Descarga la aplicación para disfrutar aún más
Vista previa del material en texto
AGA5 American Gas Association Report No. 5 Module ACCOL II Reference Manual Page AGA5-1 The AGA5 Module performs AGA-5 calculations for conversion of computed gas volume to energy equivalents as described in the Ameri- can Gas Association Report No. 5, reference Catalog No. XQ0776. Module Terminals VOLUME represents the metered volume of gas in MSCF or flow rate in MSCFH BASE_PRESS is the base pressure of the flowing gas BASE_TEMP SPEC_GRAV VOL_%_HE VOL_%_CO FPV_IN VOL_CONVERS ENERGY_CONV OUTPUT VOLUME BASE_PRESS 5 VOL_%_N2 VOL_%_O2 VOL_%_CO2 VOL_%_H2O VOL_%_H2S VOL_%_H2 Default: None, entry is required. No computation will be performed if this terminal is not wired. Format: Analog signal Input/Output: Input Default: 14.73 Format: Analog signal or constant Input/Output: Input AGA5 ACCOL II Reference Manual Page AGA5-2 AGA5 American Gas Association Report No. 5 Module ACCOL II Reference Manual Page AGA5-2 AGA5 American Gas Association Report No. 5 Module Default: 600F Format: Analog signal or constant Input/Output: Input Default: 1.0 Format: Analog signal or constant Input/Output: Input Default: 0.6 Format: Analog signal or constant Input/Output: Input Default: 0.0 Format: Analog signal or constant Input/Output: Input BASE_TEMP is the base temperature of the flowing gas FPV_IN is the supercompressibility factor of the gas. This factor is used in equations when the input volume is an uncorrected metered volume. Originally, the AGA-5 Report included the FPV factor in its calcula- tions. However, since that time, the report has been found in error. It is therefore recommended that this terminal not be wired in which case the default value of 1.0 is assumed. SPEC_GRAV is the specific gravity of the flowing gas. VOL_% The VOL_% terminals contain the following: VOL_%_CO2 - the volume % of CO2 present in the gas. VOL_%_N2 - the volume % of N2 present in the gas. VOL_%_O2 - the volume % of O2 present in the gas. VOL_%_HE - the volume % of He present in the gas. VOL_%_CO - the volume % of CO present in the gas. Default: 600F Format: Analog signal or constant Input/Output: Input Default: 1.0 Format: Analog signal or constant Input/Output: Input Default: 0.6 Format: Analog signal or constant Input/Output: Input Default: 0.0 Format: Analog signal or constant Input/Output: Input BASE_TEMP is the base temperature of the flowing gas FPV_IN is the supercompressibility factor of the gas. This factor is used in equations when the input volume is an uncorrected metered volume. Originally, the AGA-5 Report included the FPV factor in its calcula- tions. However, since that time, the report has been found in error. It is therefore recommended that this terminal not be wired in which case the default value of 1.0 is assumed. SPEC_GRAV is the specific gravity of the flowing gas. VOL_% The VOL_% terminals contain the following: VOL_%_CO2 - the volume % of CO2 present in the gas. VOL_%_N2 - the volume % of N2 present in the gas. VOL_%_O2 - the volume % of O2 present in the gas. VOL_%_HE - the volume % of He present in the gas. VOL_%_CO - the volume % of CO present in the gas. AGA5 American Gas Association Report No. 5 Module ACCOL II Reference Manual Page AGA5-3 VOL_%_H2S - the volume % of H2S present in the gas. VOL_%_H2O - the volume % of H20 present in the gas. VOL_%_H2 - the volume % of H2 present in the gas. VOL_CONVERS is a volume conversion factor, that is, a metered volume of cubic feet at 14.73 psi, 600F. If the value on the VOLUME terminal is expressed in terms of MSCF or MSCFH, you may use the default which is 1000.0. If VOLUME is expressed in terms of SCFH or SCF, set this terminal to 1. ENERGY_CONV is an energy conversion factor when dekatherms are the desired energy units. OUTPUT is the desired units of gas energy, normally in dekatherms or dekath- erms/hour. It is the flow rate calculated by the module. Default: .000001 dekatherm (1 deka- therm = 1,000,000 BTUs) Format: Analog signal or constant Input/Output: Input Default: 1000.0 Format: Analog signal or constant Input/Output: Input Default: None Format: Analog signal Input/Output: Output ACCOL II Reference Manual Page AGA5-4 AGA5 American Gas Association Report No. 5 Module ACCOL II Reference Manual Page AGA5-4 AGA5 American Gas Association Report No. 5 Module Module Equations The equation implemented by this module is taken from Section II of AGA Report No. 5. This particular equation dovetails the require- ments of the orifice metering approach and the volume metering approach. As such, several of the factors are not required for the orifice metered volume to energy conversions. This module is only used when a calorimeter signal is not available. It performs the following equation for gas volume-to-energy conversion: Ue = Uv * Ev * Fuv * Fue where: Ue = Desired units of Gas energy, totalized or rate per unit of time. Uv = Standard volume units, totalized or rate per unit time, i.e. SCFH. Note that Uv is normally calculated by AGA-3 or AGA-7 modules in MSCFH. Ev = Energy-volume ratio, Btu per cubic foot, 14.73 psi, 60 0F. Fuv = Volume conversion factor, metered volume to cubic feet at 14.73 psi, 600F. Note: Where Standard units are metered in MSCFH, Fuv = 1. Fue = Energy conversion factor, Btu per cubic foot to desired energy units. Note: Where dekatherm energy units are required, this factor equals one. (One dekatherm = 1 million BTUs) If a calorimeter signal is available, do not use this module. Instead, use a Calculator Module to solve the following equation: Ue = Uv Ev (.000001) The parameters of this formula are defined above. If Uv is expressed in units of MSCFH, change the multiplier in the equation to .001. Module Equations The equation implemented by this module is taken from Section II of AGA Report No. 5. This particular equation dovetails the require- ments of the orifice metering approach and the volume metering approach. As such, several of the factors are not required for the orifice metered volume to energy conversions. This module is only used when a calorimeter signal is not available. It performs the following equation for gas volume-to-energy conversion: Ue = Uv * Ev * Fuv * Fue where: Ue = Desired units of Gas energy, totalized or rate per unit of time. Uv = Standard volume units, totalized or rate per unit time, i.e. SCFH. Note that Uv is normally calculated by AGA-3 or AGA-7 modules in MSCFH. Ev = Energy-volume ratio, Btu per cubic foot, 14.73 psi, 60 0F. Fuv = Volume conversion factor, metered volume to cubic feet at 14.73 psi, 600F. Note: Where Standard units are metered in MSCFH, Fuv = 1. Fue = Energy conversion factor, Btu per cubic foot to desired energy units. Note: Where dekatherm energy units are required, this factor equals one. (One dekatherm = 1 million BTUs) If a calorimeter signal is available, do not use this module. Instead, use a Calculator Module to solve the following equation: Ue = Uv Ev (.000001) The parameters of this formula are defined above. If Uv is expressed in units of MSCFH, change the multiplier in the equation to .001. AGA5 American Gas Association Report No. 5 Module ACCOL II Reference Manual Page AGA5-5 For undiluted hydrocarbon gas mixtures, Ev = Vg where: Vg = (1571.5 * specific gravity) + 144 For gas mixtures containing non-hydrocarbon compounds, EV = Vg - (Vcd + Vn + Vo + Vhe + Vcm + Vhs + Vw - Vhy) where: Vcd = (Volume % CO2) * 25.318 V n = (Volume % N 2 ) * 16.639 Vo = (Volume % O2) * 18.801 Vhe = (Volume % He) * 3.612 Vcm = (Volume % CO) * 13.424 Vhs = (Volume % H2S) * 13.462 Vw = (Volume % H2O) * 11.214 Vhy = (Volume % H2) * 0.713 If the input volume is a metered volume, then Standard Volume Units are calculated from the metered volume as follows: Uv = Fp * Ft * Fpv 2 * metered volume where: Fp = Pressure Factor = PSIA * .067889 Ft = Temperature Factor = (519.67 / (459.67 + 0F)) Fpv = Supercompressibility Factor Metered Volume = Volume displaced in unitspeculiar to meter, at prevailing pressure and temperature conditions. ACCOL II Reference Manual Page AGA5-6 AGA5 American Gas Association Report No. 5 Module ACCOL II Reference Manual Page AGA5-6 AGA5 American Gas Association Report No. 5 Module Since the energy conversion factors only apply to volume units under a pressure of 14.73 psi and 600F, the above conversion also provides a secondary volume conversion when the input volume is an orifice metered volume expressed at base conditions other than 14.73 psi and 600F. In this case, 519.67 Uv = Q * (Pb * 0.067889) * 459.67 + Tb where: Q = volume of gas at any other base conditions. Pb = Any other pressure base, psia. T b = Any other temperature base, 0F. Return to the Table of Contents Return to the List of Manuals
Compartir