Non return valve: Difference between revisions
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== Inputs and Outputs == | == Inputs and Outputs == | ||
{| border="1" cellpadding="5" cellspacing="0" | {| border="1" cellpadding="5" cellspacing="0" | ||
|- | |||
| 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''' | |||
|- | |||
| '''Min''' || '''Max. ''' | |||
|- | |- | ||
| Input || Required || In || 1 || 1 || Input stream to valve. | |||
|- | |- | ||
| Output || Required || Out || 1 || 1 || Output stream from valve. | |||
|} | |} | ||
Revision as of 06:23, 30 October 2012
Navigation: Main Page -> Models -> Pressure Changing Models
To Be Completed....
General Description
The valve model will add pressure drop to the stream or operates at a specified pressure.
Diagram
The diagram shows the default drawing of the Valve, 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 valve. |
Output | Required | Out | 1 | 1 | Output stream from valve. |
Model Theory
The valve is a constant enthalpy process.
Step 1) Enthalpy can be calculated from the inlet conditions.
Step 2) Outlet temperature can be calculated from enthalpy and outlet pressure.
Data Sections
The default access window consists of a number of sections,
- The first tab has the same name as the model tag, contains the main configuration information relating to the unit.
- Optional tab Vapour Liquid Equilibrium (VLE)
- The section, Info, fully described in Info Tab Page Section.
- The section, Links, only visible in SysCAD 9.2, contains a summary table for all the input and output streams. See Links Table.
- The last section is the Audit. See Model Examples for enthalpy calculation Examples.
Tag / Symbol
|
Input / Calc
|
Options
|
Description/Calculated Variables
|
Requirements | |||
PressureMethod |
List Box |
None |
No pressure change across the unit. |
Drop |
The user specifies a pressure drop. Therefore, Pout = Pin - Pdrop | ||
Fixed |
The user specifies a fixed outlet pressure from the unit. | ||
Atmos |
The outlet pressure from the unit is set to atmospheric pressure. | ||
PDrop |
Input |
|
The required pressure drop. Visible if the Drop 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. | ||
Results | |||
Qm |
Calc |
|
The mass flow rate through the unit. |
Ti |
Calc |
|
The inlet temperature to the unit. |
To |
Calc |
|
The outlet temperature from the unit. |
Pi |
Calc |
|
The inlet pressure to the unit. |
dP |
Calc |
|
The pressure change across the unit. |
Po |
Calc |
|
The outlet pressure from the unit. |
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: Valve - Non-Return(1) |
or |
Group: |
Mass Transfer |
→ |
Units/Links |
→ |
Process: Piping: Valve - Non-Return(1) |
See Project Configuration for more information on adding models to the configuration file.
Insert into Project
|
Insert Unit |
→ |
Process |
→ |
Piping |
→ |
Valve - Non-Return(1) |
See Insert Unit for general information on inserting units.