1、BRITISH STANDARD BS ISO 14164:1999 Stationary source emissions Determination of the volume flowrate of gas streams in ducts Automated method ICS 13.040.40; 17.120.10BSISO 14164:1999 This British Standard, having been prepared under the directionof the Health and Environment Sector Committee, was pub
2、lished under the authorityof the Standards Committee and comes into effect on 15August1999 BSI 03-2000 ISBN 0 580 32793 0 National foreword This British Standard reproduces verbatim ISO14164:1999 and implements it as the UK national standard. The UK participation in its preparation was entrusted to
3、Technical Committee EH/2, Air quality, to Subcommittee EH/2/1, Stationary source emissions, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK
4、 interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications
5、 referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions
6、of a 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, theISO title page, pag
7、es ii to iv, pages 1 to 10 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 the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSISO 14164:1999 BSI 03-2000 i
8、 Contents Page National foreword Inside front cover Foreword iii Text of ISO 14164 1ii blankBSISO 14164:1999 ii BSI 03-2000 Contents Page Foreword iii 1 Scope 1 2 Normative references 1 3 Terms and definitions 1 4 Measuring principles of commercially available AMS 2 5 Numerical performance character
9、istics and their applicability 4 6 Test report 5 Annex A (normative) Determination of the main performance characteristics 6 Annex B (informative) Additional performance characteristics 9 Bibliography 10 Table 1 Main performance characteristic of continuous flow measuring systems 5 Table B.1 Additio
10、nal performance characteristics 9BSISO 14164:1999 BSI 03-2000 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical
11、committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with
12、the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part3. Draft International Standards adopted by the technical committees are circulated to the mem
13、ber bodies for voting. Publication as an International Standard requires approval by at least75% of the member bodies casting a vote. International Standard ISO14164 was prepared by Technical Committee ISO/TC146, Air quality, Subcommittee SC1, Stationary source emissions. Annex A forms a normative p
14、art of this International Standard. Annex B is for information only.iv blankBSISO 14164:1999 BSI 03-2000 1 1 Scope This International Standard describes the operating principles and the most important performance characteristics of automated flow-measuring systems for determining the volume flowrate
15、 in the ducts of stationary sources. Procedures to determine the performance characteristics of automated volume flow-measuring systems are also contained in thisInternational Standard. The performance characteristics are general and not limited to specific measurement principles or instrument syste
16、ms. NOTECommercial systems which use the operating principles described and meet the requirements of this International Standard are readily available. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this Int
17、ernational Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative docume
18、nts indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 6879:1995, Air quality Performance characteristics and related concepts for air quality measuring m
19、ethods. ISO 7935:1992, Air quality Stationary source emissions Determination of mass concentration of sulfur dioxide Performance characteristics of automated measuring methods. ISO 9096:1992, Stationary source emissions Determination of concentration and mass flow rate of particulate material in gas
20、-carrying ducts Manual gravimetric method. ISO 9169:1994, Air quality Determination of performance characteristics of measurement methods. ISO 10155:1995, Stationary source emissions Automated monitoring of mass concentrations of particles Performance characteristics, test methods and specifications
21、. ISO 10780:1994, Air quality Stationary source emissions Measurement of velocity and volume rate of flow of gas streams in ducts. ISO 10849:1996, Stationary source emissions Determination of the mass concentration of nitrogen oxides Performance characteristics and calibration of automated measuring
22、 systems. ISO 12039:, Stationary source emissions Determination of the volumetric concentration of CO, CO 2and O 2 Performance characteristics and calibration of automated measuring systems 1) . 3 Terms and definitions For the purposes of this International Standard, the following terms and definiti
23、ons apply. 3.1 automated flow-measuring system AMS system that may be attached to a duct to continuously measure and record the volume flow of a gas 3.2 analyzer that part of an AMS that measures the parameters used to calculate the volume flow of a gas 3.3 duct stack, chimney or final exit duct on
24、a stationary process, used for the dispersion of residual process gases 3.4 comparative measurements measurements of volume gas flow in the duct by the AMS under test (evaluation) and compared to volume flow simultaneously determined in the same duct in accordance with ISO10780 3.5 comparative metho
25、d method for determination of volume gas flow in a duct in accordance with ISO10780 NOTESince the purpose of the comparative test is to demonstrate that the AMS under test yields an accurate estimate of the volume flow in the duct, it is necessary for the comparative method to measure the volume flo
26、w profile of the entire duct. An AMS cannot be used as the comparative method because all AMS used for measuring volume flow measure the velocity in a small area of the duct and then extrapolate this measurement to obtain the volume flow in the duct. 3.6 standard deviation s A a measure of the worki
27、ng precision of the installed AMS 1) To be published.BSISO 14164:1999 2 BSI 03-2000 NOTE 1It is derived using the differences between the pairs of volume flow values obtained by comparative testing of the AMS against ISO10780 on the basis that a statistically sufficient number of comparative measure
28、ments are taken over the period of unattended operation (seeAnnex A). The value of s Ais expressed as a function of the full-scale range of the AMS and is calculated on the assumption that s Ais an estimate of the precision of a normally distributed set of measurements. NOTE 2Whenever possible, the
29、comparative method should measure the same portion of the gas flow as the AMS. NOTE 3It is not possible to determine directly the standard deviation of an AMS in a laboratory, because wind tunnels do not normally reproduce all the properties of stack gases and do not replicate all possible measureme
30、nt conditions. This is the reason the standard deviation is determined after the AMS has been installed in the duct. Applying the comparative method in conjunction with the test for systematic errors (seeA.4.2.3) ensures that the AMS has a satisfactory accuracy. NOTE 4In addition to random error, s
31、Acontains the effect that local site variables such as changes in the gas steams temperature, fluctuations in the electrical power supplied to the AMS and zero and span drift have on the overall precision of the AMS. It also includes the standard deviation of the comparative method. s Ais an estimat
32、e of the upper limiting value for the precision of the AMS. NOTE 5The procedure in this International Standard is suitable for finding the uncertainty of the data obtained from the AMS, as long as the standard deviation of the measured values of the comparative method, s C , is significantly smaller
33、 than the standard deviation, s D , of the difference between the pairs of measured values. 3.7 period of unattended operation period for which given values of the performance characteristics of an instrument can be guaranteed to remain within95% probability without servicing or adjustment ISO 6879
34、NOTEFor long-term monitoring installations, a minimum of seven days of unattended operation is required. 3.8 response time time it takes the AMS to display90% of the high-level calibration value on the data acquisition system, starting from the time of initiation of the high-level calibration cycle
35、NOTEThe response time may be determined either in the laboratory or after the AMS is installed. 3.9 stationary source emission gas emitted by a stationary plant or process and transported to a duct for dispersion into the atmosphere 3.10 calibrationthe setting and checking of the installed AMS befor
36、e determining its performance characteristics or before beginning any volume flow measurement 3.11 calibration function correlation over the span range of the AMS between the volume flowrate of the duct as measured by the installed AMS and as measured in accordance with the reference flowrate NOTE 1
37、ISO10780 is an example of a reference flow standard. NOTE 2A nonlinear calibration function is acceptable, provided this nonlinearity is compensated for in the output of the AMS. 3.12 linearity measure of the degree of agreement between the measurements of the comparative method (ISO10780) and the A
38、MS when the differences between the AMS and the comparative method across a range of volume flows are subjected to a linear regression 3.13 span difference between the AMS output (reading) for a known flowrate and a zero flowrate 3.14 zero drift change in the output of the AMS over a stated time int
39、erval when exposed to an unchanging zero flowrate 3.15 span drift change in the output of the AMS over a stated time interval when exposed to an unchanging flowrate near the span value 3.16 AMS location point in the duct where the AMS is installed 4 Measuring principles of commercially available AMS
40、 4.1 General Most commercially available AMS operate on one of the following three principles: pressure differential, rate of heat loss, or change in the speed of a sound wave. A brief description of each common type of AMS and the advantages and disadvantages of each are presented below. Before sel
41、ecting a specific type of AMS for installation, the characteristics of the flow profile shall be established at the location in the duct where the AMS is to be installed (see clauseA.2 in Annex A). Volume flow-measuring AMS systems should not be used in ducts where non-uniform, asymmetrical, develop
42、ing, swirling and/or stratified flow is present.BSISO 14164:1999 BSI 03-2000 3 4.2 Differential pressure-sensing systems 4.2.1 Single Pitot tube methods ISO10780, the manual reference method for measuring velocity and volume flow in ducts, uses Pitot tubes, the traditional means used to determine fl
43、ow in ducts. A number of Pitot tubes are available, but the Type-S and Type-L Pitot tubes specified in ISO10780 are those used for the vast majority of flow measurements in ducts. Some Pitot tube-based AMS simply combine devices which continuously record the pressure differential and the stack tempe
44、rature, an automated data reduction system such as a data-logger or a computer, and a Pitot tube to yield a continuous measurement of flowrate. Pitot tubes use the temperature of the gas stream and the difference in pressure measured at two or more points on the Pitots surface to determine the veloc
45、ity of the gas stream at individual points across a cross-section of the duct. The volume flowrate is then determined by multiplying the average velocity across the cross-section by the area of this cross-section. These systems are simple and relatively inexpensive to install, operate and maintain,
46、but are subject to the same errors as the Pitot tubes described in clause6 of ISO10780:1994. For example, unless special precautions are taken, Pitot tubes can give erroneous results when used to measure gas streams having any of the following conditions: a) Reynolds numbers less than1200; b) veloci
47、ties less than5m/s or greater than50m/s; c) cyclonic or angular flow; d) irregular pressure fluctuations; and e) high concentrations of particles and/or aerosols. These latter two problem areas frequently can be avoided by ensuring that the Pitot tube does not vibrate and by periodically back-purgin
48、g through the Pitot tube. Gas stream pressure fluctuations can be compensated for by employing a damping device in the measurement system. 4.2.2 Multiple-point Pitot tube (MPPT) method The MPPT is a modified form of the Pitot tube; it contains three or more openings (ports) in a pipe, located at the
49、 traverse points corresponding to the centres of equal areas of the stack cross-section. The openings facing in the direction of flow give the average impact pressure across the stack diameter, while those facing away from the direction of flow give the average wake pressure. A divider in the centre of the tube separates the two pressure legs of the MPPT. The average impact and wake pressures are compared using an electrical pressure transducer or other differential pressure-sensing device. Since the orifice locations are different for
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