ASTM D1826-94(2003)
(Test Method)Standard Test Method for Calorific (Heating) Value of Gases in Natural Gas Range by Continuous Recording Calorimeter
Standard Test Method for Calorific (Heating) Value of Gases in Natural Gas Range by Continuous Recording Calorimeter
SIGNIFICANCE AND USE
This test method provides an accurate and reliable method to measure the total calorific value of a fuel gas, on a continuous basis, which is used for regulatory compliance, custody transfer, and process control.
SCOPE
1.1 This test method covers the determination with the continuous recording calorimeter (Note 1) of the total calorific (heating) value of fuel gas produced or sold in the natural gas range from 900 to 1200 Btu/standard ft3.
Note 1—An extensive investigation of the accuracy of the Cutler-Hammer recording gas calorimeter, when used with gases of high heating value, was made by the National Bureau of Standards in 1957 under a research project sponsored by the American Gas Association.
1.2 The subjects covered in this test method appear in the following sections:SectionsAir-Gas Ratio Test11Apparatus5Basis of Measurement14Cold Balance Test10Compensation of Complicating Factors13Condition of Gas Sample7Definitions2Installation of Apparatus6MaintenanceAppendix X1Operating PrecautionsAppendix X2Operation and Checking of Apparatus9Precision15Scope1Significance and Use4Standardization of Calorimeter12Standardization, Preliminary, of Calorimeter by Hydrogen8Summary of Test Method3
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D1826 – 94 (Reapproved 2003)
Standard Test Method for
Calorific (Heating) Value of Gases in Natural Gas Range by
Continuous Recording Calorimeter
This standard is issued under the fixed designation D1826; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Terminology
1.1 This test method covers the determination with the 2.1 Definitions of Terms Specific to This Standard:
continuous recording calorimeter (Note 1) of the total calorific 2.1.1 The most important terms used in connection with the
(heating) value of fuel gas produced or sold in the natural gas determination of the calorific value of gaseous fuels in record-
range from 900 to 1200 Btu/standard ft . ing calorimetry are as follows:
2.1.2 British Thermal Unit, or Btu—is the defined Interna-
NOTE 1—An extensive investigation of the accuracy of the Cutler-
tional Tables British thermal unit (symbol Btu).
Hammer recording gas calorimeter, when used with gases of high heating
value, was made by the National Bureau of Standards in 1957 under a
NOTE 2—The defining relationships are:
research project sponsored by the American Gas Association. −1 −1
(a) 1 Btu·lb =2.326 J·g (exact)
(b) 1 lb=453.59237 g (exact).
1.2 The subjects covered in this test method appear in the
By these relationships, 1 Btu = 1 055.05585262 J (exact). For most
following sections:
purposes, the value rounded to 1 Btu = 1 055.056 J is adequate.
Sections
Air-Gas Ratio Test 11 2.1.3 combustion air—air used for combustion, a total of
Apparatus 5
the portion mixed with the gas as primary air and the air
Basis of Measurement 14
supplied around the burner tube as secondary air (theoretical
Cold Balance Test 10
Compensation of Complicating Factors 13
air plus excess air).
Condition of Gas Sample 7
2.1.4 flue gases—the products, of combustion remaining in
Definitions 2
the gaseous state, together with any excess air.
Installation of Apparatus 6
Maintenance Appendix X1
2.1.5 heat-absorbing air—the heat exchange medium used
Operating Precautions Appendix X2
to absorb the heat of combustion derived from the burning of
Operation and Checking of Apparatus 9
gaseous fuel.
Precision 15
Scope 1
2.1.6 saturated basis—the expressed total calorific value of
Significance and Use 4
a gas when it is saturated with water vapor at standard
Standardization of Calorimeter 12
temperature and pressure; 1 ft of this gas is equivalent in dry
Standardization, Preliminary, of Calorimeter by Hydrogen 8
Summary of Test Method 3
gascontentto0.9826ft ofdrygasatthestandardtemperature
of 60°F and standard pressure of 14.73 psia.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
NOTE 3—Thedefinitionsgivenin2.1.6and2.1.10arefortotalcalorific
responsibility of the user of this standard to establish appro-
(heating) values per standard cubic foot of gas. The definitions corre-
sponding to any other unit quantity of gas are obtained by substituting the
priate safety and health practices and determine the applica-
name of the desired unit in place of the term “standard cubic foot” in the
bility of regulatory limitations prior to use.
definitions. Methods of calculating calorific (heating) values per cubic
foot of gas under any desired conditions of pressure, temperature, and
water vapor content are specified in Section 14.
ThistestmethodisunderthejurisdictionofASTMCommitteeD03onGaseous
Fuels and is the direct responsibility of Subcommittee D03.03 on Determination of
2.1.7 standard cubic foot of gas—the quantity of any gas
Heating Value and Relative Density of Gaseous Fuels.
that at standard temperature and under standard pressure will
Current edition approved May 10, 2003. Published May 2003. Originally
fill a space of 1 ft when in equilibrium with liquid water.
approved in 1961. Last previous edition approved in 1998 as D1826–94(1998).
DOI: 10.1520/D1826-94R03. 2.1.8 standard pressure—is 14.73 psia.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D1826 – 94 (2003)
NOTE 4—This is the pressure base adopted by the American National
continuous basis, which is used for regulatory compliance,
Standards Institute in 1969 (Z132.1). According to Dalton’s law, this is
custody transfer, and process control.
equivalent to stating that the partial pressure of the gas is:
14.73−0.25636=14.47364 psia
5. Apparatus
where 0.25636 is the vapor pressure of water in psia at 60°F.
5.1 The recording calorimeter (Note 5) consists of two
2.1.9 standard temperature—60°F, based on the interna-
major units; the tank unit or calorimeter proper, Fig. 1, Fig. 2,
tional practical temperature scale of 1968.
and Fig. 3, in which the heating value of the test gas sample is
2.1.10 total calorific value (gross heating value, higher
measured; and the recording unit which translates the heat
heating value)—of a gas is the number of British thermal units
measurements into an indication of calorific (heating) value
evolved by the complete combustion at constant pressure of
and records it graphically on a strip chart recorder or digitally
one standard cubic foot of gas with air, the temperature of the
if the new SMART-CAL is used (Note 6).
gas, air, and products of combustion being 60°F, and all the
water formed by the combustion reaction being condensed to
NOTE 5—The previous specified pressure base was the absolute pres-
the liquid state. sure of a column of pure mercury 30 in. in height at 32°F and under
standard gravity (32.174 ft/s ). This is equivalent to 14.7346 psia.
3. Summary of Test Method
NOTE 6—Refer to specific manufacturer’s manual for pictures of the
recorder or the SMART-CAL, a digital indicating or printing device,
3.1 The heating value is determined by imparting all of the
currently used on new or retrofitted calorimeters.
heat obtained from the combustion of the test gas to a stream
of air and measuring the rise in temperature of the air. The
6. Installation of Apparatus
streams of test gas and heat absorbing air are maintained in
6.1 To secure the precise results that are possible with the
fixed volumetric proportion to each other by metering devices
recording calorimeter, it is important that the instrument be
similar to the ordinary wet test meters geared together and
installed so that the surrounding conditions will not introduce
driven from a common electric motor.The meters are mounted
errors. In general, more precise results will be secured when a
in a tank of water, the level of which is maintained and the
narrow range is maintained on the various conditions of the
temperature of which determines the temperature of the enter-
calorimeter environment.
ing gas and air.
6.2 Calorimeter Room—A typical installation of a single
3.2 The flue gas resulting from combustion of the gas
recording calorimeter is shown in Fig. 4. The detailed require-
(combustion products plus excess combustion air) is kept
ments for the calorimeter room are given in Table 1.
separate from the heat-absorbing air and is cooled to a few
degrees above the initial temperature of gas and air. The water NOTE 7—Adetailed discussion of these requirements is included in the
latest edition of the manufacturer’s instruction book covering the record-
formed in the combustion is practically all condensed to the
ing calorimeter. The information can be applied to all models of the
liquidstate.Consequently,thetemperatureriseproducedinthe
instrument.
heat-absorbing air is directly proportional to the heating value
NOTE 8—The dimensions shown in Fig. 4 are for the latest model
of the gas. Since all the heat from the combustion of the test
calorimeter.
gas sample, including the latent heat of vaporization of the
6.3 Gas Connection—Locatethesamplelinethatbringsthe
water vapor formed in the combustion, is imparted to the
gas to be tested to the calorimeter tank unit so that the heating
heat-absorbing air, the calorimeter makes a direct determina-
valueisactuallyrepresentativeoftheconditionsexistinginthe
tionoftotalheatingvalue.Thetemperatureriseismeasuredby
main gas line. Keep the sample line time lag as small as
nickel resistance thermometers and is translated into Btu per
possible by (1) locating the calorimeter tank unit close to the
standard cubic foot.
sample point, (2) running the sample line of small size pipe
4. Significance and Use
(Note 9), and (3) operating the sample line at low pressure.
4.1 This test method provides an accurate and reliable Provideanadditionalpurgeburnerorableedtoalowpressure
method to measure the total calorific value of a fuel gas, on a point.
FIG. 1 Calorimeter—Schematic Flow Diagram
D1826 – 94 (2003)
FIG. 2 Calorimeter—Layout Diagram
NOTE 9—Time lag may be calculated on the basis that the calorimeter and sludge are formed in short duration which interfere with satisfactory
uses about 1.2 ft /h. performance, it will be necessary to use distilled or demineralized water
withapHof7.
6.4 Electrical Wiring—The four leads for the resistance
NOTE 12—For actual test instructions and other information, see the
thermometers between either the recorder or the Smart-Cal
appropriate instruction book provided by the manufacturer.
junction box and the tank unit shall be of No. 12 gage,
6.6 Recorder Installation—Install the recorder so that the
insulated, solid copper wire without joints. Run in a separate
instrument is reasonably free from mechanical vibration. This
rigid metal conduit which is grounded and contains no other
is particularly important for those models in which a
leads (Note 10). Power circuit wiring should be No. 14 gage,
suspension-type galvanometer is used.
insulated, solid or stranded, copper wire. Provide the supply
line with a suitably fused disconnect switch. For the model
7. Condition of Gas Sample
using an electronic recorder, it is essential that a suitable
7.1 Physical Contamination—The gas sample should be
ground connection be made at both the recorder and the tank
free of dust, water, and other entrained solids. If experience
unit. Details are given in the manufacturer’s instructions.
indicates that the foreign materials can enter the sample line,
NOTE 10—Where outdoor or underground wiring must be used, special
install a suitable sample line filter. To avoid any problems in
care should be exercised to protect the terminals of the cables from
the line from water accumulation, pitch the line to a low point
moisture to prevent grounds in the measuring circuit.
and provide a drip leg.
6.5 Initial Installation—When the calorimeter is first in-
7.2 Chemical Contamination—The sample line should be
stalled, fill the tank unit with water (Note 11) and adjust it to
practically free from hydrogen sulfide. A small, low-capacity
a temperature that is 2 to 5°F below the normal room
purifier can be constructed using iron oxide on wood shavings
temperature. Allow the unit to operate at least 24 h before
as the purifying material. The time lag in the purifier adds to
performing the detailed calibration tests.
the sample line time lag so that the purifier should be of small
capacity. A design that will purify about 3 ft of gas/h will be
NOTE 11—The water may be ordinary tap water supplied by most
municipalities.If,however,itisfoundthatexcessivequantitiesofdeposits satisfactory.
D1826 – 94 (2003)
FIG. 3 Calorimeter Combustion Chamber
NOTE—For each additional calorimeter at least 50% additional space is required; for example, for two calorimeters the room should be 12 by 18 ft
inside; for three calorimeters 15 by 18 ft.
FIG. 4 Calorimeter Room
D1826 – 94 (2003)
TABLE 1 Calorimeter Room Requirements
Detail Requirements
Space 1000 ft, min.
Ceiling height 8 ft, min.
Side wall widths 10 and 13 ft, min.
Windows One, on side normally away from sun (in northern hemisphere, the northern side).
Doors One, wth 3-ft opening, not in window wall. A door check is desirable.
Ventilation Natural ventilation using ceiling vent and a vent at floor level. Both should be located away from the tank unit.
Tank location The tank unit should be in a draft-free location with respect to heating and cooling units and natural ventilation.
Heating and cooling Controlled in the range 60 to 75°F with a variation of not more than 2.5°F from the set point.
Foundation floor The calorimeter should remain level at all times. Design for 3000-lb static and dynamic load. The tank feet should be on load
bearing parts of the floor.
Lighting No direct sunlight permitted on calorimeter tank unit.
Condition of air Essentially free from dust and absolutely free from any combustible gas for both measurement accuracy and safety. Trace
hydrocarbons can be removed from combustion air using a Hoskins furnace and a combustion air meter hood.
Vibration No vibrations or shocks shall be transmitted to the tank unit.
Water Pure pH-7 clean water shall be available for filling the tank and replenishing the reserve tank.
Power supply 115 V, 1 phase, 60 Hz, 1000 W for small motors. Lighting, heating, and cooling in addition.
1 1
Gas supply Sample pipe shall be ⁄4-in. tubing. Pressure shall be cut at the pipeline to 1 ⁄2 to 2 psig for minimum time lag. Pressure at the
calorimeter shall be 6 to 30 in. w.c.
Water supply and drain Desirable but not essential.
Radiation Tank unit shall be shielded from any hot radiation surfaces.
Safety It should be remembered that the calorimeter has open flames. Natural ventilation is sufficient in nonhazardous locations and
where only the aforementioned ⁄4-in. tubing service for natural gas at 1 psig is used. Hydrocarbon vapor detectors and purging
means should be considered for installations where location can be hazardous, where higher pressure gas is present, or where
gases heavier than air are involved. In all installations, lighting installations should be suitable for Division I, and incoming power
from underground services should have sealoffs.
8. Preliminary Standardization of Calorimeter by mentofanyparts,andtheestablishmentofaregularinspection
Hydrogen will ensure that the high degree of precision attainable will be
maintained. The manufacturer’s appropriate instruction book
8.1 The use of preliminary standardization by hydrogen test
givesdetailsoftheprocedureforoperatingtheinstrument.The
gasbeforetheuseofstandardmethaneatthetimeoftheinitial
following points should be checked periodically:
installation o
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.