DIN 51900-2-2003 Testing of solid and liquid fuels - Determination of the gross calorific value by the bomb calorimeter and calculation of the net calorific value - Part 2 Method u.pdf

1、Ref. No. DIN 51900-2 : 2003-05English price group 08 Sales No. 010801.04DEUTSCHE NORM May 200351900-2Continued on pages 2 to 7. No part of this translation may be reproduced without the prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has t

2、he exclusive right of sale for German Standards (DIN-Normen).Determining the gross calorific value of solid andliquid fuels using the isoperibol or static-jacketcalorimeter, and calculation of net calorific valueTranslation by DIN-Sprachendienst.In case of doubt, the German-language original should

3、be consulted as the authoritative text.ICS 75.160.10; 75.160.20Prfung fester und flssiger Brennstoffe Bestimmung desBrennwertes mit dem Bomben-Kalorimeter und Berechnung desHeizwertes Teil 2: Verfahren mit isoperibolem oder static-jacketKalorimeterIn keeping with current practice in standards publis

4、hed by the International Organization for Standardization(ISO), a comma has been used throughout as the decimal marker.ForewordThis standard has been prepared by Technical Committee Prfung fester Brennstoffe of the Normenaus-schuss Materialprfung (Material Testing Standards Committee).AmendmentsThis

5、 standard differs from the August 1977 edition in that it has been revised in form and substance, withaccount being taken of the specifications of DIN 51900-1 and the Regnault-Pfaundler evaluation method asthe standard method.Previous editionsDIN DVM 3716: 1931-08; DIN DVM 3716 = DIN 53716: 1938-05;

6、 DIN 51708: 1950x-08, 1956-04; DIN 51900:1966-04; DIN 51900-2: 1977-08.References to DIN 51900-1 are to the April 2000 edition.1 ScopeThis standard specifies a method of determining the gross calorific value of solid and liquid fuels using anisoperibol or static-jacket calorimeter and of calculating

7、 the net calorific value. It may also be applied to othersolid or liquid substances.2 Normative referencesThis standard incorporates, by dated or undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text, and the titles of the pu

8、blications arelisted below. For dated references, subsequent amendments to or revisions of any of these publicationsapply to this standard only when incorporated in it by amendment or revision. For undated references, thelatest edition of the publication referred to applies.DIN 51900-1 Determination

9、 of gross calorific value of solid and liquid fuels using the bomb calorimeter,and calculation of net calorific value Part 1: General informationDIN EN 61010-1 Safety requirements for electrical equipment for measurement, control and laboratoryuse Part 1: General requirements (IEC 61010-1 : 2001)Sup

10、ersedes August 1977edition.Page 2DIN 51900-2 : 2003-053 PrincipleThe calorimetric bomb prepared as specified in DIN 51900-1 is placed in a calorimeter can, which is filled withwater and surrounded by an isoperibol or static insulating jacket. After the temperature has equalized and thefore period ha

11、s elapsed, the fuel sample is fired and the increase in temperature is recorded. Recording isterminated at the end of the after period. The gross calorific value of the sample material is calculated from thecorrected temperature rise and the effective heat capacity of the calorimeter.NOTE: The speci

12、fied method using an isoperibol or static-jacket calorimeter covers all procedures in which thetemperature of the calorimeter can differs from that of the jacket. As a result of the temperature difference,it is necessary to correct the rise in temperature for the heat exchange 1.4 ApparatusThe appar

13、atus shown below is only intended to illustrate the principle; details will vary from one manufacturerto another.4.1 Bomb calorimeter with isoperibol jacketKey1 Crucible containing the sample2 Ignition device3 Calorimeter jacket4 Calorimeter can filled with water5 Bomb16 Lid17 Stirrer18 Evaluating u

14、nit19 Temperature measuring device in calorimeter can10 Temperature measuring device in calorimeter jacketFigure 1: Bomb calorimeter with isoperibol jacket4.2 Calorimeter can, designed for accommodating the calorimeter bomb and water as heat transfer medium.4.3 Calorimeter with isoperibol or static

15、jacket, for enclosing the calorimeter can and thermally insulatingit from the surroundings. It is composed of water or some other suitable material. For both types of apparatus,heat exchange occurs between the calorimeter can and the jacket, with the thermal resistance between the tworemaining const

16、ant and being reproducible.Isoperibol calorimeters have a temperature-controlled jacket adjusted to a particular temperature.The jacket of static-jacket calorimeters has a thermal capacity such that, even without active control, itstemperature remains nearly constant during measurement.4.4 Motor-dri

17、ven stirrer, for mixing the water in the calorimeter can at constant speed. To keep the heatgenerated by stirring approximately the same, the speed shall not vary by more than 10 %.4.5 Temperature measuring device (as in DIN 51900-1).4.6 Electrical ignition device, for firing the sample in the bomb.

18、 Since the current flowing through the ignitionwire develops heat and affects the increase in temperature, the amount of energy supplied to the wire duringPage 3DIN 51900-2 : 2003-05the measurements shall not vary by more than 5 %. The ignition voltage at the connecting terminals of the bombshall co

19、mply with the specifications given in subclause 6.3.1 of DIN EN 61010-1.NOTE: The heat developed by the ignition enters into the calibration.5 Test conditionsThe equipment shall be set up strictly in accordance with the operating manual.The mass of the water in the calorimeter can shall not vary by

20、more than 0,02 % between measurements andshall completely cover the screw cap of the bomb.The temperature of the water shall be between 20 C and 30 C before and after combustion. The temperatureincrease due to the combustion of the sample shall be between 1,5 K and 3,5 K and shall be between 0,7 tim

21、esand 1,3 times the temperature rise found when determining the effective heat capacity. The temperature at theend of the main period shall be taken as the reference temperature.The thermal resistance between the calorimeter can and the jacket shall be constant and is characterized bythe cooling con

22、stant, , which can be calculated using equation (3) in subclause 7.1. The value of will dependon the equipment; its mean value shall be calculated as in clause 12 of DIN 51900-1 from the individual valuesdetermined for the effective heat capacity of the calorimeter. In all the subsequent measurement

23、s, shall notdiffer by more than 5 % from this value.NOTE: To minimize the correction for the heat exchange between the calorimeter can and the surroundings, itis advisable to adjust the temperature of the water in the calorimeter can at the beginning of the test to about1 K less than the temperature

24、 of the jacket. This will make the effect of evaporation of water in the calorimetercan negligible.6 Procedure6.1 GeneralThe calorimeter shall be prepared as specified in the manufacturers instructions.6.2 Measurement procedure6.2.1 GeneralThe temperature of the calorimeter can shall always be measu

25、red at equal x intervals, whose length is to be suchas to enable the temperature changes to be measured with sufficient accuracy (ten times the smallest detect-able temperature change). One minute intervals are generally adequate. Temperature equalization between thecalorimeter can and the rest of t

26、he system, which starts when the calorimeter is closed, shall be followed bytesting, comprising a fore period, a main period and an after period (see table A.1 and figure A.1).6.2.2 Temperature equalizationTemperature equalization starts when the calorimeter is closed and finishes when the differenc

27、es in consecutivemeasurements are less than 0,002 K/min. Increasing the equalization time by one or two intervals shall not affectthe required precision.6.2.3 Fore periodThe fore period starts with the last temperature measurement in the thermal equalization process and finishesafter at least five i

28、ntervals. During this period, the standard deviation of the mean of the measured temperaturechanges per interval shall be less than 0,001 K/min. The sample shall be fired directly upon taking the lastreading of temperature in the fore period.6.2.4 Main periodThe main period starts with the final tem

29、perature measurement in the fore period and finishes when thedifferences between consecutive measurements are less than 0,002 K/min. Extending the main period by oneor two intervals shall not affect the required precision.6.2.5 After periodThe after period starts with the final temperature measureme

30、nt in the main period and finishes after at least fiveintervals. During this period, the standard deviation of the mean of the measured temperature changes perinterval shall be less than 0,001 K/min.7 Evaluation7.1 Corrected temperature riseFor isoperibol or static-jacket calorimeters, the measured

31、temperature rise, (te ta), shall be subjected to acorrection, e, in K, resulting from Newtons law of cooling to give a corrected temperature rise, Dt, in K, asfollows 2:Dt = te ta+ e (1)Page 4DIN 51900-2 : 2003-05The value of e is given by the Regnault-Pfaundler formula 3:(2)with()2210aes0a0aesesttt

32、tzzttzztt+=(3)where in equations (1) to (3):tais the temperature at the end of the fore period (also to be the first temperature reading taken in themain period), in K;teis the temperature at the end of the main period (also to be the first temperature reading taken in theafter period), in K; is the

33、 cooling constant, calculated using equation (3);Dz is the reading interval, in min (see subclause 6.2.1);t0is the temperature at the start of the fore period, in K;tsis the temperature at the end of the after period, in K;z0is the time at the beginning of the fore period (0 min);zais the time at th

34、e end of the fore period (also to be the beginning of the main period), in min;zeis the time at the end of the main period (also to be the beginning of the after period), in min;zsis the time at the end of the after period, in min;+zzzzteais the sum of all the temperature readings taken during the m

35、ain period except the first (ta) and thelast (te).7.2 Effective heat capacityThe effective heat capacity of the calorimeter system, C, in J/K, is given by equation (4):tQmHC+=ZBvBo,(4)whereHo,vBis the gross calorific value of the reference substance (see subclause 6.2 of DIN 51900-1), in J/g;mBis th

36、e mass of the reference substance, in g;QZis the heat released, in J (see note);Dt is the corrected temperature rise, in K (see subclause 7.1).NOTE: The heat released is the sum of all the extraneous quantities of heat produced during ignition (ignitionenergy) and in the combustion of additional mat

37、ter (e.g. benzoic acid, combustion capsule or bag, cottonthread and possibly the ignition wire). These quantities contained in Qzshall be determined from the initialsample mass and the gross calorific values of the products (manufacturers data).7.3 Gross calorific valueThe gross calorific value, Ho,

38、v, in J/g, is given by equation (5):()pZSNvo,mQQQtCH+= (5)whereC is the effective heat capacity of the calorimeter system, in J/K (see subclause 7.2);Dt is the corrected temperature rise, in K (see subclause 7.1);QNis the heat released, in J (see subclause 11.2 of DIN 51900-1);QSis the heat released

39、, in J (see subclause 11.1 of DIN 51900-1);QZis the heat released, in J (see note in subclause 7.2);mpis the mass of the sample in air, in g.7.4 Net calorific valueThe net calorific value, Hu,p, shall be calculated as specified in clause 15 of DIN 51900-1.Page 5DIN 51900-2 : 2003-05Table A.1: Time a

40、nd temperature test resultsTest sequence Time, z, in min Temperature, t, in K1,0471,052Temperature1,056equalization1,0591,061z0=0 t0= 1,0631 1,064Fore period2 1,0653 1,0664 1,067Ignition za=5 ta= 1,068za+ Dz = 6 1,8297 2,9088 3,200Main period9 3,27710 3,29811 3,30312 3,305ze Dz = 13 3,304ze=14 te= 3

41、,30415 3,303After period16 3,30217 3,30218 3,301ze=19 ts= 3,300Appendix ACalculation exampleA.1 Example of measurement procedureFigure A.1: Example of time/temperature curveAfter periodIgnitionEqualiza-tion Fore period Main periodPage 6DIN 51900-2 : 2003-05A.2 Evaluation exampleA.2.1 Cooling constan

42、t, , calculated using equation (3) and values from table A.1:()2210aes0a0aesesttttzzttzztt+= ()2063,1 068,12304,3 300,30 5063,1 068,114 19304,3 300,31+=R 0,000 8 min1A.2.2 Temperature correction, e, calculated using equation (2) and the values in table A.1:() ()esesaeesaeeaea22 zzttzzttzztttzzzzz+=+

43、() ()1419304,3300,35142304,3300,3514424,24 2304,3068,11 8000,0 += 0,000 8 (26,610) 29,718 (0,007 2) R 0,002 5 KA.2.3 Corrected temperature rise, Dt, calculated using equation (1) and the values in table A.1:Dt = te ta+ e= (3,304 1,068) + ( 0,002 5) = 2,233 5 KA.2.4 Calculation of effective heat capa

44、cityGiven:a) Gross calorific value of benzoic acid standard sample 39j (measured at 25 C, with 5 ml water filling,oxygen filling at 30 bar and a bomb volume of 330 ml) = 26 464 J/gb) Initial mass in air, mB, of reference substance (see subclause 6.2 of DIN 51900-1) = 0,993 2 gc) Extraneous energy, Q

45、Z, resulting from the ignition and the combustion of additional matter (e.g. 80 J ofignition energy, 55 J of energy from the combustion of a cotton fibre according to the manufacturers data)= 135 Jd) Temperature correction, Dt, from the above calculation example = 2,233 5 KValue of effective heat ca

46、pacity, C, given by equation (4):tQmHC+=ZBvBo,5233,21352993,046426 +=R 11 829 J/KA.2.5 Calculation of gross calorific valueGiven:a) Heat capacity, C, from the above example = 11 829 J/Kb) Temperature correction, Dt, from the above example = 2,2335 Kc) Initial mass, mp, of sample in air = 0,768 0 gd)

47、 Heat released, QS, determined as in subclause 11.1 of DIN 51900-1 = 15,1 Je) Heat released, QN, determined as in subclause 11.2 of DIN 51900-1 = 13,2 Jf) Extraneous energy, QZ, resulting from the ignition and the combustion of additional matter (e.g. 80 J ofignition energy, 50 J from the combustion

48、 of a cotton thread according to the manufacturers data) = 137 JValue of gross calorific value, Ho,v, given by equation (5):()pZSNvo,mQQQtCH+=Page 7DIN 51900-2 : 2003-05Bibliography1 Hemminger, W. and Hhne, G. Grundlagen der Kalorimetrie (Fundamentals of calorimetry), Weinheim, NewYork: Verlag Chemi

49、e, 1979.2 Borrell, P., The application of computer curve fitting techniques to Regnault-Pfaundler calculations ofcalorimetric data. Thermochimica Acta, 1974: 9, 8993.3 Pfaundler, L. ber die Wrmekapazitt verschiedener Bodenarten und deren Einfluss auf die Pflanze nebstkritischen Bemerkungen ber Methoden der Bestimmung derselben (The heat capacity of various types ofsoil and its influence on v