Monitoring and maintaining flare tip temperatures
A data stream indicative of a first set of flare tip parameters is received. A second set of parameters is determined based on the first set of flare tip parameters. A control signal is sent to an actuable device based on the first set of parameters and the second set of parameters. The actuable device is configured to maintain at least one parameter of the first set of parameter and the second set of parameters within a specified range.
1 . A computer-implemented method comprising:
receiving, from a flow meter, a data stream indicative of a first set of flare tip parameters, the flow meter being included in a flare supply line supplying flare gas to a flare tip;
determining a second set of parameters based on the first set of flare tip parameters, wherein the second set of parameters comprises an adiabatic flame temperature derived by adding a reference temperature to a ratio of a lower heating value of a composition of the data stream based on a molar flow to a sum of molar coefficients and molar heat capacities;
determining mass flow based on the first set of parameters and the second set of parameters;
determining an adjustment of the mass flow for maintaining at least one parameter of the first set of parameter and the second set of parameters within a specified range;
generating a control signal for actuating an actuable device, the control signal comprising the adjustment of the mass flow to a flare stream directed from a flare header through a knock-out drum, the knock-out drum filtering liquids prior to supplying flare gas to a flare supply line guiding the flare gas towards the flare tip actuating the actuable device; and
regulating the flare flame at the flare tip by actuating the actuable device using the control signal.
2 . The computer-implemented method of claim 1 , wherein the first set of parameters comprises:
flare mass flow rate; and
flare mass flow composition.
3 . The computer-implemented method of claim 2 wherein the second set of parameters comprises an adiabatic flame temperature, or a theoretical flame temperature.
4 . The computer-implemented method of claim 3 , wherein determining the second set of parameters comprises determining the adiabatic flame temperature, wherein the adiabatic flame temperature is determined by:
T ad =T ⊕ +LHV molar /Σv i c pi ,
where T ad is the adiabatic flame temperature in degrees Kelvin (K), T ⊕ is 298 K, LHV molar is a lower heating value of a composition of the mass flow in molar basis, V i are molar coefficients, and C pi are molar thermal capacities.
5 . The computer-implemented method of claim 3 , wherein determining the second set of parameters comprises determining the theoretical flame temperature, wherein the theoretical flame temperature is determined by:
T
=
60
+
(
NHV
0.325
(
1
+
1
+
EA
)
(
7.5
×
10
-
4
)
(
NHV
)
)
,
where T is a temperature in degrees Fahrenheit, NHV is a Net Heating Valve of hydrocarbon stream in British Thermal Units per pound of excess air, and where
EA
=
0.95
Y
21
-
Y
.
6 . The computer-implemented method of claim 2 , further comprising determining a prediction of steam usage, wherein the prediction of steam usage is determined by:
W (steam)= W[ 0.68−(10.8/MW)],
where W is a flowrate of steam in pounds per hour, and where MW is a molecular weight of hydrocarbon gas in the mass flow in pounds per pound-mole.
7 . The computer-implemented method of claim 6 , wherein steam flow is regulated by the control signal, the control signal being determined based upon the prediction of steam usage.
8 . The computer-implemented method of claim 1 , wherein the actuable device is an air blower, actuation of the air blower being controlled by the control signal.
9 . The computer-implemented method of claim 1 , further comprising storing values of the first set of parameters and the second set of parameters within a database.
10 . A flare system comprising:
a flare tip;
a flare header directing a flare stream through a knock-out drum filtering liquids prior to supplying a flare gas through a flare supply line guiding the flare gas towards the flare tip;
an actuable device arranged and configured to add mass flow to the flare stream flowing through the flare header towards the flare tip; and
a controller coupled to the actuable device, the controller configured to:
receive a data stream indicative of a first set of flare tip parameters;
determine a second set of parameters based on the first set of flare tip parameters, wherein the second set of parameters comprises an adiabatic flame temperature derived by adding a reference temperature to a ratio of a lower heating value of a composition of the data stream based on a molar flow to a sum of molar coefficients and molar heat capacities; and
send a control signal to an actuable device based on the first set of parameters and the second set of parameters, the actuable device configured to maintain at least one parameter of the first set of parameters and the second set of parameters within a specified range.
11 . The flare system of claim 10 , wherein the actuable device comprises a steam supply.
12 . The flare system of claim 10 , wherein the actuable device comprises an air blower.
13 . The flare system of claim 10 , wherein the first set of parameters comprises:
a flare mass flow rate; and
a flare mass flow composition.
14 . The flare system of claim 10 , wherein the second set of parameters comprises a theoretical flame temperature.
15 . The flare system of claim 14 , wherein the adiabatic flame temperature is determined by:
T ad =T ⊕ +LHV molar /Σv i c pi ,
where T ad is the adiabatic flame temperature in degrees Kelvin (K), T ⊕ is 298 K, LHV molar is the lower heating value of a composition of the mass flow in molar basis, V i are the molar coefficients, and C pi are molar thermal capacities.
16 . The flare system of claim 14 , wherein determining the second set of parameters comprises determining the theoretical flame temperature, wherein the theoretical flame temperature is determined by:
T
=
60
+
(
NHV
0.325
(
1
+
1
+
EA
)
(
7.5
×
10
-
4
)
(
NHV
)
)
,
where T is a temperature in degrees Fahrenheit, NHV is a Net Heating Valve of hydrocarbon stream in British Thermal Units per pound of excess air, and where
EA
=
0.95
Y
21
-
Y
.