Pump 1: Difference between revisions

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| valign="top" rowspan="2" | '''Label''' || valign="top" rowspan="2" | '''Required<br>Optional''' || valign="top" rowspan="2" | '''Input<br>Output ''' |colspan="2"   | '''Number of Connections''' || valign="top" rowspan="2" | '''Description'''
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Revision as of 06:36, 30 October 2012

Navigation: Main Page -> Models -> Pressure Changing Models

Related Links: Pump 1 - Dynamic with Simple Flow Calculation Mode


General Description

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

Diagram

Models-Pump-Image001.gif

The diagram shows the default drawing of the 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. The process is reversible and adiabatic

Data Sections

The default access window consists of four sections,

  1. The first tab has the same name as the model tag, contains the main configuration information relating to the unit.
  2. Optional tab Vapour Liquid Equilibrium (VLE)
  3. The section, Info, fully described in Info Tab Page Section.
  4. The section, Links, only visible in SysCAD 9.2, contains a summary table for all the input and output streams. See Links Table.
  5. The last section is the Audit. See Model Examples for enthalpy calculation Examples.

First Tab: Pump-1

Tag / Symbol
Input / Calc
Options
Description/Calculated Variables

Common First Data Section

Requirements

PressMethod

List Box

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.

PBoost

Input

 

The required pressure increase. Visible if the Boost method is selected.

PRqd

Input

 

The required outlet pressure. Visible if the Fixed method is selected.

VLEquilibrium

List Box

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.

Qm

Calc

 

The mass flow rate.

Ti

Calc

 

The inlet temperature.

To

Calc

 

The outlet temperature.

Pi

Calc

 

The inlet pressure.

dP

Calc

 

The pressure change.

Po

Calc

 

The outlet pressure.

Vfi

Calc

 

The inlet vapour fraction.

Vfo

Calc

 

The outlet vapour fraction.

Adding this Model to a Project

Insert into Configuration file

Sort either by DLL or Group.

 

DLL:

Basic1.dll

Units/Links

Process: Piping: Pump(1)

or

Group:

Mass Transfer

Units/Links

Process: Piping: Pump(1)

See Project Configuration for more information on adding models to the configuration file.


Insert into Project

 

Insert Unit

Process

Piping

Pump(1)

See Insert Unit for general information on inserting units.