BS 1571-2-1975 Specification for testing of positive displacement compressors and exhausters - Methods for simplified acceptance testing for air compressors and exhausters《容积式压缩机与排.pdf

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1、BRITISH STANDARD CONFIRMED APRIL 1984 BS 1571-2: 1975 Incorporating Amendment Nos. 1, 2, 3 and 4 Specification for Testing of positive displacement compressors and exhausters Part 2: Methods for simplified acceptance testing for air compressors and exhausters UDC 621.512:620.1BS1571-2:1975 This Brit

2、ish Standard, having been approved by the Mechanical Engineering Industry StandardsCommittee, was published under the authority ofthe Executive Board on 30April1975 BSI 02-1999 First published July 1949 First published, as Part 2, March1975 The following BSI references relate to the work on this sta

3、ndard: Committee reference MEE/39 Draft for comment 72/33485 ISBN 0 580 08593 7 Co-operating organizations The Mechanical Engineering Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and pr

4、ofessional and industrial organizations: The Government departments and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard. Associated Offic

5、es Technical Committee* Engineering Laboratory* Association of Consulting Engineers* Department of Trade Association of Hydraulic Equipment Electricity Supply Industry in England and Manufacturers Ltd. Wales* Association of Mining Electrical and Engineering Equipment Users Association* Mechanical En

6、gineers Federation of Manufacturers of Construction British Compressed Air Society* Equipment and Cranes British Electrical and Allied Manufacturers Institution of Gas Engineers* Association* Institution of Heating and Ventilating British Gas Corporation* Engineers* British Gear Manufacturers Associ

7、ation Institution of Mechanical Engineers* British Internal Combustion Engine Institution of Plant Engineers Manufacturers Association Institution of Production Engineers British Mechanical Engineering London Transport Executive Confederation Machine Tool Trades Association British Pump Manufacturer

8、s Association Ministry of Defence* British Steel Corporation National Coal Board* British Steel Industry* Process Plant Association Crown Agents for Oversea Governments and Railway Industry Association of Administration Great Britain Department of Employment (HM Factory Royal Institute of British Ar

9、chitects Inspectorate)* Society of Motor Manufacturers and Traders Department of the Environment Ltd. Department of Industry Mechanical Telecommunication Engineering and Engineering Manufacturing Association Department of Industry National British Chemical Engineering Contractors Institute of Mining

10、 and Metallurgy Association Institution of Mining Engineers CBMPE South Wales Institute of Engineering Contractors Plant Association Individual experts Institute of Marine Engineers Amendments issued since publication Amd. No. Date of issue Comments 2219 February 1977 4454 March 1984 5576 August 198

11、7 6879 February 1992 Indicated by a sideline in the marginBS1571-2:1975 BSI 02-1999 i Contents Page Co-operating organizations Inside front cover Foreword ii 1 Scope 1 2 References 1 3 Definitions 1 4 Units and symbols 3 5 Measuring equipment and methods 4 6 Arrangement of tests 6 7 Test procedure 7

12、 8 Test report 7 9 Measurement of air flow using a nozzle in the pipeline 9 Figure 1 Diagrammatic arrangement of test layout for reciprocating compressor 14 Figure 2 Diagrammatic arrangement of test layout for reciprocating exhauster 15 Figure 3 Diagrammatic arrangement of test layout for rotary com

13、pressor 16 Figure 4 Diagrammatic arrangement of test layout for rotary exhauster 17 Figure 5 Arrangement for testing with a nozzle on the delivery side 17 Figure 5a Perforated plate for25.4mm (1in) nozzle 18 Figure 6 Arrangement for testing with a nozzle on the intake 17 Figure 7 Nozzles 25.4mm and

14、larger 17 Figure 8 15.88mm (5/8in) nozzle 17 Figure 9 9.53mm (3/8in) nozzle 17 Figure 10 5.56mm (7/32in) nozzle 17 Table 1 Capacity and specific energy consumption: tolerances for simplified test 2 Table 2 Details of perforated plate 11 Table 3 Dimensions of nozzles 11 Table 4 Rounded nozzle: nozzle

15、 constants and volume flow 12 Table 5 Rounded nozzle: tolerances on inlet volume 12 Publications referred to Inside back coverBS1571-2:1975 ii BSI 02-1999 Foreword BS 1571 was first published in 1949 under the title “Acceptance tests for positive-displacement compressors and exhausters” and this is

16、the second Part of the metric revision. The revision is published in two Parts, Part 1 “Acceptance tests” and Part2“Simplified acceptance tests for air compressors and exhausters”, and it covers the specifications previously contained in BS726 “Measurement of air flow for compressors and exhausters”

17、 and BS1571, both of which will now be withdrawn. This Part of the standard complies with annex A of Part 1:1987 and specifies the conditions under which an air compressor or exhauster can be tested provided that a compressor or exhauster of the same series has already been type tested in accordance

18、 with Part 1 of this standard. Such tests will generally be necessary to verify guarantees given for one or more of the following particulars: a) capacity; b) shaft input power or specific energy consumption; c) speed. A British Standard does not purport to include all the necessary provisions of a

19、contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 20, aninside back

20、 cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on theinside front cover.BS1571-2:1975 BSI 02-1999 1 1 Scope 1.1 General. This standard specifies acceptance tests for positive displac

21、ement air compressors and exhausters, the absolute intake pressures of which exceed approximately 1mbar 1) . In establishing the scope of this standard a positive displacement compressor is considered as a machine where a static pressure rise is obtained by allowing successive volumes of air to be a

22、spired into and exhausted out of an enclosed space by means of the displacement of a moving member. The standard applies to such machines as reciprocating and rotary compressors. 1.2 Guiding principles 1.2.1 Only those measurements necessary to verify any guarantee given by the manufacturer to the p

23、urchaser shall be taken, together with any other observations called for when placing the contract or as may be subsequently agreed between the purchaser and the manufacturer. 1.2.2 The test conditions shall be as close as is reasonably possible to the guarantee conditions, and deviations from these

24、 shall not exceed the limits specified below: speed 5%, absolute intake pressure 5%, temperature of cooling water 8C, pressure ratio 1%. Where it is not feasible to test a machine within the limitations specified above, special conditions of test or special corrections shall be agreed between the pu

25、rchaser and the manufacturer. 1.2.3 The compressor on test will be deemed to be acceptable provided the results obtained do not differ from the type test results by more than the allowances given inTable 1. The need for simplified tests at other than full capacity shall be the subject of agreement b

26、etween the manufacturer and the purchaser. 2 References The titles of the British Standards referred to in this standard are listed on the inside back cover. 3 Definitions For the purposes of this British Standard the following definitions apply. 3.1 total pressure the pressure measured at the stagn

27、ation point when a moving air stream is brought to rest and its kinetic energy is converted by an isentropic compression from the flow condition to the stagnation condition. It is the pressure usually measured by a pitot tube. In a stationary body of air the static and the total pressures are numeri

28、cally equal 3.2 static pressure the pressure measured in such a manner that no effect on measurement is produced by the air velocity 3.3 dynamic (velocity) pressure the total pressure minus the static pressure 3.4 atmospheric pressure the absolute pressure of the atmosphere measured at the test plac

29、e 3.5 gauge (effective) pressure the pressure measured above the atmospheric pressure 1) 1mbar = 10 2N/m 2= 0.1kPa.BS1571-2:1975 2 BSI 02-1999 3.6 absolute pressure the pressure measured from absolute zero, i.e. from absolute vacuum. It equals the algebraic sum of atmospheric pressure and gauge pres

30、sure 3.7 vacuum the difference between the atmospheric pressure and the absolute pressure when the latter is the smaller Table 1 Capacity and specific energy consumption: tolerances for simplified test 3.8 standard inlet point the inlet point considered representative for each compressor. This point

31、 varies with compressor design and types of installation NOTE 1The standard inlet point of a stationary compressor is generally at the inlet flange. NOTE 2The standard inlet point of a portable compressor is a point close to the compressor chosen so that the thermometer is unaffected by the compress

32、or operation. 3.9 standard discharge point the discharge point considered representative for each compressor. This point varies with compressor design and type of installation NOTE 1The standard discharge point of a stationary compressor is generally at the compressor discharge flange. NOTE 2The sta

33、ndard discharge point of a portable compressor is the outlet valve on the air receiver. 3.10 inlet pressure the average absolute total pressure at the standard inlet point NOTEThe absolute total pressure may be replaced by the absolute static pressure if it can be shown that the effect on the test r

34、esults is insignificant in relation to the accuracy of testing. 3.11 discharge pressure the average absolute total pressure at the standard discharge point NOTEThe absolute total pressure may be replaced by the absolute static pressure if it can be shown that the effect on the test results is insign

35、ificant in relation to the accuracy of testing. 3.12 pressure ratio the ratio of the discharge pressure to the inlet pressure NOTE 1Stage pressure ratio is the pressure ratio for any particular stage in a multistage compressor, the discharge pressure being taken before the intercooler. NOTE 2The ove

36、rall stage pressure ratio is the pressure ratio for any particular stage in a multistage compressor, the discharge pressure being taken after the intercooler (including separators). 3.13 total temperature the temperature that would be measured at the stagnation point if the air stream were brought t

37、o rest and its kinetic energy converted by an isentropic compression from the flow condition to the stagnation condition Compressor shaft input at normal load 100% capacity 50% capacity Capacity Specific energy consumption Capacity Specific energy consumption No load power Below 10 kW 10 kW to 100 k

38、W Above 100 kW % 6 5 4 % 7 6 5 % 7 5 % 7 6 % 20 20 20BS1571-2:1975 BSI 02-1999 3 3.14 inlet temperature the total temperature at the standard inlet point of the compressor 3.15 discharge temperature the total temperature at the standard discharge point of the compressor 3.16 free air air at the atmo

39、spheric conditions of the site and unaffected by the compressor 3.17 capacity of a compressor. (Free air delivered, F.A.D.) the actual volume rate of flow of air compressed and delivered at the standard discharge point, referred to conditions of total temperature, total pressure and composition (e.g

40、. humidity) prevailing at the standard inlet point. 3.17.1 capacity of a vacuum pump the actual volume rate of flow of air aspired and compressed by the first stage of a vacuum pump and referred to conditions of total temperature, total pressure and composition (e.g. humidity) prevailing at the stan

41、dard inlet point NOTEIt is normally assumed that the final stage of the vacuum pump discharges to a pressure of 1 bar 2)absolute. 3.18 shaft input power (absorbed power) the power required at the compressor drive shaft. Losses in external transmissions such as gears and belt drives are not included

42、4 Units and symbols 4.1 General. For the purposes of this standard the units, symbols and subscripts of4.2 and4.3 apply. The list takes into account the following requirements. a) The same symbols shall be used for the same quantities regardless of the units used. b) For any one quantity a single sy

43、mbol shall be used with subscripts added to indicate all values other than the primary one. c) The same symbols shall be used for a given concept regardless of the number of special values which occur. d) Letter subscripts shall be used to denote values under special conditions. e) Numerical subscri

44、pts shall be used to denote values at different points of a cycle. f) In general, capital letters denote absolute quantities, unless there are other overriding considerations. 4.2 Units and symbols 2) 1 bar = 10 5N/m 2= 100 kPa. Symbol Description Unit h Nozzle pressure drop mmH 2 O p Pressure bar (

45、inmmHg for9.5.2) P Power W, kW q Capacity (volume rate of flow, F.A.D.) litre/s T Thermodynamic temperature, absolute temperature K t Temperature CBS1571-2:1975 4 BSI 02-1999 4.3 Subscripts 5 Measuring equipment and methods 5.1 Measurement of temperature 5.1.1 Methods 5.1.1.1 In general, mercury-in-

46、glass thermometers with etched stems, graduated with scales suitable for the measurements to be made, shall be employed for all measurements. 5.1.1.2 Commercial or industrial metal-encased thermometers shall not be used. 5.1.1.3 The thermometers shall be inserted directly into the air stream or, whe

47、n this is not applicable, small thermometer pockets of thin steel tube shall be used. The pockets shall be clean and free from corrosion or oxide. They shall normally be filled with oil; if the temperature is likely to cause evaporation of the oil, mercury shall be used. Where the oblique position o

48、f the pockets does not allow liquid filling, copper-powder may be used. The thermometers or the pockets shall extend into the pipe a distance of100mm or one third the diameter of the pipe, which ever dimension is the less (seealso9.4.5). 5.1.1.4 In taking readings, the thermometer shall not be lifte

49、d out of the medium being measured, or out of the pocket, when such is used. 5.1.1.5 All thermometers shall be calibrated for their appropriate temperature range. 5.1.1.6 Other methods of temperature measurement may be used and are described inBS1041. 5.1.2 Precautions to be observed. Precautions shall be taken to ensure that: a) no appreciable quantity of heat is transmitted by radiation or conduction to or from the thermometer, other than that of the medium being measured; b) the immediate vi