Gas Pump

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General Description

The gas pump model will add pressure boost to the stream or operates at a specified pressure.

Diagram

The diagram shows the default drawing of the Gas Pump, with the required connecting streams. The unit will not operate unless all of the above streams are connected.

The physical location of the connections is not important, the user may connect the streams to any position on the drawing.

Inputs and Outputs

Label	Required Optional	Input Output	Number of Connections		Description
			Min	Max
Input	Required	In	1	1	Input stream to pump.
Output	Required	Out	1	1	Output stream from pump.

Model Theory

From the first law of thermodynamics, the energy balance is:

[math]\displaystyle{ \mathbf{\mathit{Work=Enthalpy_{in}-Enthalpy_{out}}} }[/math]

From the second law of thermodynamics:

[math]\displaystyle{ \mathbf{\mathit{Entropy_{in} = Entropy_{out}}} }[/math]

Calculating Work:

Step 1) Enthalpy and Entropy in is calculated from the inlet stream Temperature and Pressure.

Step 2) Outlet Temperature and Enthalpy is calculated based on the Entropy and outlet pressure.

Step 3) Work is calculated from the difference in enthalpy.

Assumptions

1. The process is in steady state and steady flow.
2. The process is adiabatic.
3. The change in Potential and Kinetics energy is ignored.
4. Process is reversible and adiabatic

Data Sections

Summary of Data Sections

1. GasPump1 tab - Contains general information relating to the unit.
2. VLE - Optional tab, only visible if the VLEquilibrium is enabled in the Evaluation Block.
3. Info tab - Contains general settings for the unit and allows the user to include documentation about the unit and create Hyperlinks to external documents.
4. Links tab, contains a summary table for all the input and output streams.
5. Audit tab - Contains summary information required for Mass and Energy balance. See Model Examples for enthalpy calculation Examples.

Gas Pump Page

Unit Type: GasPump1 - The first tab page in the access window will have this name.

Tag (Long/Short)	Input / Calc	Description/Calculated Variables / Options
Tag	Display	This name tag may be modified with the change tag option.
Condition	Display	OK if no errors/warnings, otherwise lists errors/warnings.
ConditionCount	Display	The current number of errors/warnings. If condition is OK, returns 0.
GeneralDescription / GenDesc	Display	This is an automatically generated description for the unit. If the user has entered text in the 'EqpDesc' field on the Info tab (see below), this will be displayed here. If this field is blank, then SysCAD will display the UnitType or SubClass.
Requirements
PressMethod	None	No pressure change
	Boost	The user specifies a pressure increase. Therefore, Pout = Pin + Pboost
	Fixed	The user specifies a fixed outlet pressure from the unit.
PressBoostReqd / PBoostReqd	Input	The required pressure increase. Visible if the Boost method is selected.
PressureReqd / P_Reqd	Input	The required outlet pressure. Visible if the Fixed method is selected.
VLEquilibrium	Off	Vapour Liquid Equilibrium is off.
	On	Vapour Liquid Equilibrium (VLE) is enabled. The associated section, VLE becomes visible and may be configured. Note: This option may automatically adjust the species make-up in Qo.
Results
Work	Calc	The work done.
MassFlow / Qm	Calc	The total mass of material flowing through the gas pump.
TemperatureIn / Ti	Calc	The temperature of material at the inlet of the gas pump.
TemperatureOut / To	Calc	The temperature of material at the outlet of the gas pump.
PressureIn / Pi	Calc	The actual pressure at the inlet of the gas pump.
PressChange / dP	Calc	The pressure change in the gas pump.
PressureOut / Po	Calc	The actual pressure at the outlet of the gas pump.
DensityIn / Rhoi	Calc	The density of material at the inlet of the gas pump.
DensityOut / Rhoo	Calc	The density of material at the outlet of the gas pump.
VapourFracIn / Vfi	Calc	Vapour Mass Fraction at the inlet of the gas pump.
VapourFracOut / Vfo	Calc	Vapour Mass Fraction at the outlet of the gas pump.

Adding this Model to a Project

Add to Configuration File

Sort either by DLL or Group:

	DLL:	Piping1.dll	→	Units/Links	→	Piping: GasPump - General
or	Group:	Mass Transfer	→	Units/Links	→	Piping: GasPump - General

See Model Selection for more information on adding models to the configuration file.

Insert into Project Flowsheet

Insert Unit

→

Piping

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GasPump - General

See Insert Unit for general information on inserting units.