Dynamic Simulation of Natural Gas Filter Separator Depressurization
125
overpressure of the equipment, and cannot play a role avoiding excess temperature of
the equipment, especially for vessels with non-wetted walls or vessels with high boiling
point liquids. The setting of the safety valve for the vessel alone cannot ensure the safety
of the equipment, and other protective measures such as water spray, soil covering the
vessel, or a pressure reducing system should be considered. The inclusion of a pressure
reducing system is a very effective safety measure.
In the design of the depressurization system, the composition, operating temperature, operating pressure, thermal insulation coefficient, compression factor, heat capacity
and other thermodynamic parameters of natural gas change with time during the fire,
and therefore the traditional calculation method cannot be used to accurately obtain
the physical properties of natural gas. This has a bearing on the precise design of the
depressurization system. Therefore, it is recommended to adopt the dynamic simulation
calculation method for accurate calculation of the physical properties of fluids at different times. This method is also in accordance with the dynamic simulation calculation
recommended in API 521–2014.
Using the natural gas filter separator system as an example, this paper studies and
analyzes the changes of operating pressure and operating temperature with time under
fire conditions, and obtains the temperature pressure curve of the process system. This
is compared with the maximum permissible stress of the flange to judge whether the
safety valve provides sufficient protection for the system. If the safety valve cannot be
used as an effective safety protection measure, safety protection measures suitable for
this working condition are recommended, and with the help of dynamic simulation,
the thermodynamic parameters of the discharge process are accurately obtained. This
allows the calculation of the effective throat diameter area of the orifice plate in the
depressurization system.
2 System Parameters and Dynamic Simulation
Main operation parameters of natural gas filter separator see Table 1.
Table 1. Main parameter of natural gas filter separator
Parameter
Value
Operating Pressure / (kPaG) 1300
Operating Temperature (°C)
20
Vessel Diameter (mm)
600
Vessel Height (mm)
2500
Design Pressure (kPaG)
1700
The dynamic simulation software is used to build a model of the pipe section, vessel,
safety valve and other modules, and the trend chart is used to study the dynamic changes
of the vessel operating pressure, operating temperature, fluid flow and other parameters
125
overpressure of the equipment, and cannot play a role avoiding excess temperature of
the equipment, especially for vessels with non-wetted walls or vessels with high boiling
point liquids. The setting of the safety valve for the vessel alone cannot ensure the safety
of the equipment, and other protective measures such as water spray, soil covering the
vessel, or a pressure reducing system should be considered. The inclusion of a pressure
reducing system is a very effective safety measure.
In the design of the depressurization system, the composition, operating temperature, operating pressure, thermal insulation coefficient, compression factor, heat capacity
and other thermodynamic parameters of natural gas change with time during the fire,
and therefore the traditional calculation method cannot be used to accurately obtain
the physical properties of natural gas. This has a bearing on the precise design of the
depressurization system. Therefore, it is recommended to adopt the dynamic simulation
calculation method for accurate calculation of the physical properties of fluids at different times. This method is also in accordance with the dynamic simulation calculation
recommended in API 521–2014.
Using the natural gas filter separator system as an example, this paper studies and
analyzes the changes of operating pressure and operating temperature with time under
fire conditions, and obtains the temperature pressure curve of the process system. This
is compared with the maximum permissible stress of the flange to judge whether the
safety valve provides sufficient protection for the system. If the safety valve cannot be
used as an effective safety protection measure, safety protection measures suitable for
this working condition are recommended, and with the help of dynamic simulation,
the thermodynamic parameters of the discharge process are accurately obtained. This
allows the calculation of the effective throat diameter area of the orifice plate in the
depressurization system.
2 System Parameters and Dynamic Simulation
Main operation parameters of natural gas filter separator see Table 1.
Table 1. Main parameter of natural gas filter separator
Parameter
Value
Operating Pressure / (kPaG) 1300
Operating Temperature (°C)
20
Vessel Diameter (mm)
600
Vessel Height (mm)
2500
Design Pressure (kPaG)
1700
The dynamic simulation software is used to build a model of the pipe section, vessel,
safety valve and other modules, and the trend chart is used to study the dynamic changes
of the vessel operating pressure, operating temperature, fluid flow and other parameters