN 327:2014) 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 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 for identifying any or all such patent rights. This document supersedes EN 327:2000 and EN 327:2000/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 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, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 327:2014



EN 327:2014 (E) 5 Introduction This European Standard is one of a series of European Standards dedicated to heat exchangers. SIST EN 327:2014



EN 327:2014 (E) 6 1 Scope This European Standard applies to non-ducted forced convection air cooled refrigerant condensers/gas coolers with dry air side surface within which the refrigerant changes phases or is cooled. Its purpose is to establish uniform methods of performance assessment. It does not deal with evaluation of conformity. This European Standard does not apply to air cooled condensers/gas coolers, designed primarily for installation within the machinery compartment of packaged products or in factory-assembled condensing/gas cooling units. This European Standard does not apply to condensers with an integral subcooling part. This European Standard specifies methods to test and ascertain the following: — product identification; — standard capacity; — nominal air flow rate; — nominal fan power. This European 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 dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 60034-1, Rotating electrical machines - Part 1: Rating and performance (IEC 60034-1) EN ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories (ISO/IEC 17025) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1
forced convection air cooled refrigerant condenser refrigeration system component that condenses refrigerant vapour by rejecting heat to air, which is mechanically circulated over its dry heat transfer surface by integral fans and fan drives Note 1 to entry: The heat transfer coil includes distributing and collecting headers. Note 2 to entry: In the following “forced convection air cooled refrigerant condenser” is referred to as “condenser”. 3.2
forced convection air cooled refrigerant gas cooler refrigeration system component that cools the refrigerant by rejecting heat to air, which is mechanically circulated over its dry heat transfer surface by integral fans and fan drives Note 1 to entry: In the following “forced convection air cooled refrigerant gas cooler” is referred to as “gas cooler”. SIST EN 327:2014



EN 327:2014 (E) 7 3.3
refrigerant working fluid used for heat transfer in a cooling system, which absorbs heat at a low temperature and a low pressure and rejects heat at a higher temperature and a higher pressure usually involving changes of the state of the fluid 3.4
capacity total heat flow rejected by the refrigerant. This total heat flow of rejection is equal to the product of the mass flow rate of the refrigerant and the difference between the enthalpies of the refrigerant at the condenser/gas cooler inlet and outlet connections 3.5
pressures 3.5.1
condensing/gas cooling pressure pressure of the refrigerant at the inlet connection of the condenser/gas cooler 3.5.2
evaporating pressure pressure of the refrigerant at the outlet connection of the calorimeter (applicable only to low pressure calorimeter method) 3.5.3
calorimeter pressure pressure in the secondary fluid side of the calorimeter vessel (applicable only to low pressure calorimeter method and high pressure calorimeter with indirect heat inducement) Note 1 to entry: All pressures are average values ascertained over the test duration, and are absolute pressures. 3.6
temperatures Note 1 to entry: All air temperatures are dry bulb temperatures. 3.6.1 air inlet temperature average dry bulb temperature of the air at the inlet of the condenser/gas cooler taking into consideration the local air velocities 3.6.2 ambient air temperature average temperature of the air surrounding the calorimeter, responsible for the heat exchange with the ambient 3.6.3 inside air temperature average temperature of the air inside the calorimeter, responsible for the heat exchange with the ambient 3.6.4 refrigerant temperatures 3.6.4.1 dew point temperature temperature of the refrigerant corresponding to the condensing pressure 3.6.4.2 condenser/gas cooler inlet temperature temperature of the refrigerant vapour at the inlet connection of the condenser/gas cooler SIST EN 327:2014



EN 327:2014 (E) 8 3.6.4.3 subcooled refrigerant temperature temperature of the liquid refrigerant in the receiver 3.6.4.4 gas cooler outlet temperature temperature of the refrigerant gas at the outlet connection of the gas cooler 3.6.4.5 evaporating temperature dew point temperature of the refrigerant corresponding to the evaporating pressure (applicable only to low pressure calorimeter method) 3.6.4.6 vapour temperature temperature of the refrigerant at the calorimeter outlet connection 3.6.4.7 bubble point temperature at condenser outlet temperature corresponding to the absolute pressure of the refrigerant at the outlet connection of the condenser 3.6.5
water temperatures (applicable only to air side calorimeter method) 3.6.5.1 water inlet temperature temperature of the water as it enters the calorimeter 3.6.5.2 water outlet temperature temperature of the water as it leaves the calorimeter Note 1 to entry: All temperatures are average values ascertained over the test duration. 3.7
temperature differences 3.7.1
condenser inlet temperature difference difference between the condensing temperature and the air inlet temperature 3.7.2
gas cooler inlet temperature difference difference between the gas cooler inlet temperature and the air inlet temperature 3.7.3
superheating difference between the condenser inlet temperature and the condensing temperature 3.7.4
subcooling difference between the bubble point temperature and the subcooled refrigerant temperature 3.8
high glide refrigerant where the difference between the condensing and bubble point temperatures at a condensing temperature of 40 °C is greater than 3 K SIST EN 327:2014



EN 327:2014 (E) 9 3.9
fan power electrical power, absorbed by the fan motor(s) measured at the electrical terminals of the motor(s) 3.10
nominal fan power fan power measured during the air flow test and corrected to the nominal atmospheric pressure of 1 013,25 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 proportion of the total cooling load, the deviations are considered to be negligible. 3.11
rotational speed of the fans average rotational speed of the fans 3.12
nominal air flow air volume flow rate, flowing through the condenser/gas cooler 3.13
internal volume volume of the refrigerant containing parts of the condenser/gas cooler between its two connections 3.14
fouling resistance thermal resistance due to 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. Note 2 to entry:
Clean, in this context, means that all production residues have been removed from the heat transfer surface and the fan(s) by the factory’s cleaning process. 3.15
oil content the proportion of oil by mass in the pure refrigerant circulating in the heat exchanger 4 Symbols For the purposes of this document, the symbols of Table 1 apply: SIST EN 327:2014



EN 327:2014 (E) 10 Table 1 — Symbols E energy supply to the calorimeter (refrigerant side calorimeters) kWh HLF heat loss factor from calorimeter kW/K hsup spec. enthalpy of superheated vapour at condenser inlet connection kJ/kg hsub spec. enthalpy of subcooled liquid refrigerant at condenser outlet connection kJ/kg hR1 specific enthalpy of the refrigerant at gas cooler inlet connection kJ/kg hR2 specific enthalpy of the refrigerant at gas cooler outlet connection kJ/kg hR4 specific enthalpy of the refrigerant at inlet connection of the calorimeter kJ/kg hR5 specific enthalpy of the superheated refrigerant at outlet connection of the calorimeter kJ/kg hW1 specific enthalpy of water entering the calorimeter kJ/kg hW2 specific enthalpy of water leaving the calorimeter kJ/kg N rotational speed of the fans min -1 Pfan electrical power of the fan(s) kW patm atmospheric pressure hPa pc condensing or gas cooling pressure kPa pR1 gas cooler inlet pressure kPa pR2 gas cooler outlet pressure kPa pe evaporating pressure kPa pi pressure of the secondary fluid in the calorimeter kPa qmR mass flow rate of refrigerant kg/s qmW mass flow rate of water kg/s qva volumetric flow rate of the air m3/s tA1 air inlet temperature °C tR refrigerant temperatures °C tR1 gas cooler inlet temperature °C tR2 gas cooler outlet temperature °C tRM refrigerant temperature at flow meter °C tsup superheated vapour temperature °C tsub subcooled refrigerant temperature °C tW water temperatures °C tWM water temperature at flow meter °C tamb ambient temperature °C ti temperature inside calorimeter °C SIST EN 327:2014



EN 327:2014 (E) 11 ût1 inlet temperature difference K ûtsup superheating K ûtsub subcooling K 2 test duration S U Supply voltage V NOTE 1 bar = 100 kPa = 1 000 hPa Subscripts m mass; v volume; W water; R
refrigerant. Superscripts st standard Numbers. Position as defined in the annexes. 5 Standard capacity 5.1 Basis for standard capacity data The influence of the refrigerant mass flow, the heat flux and the condensing temperature on the overall heat transfer of an air cooled condenser is low. As a result, in the range of temperature differences between 10 K and 20 K, the capacity is almost proportional to the temperature difference. The influence of superheat on the capacity is also low; it is below + 0,5 % per K superheat. For refrigerants which are cooled but not condensed in the gas cooler the test conditions shall be observed with the greatest possible accuracy, as conversion to standard conditions can be very extensive. The airflow through a condenser/gas cooler has great influence on its capacity. Because of the complicated relations a simple conversion to other air flows is not possible with sufficient accuracy. Therefore the electrical values which influence the fan speed (voltage and frequency) shall correspond with the standard supply conditions. 5.2 Standard capacity conditions The standard capacity shall be based on tests performed on a clean and dry condenser/gas cooler under the following operating conditions: SIST EN 327:2014



EN 327:2014 (E) 12 Table 2 —Standard conditions for condensers Standard condition tA1 ût1 ûtsub °C K K SC 1 25 15 ≤ 3 SC 2 25 10 ≤ 3 Table 3 — Standard conditions for gas coolers Standard
condition tA1 °C pR1 bar tR1 °C tR2 °C
SC 10 25 90 110 35 puperheating ûtsup for some selected refrigerants shall be according to Table 4: Table 4 — Superheating values Refrigerant ûtsup K R134a 25 R404A/R507A 25 R407C 35 R410A 40 R717 (NH3) 50 For all other refrigerants this shall be related to superheating that results when the refrigerant is subjected to isentropic compression from – 10 °C evaporating temperature at + 10 °C superheated vapour temperature to + 40 °C condensing temperature. 5.3 Conditions for the nominal air flow rate The nominal air volume flow rate refers to an air temperature of + 20 °C and an atmospheric pressure of 1 013,25 hPa. NOTE 1 For refrigerant R744 (CO2) the optimal high pressure has been taken as the basis for determining the gas cooler inlet temperature. NOTE 2 The air volume flow is not influenced by atmospheric pressure and temperature if the fan speed is constant. 5.4 Conditions for nominal fan power The nominal fan power refers to an air temperature of + 20 °C and to an atmospheric pressure of 1 013,25 hPa. 6 Manufacturer’s data To identify the condenser/gas cooler and to allow its traceability the manufacturer or supplier shall provide the following minimum information for each condenser/gas cooler type: a) manufacturer's identification; SIST EN 327:2014



EN 327:2014 (E) 13 b) model designation of unit; c) model designation of fan; d) rating of the fan motor(s) according to EN 60034-1; e) standard capacity for the standard conditions in the range of application, stating the refrigerants used; f) nominal air flow; g) nominal fan power; h) nominal voltage and frequency; i) total heat transfer surface (air side); j) fin pitch and thickness; k) tube outside diameter and internal enhancement; l) tube pattern; m) circuiting arrangement; n) internal volume including headers; o) installation instructions; p) maximum permissible operating pressure PS. 7 Measurements 7.1 Uncertainty of measurements The permissible uncertainty of significant measurements is given in Table 5: SIST EN 327:2014



EN 327:2014 (E) 14 Table 5 — Uncertainty of measurements Measured quantity Unit Uncertainty of measurements Air —
inlet temperature
°C
± 0,2 K —
other temperatures °C ± 0,5 K Refrigerant —
temperature (general)
°C
± 0,2 K —
pressure for condensers
and gas coolers Pa Pa Shall ensure that the condensing temperature to be obtained within ± 0,2 K and of the gas cooler pressure within ± 1,0 bar —
volume flow ratea
kg/s m3/s ± 2 % Liquid — temperature —
temperature difference
°C K
± 0,2 K ± 0,1 K
—
volume flow ratea m3/s ± 1 %
Electrical quantities
electrical power input W ± 1 % or at least 1 W —
Current —
Voltage —
Frequency A V Hz ± 0,5 %
± 0,5 %
± 0,5 %
Oil content in the refrigerant kg ± 20 % of the measured value Atmospheric pressure hPa ± 5 hPa Fan speed min−1 ± 1 %
a
Also mass flow rate with equivalent uncertainty can be used. 7.2 Measurement criteria 7.2.1 Pipe side temperature measurement Refrigerant temperatures shall be measured using one of the following methods: a) Method A When the temperature is measured on the outside of the connecting pipe it shall be measured at two opposite points of the same cross-section and, if the pipe is horizontal, there shall be one point above and one below. The pipe shall be insulated on each side of the temperature measuring point for a length of at least 10 times of its outside diameter. It shall be ensured, that good thermal contact exists between the sensor and the pipe at the measuring point. The measured value is the arithmetic mean of both individual values. b) Method B When the temperature is measured by a sensor immersed in the pipe, care shall be taken that temperatu
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