View source for Tank

[[Category:Models]]
{{Navigation|[[Models]]|[[Models#General Models|General Models]]}}

{| border="1" cellpadding="5" cellspacing="0"
!Width=250 font style="background: #ebebeb" |[[Tank]]
!Width=250 |[[Tank - Dynamic Mode]]
!Width=400 |[[Dynamic Tank - Optional Data Sections]]
|}

----
{{TOC}}
== General Description ==
This page is for the Tank model when used in '''Steady State''' mode. For help on the Tank model in Dynamic mode, please see '''[[Tank - Dynamic Mode]]''' (there are significant differences in the tank behaviour between Steady State and Dynamic).

In Steady State, the tank model is very similar to the [[Tie]] model.  When materials are mixed in the tank, a homogeneous product is produced.

=== Available Sub-Models ===

Evaluation Block:

# [[Makeup Block (MU)|Makeup Blocks]] (one or more) may be enabled in a Tank.  This allows the user to control the addition of streams such as reagents, water, air, etc. to the tank, often without having to use a PID or General controller.
# The [[Reaction Block (RB)]] allows the user to configure any number of reactions within the tank.
# The [[Environmental Heat Exchanger (EHX)|Environmental Heat Exchanger Block]] allows the user to add or remove energy from the tank using a number of different methods.
# The [[Evaporation Block (Evap)|Evaporation Block]] allows the user to set the evaporation of either water only or a mixture of water and all other species that are specified as both liquid and vapour.
# The [[Vapour Liquid Equilibrium (VLE)|Vapour Liquid Equilibrium Block]] will attempt to ensure that the vapours and liquids of the selected species will be in equilibrium in the Tank.  For example, if the equilibrium species is water and the tank is at atmospheric pressure, then SysCAD will maintain the temperature at, or below, the saturated temperature of 99.97°C by evaporating water if required.
# [[Discard Block (DB)|Discard Blocks]] (one or more) may be enabled in a Tank. This allows the user to control the discarding of material from the Tank, usually without having to use a PID or General controller.

Options:

# The [[General Model (GM)]] may be enabled in the tank in Steady State, allowing the user to control the split between the outgoing stream flows.
# The [[General Model Thermal (GMT)|Thermal Split]] may also be enabled in Steady State '''IF''' the General Model is enabled.  This option is used to adjust the temperatures of the outgoing streams from the unit.
# The [[Heat Exchanger (HX)]] may be enabled.  The user must also connect links to the HX input and the HX output. The Heat Exchange page needs to be configured with the relevant heat exchange area and overall heat transfer coefficient. The model combines all of the incoming streams, performs any reactions, and then carries out the heat exchange operation.  Please note that the fluid in the heat exchanger will transfer energy via sensible heat ONLY.  There is NO condensing or boiling in the heat exchanger.

=== Model Procedures ===

[[Model Procedures]] allows the user to implement code directly within the Tank.  

To enable this, on the '''[[Common Data Sections#Common Data on Info Tab Page|Info]]''' tab page tick the "Procedures" tickbox.

== Diagram ==

[[Image:Tank.jpg]]

The diagram shows a drawing of the tank, with a number of connecting streams. When the user inserts the tank into a flowsheet, a different graphics symbol can be selected from a pull down menu. The streams may be connected to any area of the drawing without affecting the actual connection point as SysCAD ignores the physical position of the connection. In dynamic mode, you can set the connection height of the links.

== Inputs and Outputs ==

{| 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 || 1 Required  || In   ||1 || 30 || General purpose inlet (limit increased from 20 in {{Available138|25939||y}}) 
|-
| Output || 1 Required || Out  ||1 || 20 || General purpose outlet
|-
| HX_in || Optional    || In   || 0/1* || 20 || Heat exchanger inlet (*only required if HX block is selected) (No condensing or evaporating allowed.  See [[#Available_Sub-Models|notes on options]].) 
|-
| HX_Out || Optional   || Out  || 0/1* || 20 || Heat exchanger outlet (*only required if HX block is selected) (No condensing or evaporating allowed.  See [[#Available_Sub-Models|notes on options]].) 
|}

== Model Theory ==

In Steady State, all the input streams (excluding the HX streams) are perfectly mixed, then any sub-model actions occur on the mixture. This is very similar to the [[Tie]] model.

=== Flowchart ===

The following flowchart shows the sequence of events if any Evaluation Block sub-model options or the HX Block are enabled:

[[Image:Tank-ProBal.png]]

== Data Sections ==

=== Summary of Data Sections ===

The tank access window may consist of a number of sections. This number may increase or decrease, based on user configuration and / or number of species.

# '''[[#Tank Page|Tank-1]]''' tab - Contains general information relating to the unit.
# '''[[Phase Change (PC)|PC]]''' - Optional tab that is visible if EB.Solubility.On and/or EB.PhaseChange@T.On is enabled on the first tab.
# '''[[MU]]''' - Optional tab, or multiple tabs if more than 1 Makeup is selected.  Only visible if one of more Makeups are enabled in the Evaluation Block.
# '''[[RB]]''' - Optional tab, only visible if the Reactions are enabled in the Evaluation Block.
# '''[[Heat Exchanger (HX)|HX]]''' - Optional tab, only visible if streams (in and out) have been connected to the Tank.HeatExchange IO connection ports. 
# '''[[EHX]]''' - Optional tab, only visible if the EnvironHX is enabled in the Evaluation Block.
# '''[[Evap]]''' - Optional tab that is visible if Evaporator is enabled.
# '''[[VLE]]''' - Optional tab, only visible if the VLEquilibrium is enabled in the Evaluation Block.
# '''[[DB]]''' - Optional tab, or multiple tabs if more than 1 Discard Block is selected.  Only visible if one of more Discard Blocks are enabled in the Evaluation Block.
# '''[[#Split (Flow) Tab Page|Split]]''' - Optional tab, only visible if ''SplitFlows'' is enabled. 
#* This tab is only available for Steady State mode.
# '''[[#Split Thermal Tab Page|SplitT]]''' - Optional tab, only visible if ''SplitThermal'' is enabled. 
#* This may only be enabled after SplitFlow has been enabled.
#* This tab is only available for Steady State mode.
# {{Q Container | TabName=Feed | UnitType=tank |SetP=yes}}
#* This is before any [[Evaluation Blocks|Evaluation Block]] sub-models or the HX are evaluated.
# {{Q Container | TabName=Prod | UnitType=tank |ProdSplit=yes}}
#* This is after any [[Evaluation Blocks|Evaluation Block]] sub-models or the HX are evaluated, but before flow splits.  
#* This tab is only available for Steady State mode.
# '''[[Common Data Sections#Common Data on Info Tab Page|Info]]''' tab - Contains general settings for the unit and allows the user to include documentation about the unit and create Hyperlinks to external documents.
# '''[[Model Procedures#MP Page|MP]]''' tab - Optional tab, only visible if ''Procedures'' have been enabled on the '''[[Common Data Sections#Common Data on Info Tab Page|Info]]''' tab page.
# '''[[Links Table|Links]]''' tab, contains a summary table for all the input and output streams. 
# '''[[Audit]]''' tab - Contains summary information required for Mass and Energy balance. See [[Model Examples]] for enthalpy calculation Examples.
# Additional fields are shown in Dynamic mode. These are described in the [[Tank - Dynamic Mode]].

===Tank Page===
'''Unit Type: Tank-1''' - The first tab page in the access window will have this name.

{| border="1" cellpadding="5" cellspacing="0" 
|-
! Tag (Long/Short) || Input/ Calc || Description'''
{{Common Data on First Tab Page}}
|-
|  colspan="3" font style="background: #ebebeb"    | '''''Requirements''''' 
{{OperatingP}}
|-
|  colspan="3" font style="background: #ebebeb"    | '''''ResTime (Residence Time)'''''
{{ Residence Time Data Section | UnitOp=Tank}}
|-
|  colspan="3" font style="background: #ebebeb"    | '''''EB (Flow Evaluation Block)''''' 
{{EB Evaluation Data Section | Makeups = Yes | Reactions = Yes | HeatXChg = Yes | EnvironHX = Yes | Evaporation = Yes | VLE = Yes | Discard = Yes}}
|-
|  colspan="3" font style="background: #ebebeb"    | '''''Options''''' 
|-
| SplitFlows || Tick Box || This can be used to enable the Flow separate for output streams. If this box is checked then the associated page, '''[[General Model (GM)|Split]]''', becomes visible and may be configured.<br> '''Notes:'''
# This option is used to adjust the outgoing streams from the unit.  It cannot be changed while the model is solving.
# This option is not available in Dynamic mode.
|-
| SplitThermal || Tick Box || This option is only visible if the SplitFlows option has been chosen. This can be used to enable the uneven Energy distribution for output streams. If this box is checked then the associated page, '''[[General Model Thermal (GMT)|SplitT]]''', becomes visible and may be configured. <br> '''Notes:'''
# This option is used to adjust the temperatures of the outgoing streams from the unit.  It cannot be changed while the model is solving.
# This option is not available in Dynamic mode.
|-
| ShowQFeed || Tick Box || QFeed and associated tab pages (e.g. Sp) will become visible, showing the properties of the combined feed stream. See [[Material Flow Section]]. This will be prior to any sub-model (e.g. reactions) actions.
|-
| ShowQProd || Tick Box || QProd and associated tab pages (e.g. Sp) will become visible, showing the properties of the products.  See [[Material Flow Section]]. This will be after the actions of any sub-models and before any flow splits with the [[GM]] model. This option is not available in Dynamic mode.
|}

=== Split (Flow) Tab Page ===

{{Split Flow Data Section}}

=== Split Thermal Tab Page ===

{{Split Thermal Data Section}}

=== Dynamic Mode Data Sections ===
The fields which appear in the access window for the tank in Dynamic mode only are shown in [[Tank - Dynamic Mode]].

== Adding this Model to a Project ==

{{Adding Model to a Project | DllName=Basic1 | DllSubGroup=Process | UnitOp=Tank(1) | Group=General}}

== Hints and Comments ==

# If the user configures the GM, and then at a later stage adds or removes a stream (input or output), this may have an impact on the GM configuration. It is recommended that the user check the GM every time a stream change is made.
# In Steady State, the [[Tie]] model is almost identical to the tank model, except that the Tie does not have the [[Heat Exchanger (HX)]] sub-model.
# In Steady State, the tank model can be used with [[Demand]].
# There may be mass entering or leaving the tank via the Reaction Block source or sink, so if the outgoing mass is not the same as the incoming mass, this may be a place to check first.
# If the user 'Resets' or uses the 'Empty Process' SetState option, then all connecting flanges will also be set to zero flow. 
# If the user defined pressure is very different to the feed stream pressure, then this may cause the temperature change to be quite significant.  If the inlet temperature is already high, then it is possible for the temperature to go above the critical temperature of water. In this case, the unit will return an energy imbalance error message.  To avoid this issue, please consider using the [[Flash Tank 2|Flash Tank]] so that VLE, T and P can be solved simultaneously in an iterative process.