Steam Library

Compressor

Model

Models a centrifugal or axial compressor. This model uses thermodynamic properties to perform isentropic calculations and then uses an adiabatic or polytropic efficiency to calculate outlet properties and brake power.

ClosedLoop

Model

Allows you to specify the composition and flowrate of a utility stream circulating in a closed system and avoid the need for a makeup or bleed arrangement.

DefHXSide

Submodel

Provides a default replaceable submodel that contains calculations for pressure drop and heat transfer for heat exchanger models (HX and HXC).

Desup

Model

Models a simple steam desuperheater that calculates the required boiler feedwater to achieve the specified degrees of superheat. You typically use Desuperheaters after letdown valves.

Drum

Model

Models the separation of vapor and liquid. Use this model as a heat recovery steam generator (HRSG) drum with heat entering from a heat stream.

ExtTurb

Model

Models a steam turbine which has options to draw steam at various extraction pressures. It can have up to three extractions.

GasSink

Model

Sets the downstream pressure at the process boundary for Fluid Flow and Dynamics mode. The GasSink typically models the stack of the heat recovery steam generator (HRSG).

GasSource

Model

Defines the flow and thermodynamic state of a compositional gas stream. This model has typical defaults to model the hot gas turbine exhaust that feeds the heat recovery steam generator (HRSG).

Generator

Model

Sets the power demand on a shaft in Dynamics mode.

Header

Model

Models either a Header to represent a large piping manifold with low pressure drop or a mixing junction to represent a piping tee.

HX

Model

Models a one-sided or two-sided shell-and-tube heat exchanger. The number of stream connections defines the number of sides.

HXC

Model

Models a one-sided heat exchanger that you can use to represent coils with a Drum model. Connect the HXC model to a Drum model with a Heat Stream. You typically use the HXC model as a heat recovery steam generator (HRSG) coil with gas turbine exhaust to heat up boiler feed water or steam.

HXSC

Model

Models a simple process heater and steam condenser to use in both a steam balance. You can also use this model in a dynamic simulation of a steam distribution network. The HXSC model always condenses all of the steam and provides a saturated liquid condensate as the outlet stream.

MotiveAir

Submodel

Serves as a replaceable submodel for the MotiveModelType parameter in the Valve model. This submodel is set with air as the motive power.

NoMotivePwr

Submodel

Serves as a replaceable submodel for the MotiveModelType parameter in the Valve model. This submodel is set with no motive power.

Orifice

Model

Models a reduction in pressure or a flow restriction orifice (RO) device. This model is based on orifice equations in Crane Technical Paper 410. It uses a curve for a square-edged orifice coefficient based on the assumption that the flow is fully turbulent.

ParHX

Model

Models multiple condensing heat exchangers in parallel. You can select the number of parallel exchangers for steam balance calculations. The separate exchanger path duty calculations are identical to the HX model.

ParTurb

Model

Models multiple steam turbines in parallel. You can select the number of parallel turbines. The separate turbine path power calculations are identical to the Turbine model.

Pipe

Model

Models flow-based equipment. This model uses a constant-density Darcy equation designed to model pipes with moderate pressure drop. You can use the Pipe model for up to 10% pressure drop (per Crane Technical Paper 410). If the pressure drop is greater than 10%, you should use multiple pipes in series. The pipe uses the density based on the average of the inlet and outlet pressure.

PipeRig

Model

Models a multi-segment, flow-based rigorous pipe model. This model can 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.

PSV

Model

Models a pressure relief valve. In Process and Fluid Flow modes, this model remains inactive with zero flow. In Dynamics mode, it opens and passes a flow calculated from the pressure difference and valve orifice area. The PSV model also includes an optional Out port for automatic calculation of backpressure in Dynamics mode. You can also connect a pressure transmitter signal to the Pilot port to model a pilot valve assembly.

Pump

Model

Models a dynamic pump (for example, a centrifugal or axial pump). This model uses performance curves to relate pressure rise and brake power to flowrate. It also uses affinity laws (fan laws) or multi-curve interpolation to calculate the effects of speed or impeller diameter on the performance curve.

Recip

Model

Models a reciprocating compressor. This model uses the same thermodynamic properties as the centrifugal Compressor model to perform isentropic power calculations.

Recycle

Model

Improves the convergence of recycles through iterative sequential updates rather than by solving it simultaneously. This method is commonly known as tearing. Sometimes tearing may help difficult convergence problems solve. The Recycle model also has a Source operation option where the Recycle model acts like a Source model and you can specify the source conditions. When you use the Recycle model as a Source model, you can troubleshoot your simulation to see if the conditions entering the Recycle match the conditions leaving it.

Seq

Model

Allows the position of a unit such as a valve or extraction turbine to open or close depending on the priority.

Shaft

Model

Represents the physical linkage between rotating equipment items. You can connect multiple mechanical stream inputs to the shaft.

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.

Source

Model

Defines the flow and thermodynamic state of a feed stream. In Process mode, specify the pressure, temperature, and flow of the stream. In Fluid Flow and Dynamics mode, the flow is typically calculated.

Stream

Model

Reports stream properties. For simulations created with the Process or Steam simulation template, the simulation automatically uses this model as the connection model for streams. All variables are calculated based on the actual direction of flow.

SubSplit*

Submodel

Serves as the outlet split submodel for the ExtTurbine model.

SubTurbine*

Submodel

Serves as the steam turbine stage submodel for the ExtTurbine model.

Turbine

Model

Models a simple steam turbine. It uses the IF97 properties to perform isentropic power calculations based on power.

Valve

Model

Models incompressible (liquid) flow or compressible (vapor) flow including choked flow.