Development history


Changes made from version 2.5.1 to version 2.5.2 (2016-05-07)

  1. Hint text when hovering over mid-half of a boundary. The boundary is then selectable. The outer two quarters are correspondingly used for the component at hand.
  2. When Cntrl-clicking a component boundary for attaching it with another, the owning component with higher inertia is attracting the other and not moving itself.
  3. Eliminated text smudging when moving components.

Changes made from version 2.5 to version 2.5.1 (2016-04-24)

  1. Fixed output of result (*.rsl) and report (*.rep) files, see Results.
  2. Corrected irregularities in Temperature zone model.
  3. Fixed error when using Preferences dialogue reset button.

Changes made from version 2.4.2 to version 2.5 (2008-01-01)

  1. Eleven new models: Oil-fired boiler, Electricity-powered boiler, Electric heater, Temperature boundary, Convective boundary, Pipe with heat loss, Electric power cable, Residential house, Simple building, Temperature zone (Heat accumulating room model) and Heat conducting wall.
  2. Six new component symbols General boiler, Electricity-powered boiler, Electric heater, Residential house, Temperature zone and Heat conducting wall.
  3. All secondary refrigerants have a new property Fuel value.
  4. The framing mechanism for marking multiple components for duplication, deletion etc. has been extended by allowing use of Ctrl+Click at more components, as is commonplace by Windows programs.
  5. Multiple-selected components can now be dragged to a new position.
  6. Two kinds of plant example sets: Plant templates (as before) and Demo plant that demonstrates extreme use of FrigoSim, hence not being a good basis for a new plant.
  7. After a simulation has been performed, a number of calculated values are displayed as hint texts over relevant plant symbols, the performance of most components, the variables of each connector, the enforced value from boundary conditions, the relevant control value of each control, and for components having one-dimensional heat conduction the average temperature of each layer. Prior to the simulation, initially applied values of many of the same elements are shown.
  8. The File|Save as has been changed so that after a simulation, all plant change functionality is reenabled.
  9. Viewing of equations and variables has been moved from the preferences dialogue to a view menu item.
  10. Display of simulation warnings in the preferences dialogue is now default, ref. Reset button.
  11. Load and store of basis components and user-specified media have been moved to basis component and fluid windows popup commands from File|Open menu command and dialogues for input of basis components and fluids.
  12. Possible to give fluids of specific concentrations a user-specified name that is different from the default substance name.
  13. New variable display legend to explain display of connector variables, type and current unit.
  14. Viewing connector enthalpies also applies for secondary fluids, including humid air.
  15. More symbols with animation ("fchCls4 " og "fchCool3 ").
  16. Hint text display of connector temperature, pressure and enthalpy in enthalpy-pressure diagrams, and temperature, pressure, entropy and enthalpy in temperature-entropy diagrams. This display is suppressed when there are iso-lines present.
  17. User-selection of number format as alternative to automatic, for every type of quantity through the Set|Quantity units dialogue. Output decimal separator can be a comma (","), alternatively to point(".").
  18. Allowing comma as decimal separator in numerical input. Handled in parallel with point, not requiring a user setting.
  19. For heat conduction components there is a display of hint text over each layer element showing layer no, size, material and, if calculation has been performed the layer geometrical mean temperature.
  20. Component angle is displayed and can be changed in the component position and size dialogue.
  21. Fluid pressure can now be set in humid air circuits, depending on components used.
  22. New menu item setting Set|Edits after a simulation, allowing to do most edits after a simulation (default off).
  23. Better handling of calculation errors.
  24. New inspection dialogue for the entire heat conduction object of same type as layer inspection dialogue, which has got a next and previous layer button.
  25. New articles Optimisation of components and Calculation accuracy.

Changes made from version 2.4.1 to version 2.4.2 (2005-03-22)


  1. Corrected plot of equidistant table.
  2. Corrected indication of phase in H-logP and T-S diagrams.
  3. Corrected correlation function dialogue.
  4. Removed error in moving basis components.
  5. Improved installation robustness.
  6. When viewing heat flow balance and mass flow balance equations by setting equations and variables in (Set|Preferences dialogue, it is now possible to check individual coefficients and right-hand sides by moving the mouse cursor over the equations diagram in the upper left corner of the plant window.
  7. Heat flow balance and mass flow balance equations can be viewed (View|Equations).

Changes made from version 2.4 to version 2.4.1 (2004-03-22)


  1. The illustration item has been equipped with an additional mechanism for representing a polygon of any number of vertices. This is in addition to the original predefined-symbol representation. The polygon can be rotated as the ordinary symbol. Scaling is not enabled here, as such a polygon is meant to represent a fixed-sized object. This also applies to flipping (mirroring).
  2. The illustration item has been added to the item list of the Instant change mechanism. The instant change is to the rotation angle of the illustration symbol or polygon.
  3. When displaying equations and variables set through the preferences dialogue, there is now a hint text display when moving the mouse cursor over the equations. The text shows the origin of the currenly pointed-to equation (component, boundary condition or control). In addition it displays the text of the variable that corresponds to the coefficient. These hint texts are displayed both for the heat flow balance equations and those of the mass flow balances (one for each circuit). The hint texts must be active, set through the preferences dialogue (default). Note that the coefficient colours shown prior to a calculation is in disagreement with the hint texts, as the colouring depends on coefficients being calculated first.

Changes made from version 2.3 to version 2.4 (2004-03-01)


  1. New language selection mechanism through a new menu command Set|Language. Each language is represented by a file pair: Lang-XX.ini and Info-XX.ini, where XX is the corresponding international language code (a little simplified). Standard available are EN (British English), US (US English) and NO (Norwegian). Additional languages are DE (German), IT (Italian), ES (Spanish) and FI (Finnish). These can be made available by special order, receiving the corresponding file pair/s and a license file with added entries.
  2. New refrigerant library based on equations-of-states by Martin-Hou, Peng-Robinson-Styjek, Baehr, IUAPAC and SRK. The calculations are more accurate than before, but also more calculation-intensive.
  3. Two new refrigerants: R50 (Methane) and R728 (Nitrogen). Two original refrigerants R410A and R717 now have calculation variants to corresponding state based on Martin-Hou equations-of-state.
  4. Moving the mouse pointer over elements in either of the three windows produces hint texts, if this mechanism has been turned on in Preferences (default: on). This operates whether the plant layout is viewed, or the Hlog-P, T-S or phychrometric charts. The symbols display also has hint texts when moving over each symbol. Special for the Hlog-P diagram is that if View|Numbers is set, the hint text returns the set of state variables as given by the refrigerant library.
  5. The previous instant change mechanisms in the basis component and plant windows have been collected into one. It enables instant change of basis component size, functions of boundary conditions and controls, plus one new item: Aqueous fluid concentration. Select an aqueous fluid in the fluids window and the concentration is connected to the track bar. (See more in Instant change mechanism.)
  6. All table dialogues have got a Copy to Clipboard button for easy transfer to other programs.
  7. New menu command Edit|Adjust to Grid. This command moves a selected component or connector to the closest grid point. Grid spacing are set in the Preferences dialogue.
  8. A new Apply button in the Edit|Move/Scale command.
  9. New menu command Output|1D Heat Conduction to produce result output to file from one-dimensional heat conduction calculations.
  10. In the layer inspection dialogue, it is now possible to see the numerical values of all types of quantities, not only temperature.
  11. A weight function can be specified for a basis component. This function is evaluated for all plant components being of this kind of basis component, and is summed up and presented in the Title bar, just as the total plant cost.
  12. A number of View menu commands have been moved into the Preferences dialogue.
  13. The size indication by a circle or cross has been changed from being proportional to the diameter to now the area, in order to have a bigger possible range.
  14. The maximum number of components has been increased from 200 to 1000 (valid for commercial licenses).
  15. New articles Languages, Black elements, Handling results, Instant change mechanism and Cost and weight of a plant.

Changes made from version 2.2 to version 2.3 (2001-02-19)


  1. New refrigerants R404A, R407C, R600 (Butane), R600A (Iso-butane) and R1270 (Propene)
  2. New menu command File|Append allowing to place one or a number of previously specified plant/s alongside current plant. This way it is possible to combine several more or less complex plants into one.
  3. New menu command View|Animation giving life to a number of component symbols. This can be useful in an educational context, demonstrating the physical processes taking place in a plant. It may also capture some attention at exhibitions.
  4. New plant-window pop-up menu command Instant change . This reveals a window with a track bar, enabling direct change of function values in boundary conditions, and most of the controls. The current function value and the allowed range of values are indicated. Right-click a boundary condition or a control to activate this mechanism. While the track bar window is open, it is possible to click another boundary condition or control and continue changes here. When dragging the track bar, there is an immediate calculation of the plant. The instant results can be viewed in the plant layout or through the special charts (HlogP/TS/Psychrometric). Note that for regulator controls and even more so for capacity controls, the response is slower than for other items, because these controls trigger a more elaborate calculation.
  5. New license file structure.
  6. Sort mechanism for basis components and fluids in their respective windows. The sorting is performed by name and category and is activated through the corresponding popup menu.
  7. New button in warning message boxes allowing to ignore the specific type of warning for the rest of the simulation.
  8. New articles Temperature Control, Function Modifier Specification, Parallel Heat Exchangers and Roughness heights of various materials.
  9. Corrected handling of q in model Heated mixed storage tank.
  10. All *.sys files are changed to *.ini to prevent file hiding and other special treatment by Windows.
  11. This version is generated by Delphi 5, while previous 2.x versions originated from Delphi 3. One effect is that it is no longer necessary (as described below for version 2.1) to set a certain tool bar height for a specific screen resolution. This fix was necessary due to a bug in Delphi 3.


Changes made from version 2.1 to version 2.2 (1999-10-14)


  1. New mechanism allowing slide bar control of the capacity of a chosen basis component, producing immediate plant calculation. See last two paragraphs in Capacity change mechanisms.
  2. New menu command View|Basis components and fluids for turning on/off display of Basis set and Fluid set windows.
  3. New dialogue for directly accessing position and scale of a component. Accessed via button in the component dialogue.
  4. New separate dialogue for setting position and line width of a connector. Accessed via button in the connector dialogues.
  5. New menu command Inspect|Installation.
  6. One new refrigerant R508B.
  7. New articles on One-dimensional heat conduction, Capacity change mechanisms, The year 2000 challenge, User countries and FrigoSim file types.
  8. In the Multiple Simulations dialogue it is now possible to save the set of plant specifications to a specific file of type *.jbs .
  9. Introduction of temperature lines in Hlogp diagram and pressure lines in TS diagram. These are turned on/off through the menu command View|Variables (temperature and pressure display).
  10. The mechanism for setting total plant capacity is moved from dialogue Specify derived quantity to parent dialogue Derived quantities . This enables using any power/heat type derived quantity as plant capacity.
  11. Models Suction gas heat exchanger and Closed flash chamber with 4 ports are made transcritically operable.
  12. All refrigerant adapters, i.e. Dew-point temp. adapter for refrigerant circuit, Enthalpy adapter for refrigerant circuit and Mass flow adapter for refrigerant circuit are made supercritically operable.
  13. The Gas cooler model has been improved so it will contribute to better convergence.
  14. Alignment both left to right and right to left. The two choices are grouped as submenus under a common menu command Edit|Align.
  15. The FrigoSim Instruction Manual is now available through Internet. Just access through the menu command Help|Web.
  16. Correction of error in temperature type valve control.
  17. Correction of the way correlations are handled for heat exchanger models that have individual heat transfer coefficients for both sides.

Changes made from version 2.0 to version 2.1 (1999-07-05)


  1. Two new component models for rotational speed controlled compressors, one uncooled and one cooled.
  2. A new model for speed controlled refrigerant pump. Pressure increase and Efficiency are specified as functions of Volume flow and Rotational speed .
  3. A new model for outdoor climate impact has been introduced.
  4. A new model for a fluidised bed for drying purposes. This model is still under development, but it can already be used in close cooperation with SINTEF Energy Research and Thorbergsen Frigosoft.
  5. Two new refrigerants R141b and CO2 . The latter one can be used supercritically, preferably with model Gas cooler.
  6. The right mouse-button now activates pop-up menus with items relevant for the three main windows.
  7. The user may connect FrigoSim to own code by making a dynamic link library. The connection is set through the Function dialogue.
  8. A new function type has been introduced enabling the use of correlations for component data. These correlations enable more complex dependencies directly accessing fluid properties data from both refrigerants and secondary fluids properties libraries. So far this is limited to heat transfer coefficients.
  9. The function dialogue Load and Store buttons handle two-column-valued files (of type *.xy ) in addition to the ordinary *.fnc files.
  10. A new kind of derived quantity by which it is possible to get the total time during the simulation where any other derived quantity is within a value range.
  11. Any derived quantity of type power/heat can be set as representing the plant capacity. If set, the corresponding calculated value will be displayed in the title bar.
  12. Previously opened specification files are readily accessible from File|"File name", as is commonplace in Windows programs. Maximum number of files is set through Set|Preferences command. Default is 5, maximum is 10.
  13. The menus Add|Basis component, Add|Fluid and Add|Control have got submenus replacing the previous selection dialogues.
  14. New menu command Edit|Duplicate and connect. This command makes a copy of the current component and connects the copy to the original. This requires that the component is partly or entirely unconnected to other components. Otherwise it will only duplicate in the ordinary sense.
  15. New menu command Edit|Duplicate Plant. This corresponds to framing everything and then selecting Edit|Duplicate.
  16. New menu command Edit|Align, aligning all framed components plus connectors inside the frame. The components and connectors are all given the lowest x or y coordinate among them, applying the one (x or y) with the smallest original value range.
  17. Component and connectors can be marked and inspected also in the refrigerant properties diagrams and psychrometric charts. This can be also used for zooming around a particular area of interest. Note that components appearing more than once in a diagram, due to multiple local refrigerant or humid air circuits, can only be accessed through one of these (the one with the lowest local circuit number).
  18. New template for combined refrigerating plant and small heat pump on top.
  19. New symbols for flooded evaporator and cooled general compressor.
  20. When View|Results on the fly is off, a progress bar is displayed during simulation. This is recommended for lengthy calculations.
  21. Through the Add|Fluid menu command all refrigerants and all pure secondary fluids can be made available in one operation. After use these can be removed through the menu command Edit|Delete unused basises/fluids.
  22. All controls may now be temporarily disabled (set inactive). The plant then operates as if such controls were deleted. This may save time when testing alternative conditions.
  23. The boundary condition of a refrigerant circuit connector can be set to a specific pressure as alternative to dew-point temperature.
  24. The number of undo levels can be set to a maximum of 32767, using the Set|Preferences command. Default is 10.
  25. It is possible to turn on sound to illustrate some of the user actions. The sounds are carried by *.wav files, see sound files. If you enjoy having some of the sound illustrations, but not all, you may delete the files with the undesired sounds or alternatively replace them with other sound files. Sound is turned on and off in the Set|Preferences dialogue.
  26. As printer are differing in employed margins, it is possible to set the print margins in the Set|Preferences dialogue. The unit is the size of the header font, which can be set the same dialogue.
  27. The method in valve control has been changed, making it more robust.
  28. More dialogues accept double-clicking in list boxes (where appropriate).
  29. Graphics in dialogues are now visible whenever sufficient information is available. The separate Draw buttons have been removed. This applies to the Function dialogue, the Layer dialogue, the Basis component dialogue, the Refrigerant library dialogue, the Secondary fluid library dialogue and the User's own secondary fluid data dialogue.
  30. The tool bar is partly covered on some screen resolutions, presumably a Delphi problem (the development tool). This can be corrected by setting an explicit tool bar height in Set|Preferences dialogue. The setting is kept between sessions.
  31. The result and report files are reset only when starting a new calculation. Therefore these files are no longer affected (blanked) if FrigoSim is started again after a previous simulation.
  32. The capacity scaling feature has been changed to allow scaling to a specific capacity, not only a relative scaling. The new type of scaling can only be specified after first having selected a plant capacity in Output|Derived quantities and then performed a calculation with a subsequent reload (File|Reload).
  33. The default setting for command Set|Confirm deletion has changed from Yes to No, since the Edit|Undo makes deletion less dangerous.
  34. The component model Speed controlled secondary fluid pump, previously known as Pump with given characteristic , has been improved, allowing influence from Rotational speed on Pressure increase and Efficiency .
  35. A general code error prevented the Closed flash chamber with 4 ports to function properly. This model was used in the Cascade plant template .
  36. The menu commands Edit|Connect and Edit|Disconnect have been removed, as they are not considered to be of value anymore.
  37. The menu commands Set|Confirm Deletion, Set|Warnings and Set|Autoadjust have been deleted, with the settings instead in the Preferences dialogue (Set|Preferences).

Changes made from version 1.4.1 to version 2.0 (1998-11-16)


  1. FrigoSim has been converted to Windows 95/98/NT (WIN32). The new version cannot run under Windows 3.x, at least not without a WIN32S.dll installed.
  2. A tool bar has been introduced with buttons for the most frequently used menu commands. If the menu command is disabled (greyed), the corresponding tool button is also greyed. The buttons are grouped as the menu commands.
  3. New menu commands Edit|Undo and Edit|Redo. Each time a change is performed, the result is recorded. An undo will "rewind" to previous versions. A redo will correspondingly "wind forward" to a more recent version. A maximum of five versions are recorded on files _Undo-n_.sim , n = 1..5. If a crash occurs during a FrigoSim session (hopefully not caused by FrigoSim), check the time stamps of the Undo files, and rename the most recent file to the name of the current specification (ref. FrigoSim.ini ).
  4. New menu command Edit|Find, to facilitate finding an item in a large plant. After selecting an item and leaving the find dialogue, editing may be applied.
  5. New menu command Edit|Push behind, so that a component, completely covered by another larger-sized component, can be accessed.
  6. New menu command View|Relative capacities to pin-point ill-sized components. A circle is drawn around most components to indicate the relative capacity. These circles should normally be of the same magnitude.
  7. An addition to the previous menu command View|Equations. Now it is called View|Equations and Variables. In addition to showing the set of heat flow balance equations and the sets of mass flow balance equations (one per circuit), the variable numbers related to the connectors are displayed (in colours corresponding to the quantity type).
  8. A new selection in the menu command Add|Basis components: Making one basis component for each of the models that requires no data.
  9. Dialogs are alternatively OK'ed with double-click to list box items, wherever possible.
  10. Six new component models: Accurate heat exchanger , Accurate condenser , Accurate evaporator , Gas cooler (an accurate superheat exchanger), Evaporator with given capacity and Evaporator for humid air . At the same time the Air cooler with given capacity has been set to obsolete. This means that the model can still be used on old plant specifications, but can not be used when making new plants. Use the Evaporator with given capacity instead.
  11. File for one-sided heat exchanger data (*.hx1) has changed structure and extension. Data has been included to enable calculation of pressure drop. The new extension is "hx_s ".
  12. File for two-sided heat exchanger data (*.hx2) has changed structure and extension. Data has been included to calculate heat transfer and pressure drop in a temperature range. The new extension is "hx_ss ".
  13. A new type of two-sided heat exchanger data has been introduced, with refrigerant on one side and secondary fluid on the other. On last 3 points see Indirect specification of data for details.
  14. Larger scrolling range for the plant layout and diagrams.
  15. Introduction of x and y based mirroring of illustrations.
  16. Five new pure or fixed-blended fluids: Diethylbenzene mixture , Hydrocarbon mixture - Gilotherm D12 (Rhône-Poulenc) , Hydrofluoroether - HFE-7100 (3M) , Polydimethylsiloxan 1 - Baysilone KT3 (Bayer) (variant of previously available fluid), and Saturated Liquid Carbon Dioxide .
  17. One new aqueous fluid Potassium Acetate .
  18. The license files structure and parameters have been changed. Present FrigoSim users need new license files to run version 2.0.
  19. The function dialogue and the layer dialogue have got a Print button.
  20. The basis component price can now be specified as a function of size. In such a case when doing a plant scaling (Edit|Capacity), the plant price is automatically adjusted.
  21. Maximum number of components approx. doubled to 200 (valid for commercial licenses).

Changes made from version 1.4 to version 1.4.1 (1998-03-20)


  1. Improvement of server setup. Suppressing all attempts to write to the server directory.
  2. The result file is opened just as simulation starts. This prevents inadvertent blanking of a previously generated result file after case reload or FrigoSim restart.
  3. Tightening of memory leaks. No more problems with many consecutive File|Open commands.
  4. Aqueous secondary fluids from the fluid library now get a default colour, indicated as Automatic , accurately reflecting the concentration (in up to 256 steps for each colour component Red, Green and Blue).
  5. Improvement of Boundary condition dialogue.
  6. Justification of numerical field sizes in dialogues.
  7. Removed irregularities in the optimisation feature.
  8. Fixed some details of a few symbols.
  9. Features attainable from a demo license have been tightened. The number of plant components that can be simulated has been reduced from 15 to 10. The library fluids have been restricted to refrigerant R12 and secondary fluid Sea water . User-specified fluids are not possible to use. The single heat conduction based component (as before) may now only have one layer. The first two templates are possible to calculate from a demo license.

Changes made from version 1.3 to version 1.4 (1998-03-04)


  1. New kind of function: Table values based on equidistant x values, thus only y values have to be stored in memory and on file. A maximum of 10,000 points is possible. Through this hour values for a year can be specified.
  2. New model for setting a specific flux on a boundary: Heat flux load ("hxFlux ").
  3. New component model Temperature source ("srcT ") with 5 outlet ports. This is an alternative to using temperature boundary conditions, especially when there is a need for the same temperature function at several positions in the plant. The unused ports must be equipped with a zero value mass flow rate boundary condition.
  4. Implementation of a new menu command Perform|Multiple Simulations. This enables performing several simulations in one operation. The command could be useful when doing lengthy simulations, making the most of the PC outside office hours.
  5. Dragging a basis component and fluid to a new position changes the sequence.
  6. Implemented mechanism to redraw screen elements erased by dragged elements. This requires a high capacity computer to avoid screen flickering. It is therefore connected to a new menu command Set|Computer preferences by which this mechanism may be turned on or off. The previous Set|Font sizes has been embedded in the new command.
  7. Introduction of a new Accuracy requirement set of radio buttons in the Accuracy dialogue. This setting changes the convergence criterion and various calculation schemes used.
  8. Internal fluxes display in Layer dialogue.
  9. New template for heat conduction with title Pavement Heating by Heat Pump .
  10. New secondary fluid Potassium Formate ("KCOOH ").
  11. A new Practical hints entry in the help texts.
  12. The menu commands View|Names, View|Numbers, View|Whole, View|Zoom In 2x and View|Zoom Out 2x are made effective for diagrams. View|Names also works for viewing symbols and colours.
  13. Dialog buttons (except standard buttons) are equipped with underlined character for keyboard selection.
  14. Tics positions of graph axes are based on current quantity setting, not internal SI units.
  15. The number format in dialogues is based on the actual values, not a fixed format based on the current unit selection. This prevents loss of accuracy when returning values from the dialogues, including complete underflow (like a small number changing to 0).
  16. Handling of boundary containing components has been improved.
  17. All templates now use fluid library properties, not user specified properties.
  18. Improvement of the derived quantities dialogues.
  19. Corrected errors in Layer dialogue.
  20. Quantity unit indication in valve control dialogue. Improved valve control operation.
  21. The Abort dialogue is made robust.
  22. Removed irregularities in production of result file when changing SIM file name.
  23. Correction of faulty initial marking of rectangular basis components.
  24. Corrected unmarking of elements after a scroll.
  25. Removed ghost corners from disconnected connectors. Added corners positioned right after marked connector or corner.
  26. Modifiers now handles changed plant or basis component name.
  27. Corrected content of result file when a simulation is performed in a number of portions.
  28. All component related symbols now have a fill colour so that incomplete specification can be indicated.
  29. Fixed error in difference type derived quantity.
  30. Correct display of equation structure displaying the original equation, not the result after Gauss elimination operations.
  31. Corrected area conflict attachment of Heat exchanger with buffer to internal position of 1D heat source/sink .
  32. Corrected layer temperature average for cylinder and sphere geometry. A new enthalpy based average available in 1D heat source/sink component model.

Changes made from version 1.2.3 to version 1.3 (1997-12-22)


  1. Introduction of a new screen object type called an Illustration. This is an element that is put in the background of other elements, adding to the visual impression of the plant layout. In addition, explanatory text labels may be added to the plant through such objects.
  2. Introduction of a new component model class called Illustrative components. These only serve to describe a real plant and have no implications on the calculation.
  3. Introduction of a Psychrometric chart, visible through selecting View|Psychrometric Chart. Connectors carrying a value for absolute humidity will be drawn in the chart along with adjacent components.
  4. A Scale button is added to the function dialogue. This multiplies constants and all ordinate values of tables and templates by a specific factor. Just specify the factor and press the button and you will see the immediate impact in the function graph.
  5. Selecting View|Capacities will show the size or capacity of relevant components.
  6. Selecting Edit|Replace basis component after marking a plant component, will enable replacement of the employed basis component with another one of the same model. This relieves you from having to delete the component, add a new plant component from the other basis component with specification of the initial quantities, and finally reconnect it into the plant and adjust it into position.
  7. Introduction of Help button in the basis component dialogues, so that a model description is directly available.
  8. Introduction of separate arrows in symbols. These may be turned on and off (View|Arrows).
  9. The number of symbols has approximately doubled. All symbols are viewed together by selecting View|Symbols.
  10. A new model One-dimensional heat source/sink . With this component it is possible to perform a one-dimensional heat conduction calculation with heat transfer on both sides, and also a number of internal heat transfers (internal heat generation) at material layer interfaces. Using the same material in adjacent layers, enables having a heat source/sink in any position in an actual material layer.
  11. Boundary conditions can be moved from one connector to another by mouse dragging. Holding down the Ctrl button while dragging and releasing, the boundary condition is copied to the other connector. The same mechanism is applicable to enthalpy and valve controls.
  12. In addition to the Set|Autoadjust mechanism, you may now activate an immediate autoadjust by holding down the Ctrl button while dragging components and connectors.
  13. Some old models now have an optional boundary to interface them with heat conduction component models. For these models an extra check box is added to the basis component dialogue to turn on or off this boundary.
  14. Now scaling and movement is possible for the current object and also for controls in addition to components and connectors. Direct rotation of components is also enabled.
  15. All dialogues now show employed quantity units for input.
  16. The type (temperature or pressure etc.) of derived quantities is now handled so that previously selected quantity units may be used directly.
  17. The mechanism for inspecting results and reports is changed from using an internal file viewer, to activating the Windows-bundled Notepad and WordPad editors.
  18. SI unit standard for angle is now radians instead of degrees. Check your turbo compressor prerotation vane angles!
  19. Changes have been made to facilitate the translation of FrigoSim from English to other languages.
  20. Removed Potassium Carbonate and Potassium Acetate from the group of pure substances (as they were eutectic aqueous solutions).
  21. The Stratified storage tank model has been improved. A variant of this having internal heating has been introduced. The mixed storage tank also has got a model variant with internal heating.
  22. Corrected wrong polarity in tubes with elevation.
  23. Corrected problem in showing negative constants in the function dialogue.

Changes made from version 1.2.2 to version 1.2.3 (1997-09-18)


  1. Corrected error in deleting one or more plant components (forcing early release of a new version).
  2. Improved robustness when selecting Add|Control followed by irregular actions.
  3. Checking and replacing entry of blanks in names, since blanks are separators at input.
  4. Checking and replacing entry of improper characters in names of basis components, fluids and functions, when used as file names for individual saving.
  5. Now symbol angle justification to nearest multiple of 90° is only made for small deviations.
  6. Changed server license arrangement so that each user must have it's own license file put on c:\.

Changes made from version 1.2.1 to version 1.2.2 (1997-08-28)


  1. Corrected error in changing the number of layers for the 1D heat source with external heat exchanger model.
  2. Corrected calculation error in the model Stratified liquid storage tank .
  3. Changed model Closed flash chamber with 4 ports .
  4. Introduced Insert and Delete buttons in 1D table dialogue and 2D table dialogue .
  5. Introduced Delete level, Insert level and Delete Component buttons in Strategy dialogue .
  6. Preserving view settings between sessions.
  7. Introduction of a 145 pages FrigoSim Report, a hardcopy version of the FrigoSim help texts.
  8. Introduction of an 18 pages FrigoSim Instruction Manual with exercises to help the user getting started.
  9. Removed minor irregularities.

Changes made from version 1.2 to version 1.2.1 (1997-07-16)


  1. Corrected function editing. Could loose a function when saving the plant.
  2. The bypass control is fixed and re-enabled.
  3. In the search for names of models and quantities, the program tries to match with the closest resembling name.
  4. Completed the introduction of volumetric thermal expansion property of fluids, used for free convection calculations.
  5. Tightened memory leaks.
  6. Corrected title dialogue.
  7. Corrected display of entropy values in connector dialogue and variable display.
  8. Corrected forced convection transitional heat transfer coefficient correlation.
  9. Improved "termination control" mechanism for stopping a simulation on given conditions (ref. Set|Simulation conditions).
  10. Minor changes of quantities names.

Changes made from version 1.1.1 to version 1.2 (1997-06-03)


  1. New mechanism for (indirectly) specifying basis components based on more practically available data. Use menu command Add|Basis component + Select Indirect basis component specification .
  2. New model for calculation of one-dimensional multi-layered transient heat conduction with phase change. Select from Secondary fluid heat exchangers the one called 1D heat source with external inside heat exchanger .
  3. Changed function dialogue adding graph button and presenting a more intuitive edit, load and store feature.
  4. New option to sort output component quantities with respect to type and component relation. After selecting menu command Output|Component quantities, check the box Sort quantities by type and component . This facilitates handling of results by spreadsheet programs.
  5. Setting font size of names and numbers. Use menu command Set|Font sizes. This enables using low resolution screens.
  6. Display of superheat/subcooling in the refrigerant circuit connector dialogue.
  7. More natural sequence of quantities in listbox for unit selection, menu command Set|Quantity units.
  8. Dedicated update button in refrigerant and fluid dialogues.
  9. All control symbols may be dragged to arbitrary position.
  10. Improved robustness versus user mistakes.
  11. A major set of minor corrections.

Changes made from version 1.1 to version 1.1.1 (1997-03-06)


  1. A set of minor corrections (espec. Output menu commands) and robustness and consistency improvements.
  2. Improved with respect to server license installation.
  3. Possible now to perform a simulation in several consecutive portions.

Changes made from version 1.0 to version 1.1 (1997-02-06)


  1. The File|Print menu command has been significantly improved.
  2. All screen and print graphics is now vector-based (no more bitmaps and icons) to take full advantage of available printer resolution. This includes the title plate and some control symbols.
  3. Different printer resolution in x and y direction is adjusted for.
  4. The regulator control symbol has been made movable.
  5. The accStrat model (stratified storage tank) has been improved.
  6. Introduction of axes for the H-logP and T-S diagrams.
  7. The two menu commands Output|Deducted quantities and Perform|Optimisation have been reintroduced, after having been disabled in the 1.0 version due to non-robust behaviour.
  8. A set of minor corrections.

Changes made from 1.0 beta 7 to the final 1.0 release (1996-12-20)


  1. Help texts have been augmented, with more on terminology and what you can do with the program.
  2. Deletion of framed components corrected.
  3. Using selected quantity units also in result and report files.
  4. All secondary fluids are given default colours, for aqueous fluids also varying with concentration.
  5. Corrected component scaling.
  6. Removed overlapping variable display.
  7. Output file changed to report file with name as the specification and result files.
  8. Result file name now changes to new name after File|Save As.
  9. Showing colour in Refrig+Fluid+Med dialogues.
  10. Improved on specific window repaint.
  11. No generation of hea type file when not using special models in need of this.
  12. Several minor errors and irregularities removed.

Changes made from 1.0 beta 6 to 1.0 beta 7 (1996-10-28)


  1. Removed the specific component drag symbol. Uses the real symbol instead.
  2. Introduction of save button in Function dialogue.
  3. Connector numbers and circuits numbers can be viewed (View|Numbers).
  4. Heat flow balance and mass flow balance equations can be viewed (View|Equations).
  5. Introduced more colours of non-dithered types.
  6. Selectable colours can be viewed (View|Colours).
  7. Deletion confirmation can be turned on/off (Set|Confirm deletion).
  8. A number of errors and inconsistencies are removed. In particular a problem with using Enter-key in component dialogues is fixed.
  9. New model: Fluidised bed for product drying.

Changes made from 1.0 beta 5 to 1.0 beta 6 (1996-09-21)


  1. Menu greying (disabling) when not applicable.
  2. The number of name characters has been increased from 5 to 8.
  3. The basis for intrinsic names (e.g. model names and component quantities) has been changed from Norwegian to English (even though these names are normally hidden from the user).
  4. All language specific text are placed in separate (no-code) files for easy translation.
  5. Component deficiencies and circuits inconsistencies can be viewed (View|Deficiencies).
  6. Some minor changes and improvement of robustness.

Changes made from 1.0 beta 1 to 1.0 beta 5


  1. Plant capacity modification by scaling factor.
  2. A library of secondary fluids containing 10 substances as aqueous solutions with user specified concentration in a large value range. In addition 10 pure fluids. In the selection dialogue, properties are displayed at user-specified temperatures and concentration.
  3. Information on characteristic refrigerant properties in the refrigerant selection dialogue.
  4. New model for stratified storage tank.
  5. Setting different unit systems (e.g. SI or English units) and individual quantity units.
  6. Automatic optimisation.
  7. Inspecting characteristic numbers.
  8. Framing of component group (or all plant) for deletion or duplication in one operation. The duplication not only applies to components, but also to connections, boundary conditions and controls.
  9. Zoom out for having space to add new components.
  10. A range of components symbols for each model. This is not fully exploited yet.
  11. Component connection lines with user selectable width.
  12. The possibility to perform the simulation iteration by iteration or time step per time step in addition to the full simulation.
  13. Built-out help texts.
  14. A new model for stratified storage tanks with user-specified accuracy.
  15. A number of plant templates to be used as basis for your own specifications.

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