1、December 2013 Translation by DIN-Sprachendienst.English price group 15No 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 27.080; 27.200!%*z“2078756www.din.deDDIN EN 13136Refrigerating systems and heat pumps Pressure relief devices and their associated piping Methods for calculation;English version EN 13136:2013,English translation of DIN EN 13136:2013-12Klteanlagen und Wrmepumpen Druckentlastungseinrichtungen und z
3、ugehrige Leitungen Berechnungsverfahren;Englische Fassung EN 13136:2013,Englische bersetzung von DIN EN 13136:2013-12Systmes frigorifiques et pompes chaleur Dispositifs de limitation de pression et tuyauteries associ es Mthodes de calcul;Version anglaise EN 13136:2013,Traduction anglaise de DIN EN 1
4、3136:2013-12SupersedesDIN EN 13136:2005-12www.beuth.deIn case of doubt, the German-language original shall be considered authoritative.Document comprises 35 pages 11.13DIN EN 13136:2013-12 2 A comma is used as the decimal marker. National foreword This document (EN 13136:2013) has been prepared by T
5、echnical Committee CEN/TC 182 “Refrigerating systems, safety and environmental requirements” (Secretariat: DIN, Germany). The responsible German body involved in its preparation was the Normenausschuss Kltetechnik (Refrigera-tion Technology Standards Committee), Working Committee NA 044-00-01 AA Sic
6、herheit und Umweltschutz. Amendments This standard differs from DIN EN 13136:2005-12 as follows: a) Clause 2 “Normative references” has been revised; b) the application of CO2as a refrigerant has been taken into account. Previous editions DIN EN 13136: 2001-09, 2005-12 EUROPEAN STANDARD NORME EUROPE
7、NNE EUROPISCHE NORM EN 13136 October 2013 ICS 27.080; 27.200 Supersedes EN 13136:2001English Version Refrigerating systems and heat pumps - Pressure relief devices and their associated piping - Methods for calculation Systmes frigorifiques et pompes chaleur - Dispositifs de limitation de pression et
8、 tuyauteries associes - Mthodes de calcul Klteanlagen und Wrmepumpen - Druckentlastungseinrichtungen und zugehrige Leitungen -Berechnungsverfahren This European Standard was approved by CEN on 24 August 2013. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate t
9、he 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 Standar
10、d 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 nation
11、al 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, Slova
12、kia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2013 CEN All rights of exploitation in any form and by any means
13、 reserved worldwide for CEN national Members. Ref. No. EN 13136:2013: EEN 13136:2013 (E) 2 Contents Page Foreword . 3 Introduction 4 1 Scope 5 2 Normative references . 5 3 Terms and definitions 5 4 Symbols 6 5 General . 8 6 Pressure relief devices for protection of system components 8 6.1 General .
14、8 6.2 Excessive pressure caused by heat sources . 9 6.2.1 External heat sources 9 6.2.2 Internal heat sources . 10 6.3 Excessive pressure caused by compressors . 11 6.4 Excessive pressure caused by liquid expansion . 11 7 Discharge capacities of pressure relief devices . 12 7.1 General . 12 7.2 Dete
15、rmination of pressure relief valve performance 12 7.2.1 Determination of coefficient of discharge . 12 7.2.2 Critical and sub-critical flow 12 7.2.3 Function of the isentropic exponent (C) . 12 7.2.4 Correction factor for sub-critical flow . 13 7.2.5 Discharge capacity of pressure relief valves 13 7
16、.3 Calculation of capacity and flow area of bursting discs or fusible plugs . 14 7.4 Pressure loss in upstream/downstream lines. 14 7.4.1 General . 14 7.4.2 Pressure loss in components 14 7.4.3 Pressure loss in the upsteam line . 15 7.4.4 Pressure loss in the downstream line . 15 Annex A (normative)
17、 Values of functions, factors and properties of refrigerants . 17 Annex B (informative) Calculation of flow areas for non-evaporating and evaporating liquids 24 B.1 Calculation of the flow area for non-evaporating liquids . 24 B.2 Calculation of the flow area for evaporating liquids . 24 Annex C (in
18、formative) Example of calculation for sizing pressure relief devices with the corresponding pipes 26 C.1 Assumptions for the calculation example. 27 C.2 Calculation of the required minimum discharge capacity, Qmd at standard heat flow rate . 27 C.3 Calculation of the required minimum discharge capac
19、ity Qmd at reduced heat flow rate 28 C.4 Calculation of flow area Ac, selection of pressure relief valve . 28 C.5 Pressure loss in upstream line (from vessel to pressure relief valve). 29 C.6 Pressure loss in downstream line (from pressure relief valve to atmosphere) . 30 Annex ZA (informative) Clau
20、ses of this European Standard addressing essential requirements or other provisions of EU Directives . 32 Bibliography 33 DIN EN 13136:2013-12 EN 13136:2013 (E) 3 Foreword This document (EN 13136:2013) has been prepared by Technical Committee CEN/TC 182 “Refrigerating systems, safety and environment
21、al requirements”, 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 April 2014, and conflicting national standards shall be withdrawn at the latest by April
22、2014. 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 13136:2001. This document has been prepared under a
23、mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s). For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this document. Compared to EN 13136:2001, EN 13136:2013 takes
24、 into account the application of CO2 and the amendment A1, published in 2005. According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic,
25、 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. DIN EN 13
26、136:2013-12 EN 13136:2013 (E) 4 Introduction This European Standard is based on applicable parts of EN ISO 4126-1:2013, EN ISO 4126-2:2003 and EN 12284. It is suited to the specific requirements, and includes the data, of refrigerating systems. It provides means of satisfying the pressure relief dev
27、ices requirements of EN 378-2:2008+A2:2012. DIN EN 13136:2013-12 EN 13136:2013 (E) 5 1 Scope 1.1 This European Standard describes the calculation of mass flow for sizing pressure relief devices for components of refrigerating systems. NOTE The term “refrigerating system“ used in this European Standa
28、rd includes heat pumps. 1.2 This European Standard describes the calculation of discharge capacities for pressure relief valves and other pressure relief devices in refrigerating systems including the necessary data for sizing these when relieving to atmosphere or to components within the system at
29、lower pressure. 1.3 This European Standard specifies the requirements for selection of pressure relief devices to prevent excessive pressure due to internal and external heat sources, the sources of increasing pressure (e.g. compressor, heaters, etc.) and thermal expansion of trapped liquid. 1.4 Thi
30、s European Standard describes the calculation of the pressure loss in the upstream and downstream line of pressure relief valves and other pressure relief devices and includes the necessary data. 1.5 This European Standard refers to other relevant standards in Clause 5. 2 Normative references The fo
31、llowing 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 378-1:2008
32、+A2:2012, Refrigerating systems and heat pumps Safety and environmental requirements Part 1: Basic requirements, definitions, classification and selection criteria EN 378-2:2008+A2:2012, Refrigerating systems and heat pumps Safety and environmental requirements Part 2: Design, construction, testing,
33、 marking and documentation EN 764-1:2004, Pressure equipment Part 1: Terminology Pressure, temperature, volume, nominal size EN 764-2:2012, Pressure equipment Part 2: Quantities, symbols and units EN 12284:2003, Refrigerating systems and heat pumps Valves Requirements, testing and marking EN ISO 412
34、6-1:2013, Safety devices for protection against excessive pressure Part 1: Safety valves (ISO 4126-1:2013) EN ISO 4126-2:2003, Safety devices for protection against excessive pressure Part 2: Bursting disc safety devices (ISO 4126-2:2003) ISO 817, Refrigerants Designation system 3 Terms and definiti
35、ons For the purposes of this document, the terms and definitions given in EN 378-1:2008+A2:2012, EN 12284:2003, EN ISO 4126-1:2013, EN ISO 4126-2:2003 and EN 764-1:2004 apply. DIN EN 13136:2013-12 EN 13136:2013 (E) 6 4 Symbols For the purposes of this document, the symbols given in EN 764-2:2012 and
36、 the following apply: Symbol Designation Unit A Flow area of the pressure relief valve =42dAmm2AcCalculated flow area mm2ADNValve cross section related to DN mm2AinInside area of inlet tube mm2AliqCalculated flow area of liquid after expansion mm2AoutInside area of outlet tube mm2ARInside area of tu
37、be mm2AsurfExternal surface area of the vessel m2AvapCalculated flow area of vapour after expansion mm2C Function of the isentropic exponents (Table A.2) DN Nominal size (see EN ISO 6708:1995) d Actual most narrow flow diameter of the pressure relief valve mm dcCalculated flow diameter of the pressu
38、re relief valve mm dinInside diameter of inlet tube mm doutInside diameter of outlet tube mm DROutside diameter of tube (Table A.4) mm dRInside diameter of tube mm hvapHeat of vaporisation calculated at 1,1 times the set pressure of the pressure relief device (for super critical or superheated condi
39、tions see 6.1) kJ/kg KbTheoretical capacity correction factor for sub-critical flow (Table A.3) KdCertified coefficient of discharge taking into account the backpressure ratio pb/poand the possible reduced stroke of the pressure relief valve KdrDe-rated coefficient of discharge 9,0=ddrKK KdrlDe-rate
40、d coefficient of discharge for liquid 8,0drdrlKK KvsValve constant (the rate of water flow for a differential pressure p of 1 bar at the rated full opening) m3/h KvViscosity correction factor DIN EN 13136:2013-12 EN 13136:2013 (E) 7 K Isentropic exponent of the refrigerant; for calculation, the valu
41、e of K shall be as measured at 25 C and 1,013 bar L Length of tube mm LinLength of inlet tube mm LoutLength of outlet tube mm n Rotational frequency min- 1patmAtmospheric pressure (1 bar) bar pbBack pressure at outlet of pressure relief device, absolute bar pcCritical absolute pressure bar poActual
42、relieving pressure po= 1,1 pset+ patmbar psMaximum allowable pressure of a component, gaugeabar psetSet pressure, gauge (the pre-determined pressure at which a pressure relief valve under operation starts to open) bar P1Pressure at the inlet to downstream line absolute (in practice = pb) bar P2Press
43、ure at the outlet of downstream line absolute bar p Differential pressure bar pinPressure loss in the upstream line of pressure relief valve bar poutPressure loss in the downstream line of pressure relief valve bar QhRate of heat production, internal heat source kW QliqFlow of liquid after expansion
44、 kg/h QmCalculated refrigerant mass flow rate of the pressure relief device kg/h qmTheoretical discharge capacity kg/h mm2qmActual discharge capacity determined by tests kg/h mm2QmdMinimum required discharge capacity, of refrigerant, of the pressure relief device kg/h QmdAdjusted discharge capacity
45、of refrigerant, of the pressure relief device, used for pressure drop calculation kg/h QvapFlow of vapour after expansion kg/h R Bending radius of tube (Table A.4) mm Re Reynolds number s Thickness of insulation m V Theoretical displacement m3voSpecific volume of vapour or liquid m3/kg w0Actual flow
46、 speed of liquid in the smallest section of pressure relief valve m/s w1Speed at the inlet into the downstream line m/s x Vapour fraction of refrigerant at pC DIN EN 13136:2013-12 EN 13136:2013 (E) 8 Flush connection angle (Table A.4) Pressure loss coefficient =nnn1 DNPressure loss coefficient relat
47、ed to DN nPressure loss coefficient of a single component vVolumetric efficiency estimated at suction pressure and discharge pressure equivalent to the pressure relief device setting Friction loss coefficient of tube (plain steel tube 0,02) Kinematic viscosity m2/s Density of vapour or liquid ( = 1/
48、vo) kg/m310Vapour density at refrigerant saturation pressure/dew point at 10 C kg/m3 Density of heat flow rate kW/m2redReduced density of heat flow rate kW/m2aThe Pressure Equipment Directive 97/23/EC identifies the maximum allowable pressure by the symbol “PS“. 5 General Requirements for protection
49、 against excessive pressure in refrigeration systems and heat pumps are given in EN 378-2. For design and manufacturing of bodies, bonnets and bolts for pressure relief devices safety valves and bursting discs specification of strength pressure test, EN 12284 applies. For other aspects, the requirements of EN ISO 4126-1:2013 Safety Valves, Clause 3, Terms and definitions, Clause 5, Design, Clause 7, Type tests and Clause 10, Marking and sealing
