Flare Library

ChangeExample

Submodel

Represents an example that illustrates how to create a custom component change model to use with the FluidChange model. See the Model Help for the FluidChange model for more information.

Converter

Model

Converts a compositional Fluid Type to a simple molecular-weight-based flare gas fluid that requires only the specific heat ratio and molecular weight to generate the fluid properties. The resultant Fluid Type does not contain the composition data.

DefChange

Submodel

Represents a default replaceable submodel for the CompModelType parameter in the FluidChange model. This submodel returns a composition to the FluidChange model.

DirectIntegration*

Submodel

Provides the two-phase relief sizing by using the Direct Integration method from API 520.

Drum

Model

Models the separation of vapor and liquid. Use this model as a flash drum for heat and material balances and a vessel for Fluid Flow and Dynamics simulation.

Enlarger

Model

Represents flow-based equipment that can model a pipe enlargement or contraction.

Flag

Model

Demarks and isolates the flowsheet boundaries that you want to analyze independently in flare simulations. When the Flag model uses the Isolate option, it allows you to isolate the downstream section from the upstream process and to solve the downstream section independently.

FluidChange

Model

Changes the Fluid Type of the stream entering the model to a new Fluid Type leaving the model. The new Fluid Type may use a different thermodynamic method, different phases, or a different component slate.

Miller*

Submodel

Provides the Miller pressure drop for branch and run connections. It uses Bassett and Gardel correlations.

Mix

Model

Mixes two streams into one stream. In Process mode, the mixer includes the pressure difference slack so that you can independently size each flare pipe lateral. However, in Fluid Flow and Dynamics modes, this slack is zero automatically.

Omega*

Submodel

Provides the two-phase relief sizing by using the Omega method from API 520.

Orifice

Model

Calculates flow through an orifice by using API 520 relief valve equations for gas or vapor flow through a restriction orifice. The sizing equations depend on whether the flow is critical or subcritical.

Pipe

Model

Models a single-element pipe that uses an integrated equation such as Darcy’s law, the isothermal, or the adiabatic flow equations. Because the Pipe uses an integrated flow equation, it is very accurate for single-phase flow.

PipeRig

Model

Models a multi-segment, flow-based rigorous pipe model. It may be horizontal or inclined. You typically use this model for transportation of multiphase or single-phase fluids. It uses the Beggs-Brill-Moody and Beggs-Brill-Moody High Velocity correlations to predict the total pressure drop.

ProConvert

Model

Connects simulations built in the Process Library to relief valves on the Flare Library. It converts a connection from a model that uses the Standard Port, as found in Process Library, to a model that uses the Flare Port.

PRV

Model

Calculates flow through a pressure relief valve (PRV) by using API 520 equations for vapor, steam, liquid, and two-phase service in a relief valve. The PRV sizing equations fall into two general categories depending on the fluid inlet and outlet phases.

PSV*

Model

Calculates flow through a pressure safety valve (PSV) by using API 520 equations for gas or vapor flow in a relief valve. The sizing equations depend on whether the flow is critical or subcritical.

We provide this model for backwards compatibility only. We recommend that you use the PRV model instead.

Pump

Model

Uses pump performance curves to calculate pressure rise.

Radiation*

Submodel

Provides the Flare sizing and radiation calculations.

RD

Model

Calculates flow through a rupture disk (RD) by using API 520 equations for vapor, steam, liquid, and two-phase service. The RD sizing equations fall into two general categories depending on the fluid inlet and outlet phases.

SealDrum

Model

Represents the static head due to a seal fluid, typically water. You typically place seal drums at the base of a stack to prevent the back flow of air into the flare system, which can occur if there were a flare gas recovery compressor.

Sink

Model

Sets the downstream pressure at the process boundary in all modes. However, for refinery steam systems, you may want to use the sink to set flow rates to typical refinery steam consumers.

SlopePSV

Model

Calculates the relieving capacity that should appear on a pressure relief valve set at or between the minimum and maximum listed set pressures in a Series Capacity chart. It uses equations from the National Board Inspection Code (NBIC).

Source

Model

Defines a vessel’s relieving fluid and the required flow rate during an overpressure event.

Split

Model

Splits one stream into two streams.

Stack

Model

Terminates the simulation so that you can change from Process mode to Fluid Flow and Dynamics modes. In comparison to Sink models found in other Model Libraries, the FlareLib Stack model sets its pressure to the flare tip to atmospheric pressure when you change to Fluid Flow mode so that you do not have to remember to do this.

Valve

Model

Calculates compressible (vapor) flow including choked flow.

VaporRelief*

Submodel

Provides the vapor relief sizing equations from API 520-5.6. It calculates the C, Pc, and F2 variables for the main sizing equations in the parent PRV model.