View source for Reboiler/Condenser Heat Exchanger

[[Category:Models]]
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{{Navigation|[[Models]]|[[Models#Energy Transfer Models|Energy Transfer Models]]|altname=Reboiler/Condenser Heat Exchanger}}

'''Related Links:''' [[Example - 03UnitModels Projects 2#Reboiler Condenser Heat Exchanger Example|Reboiler Condenser Heat Exchanger Example]]
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== General Description ==
The Reboiler/Condenser Heat Exchanger (RCX) is used to transfer heat from one stream to another. The RCX Heater unit model is based on patented technology[[#References|<sup>[1]</sup>]] and was developed with in association with the patent holder[[#References|<sup>[2]</sup>]]. In principle, an internally-recirculating heat transfer fluid (HTF) transports heat from the "hot" stream to the "cold" stream, similar to a Heat Pipe (see [https://en.wikipedia.org/wiki/Heat_pipe Wikipedia]). The HTF is in the shell side, while the hot and cold streams are in separate tube sides. The RCX Heater unit can be used in a single- or dual-shell arrangement as shown below.
#In the Hot Side ('''Reboiler'''), heat is transferred from the hot stream to the HTF, cooling the hot stream and boiling the HTF.
#The HTF vapour then reports to the Cold Side ('''Condenser''') where energy is transferred to the cold stream, heating the cold stream and condensing the HTF.
#The condensed HTF is then returned to the Hot Side, completing the recycle.

[[File:KX Diagram.png|link=]]

[[File:KX Flowsheet.png|link=|550px|right]] In a single-shell arrangement the HTF pressure is constant. However, in a dual-shell arrangement as shown to the right, the HTF vapour between Hot Side and Cold Side can be subject to mechanical vapor recompression (MVR) to increase pressure, temperature and boiling point. In this arrangement, the Hot and Cold shell sides operate at different pressures. It is then possible for the "hot" stream (the heat source used to boil the HTF) to be '''''colder''''' than the "cold" stream (the heat sink used to condense the HTF), thereby transferring energy from a colder stream to a hotter stream!

In dual-shell arrangement, the HTF may also be subcooled by partially flooding the Condenser, in order to minimise any flashing which would occur through the Reducer valve separating the Cold and Hot Sides. Due to adiabatic inefficiency, energy is added to the system via MVR. Energy is also lost from the system due to ambient heat loss from the shell(s).

=== Diagram ===
[[File:KX Heater.png|link=]]

== 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''' 
|- 
|    |Hot In     ||1 Required             ||In                    || 1                        ||  10               || The stream inlet to the Hot Side (Reboiler).
|- 
|    |Cold In    ||1 Required             ||In                    || 1                        || 10                || The stream inlet to the Cold Side (Condenser).
|- 
|    |Hot Out    ||1 Required               ||Out                   ||1                         || 1                 || The stream outlet from the Hot Side (Reboiler). 
|- 
|    |Cold Out   ||1 Required               ||Out                  || 1                        || 1                 || The stream outlet from the Cold Side (Condenser). 
|}

Note that the recirculating HTF (Heat Transfer Fluid) is an ''internal'' flow and has no connections.

== Behaviour when Model is OFF ==

If the user disables the unit, by un-ticking the ''On'' tick box, then the following actions occur:
* All streams connected to the 'Hot In' inlet will flow out of the 'Hot Out' outlet with no temperature or phase change
* All streams connected to the 'Cold In' inlet will flow out of the 'Cold Out' outlet with no temperature or phase change
* Any sub-models, such as Reaction Block, will not occur
* No energy exchange will occur

So basically, the unit will be 'bypassed' without the user having to change any connections.

== Model Theory ==

The KCX Heater is a composite model comprised of multiple embedded unit models. While this unit model could be built in SysCAD from its component parts and the HTF recirculation loop, such a model would be complex to implement, difficult to robustly control, and cumbersome to use within project flowsheets. As such, the implementation as a composite model with internal iterative solver and control provides a robust standalone unit model.

The user specifies the following:
* Hot and cold streams (by [[Pipe]] connection)
* HTF component (internally recirculating shell-side species, no SysCAD stream connection required)
* Hot and Cold Side tube details:
** HTC
** Area
** Reactions
** Pressure drop
* Hot and Cold Side heat loss from shell
* Physical layout:
** Single- or dual-shell
** MVR (if dual-shell):
*** Temperature or pressure change
*** Mechanical and adiabatic efficiencies
** Subcooling (if dual-shell):
*** HTC
*** Flooded fraction of Cold Side area

The RCX Heater unit model uses internal iterative calculations to determine the required '''HTF temperature(s), pressure(s) and mass flowrate''' to satisfy the energy balance. This uses the nominated HTF component thermodynamic data from the [[Species Database]]. Note that both the liquid and gas phases of the HTF component must be defined.

Internally, both the Hot and Cold Sides use the same [[Shell and Tube Heat Exchanger 2#General Theory|LMTD heat transfer logic]] as any heater. Tube-side reactions (including heat of reaction) and pressure drop are evaluated before heat exchange. The RCX Heater iterative solver is bound by the following requirements:
# Energy transfer from Hot Stream by LMTD = Energy absorbed in vaporising HTF at Hot Side saturation temperature
# Energy transfer to Cold Slurry by LMTD  = Energy released by condensing HTF at Cold Side saturation temperature
# Energy into the system = Energy out of the system (this is complicated by MVR adiabatic inefficiency, tube-side heat of reaction, and ambient heat loss)

This iterative calculation also includes checks and stops for various forbidden/unsolvable cases, such as Shell-Tube temperature crossover, HTF pressure below minimum allowance, and HTF temperature approaching the component's critical temperature.

== Data Sections ==

The default access window consists of several sections: 

# '''[[#KX Heat Exchanger Page|HeaterKX]]''' tab - This first tab contains general information relating to the unit.
# '''[[#Results Tab|Results]]''' tab - This tab contains unit results and intermediate values used for calculation of energy balance.
# '''[[RB|HotRB]]''' - Optional tab, only visible if the Reactions are enabled on the Hot side. Please note that the RCX Heater unit will IGNORE any Source, Sink or HX in the reaction file.
# '''[[RB|ColdRB]]''' - Optional tab, only visible if the Reactions are enabled on the Cold side. Please note that the RCX Heater unit will IGNORE any Source, Sink or HX in the reaction file.
# '''[[Material Flow Section|QHotFeed]]''' - Optional tab, only visible if ''ShowQHotFeed'' is enabled. This and subsequent tab pages, e.g. QHotFeed.. and Sp, shows the properties of the mixed stream as the feed to the Hot side. 
# '''[[Material Flow Section|QColdFeed]]''' - Optional tab, only visible if ''ShowQColdFeed'' is enabled. This and subsequent tab pages, e.g. QColdFeed.. and Sp, shows the properties of the mixed stream as the feed to the Cold side. 
# '''[[Material Flow Section|QHotProd]]''' - Optional tab, only visible if ''ShowQHotProd'' is enabled. This and subsequent tab pages, e.g. QHotProd.. and Sp, shows the properties of the product stream from the Hot side. 
# '''[[Material Flow Section|QColdProd]]''' - Optional tab, only visible if ''ShowQColdProd'' is enabled. This and subsequent tab pages, e.g. QColdProd.. and Sp, shows the properties of the product stream from the Cold side. 
# '''[[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.
# '''[[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.

=== RCX Heat Exchanger Page ===

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

{|   border="1" cellpadding="5" cellspacing="0" width="100%"
| '''Tag (Long/Short)'''||'''Input / Calc'''||'''Description / Calculated Variables / Options'''
|-
{{Common Data on First Tab Page}}
|-
|  colspan="3" font style="background: #ebebeb"    | '''Requirements'''
|-
| On|| Tick Box || Switches the RCX Heat Exchanger on/off.
|- 
|  colspan="3" font style="background: #ebebeb" | '''Shell ...'''
|- 
| HTF.Component || List Box || Selection from list of HTF (Heat Transfer Fluid) component. Any component with species in both the gas and liquid phases found in the [[Species Configuration|project species configuration]] will appear in this list. Water is always available as H2O(l) and H2O(g) are always required species in project configuration.
|- 
| HTF.LiquidSp || style="background: #ebebeb"|Calc || The liquid species of the selected HTF component.
|-
| HTF.VapourSp || style="background: #ebebeb"|Calc || The gas species of the selected HTF component.
|-
| HTF.CriticalT || style="background: #ebebeb"|Calc || The critical temperature of the selected HTF component.
|-
|  colspan="3" font style="background: #ebebeb" | '''Layout'''
|-
| rowspan=3| MVR.Option || None || No MVR (Mechanical Vapour Recompression) is included. This allows selection between one or two shell operation.
|- 
| Increase Pressure || MVR is enabled with control over the increase in HTF saturation pressure (saturation temperature change is a result).
|- 
| Increase Temperature || MVR is enabled with control over the increase in HTF saturation temperature (saturation pressure change is a result).
|- 
| TwoShells || Check Box || Only available if ''MVR.Option'' = '''None'''. If this is true, Hot and Cold sides are separate shells with independent heat loss options. If this is false, the unit has a single shell and heat loss is only available for the Hot side.
|-
| rowspan=2| Subcooling || None || No sub-cooling of the HTF inside the Cold side shell.
|- 
| Flood Fraction || Sub-cooling is enabled within the Cold side shell by partial flooding.
|-
| FloodFraction || Input || The fraction of Cold side heat transfer area which is flooded.
|-
| LiquorHTC || Input || The heat transfer coefficient of the flooded Cold side tubes (i.e. between the Cold side stream and the liquid phase HTF).
|-
|  colspan="3" font style="background: #ebebeb"    | '''HotSide / ColdSide ...''' - Note that the Hot (Reboiler) and Cold (Condenser) side input fields are identical.
|-
| UserHTC || Input || The heat transfer coefficient of this side's heat transfer area.
|-
| rowspan=2| Layout || Overall || The heat transfer area is defined by area input.
|- 
| Tube Detail || The heat transfer area is defined by tube sizing and layout. This is calculated by <math>\pi \times TubeOD \times Tubes \times Passes \times PassLength</math>
|-
| UserArea || Input || Available if ''Layout'' = '''Overall'''. The defined heat transfer area for this side.
|-
| TD.TubeOD || Input || Available if ''Layout'' = '''Tube Detail'''. The diameter of the heat transfer tubes.
|-
| TD.Tubes || Input || Available if ''Layout'' = '''Tube Detail'''. The number of heat transfer tubes.
|-
| TD.Passes || Input || Available if ''Layout'' = '''Tube Detail'''. The number of passes of heat transfer tubes.
|-
| TD.PassLength || Input || Available if ''Layout'' = '''Tube Detail'''. The length of each pass of heat transfer tubes.
|-
| PressDropReqd || Input || The required pressure drop through the tube side. Note that this is a pressure change ''inside'' the tubes and does not affect the pressure of the HTF.
|-
| rowspan=4| HeatLoss.Method <br> (Not available for ColdSide if Single Shell.) || None || No heat loss.
|- 
| Fixed HeatFlow || Heat loss is a user input power value.
|- 
| Fractional || Heat loss is calculated as a fraction of heat transfer within this side.
|- 
| Loss to Ambient || Heat loss is calculated using shell surface area, HTC and external temperature.
|-
| HeatLoss.HeatFlowReqd || Input || Available if ''HeatLoss.Method'' = '''Fixed HeatFlow'''. The required heat loss from the shell of this side.
|-
| HeatLoss.FracReqd || Input || Available if ''HeatLoss.Method'' = '''Fractional'''. The required fraction of heat transfer as heat loss from the shell of this side.
|-
| Shell.Diameter || Input || Available if ''HeatLoss.Method'' = '''Loss to Ambient'''. The shell diameter of this side. Used for calculating shell area.
|-
| Shell.Length || Input || Available if ''HeatLoss.Method'' = '''Loss to Ambient'''. The shell length of this side. Used for calculating shell area. <br> '''NOTE:''' This is the same value as TD.PassLength. Changing one will change the other.
|-
| Shell.SurfaceArea || style="background: #ebebeb"|Calc || Available if ''HeatLoss.Method'' = '''Loss to Ambient'''. The shell surface area of this side. Calculated as <math>/pi /times Shell.Diameter /times / Shell.Length</math>. Note that the "end caps" are not considered.
|-
| Shell.HTC || Input || Available if ''HeatLoss.Method'' = '''Loss to Ambient'''. The heat transfer coefficient of the shell (i.e. between the HTF and the external conditions).
|-
| AmbTOverride || Input || Available if ''HeatLoss.Method'' = '''Loss to Ambient'''. Optional override of the ambient temperature. To use the project [[Plant Model - Environment#Ambient and Environment Conditions|environment ambient temperature]] set this to * (undefined).
|- 
| Ambient_T || style="background: #ebebeb"|Calc || Available if ''HeatLoss.Method'' = '''Loss to Ambient'''. The external temperature used for heat loss calculation from the shell. This is equal to the project [[Plant Model - Environment#Ambient and Environment Conditions|environment ambient temperature]] if '''AmbTOverride is undefined.
|-
| rowspan=2| Reactions || On || Enables [[RB|Reaction Block (RB)]] for this side. Reactions are applied ''inside'' the tubes and do not affect the HTF. Note that the RCX Heater unit will IGNORE any Source, Sink or HX in the reaction file.
|- 
| Off || No reaction for this side.
|-
|  colspan="3" font style="background: #ebebeb"    | '''MVR ...'''
|-
| rowspan=3| Option || None || No MVR (Mechanical Vapour Recompression) is included. This allows selection between one or two shell operation.
|- 
| Increase Pressure || MVR is enabled with control over the increase in HTF saturation pressure.
|- 
| Increase Temperature || MVR is enabled with control over the increase in HTF saturation temperature.
|- 
| dT_Reqd || Input || Available if ''Option'' = '''Increase Temperature'''. The required change in HTF saturation temperature across the MVR. Pressure change is a result.
|- 
| dP_Reqd || Input || Available if ''Option'' = '''Increase Pressure'''. The required change in HTF saturation pressure across the MVR. Temperature change is a result.
|- 
| AdiabaticEfficiency / AdiabaticEff || Input || The adiabatic efficiency of the MVR. Inefficiency is added as heat to the HTF.
|- 
| MechanicalEfficiency / MechanicalEff || Input || The mechanical efficiency of the MVR. This is used for calculation of the overall MVR compressor power requirement and has no effect on the HTF.
|- 
|  colspan="3" font style="background: #ebebeb" | '''Specified Configuration''' - This will show a text description of the physical configuration. E.g. ''Two Shells, Mechanical Vapour Recompression''.
|- 
|  colspan="3" font style="background: #ebebeb" | '''Options'''
|- 
| ShowQHotFeed || Tick Box || QHotFeed and associated tab pages (e.g. Sp) will become visible, showing the properties of the combined Hot stream feed flow. See [[Material Flow Section]]. This will be prior to any sub-model actions (e.g. Reactions).
|-
| ShowQColdFeed || Tick Box || QColdFeed and associated tab pages (e.g. Sp) will become visible, showing the properties of the combined Cold stream feed flow. See [[Material Flow Section]]. This will be prior to any sub-model actions (e.g. Reactions).
|-
| ShowQHotProd || Tick Box || QHotProd and associated tab pages (e.g. Sp) will become visible, showing the properties of the combined Hot stream outlet flow. See [[Material Flow Section]].
|-
| ShowQColdProd || Tick Box || QColdProd and associated tab pages (e.g. Sp) will become visible, showing the properties of the combined Cold stream outlet flow. See [[Material Flow Section]].
|- 
|  colspan="3" font style="background: #ebebeb" | '''User Warning Limits'''
|- 
| TrackHTF.MinP || Tick Box || Generate a warning message if the calculated HTF pressure falls below a specified value. E.g. to prevent ingress of ambient air.
|-
| TrackHTF.CriticalT || Tick Box || Generate a warning message if the HTF temperature approaches the critical temperature of the component.
|- 
| HTF.MinP || Input || Available if ''TrackHTF.MinP'' is ticked. The minimum pressure allowed for the HTF. Note that the unit will still solve, but a warning will be generated.
|-
| HTF.ApproachCriticalT || Input || Available if ''TrackHTF.CriticalT'' is ticked. The dT approach to the critical temperature. Note that in this range the unit will still solve, but a warning will be generated. Above the critical temperature, the unit will not solve and will always give an error.
|-
|  colspan="3" font style="background: #ebebeb" | '''Convergence ...'''
|- 
| RelTol || Input || The relative tolerance for the internal iterations to find HTF saturation temperature (internal iterations will stop when the step change is less than this value).
|-
| MaxIterCount || Input || The maximum number of internal iterations on a single Solver step for the internal convergence loop.
|-
| IterCount || font style="background: #ebebeb"|Calc || The actual number of internal iterations used on the previous Solver step.
|-
| RelError || font style="background: #ebebeb"|Calc || The relative error of the last internal iteration at end of the previous Solver step. (This must be lower than ''RelTol'' for the model to be "solved".)
|}

=== Results Page ===

This page provides the results of the unit model calculations, including details for the internal recirculating HTF stream.

{|   border="1" cellpadding="5" cellspacing="0" width="100%"
| '''Tag (Long/Short)'''||'''Input / Calc'''||'''Description / Calculated Variables / Options'''
|-
|  colspan="3" font style="background: #ebebeb" | '''Specified Configuration''' - This will show a text description of the physical configuration. E.g. ''Two Shells, Mechanical Vapour Recompression''.
|- 
|  colspan="3" font style="background: #ebebeb"    | '''HotSide / ColdSide ...''' - Most Hot (Reboiler) and Cold (Condenser) side result fields are identical. <br> For the ColdSide, this applies to tubes in the condensing HTF vapour space only (i.e. excludes subcooling, if enabled).
|-
| HTC || font style="background: #ebebeb"|Calc || The Heat Transfer Coefficient used for this side.
|-
| Area || font style="background: #ebebeb"|Calc || The Area used for this side.
|-
| TemperatureIn / Ti || font style="background: #ebebeb"|Calc || The temperature of the combined streams into the tubes for this side (i.e. Hot In or Cold In temperature).
|-
| TemperatureOut / To || font style="background: #ebebeb"|Calc || The temperature of the stream out of the tubes for this side (i.e. Hot Out or Cold Out* temperature). <br> *For ColdSide, if subcooling is enabled, this is the temperature out of HTF vapour space only. 
|-
| LMTD || font style="background: #ebebeb"|Calc || The Log Mean Temperature Difference for this side.
|-
| DeltaT  / dT || font style="background: #ebebeb"|Calc || The change in temperature through the tubes for this side.
|-
| PressureIn / Pi || font style="background: #ebebeb"|Calc || The pressure of the combined streams into the tubes for this side (i.e. Hot In or Cold In pressure).
|-
| PressureChange / dP || font style="background: #ebebeb"|Calc || The change in pressure through the tubes for this side.
|-
| PressureOut / Po || font style="background: #ebebeb"|Calc || The pressure of the stream out of the tubes for this side (i.e. Hot Out or Cold Out pressure).
|-
| MassFlow / Qm || font style="background: #ebebeb"|Calc || The mass flow through the tubes for this side.
|-
| HeatTransfer / HX || font style="background: #ebebeb"|Calc || The heat transfer with HTF for this side. <math>HX = HTC \times Area \times LMTD </math> (<math>= UA \times LMTD </math>) <br> '''HotSide''': This is the heat flow from the Hot stream to vaporise HTF. (= '''A''') <br> '''ColdSide''': This is the heat flow from condensing HTF to the Cold stream. (= '''D''')
|-
| HeatLoss || font style="background: #ebebeb"|Calc || Environmental heat loss from the shell of this side. <br> '''HotSide''': Heat loss from Hot shell. (= '''B''') <br> '''ColdSide''': Heat loss from Cold shell. (= '''E''')  (Not available for Single Shell)
|-
| RB.HeatOfReaction / RB.HOR || font style="background: #ebebeb"|Calc || (Only visible if Reactions are enabled) Heat of reaction within the tubes for this side.
|-
| RB.TemperatureOut / RB.To || font style="background: #ebebeb"|Calc || (Only visible if Reactions are enabled) The temperature of the combined streams into the tubes after evaluation of reactions (RB), before any heat exchange.
|-
| HTF.CondensingPower || font style="background: #ebebeb"|Calc || (ColdSide only, visible if Two Shell operation) Power from HTF condensation at cold side HTF conditions. (= '''D''' + '''E''')
|-
| HTF.FlashPower || font style="background: #ebebeb"|Calc || (ColdSide only, visible if Two Shell operation) Excess energy released flashing HTF condensate to hot side HTF conditions. (= '''F''') 
|-
| HTF.FlashMassFlow / HTF.FlashQm || font style="background: #ebebeb"|Calc || (ColdSide only, visible if MVR is online) Mass flow of vapour generated in flash to hot side HTF conditions.
|-
|  colspan="3" font style="background: #ebebeb"    | '''Shell ...''' (Hot side shell if Two Shell operation)
|-
| HTF.TransferPower / HTF.Power || font style="background: #ebebeb"|Calc || Total power transfer to HTF. (= '''A''' - '''B''' + '''F''')
|-
| HTF.Temperature / HTF.T || font style="background: #ebebeb"|Calc || HTF temperature.
|-
| HTF.Pressure / HTF.P || font style="background: #ebebeb"|Calc || HTF saturation pressure.
|-
| HTF.SatT@P || font style="background: #ebebeb"|Calc || HTF saturation temperature at pressure. (= ''HTF.T'')
|-
| HTF.MassFlow / HTF.Qm || font style="background: #ebebeb"|Calc || HTF recirculating mass flowrate.
|-
| HTF.LatHtVap || font style="background: #ebebeb"|Calc || HTF latent heat of vaporisation at shell temperature and pressure.
|-
|  colspan="3" font style="background: #ebebeb"    | '''MVR ...''' (only available if MVR is online)
|-
| EntropyIn / Si || font style="background: #ebebeb"|Calc || HTF entropy at MVR inlet temperature and pressure.
|-
| PressureIn / Pi || font style="background: #ebebeb"|Calc || HTF pressure at MVR inlet (= ''HTF.P'')
|-
| TemperatureIn / Ti || font style="background: #ebebeb"|Calc || HTF temperature at MVR inlet (= ''HTF.T'')
|-
| IdealPower || font style="background: #ebebeb"|Calc || Required MVR power input to HTF vapour at 100% adiabatic efficiency to achieve specified dT or dP.
|-
| Power || font style="background: #ebebeb"|Calc || Actual MVR power input to HTF vapour at defined adiabatic efficiency. (= '''C''')
|-
| InputPower || font style="background: #ebebeb"|Calc || Power input to MVR compressor at defined mechanical efficiency.
|-
| PressChange / dP || font style="background: #ebebeb"|Calc || Pressure change through MVR.
|-
| PressureOut / Po || font style="background: #ebebeb"|Calc || HTF pressure at MVR outlet.
|-
| SatT@P || font style="background: #ebebeb"|Calc || HTF saturation temperature at MVR outlet pressure.
|-
| TemperatureOut / To || font style="background: #ebebeb"|Calc || HTF temperature at MVR outlet.
|-
| EntropyOut / So || font style="background: #ebebeb"|Calc || HTF entropy at MVR outlet temperature and pressure.
|-
|  colspan="3" font style="background: #ebebeb"    | '''Subcool ...'''
|-
| SubcoolingPower / Power || font style="background: #ebebeb"|Calc || Power transfer for subcooling of HTF condensate to Cold stream. (= '''G''')
|-
| HTF.Temperature / HTF.T || font style="background: #ebebeb"|Calc || Temperature of subcooled HTF condensate.
|-
| Flooded.MassFlow / Flooded.Qm || font style="background: #ebebeb"|Calc || Mass flow of Cold stream used for subcooling.
|-
| Flooded.TemperatureOut / Flooded.To || font style="background: #ebebeb"|Calc || Outlet temperature of Cold stream used for subcooling.
|-
| ColdOutlet.TemperatureOut / ColdOutlet.To || font style="background: #ebebeb"|Calc || Outlet temperature of the combined Cold stream (i.e. Cold Out temperature).
|-
| ColdOutlet.DeltaT / ColdOutlet.dT || font style="background: #ebebeb"|Calc || The overall Cold stream temperature change.
|-
|  colspan="3" font style="background: #ebebeb"    | '''Results'''
|-
| EnergyBalance || font style="background: #ebebeb"|Calc || The overall energy balance, this should be zero when solved. (= '''A''' - '''B''' + '''C''' - '''D''' - '''E''' - '''F''' - '''G''')
|-
| HeatFlow || font style="background: #ebebeb"|Calc || Total external heat flow to the RCX Heater unit. (= - '''B''' + '''C''' - '''E''')
|-
| HTF.LiqEnthalpy || font style="background: #ebebeb"|Calc || HTF liquor phase enthalpy at ''HTF.T'' and ''HTF.P'' (HotSide).
|-
| HTF.VapEnthalpy || font style="background: #ebebeb"|Calc || HTF gas phase enthalpy at ''HTF.T'' and ''HTF.P'' (HotSide).
|-
| HTF.VapEnthalpy_MVR || font style="background: #ebebeb"|Calc || HTF gas phase enthalpy at ''MVR.To'' and ''MVR.Po'' (MVR outlet / ColdSide feed).
|-
| HTF.LiqEnthalpy_Cond || font style="background: #ebebeb"|Calc || HTF liquor phase enthalpy at ''MVR.SatT'' and ''MVR.Po'' (ColdSide).
|-
| HTF.LiqEnthalpy_Sub || font style="background: #ebebeb"|Calc || HTF liquor phase enthalpy at ''SubCool.HTF.T'' and ''MVR.P'' (ColdSide subcooling).
|-
|}

== Adding this Model to a Project ==

{{Adding Model to a Project | DllName=HeatExchange | DllSubGroup=Heat Transfer | UnitOp=Reboiler/Condenser Heat Exchanger | Group=Energy Transfer}}

== Example Project ==

*[[Example_-_03UnitModels_Projects_2#Reboiler_Condenser_Heat_Exchanger_Example|Reboiler Condenser Heat Exchanger Example]]

== References ==
#Clegg, R.L. (2020) ''[https://patents.google.com/patent/US20200284514A1/ "Heat Exchanger"]'', United States Patent Application US 2020/0284514 A1
#*Note that the technology is patented or patent-pending in various global regions, including Australia, China (ZL 2018800578696), Europe, West Africa and U.S (US20200284514A1).
#Clegg, R.L. (July 2020) ''Private Correspondence between KWA Kenwalt Australia and Refina''
<!--
::{| class="wikitable"
! Country/Region !! Serial Number !! Patent Status
|-
| Australia || 2018329209 || Pending Application - Under Examination
|-
| China || 2018800578696 || Patented
|-
| Europe || 18853105.7 || Pending Application - Under Examination
|-
| OAPI (West Africa) || 20115 || Patented
|-
| United States || 16/644969 || Pending Application - Under Examination
|}
-->