AGA REPORT 10-2003 Speed of Sound in Natural Gas and Other Related Hydrocarbon Gases (XQ0310)《天然气和其他相关碳氢液体中的声速.XQ0310》.pdf

1、 AGA Report No. 10 Speed of Sound in Natural Gas and Other Related Hydrocarbon Gases Catalog # XQ0310 Prepared by Transmission Measurement Committee Copyright 2003 American Gas Association All Rights Reserved 400 North Capitol Street, NW, 4thFloor Washington, DC 20001, USAiiDisclaimers and Copyright

2、 Nothing contained in this publication is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use in connection with any method, apparatus, or product covered by letters patent, or as insuring anyone against liability for infringement of letters patent.

3、The American Gas Associations Transmission Measurement Committee developed this publication as a service to the natural gas industry and to the public. Use of this publication is voluntary and should be taken after an independent review of the applicable facts and circumstances. Efforts have been ma

4、de to ensure the accuracy and reliability of the data contained in this publication; however, the American Gas Association (AGA) makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for loss or damage resul

5、ting from its use or from the use of any product or methodology described herein; for any violation of any federal, state, or municipal regulation with which this publication may conflict; or for the infringement of any patent from the use of this publication. Nothing contained in this publication s

6、hould be viewed as an endorsement by AGA of any particular manufacturers products. Permission is granted to republish material herein in laws or ordinances, and in regulations, administrative orders, or similar documents issued by public authorities. Those desiring permission for other publications

7、should consult the Operating and Engineering Section, American Gas Association, 400 North Capitol Street, NW, 4thFloor, Washington, DC 20001, USA. Copyright 2003 American Gas Association, All Rights Reserved. iiiFOREWORD This report outlines a method for the calculation of the speed of sound in natu

8、ral gas and the individual components that make up natural gas. It also calculates the entropy, enthalpy and C* coefficient for sonic nozzles. This information is based on research that was developed and managed by the Gas Technology Institute (formerly the Gas Research Institute). The research indi

9、cates that the calculation is highly accurate and is consistent with the equation-of-state used in AGA Report No. 8, Compressibility Factors of Natural Gas and Other Related Hydrocarbon Gases. The original work for AGA Report No. 8 was developed under the auspices of the Gas Research Institutes Basi

10、c Fluid Properties Research Program, the AGA Transmission Measurement Committee, the Gas European de Researchers Group (GERG), members of the American Petroleum Institute (API) and the International Standards Organization (ISO). The purpose of this report is to provide the natural gas industry with

11、a method for solving problems involving thermodynamics. Industrys incentive for establishing these methods was spurred by the advent of ultrasonic gas meters. However, the value of these methods is apparent for other applications of natural gas thermodynamics, such as compression. The audience of th

12、e report is gas measurement engineers, especially those supporting ultrasonic meters, as well as those who intend to apply the principles of thermodynamics to gas production, transmission or distribution. The intended benefits to users of this report are: clear traceability to recognized scientific

13、sources extensive testing and validation an implementation example upon which to build The report is based on scientific data collected for pure gases and natural gas mixtures. As such, the range of application is focused on the single-phase natural gas mixtures common to industry. The performance o

14、f the methods is intended to meet the needs of the gas industry. Caution is advised to users applying this technology to other purposes and other fluids. It may become necessary to make revisions to this document in the future. Whenever any revisions are advisable, recommendations should be forwarde

15、d to the American Gas Association, 400 N. Capitol Street, NW, 4thFloor, Washington, DC 20001, USA. A form has been included at the end of this report for that purpose. ivACKNOWLEDGEMENTS AGA Report No. 10, Speed of Sound in Natural Gas and Other Related Hydrocarbon Gases, was developed by an AGA Tra

16、nsmission Measurement Committee task group chaired by Jerry Paul Smith (retired), Williams Gas Pipeline-Transco. AGA is especially thankful for the significant contributions of Warren Peterson, TransCanada PipeLines, who prepared the first draft of this report and wrote the computer program to calcu

17、late the speed of sound and other related properties. He also completed the final version of this report. Those who deserve special recognition and appreciation for their help, suggestions and guidance in finalizing this report are Dr. Eric Lemmon, National Institute of Standards and Technology; Pau

18、l J. LaNasa, CPL Dr. Kenneth Starling, Starling Associates, Inc.; and Dr. Jeff Savidge, Consultant. This report was originally initiated under the chairmanship of late Ron Rich, Natural Gas Pipeline, who could not complete it because of his untimely death. He is respectfully remembered and recognize

19、d for his contributions in initiating this document. Others who participated during the development of this report, reviewed the final draft or provided comments and should also be acknowledged are: Last Name First Name Organization Baldwin Stephen Unocal, Inc.Bowen James W. Instromet, Inc. Bowles,

20、Jr. Edgar B. Southwest Research Inst. Brown Frank CMS EnergyCaldwell Steve CEESI Ceglia Paul GE PanametricsFarestvedt Lars FMC Measurement Solutions French Charles E. Gas Technology Institute Gallagher James E. Savant Measurement Corp. Mercer Dannie Oncor Pipeline Services Moir Kevin MichCon Naber J

21、ohn Daniel Measurement Overgaard Chris NicorPeters Robert J. McCrometerPodgers Alex R. American Meter Co. Poellnitz Henry W. Southern Natural Gas Poon King Thermo Flow Systems Raper Jimmy BP Americas Rebman Daniel H. WGP Transco Sandlin Mike CITGOSchieber, II William M. Solar Turbines, Inc. Stappert

22、 Karl Daniel Measurement Stuart John W. Stuart Consulting Weatherly Dennis El PasoWitte James El PasovThe experimental data and modeling efforts used to develop and analyze both the speed of sound data and the associated models were obtained from various independent laboratories and research sources

23、. Significant amounts of data were obtained through Gas Technology Institutes (formerly the Gas Research Institute) speed of sound and physical properties basic research program. Laboratories in both the United States and Europe carried out the research work. Contributions of all the research organi

24、zations and laboratories are acknowledged. Lori Traweek Ali Quraishi Sr. Vice President Director Operations density at 60 F, 14.73 psia. * Reference Conditions: Combustion at 25 C, 0.101325 MPa; density at 0 C, 0.101325 MPa. # The normal range is considered to be zero for these compounds. Table 1: R

25、ange of Gas Mixture Characteristics Consistent with this Report 2Temperature, C-130 -60 -8 62 120 20020000 140Region 4 1.0%10000 70Region 3 0.5%Pressure, psiaa2500 0.3% 17Region 21750 0.1% 12Region 1-200 -80 17 143 250 400Temperature, FPressure,MPPressure, MPa Figure 1: Targeted Uncertainty for Natu

26、ral Gas Speed of Sound Using the AGA Report No. 10 Method 1.6. Types of Conditions This report is for the gas phase only. The methods can be applied for temperatures from -130 C to 200 C (-200 F to 400 F) at pressures up to 138 MPa (20,000 psia). Application at extreme conditions should be verified

27、by other means (e.g., experimental verification). Use of the calculation method is not recommended within the vicinity of the critical point. For pipeline-quality gas, this is usually not a constraint because operating conditions near the critical point generally are not encountered. 32. Uncertainty

28、 The uncertainty of calculated speed of sound depends on natural gas temperature, pressure and composition. The uncertainties of speed of sound methods were evaluated by comparing calculated values to experimentally measured speed of sound from NIST Monograph 178 7. Calculations were compared with e

29、xperimental measured values for 17 gravimetrically prepared natural gas mixtures, listed in Table 2, over the range of 250 K to 350 K (-10 F to 165 F) and pressures up to 17 MPa (2500 psia). Some of the gas mixtures included in the uncertainty analysis are outside of the range of Table 1. The measur

30、ements conducted demonstrate that the uncertainty in the speed of sound is within 0.1% for Gulf Coast, Amarillo and Ekofisk gases for pressures up to 12 MPa (1750 psia) and temperatures between 250 K and 350 K (-10 F and 165 F). The uncertainty in the speed of sound is also within 0.1% for other gas

31、 mixtures whose characteristics fall within the normal range of Table 1. Higher levels of uncertainty are indicated for gases outside of the normal range of Table 1. Statistical analyses of the differences between calculated and experimental values were performed to evaluate the uncertainties in the

32、 calculated speed of sound values. Statistics were calculated using the following equations where N is the number of data points: 100expexpxWWWWcalcdiff=(2.1) =NiidiffWNBIAS1,1(2.2) ()=NiidiffWNAAD1212,1(2.3) ()2112,11=NiidiffBIASWNDevStd(2.4) where: Wdiff= relative percentage difference between cal

33、culated and experimental speed of sound Wdiff,i= Wdifffor ith data point Wcalc= calculated speed of sound Wexp= experimental speed of sound AAD = average absolute deviation BIAS = bias Std.Dev. = standard deviation 4Gas No. Methane Nitrogen Carbon Dioxide Ethane Propane Isobutane Normal Butane Isope

34、ntane Normal PentaneNormal Hexane 2 0.94985 0 0 0.05015 0 0 0 0 0 03 0.84992 0 0 0.15008 0 0 0 0 0 04 0.68526 0 0 0.31474 0 0 0 0 0 05 0.50217 0 0 0.49783 0 0 0 0 0 06 0.34524 0 0 0.65476 0 0 0 0 0 07 0.90016 0 0 0 0.09984 0 0 0 0 08 0.95114 0.04886 0 0 0 0 0 0 0 09 0.8513 0.1487 0 0 0 0 0 0 0 010 0

35、.71373 0.28627 0 0 0 0 0 0 0 011 0.94979 0 0.05021 0 0 0 0 0 0 012 0.85026 0 0.14974 0 0 0 0 0 0 013 0.69944 0 0.30056 0 0 0 0 0 0 014 0 0.49593 0.50407 0 0 0 0 0 0 015 0.96561 0.00262 0.00597 0.01829 0.0041 0.00098 0.00098 0.00046 0.00032 0.0006716 0.90708 0.03113 0.005 0.04491 0.00815 0.00106 0.00

36、141 0.00065 0.00027 0.0003417 0.8398 0.00718 0.00756 0.13475 0.00943 0.0004 0.00067 0.00013 0.00008 018 0.74348 0.00537 0.01028 0.12005 0.08251 0 0.03026 0 0.00575 0.0023Table 2: Gas Mixture Characteristics Included in Statistical Analysis Gas No. No. Points AAD % Bias % Std. Dev. %2 80 0.021 -0.026

37、 0.0263 67 0.079 0.016 0.1334 95 0.600 0.317 1.0945 78 0.418 0.103 0.8036 72 0.086 -0.011 0.1277 76 0.327 0.144 0.7218 81 0.021 -0.037 0.0269 87 0.024 -0.036 0.02910 97 0.025 -0.023 0.03311 80 0.026 -0.053 0.03812 71 0.024 -0.041 0.03913 90 0.096 -0.009 0.18414 65 0.148 0.230 0.20515 83 0.030 -0.045

38、 0.04016 82 0.031 -0.026 0.05117 91 0.094 0.001 0.15318 44 0.148 0.068 0.224Table 3: Statistical Analysis of the Differences between Calculated and Experimental Speed of Sound Values for 17 Natural Gas Mixtures 53. Calculations 3.1. Symbols TB First partial derivative of B wrt T Second partial deriv

39、ative of B wrt T 22TB First partial derivative of Z wrt T TZ Second partial derivative of Z wrt T First partial derivative of Z wrt 22TZ ZMolar density Isentropic exponent B Second virial coefficient cpConstant pressure heat capacity (real gas) cp Constant pressure heat capacity (ideal gas) cvConsta

40、nt volume heat capacity (real gas) cv Constant volume heat capacity (ideal gas) H Enthalpy (real gas) HoEnthalpy (ideal gas) MrMolar mass P Absolute pressure R Universal gas constant S Entropy (real gas) SoEntropy (ideal gas) T Temperature W Speed of sound XiMole fraction of ith component Z Compress

41、ibility Factor 3.2. Overview of Calculation Method and Sequence The speed of sound is related to the compressibility of a gas and can be computed from its fundamental physical property relationships. The information contained in this report and in AGA Report No. 8 is needed to implement the AGA spee

42、d of sound calculation. The method used in this report utilizes a detail characterization of the gas composition (i.e., a representative gas analysis). As such, implementation is limited to methods provided in the AGA Report No. 8, “Detail Characterization Method.” The reliability of calculation res

43、ults is dependent on the reliability of the gas composition data, temperature data and, to a lesser extent, pressure data. 6Except where noted, all computations are performed in metric units. For conversions to other unit systems, users are referred to applicable documents by NIST10 and the Canadian

44、 Standards Association11. Pure fluid ideal gas heat capacities, enthalpies and entropies are computed from equations given by Aly and Lee3, with the additions given by McFall2. The originally published constants and units of measure have been preserved for this set of equations, necessitating conver

45、sion from thermochemical calories to joules. In this document, all references to the Btu refer to the International Table Btu (Btu(IT). In the appendix to this report, real gas heat capacity, enthalpy and entropy are solved through numerical integration, applying gaussian quadrature. Alternative sol

46、ution methods are feasible but users are advised to carefully evaluate the potential impact on accuracy and robustness. Several partial derivatives are solved during computation. Three of these ( Z T , 22TZ , Z ) are solved using the approach given in AGA Report No. 8 for subroutine “ZDETAIL.” Two o

47、ther derivatives, TB and 22TB are solved as minor additions to subroutine “B,” also given in AGA Report No. 8. The general procedure for computing speed of sound at the flowing or operating condition of interest is: 1. Input the operating temperature (T), operating pressure (P) and gas analysis. 2.

48、Calculate the molar mass of the mixture. 3. Calculate the compressibility and density of the fluid at the conditions of interest. 4. Calculate the ideal gas constant pressure heat capacity at the operating temperature. 5. Calculate the real gas constant volume heat capacity at the operating conditio

49、ns. 6. Calculate the real gas constant pressure heat capacity at the operating conditions. 7. Calculate the ratio of heat capacities, cp/cv, at the operating conditions. 8. Calculate the speed of sound, based on the results of the preceding steps. 9. Calculate the isentropic exponent, . 3.3. Compliance To be compliant with this AGA Report, a computational solution by this or any other method must demonstrate agreement within 50 parts per million of the sound speeds given in Section 8.2, Tabl