Below is a version history for Double Pipe Heat Exchanger Design (DHex) software:

DHex 3.1.0.5

+ Maintenance release
fixed bug to address failing to calculate the thermal capacity ratio
fixed bug to address failing to calculate the number of transfer unit
fixed bug to address failing to calculate pressure drop in annulus side

DHex 3.1.0.4

+ Maintenance release

DHex 3.1.0.3

+ Added used hydraulic diameter for Nusselt number calculation, this feature can be accessed through the software setting screen
+ Minor fixes to interface

DHex 3.1.0.2

+ Software upgrade to Microsoft dot Net 4.8 Framework
+ fixed bug affecting retrieving film heat transfer coefficient user database entries
+ Added water and steam properties
+ Added check for software update

DHex 3.1.0.1

+ Fixed bug affecting retrieving Nusselt user correlations when user is using comma for decimal point separator

DHex 3.1.0.0

+ Maintenance release addressing software licensing on new activation server
+ Added license information screen can be accessed from Help menu

DHex 3.0.0.3

+ Maintenance release addressed software digital signature and end user license agreement

DHex 3.0.0.2

+ Ability to designate Nusselt user correlations to inner pipe or outer pipe side
+ Plot temperature profile for hot and cold sides, check temperature cross chart
+ Multi case feature will now save cases in a case list and reload a case upon request during run time.

DHex 3.0.0.1

+ Maintenance release

DHex 3.0.0.0

+ Software upgrade to Microsoft dot Net 4.6 Framework
+ New user interface
+ Added pumping power calculation
+ Add your own Nusselt correlations to use in software calculations
+ Added Unit converter includes 23 measurements units with 200-unit conversion
+ Added Input Consistency check – to reduce input errors related to decimal point separator
+ Some enhancement to results display
+ Added Re-Save feature faster saving for edited files
+ Added ability to enter heat transfer coefficient on both inner pipe side and outer pipe side
+ Ability to enter Heat Duty
+ Ability to calculate unknown exit temperatures on both sides or any two temperatures on both sides.
+ Ability to add multiple cases to one results grid.
+ Ability to add heat transfer coefficients in a user database table and load it during calculation.
+ Added the following Nusselt number correlations:
– Petukhov and Popov
– Sleicher and Rouse
– Gnielinski
– Prandtl
– Modified Dittus-Boelter
+ Pressure drop friction factor chart under finned tube option has been removed and calculation of this friction factor is now done by the software
+ Enhance summary of results presentation

DHex v2.1.0.0

+ Added Ability to export results to Engineering Datasheet format (To Microsoft Excel)

DHex v2.0.0.0

+ Enhanced User Interface
+ Added support for WeBBusterZ Physical properties database
+ Added fouling factors
+ Fixed some small programming bugs

DHex v1.0.0

+ First release