BS PD CEN TR 13930-2009 Rotodynamic pumps nDesign of pump intakes Recommendations nfor installation of npumps《转子动力泵 泵吸入口的设计 泵的安装建议》.pdf

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1、PD CEN/TR 13930:2009 ICS 23.080 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW PUBLISHED DOCUMENT Rotodynamic pumps Design of pump intakes Recommendations for installation of pumps Incorporating corrigendum June 2010National foreword This Published Document is the UK implemen

2、tation of CEN/TR 13930:2009, incorporating corrigendum June 2010. The UK participation in its preparation was entrusted to Technical Committee MCE/6, Pumps and pump testing. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not p

3、urport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. PD CEN/TR 13930:2009 This Published Document was published under the authority of the Standards Policy an

4、d Strategy Committee on 28 February 2009 BSI 2010 Amendments/corrigenda issued since publication Date Comments 31 August 2010 Implementation of CEN/TR corrigendum June 2010; Figure 23 a) replaced ISBN 978 0 580 71461 0TECHNICAL REPORT RAPPORT TECHNIQUE TECHNISCHER BERICHT CEN/TR 13930 January 2009 I

5、CS 23.080 Supersedes CR 13930:2000 English Version Rotodynamic pumps - Design of pump intakes - Recommendations for installation of pumps Pompes rotodynamiques - Conception des ouvrages daspiration - Recommandations dinstallation des pompes Kreiselpumpen - Gestaltung der Einlaufbauten - Empfehlungen

6、 zur Installation der Pumpen This Technical Report was approved by CEN on 13 October 2008. It has been drawn up by the Technical Committee CEN/TC 197. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Gree

7、ce, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Manageme

8、nt Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN/TR 13930:2009: E Incorporating corrigendum June 2010PD CEN/TR 13930:2009 CEN/TR 13930:2009 (E) 2 Contents Page Foreword 3 Introducti

9、on . 4 1 Scope 5 2 General 5 2.1 Factors which influence the operation of the plant . 5 2.2 General design principles for a pumping plant 6 3 Plant with vertical suction inlet 7 3.1 General arrangements . 7 3.2 Diameter (D) at the entrance of the bellmouth or the tapered suction. 9 3.3 Distance (C)

10、between the bellmouth or the tapered suction inlet and floor 10 3.4 Distances between suction inlet axis and walls . 11 3.4.1 Distance (L) between suction inlet axis and side walls . 11 3.4.2 Distance (E) between suction inlet axis and rear wall . 11 3.5 Submergence (S) . 11 3.5.1 Conditions to be s

11、atisfied for the determination of submergence . 11 3.5.2 Determination of submergence (S) 12 3.6 Strainer . 12 3.7 Feed intake - Pump environment . 13 3.7.1 Feed intake . 13 3.7.2 Immediate environment of the pump . 20 3.8 Case of pumping plant with vertical suction inlet and flow rate less than 50

12、m 3 /h 23 4 Plant with intake with top suction inlet . 23 5 Plant with intake with floor suction inlet . 24 5.1 Bellmouth . 25 5.2 Submergence of horizontal plate . 25 5.3 Special anti-vortex devices . 25 6 Plant with intake with wall suction inlet 25 6.1 Shape and position of suction inlet . 25 6.2

13、 Submergence . 27 6.3 Special anti-vortex devices . 27 Bibliography 29 PD CEN/TR 13930:2009 CEN/TR 13930:2009 (E) 3 Foreword This document (CEN/TR 13930:2009) has been prepared by Technical Committee CEN/TC 197 “Pumps”, the secretariat of which is held by AFNOR. Attention is drawn to the possibility

14、 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 CR 13930:2000. PD CEN/TR 13930:2009 CEN/TR 13930:2009 (E) 4 Introduction In addition to the risks

15、of cavitation that may exist at the intake of any pump depending on the NPSH available, pumping from a sump poses specific problems. In fact, if the water passes from a flow state with an exposed surface to flow under pressure, significant swirling movements may occur and sometimes be amplified, thu

16、s creating a sort of funnel or vortex which opens out into the exposed surface of the sump with a risk of air being entrained or creating a swirling chimney, or whirl between the bottom and the intake producing degassing or vaporisation of the liquid in the entrance of the pump (see Figures 1a) and

17、1b) below). These phenomena, which are generally unsteady, can have unwanted effects on the plant: undesirable vibration of various pump components; increased risk of cavitation; drop in efficiency; reduction in flow rate and/or head; risk of floating bodies being sucked in; intense and irregular no

18、ise. Compliance with the recommendations in this document makes it possible, in most commonly encountered industrial applications, to avoid or at least limit the phenomena mentioned above. 1a) Vortex causing entrainment of air in suction piping 1b) Chimney or whirl between the floor and the suction

19、inlet Figure 1 Types of possible disturbances PD CEN/TR 13930:2009 CEN/TR 13930:2009 (E) 5 1 Scope 1.1 This technical Report contains recommendations for the design of pump intakes and the installation of pumps. As far as possible, these recommendations should be adhered to in order to obtain correc

20、t operation of the plant. These recommendations are applicable regardless of the flow rate of the plant: plant which works with clear water (or relatively unclouded) and relatively non-aerated water or any other liquid having physical and chemical properties which are similar to those of water; NOTE

21、 This document nevertheless contains several general recommendations for operation with cloudy (or very cloudy) water. pumping plant which has its own floor. 1.2 This document deals with various intake configurations: Clause 3 contains recommendations which apply to intakes with vertical suction inl

22、et; Clause 4 contains recommendations applicable to intakes with top suction inlet; Clause 5 contains recommendations applicable to intakes with floor suction inlet; Clause 6 contains recommendations applicable to intakes with side-wall suction inlet. 2 General 2.1 Factors which influence the operat

23、ion of the plant The following factors have an effect on the operation of the plant: a) Characteristics and position of the suction inlet: arrangements of the suction inlet (vertical with bellmouth or tapered suction, top, floor or side-wall intake); presence or absence of a bellmouth or tapered suc

24、tion; distance between suction inlet and floor; distance between suction inlet and side-walls; submergence (level of liquid relative to suction inlet); strainer. b) Inflow of liquid to the intake: inflow velocity of the liquid; shapes and dimensions of inflow; PD CEN/TR 13930:2009 CEN/TR 13930:2009

25、(E) 6 position of inflow. c) Environment of the pump in the plant: velocity of liquid close to the pump; shapes and dimensions of the plant; special devices (gratings), anti-vortex device; relative positions of pumps to each other and in the plant. Clauses 3 to 6 below contain recommendations concer

26、ning the determining factors for each arrangement of the suction inlet. NOTE If the liquid is charged with solid particles in suspension, the following recommendations may be amended. Prevent the velocity of the fluid falling below a value which allows the deposition of solid materials. A minimum va

27、lue of 0,7 m/s close to the suction inlet is currently admitted. 2.2 General design principles for a pumping plant In order for the pump to be fed under the best possible conditions, effort should be made to obtain a permanent, uniform and even flow in the suction pipe. To achieve this, it is necess

28、ary to: supply the suction pipe for each pump with a balanced flow which is free from swirl; ensure that the water accelerates gradually along the intake; any deceleration generates flow instabilities; avoid any entrainment of air by suction (vortex) or by churning (weir). Ensure that these conditio

29、ns are adhered to as closely as possible regardless of the operating conditions of the plant (one or more pump(s) working, one or more intake sluice(s) or filter(s) in service, high water level or low water level, etc.). The stipulations in the following clauses are aimed at achieving this. In those

30、, inevitably numerous, situations that are not dealt with in this document, the plant designer should adopt the following principles: a) in water inflows intakes, stay within moderate velocities which allow gradual acceleration: examples of such velocities are those of the order of 0,3 m/s in the ap

31、proach channel, 0,5 m/s in the strainer, 1,5 m/s in the bellmouth or tapered suction, and 4 m/s in the suction pipe; b) avoid excessively large chambers and dead zones which generate overall swirl in the flow and vortices as well as the deposition of solids if the water contains substances in suspen

32、sion; c) prevent separation by avoiding sudden widening and excessively divergent angles by preferring shaped forms for pillars, low walls, bellmouth or tapered suction, etc; d) avoid sudden changes in direction caused, for instance, by lateral feed and excessively sloping falls; e) eliminate any ob

33、stacle which might interfere with flow over a sufficient distance (of the order of 10 times the diameter D at the entrance to the bellmouth or tapered suction) before the suction pipe; f) avoid any asymmetry in the mode of operation as well as in the design of structures; g) at the entrance to the s

34、uction pipe, ensure an adequate submergence for the minimum working level and increase the submergence recommended below in this standard significantly if flow conditions are mediocre; h) if a chamber is fed with water by an overflow, ensure that the later does not entrain air and provide a baffle d

35、evice. PD CEN/TR 13930:2009 CEN/TR 13930:2009 (E) 7 It is far preferable to design a plant which is intrinsically problem-free from the outset rather than to rely on baffles or anti-vortex accessories which are often only a palliative offering efficiency which is difficult to predict. In difficult c

36、ases and if the importance of the plant justifies it, it is recommended to use a reduced model to check whether there is any need to improve the arrangements made. 3 Plant with vertical suction inlet 3.1 General arrangements In these configurations the presence of a bellmouth is necessary but altern

37、atively, the bellmouth may be replaced by a tapered suction. Installations with a vertical suction are shown diagrammatically in Figures 2 and 3. a) The pump design may be: axial flow without exceeding the outside diameter of the bellmouth or tapered suction greatest diameter; centrifugal or mixed f

38、low with bellmouth possibly wider than diameter of the bellmouth or tapered suction greatest diameter. b) The position of the pump on the piping can be: horizontal or vertical; immersed or not immersed. Figure 2 Vertical suction inlet with bellmouth - Normal configuration PD CEN/TR 13930:2009 CEN/TR

39、 13930:2009 (E) 8 3a) Centrifugal impeller a )a) The number of stages is stated for information only 3b) Mixed-flow impeller a )a) The number of stages is stated for information only 3c) Axial flow impeller a )a) The number of stages is stated for information only 3d) Non-immersed horizontal pump 3e

40、) Non immersed vertical pump 3f) Non immersed vertical pump 3g) Immersed vertical pump Figure 3 Vertical suction inlet with bellmouth (or with tapered suction) - Example of possible configurations PD CEN/TR 13930:2009 CEN/TR 13930:2009 (E) 9 3.2 Diameter (D) at the entrance of the bellmouth or the t

41、apered suction Figure 4 shows typical profile of bellmouth. Figure 4 Bellmouth The diameter D at the entrance to the bellmouth is a result of the bellmouth profile, which is generally a quarter ellipse of which the short and long axes have the values 2a and 2b respectively. If D ois the diameter of

42、the piping at the entrance to the impeller of the pump, the value of D is generally between 1,4 D o and 1,8 D oinclusive, the most common values are between 1,5 D oand 1,6 D o inclusive. It is this value which is used as a reference for the recommendations given in sub-clause 3.3 and so on. As an al

43、ternative of a suction by bellmouth, Figure 5 illustrates typical profile of tapered suction. Figure 5 Alternative with tapered suction PD CEN/TR 13930:2009 CEN/TR 13930:2009 (E) 10 3.3 Distance (C) between the bellmouth or the tapered suction inlet and floor Figure 6 indicates the recommended dimen

44、sions between suction inlet and the floor, in the case of a bellmouth. Figure 6 Distance between the bellmouth and the floor The distance (C) between the suction inlet and the floor should be between 0,25 and 0,5 times the diameter (D) at the entrance to the bellmouth; the most common values are bet

45、ween 0,4 and 0,5 D inclusive. NOTE In the case of an intake on a natural floor (river, pond, sea, etc.) where there is always a risk of filling with sand, silting up or changing water levels, the distance (C) should be increased. Its value should be specified jointly with the pump manufacturer. As a

46、n alternative of bellmouth suction, the case of tapered suction inlet is illustrated by Figure 7. Figure 7 Distance between the tapered suction inlet and the floor PD CEN/TR 13930:2009 CEN/TR 13930:2009 (E) 11 3.4 Distances between suction inlet axis and walls Figure 8 indicates the dimensions betwe

47、en suction inlet axis and walls. Key 1 Rear wall 2 Water inflow Figure 8 Distance between suction inlet axis and walls 3.4.1 Distance (L) between suction inlet axis and side walls The recommended dimension (L) is 1 D. 3.4.2 Distance (E) between suction inlet axis and rear wall The recommended dimens

48、ion (E) is 0,75 D. NOTE If cloudy or very cloudy water is sucked in, consult the pump manufacturer before specifying dimensions (L) and (E). In fact, it is necessary to take into account the risks of the pump feed being disturbed if deposits form (see note to sub-clause 2.1). 3.5 Submergence (S) 3.5

49、.1 Conditions to be satisfied for the determination of submergence Figure 9 shows a typical submergence. Key S = 1 D to 1,5 D Figure 9 Submergence PD CEN/TR 13930:2009 CEN/TR 13930:2009 (E) 12 The submergence value (S) should satisfy two conditions: a) the NPSH available should exceed the NPSH required at the maximum fl