Flowstead v3.2.2

Flowstead v3.2.2 (app version 3.2.2).

Phase envelopes you can trust

• Phase envelope: for some rich gases and condensates DWSIM traces the bubble and dew curves as two pieces that never meet. The app used to report the end of the bubble curve as the critical point and the cricondenbar, below dew points the PVT laboratory finds. It now says the envelope did not close and shows no critical point, cricondenbar or cricondentherm for it; the curves are still drawn as DWSIM traced them.
• Vapour-fraction (quality) lines: near the critical point DWSIM's flash could give up and return a made-up temperature, which drew a stray line across the plot. Every point is now checked with a second flash, and a line stops where the flash stops working.

Install: download flowstead-v3.2.2.apk on your Android phone (Android 8.0 or newer, 64-bit), open it and allow installing from this source.

Coming from a 0.x test build? Those were signed with the public debug key and this release is signed with the release key, so Android can't install it over them: export each project you want to keep (project menu → Export DWSIM file), uninstall the old app, install this one and import the files (Projects → Import DWSIM file). Data-sheet fields and line-sizing criteria are not part of a DWSIM file. Later releases install as updates.

Solves on the phone: DWSIM runs on the device (Settings → Engine → On this phone, the default); the first solve after starting the app takes a few seconds while DWSIM loads. A remote Flowstead engine (docs/engine-setup.md) is optional.

Release certificate SHA-256: d7883cfc24f1cb62db989086d69d217beed109b5b84164ff5394ad9e3e0bb921. flowstead-v3.2.2-mapping.txt de-obfuscates crash reports. Status and known limitations: docs/STATUS.md.

Commit: 45bd848

Flowstead v3.2.1

Flowstead v3.2.1 (app version 3.2.1).

No more overlapping text

• Phase envelope: the labels of points close together, such as the critical point and the cricondenbar, no longer print on top of each other. Each label moves to a free place next to its point and stays inside the plot.
• Plot legends wrap onto a second row instead of being cut off at the edge of the screen.
• Safety → relief valve → inlet and outlet lines: the length and fittings (equivalent length) fields each have their own row, so the label no longer runs over the field's border. Other number fields keep a long label on one line.

Install: download flowstead-v3.2.1.apk on your Android phone (Android 8.0 or newer, 64-bit), open it and allow installing from this source.

Coming from a 0.x test build? Those were signed with the public debug key and this release is signed with the release key, so Android can't install it over them: export each project you want to keep (project menu → Export DWSIM file), uninstall the old app, install this one and import the files (Projects → Import DWSIM file). Data-sheet fields and line-sizing criteria are not part of a DWSIM file. Later releases install as updates.

Solves on the phone: DWSIM runs on the device (Settings → Engine → On this phone, the default); the first solve after starting the app takes a few seconds while DWSIM loads. A remote Flowstead engine (docs/engine-setup.md) is optional.

Release certificate SHA-256: d7883cfc24f1cb62db989086d69d217beed109b5b84164ff5394ad9e3e0bb921. flowstead-v3.2.1-mapping.txt de-obfuscates crash reports. Status and known limitations: docs/STATUS.md.

Commit: 37e7350

Flowstead v3.2.0

Flowstead v3.2.0 (app version 3.2.0).

Compound and data tools, flowsheet tools, McCabe–Thiele and catalytic reactions

Compounds and data (Fluid package → Compound and data tools):

• A compound from its structure. Type a SMILES string, such as CCO or Cc1ccccc1, or count Joback's groups by hand. The engine then estimates the boiling point, critical constants, heat capacity and formation energies with DWSIM's Joback method. For n-hexane it matches Joback's published method exactly. Example 22 shows one in a flowsheet.
• Look a compound up on PubChem. A name or CAS number brings its structure from NCBI's PubChem (needs the internet). The properties are still the engine's estimates.
• VLE regression. Fit a pair's kij, or its NRTL or UNIQUAC parameters, to measured bubble points, see the deviations before and after, and use the fitted values in the fluid.
• Reaction finder. DWSIM's reaction finder suggests combustion, kinetic and catalytic reactions among your components, with their equilibria. Add any of them to the flowsheet. Its rates are literature values: check them before design use.
• Catalytic reactions. Langmuir–Hinshelwood rates per kg of catalyst, in a PFR or CSTR with a catalyst loading (and, in a PFR, a bed void fraction and optional particle size).

Flowsheet tools (⋮ → Tools):

• Check: everything that stops a solve or makes a result doubtful, in one list. Tap an item to open its object.
• Watch: results pinned on the canvas.
• Spreadsheet: formulas on solved results, such as =[K-100.power]+[K-200.power], with cells you can export to specifications.
• Scenarios: save cases, compare them side by side and restore one.
• Optimiser: minimise or maximise a result, or a sum of results, by moving up to six specifications within bounds, with constraints. For a two-stage compressor it finds the textbook interstage pressure.
• PID tuning: a step test in the dynamic run, a fitted process model, and SIMC, IMC, Ziegler–Nichols and Cohen–Coon settings, each one tap to use.
• McCabe–Thiele: a binary column stage by stage on the engine's equilibrium curve, with minimum stages and minimum reflux; the diagram draws both operating lines meeting on the q-line.
• Report: the whole case as Markdown to share.

Also:

• Column internals: the column sizing now rates its sieve trays. It gives the weir crest, tray pressure drop, downcomer backup and residence time, and the percentage of flood at the chosen diameter.
• Custom unit sets: save your own named sets in Settings → Units.
• Sample library: search and filter the examples in Help → Examples.
• Backups: a copy of each project is kept every 10 minutes of editing, and a deleted project can be recovered (Projects → ⋮ → Backups, or "Recover a deleted project").
• A changed kij now always takes effect: DWSIM's cubic packages kept an older kij matrix in some calculations.

Install: download flowstead-v3.2.0.apk on your Android phone (Android 8.0 or newer, 64-bit), open it and allow installing from this source.

Coming from a 0.x test build? Those were signed with the public debug key and this release is signed with the release key, so Android can't install it over them: export each project you want to keep (project menu → Export DWSIM file), uninstall the old app, install this one and import the files (Projects → Import DWSIM file). Data-sheet fields and line-sizing criteria are not part of a DWSIM file. Later releases install as updates.

Solves on the phone: DWSIM runs on the device (Settings → Engine → On this phone, the default); the first solve after starting the app takes a few seconds while DWSIM loads. A remote Flowstead engine (docs/engine-setup.md) is optional.

Release certificate SHA-256: d7883cfc24f1cb62db989086d69d217beed109b5b84164ff5394ad9e3e0bb921. flowstead-v3.2.0-mapping.txt de-obfuscates crash reports. Status and known limitations: docs/STATUS.md.

Commit: 98a9d84

Flowstead v3.1.2

Flowstead v3.1.2 (app version 3.1.2).

New example: instrument air with a saturator and the wet air receiver's PSV

• Help → Examples → "Instrument air: saturator and wet air receiver with its PSV". Dry compressed air (500 Nm³/h at 40 °C, 9 barg) is saturated with water in a mixer, with more water than it can hold. It settles in the wet air receiver V-100 (1.29 m × 1.84 m, vertical, 0.3 m of condensate), with wet air out at the top and condensate at the bottom.
• The example comes with PSV-100, set at 10 barg, and two scenarios: fire and blocked outlet. Open Safety and press Size: the fire boils the receiver's water (API 521 wetted fire, D102) and needs a 1D2 valve, the same as HYSYS. The blocked outlet relieves the whole feed, about 650 kg/h of wet air, and governs with a 1E2 valve.
• A two-phase separator now solves when free water forms. Its liquid outlet carries both liquids, as in HYSYS. Before, any separator that condensed water (a wet air receiver, a knock-out drum on wet gas) stopped with "connect another stream to the second liquid phase outlet". A three-phase separator still sends the water to its own outlet.
• Liquid densities no longer change at random from one solve to the next. The COSTALD rule for hydrocarbon liquids (3.0) could, at times, also be applied to free water calculated at the same moment on another thread. In example 4 the water came out at 994.2 or 990.6 kg/m³ depending on the run. It is now always 990.6.

Install: download flowstead-v3.1.2.apk on your Android phone (Android 8.0 or newer, 64-bit), open it and allow installing from this source.

Coming from a 0.x test build? Those were signed with the public debug key and this release is signed with the release key, so Android can't install it over them: export each project you want to keep (project menu → Export DWSIM file), uninstall the old app, install this one and import the files (Projects → Import DWSIM file). Data-sheet fields and line-sizing criteria are not part of a DWSIM file. Later releases install as updates.

Solves on the phone: DWSIM runs on the device (Settings → Engine → On this phone, the default); the first solve after starting the app takes a few seconds while DWSIM loads. A remote Flowstead engine (docs/engine-setup.md) is optional.

Release certificate SHA-256: d7883cfc24f1cb62db989086d69d217beed109b5b84164ff5394ad9e3e0bb921. flowstead-v3.1.2-mapping.txt de-obfuscates crash reports. Status and known limitations: docs/STATUS.md.

Commit: 049bb3c

Flowstead v3.1.1

Flowstead v3.1.1 (app version 3.1.1).

Fire relief on wet gas vessels, and a correct latent heat

• Fire on a vessel of saturated gas, such as a wet instrument-air receiver, now boils the water that collects at the bottom. If the contents are all vapour at operating conditions but you give a liquid level, and the gas is at its dew point (within 5 K), the liquid is taken as the condensate (the dew-point liquid). It is sized with API 521's wetted-fire method, as in HYSYS. A dry gas stays gas-filled whatever level you enter, with a warning. A 1.29 m × 1.84 m air receiver with 0.3 m of water, set at 10 barg, now needs a 1D2 valve, the same as HYSYS. Before, it got 1½F2 from the unwetted-wall method.
• The fire case's latent heat is right when the liquid holds dissolved gas. It used to be the enthalpy of the first 5 % vaporised, measured from the bubble point. A trace of dissolved light gas pulls the bubble point far down, so that figure included sensible heat. For water with a trace of dissolved air at 13 bar it gave 14.6 MJ/kg, about seven times too high, and the relief load came out seven times too small. It is now the enthalpy of the next 5 % (5 % to 10 % vaporised): 2.04 MJ/kg against 1.96 MJ/kg from the steam tables. This affects any fire case on a liquid with dissolved light ends, such as a separator's liquid.
• The exposed area of a gas-filled vertical vessel now includes the top head, as API 521 asks for (when it is within 7.6 m of grade). Before, it was left out, so the fire load was low. For the receiver above, the area is now 11.06 m² instead of 9.26 m².

Install: download flowstead-v3.1.1.apk on your Android phone (Android 8.0 or newer, 64-bit), open it and allow installing from this source.

Coming from a 0.x test build? Those were signed with the public debug key and this release is signed with the release key, so Android can't install it over them: export each project you want to keep (project menu → Export DWSIM file), uninstall the old app, install this one and import the files (Projects → Import DWSIM file). Data-sheet fields and line-sizing criteria are not part of a DWSIM file. Later releases install as updates.

Solves on the phone: DWSIM runs on the device (Settings → Engine → On this phone, the default); the first solve after starting the app takes a few seconds while DWSIM loads. A remote Flowstead engine (docs/engine-setup.md) is optional.

Release certificate SHA-256: d7883cfc24f1cb62db989086d69d217beed109b5b84164ff5394ad9e3e0bb921. flowstead-v3.1.1-mapping.txt de-obfuscates crash reports. Status and known limitations: docs/STATUS.md.

Commit: 01017ea

Flowstead v3.1.0

Flowstead v3.1.0 (app version 3.1.0).

DWSIM files, petroleum assays, black oil and thermodynamics tools

• DWSIM files keep more. Pipe segments can be made of several runs and fittings (DWSIM's 28: elbows, valves, tees, entrances, exits, reducers), edited in the pipe segment, shown on its profile and data sheet, and read from DWSIM files instead of being merged into one straight pipe. Adjusts, controllers and Sets are written to DWSIM files and read back. Streams given by pressure and entropy import, and the engine's own energy streams no longer appear after a round trip.
• Petroleum assays. Fluid package → Characterise an assay: a TBP, ASTM D86, D1160 or D2887 curve with the bulk SG and MW and light ends, or a plus fraction from its bulk properties, cut into pseudo-components. They become hypotheticals, and a new stream gets the assay's composition. The D86 conversion matches the API Technical Data Book's example within 0.3 °F.
• A stream's distillation curves. In the stream editor: TBP, D86, D1160, D2887 and EFV curves and product properties (flash, pour, cloud and freezing points, cetane index, Reid vapour pressure and more, by the API correlations).
• Black oil. A new Black Oil fluid package: add a black oil from its API gravity, gas gravity, GOR and water cut. DWSIM's own black-oil code is corrected in Flowstead's build: the oil now keeps its gas above the bubble point and gets denser with pressure, and the gas and oil flows add up to the stream's. Densities and liberated gas match Standing's and Vasquez–Beggs' correlations worked by hand.
• Thermodynamics tools. Fluid package → Thermodynamics tools: binary T–x–y and P–x–y diagrams (with the region where two liquids form), ternary diagrams with tie lines, the true critical point, up to eight fluid packages compared on one composition, and property charts along temperature or pressure. Checked against NIST boiling points, vapour pressures and critical constants.
• Fixed: when every controller already met its target (as in a file saved solved), the solve showed the numbers of a test step instead of the solution.

Install: download flowstead-v3.1.0.apk on your Android phone (Android 8.0 or newer, 64-bit), open it and allow installing from this source.

Coming from a 0.x test build? Those were signed with the public debug key and this release is signed with the release key, so Android can't install it over them: export each project you want to keep (project menu → Export DWSIM file), uninstall the old app, install this one and import the files (Projects → Import DWSIM file). Data-sheet fields and line-sizing criteria are not part of a DWSIM file. Later releases install as updates.

Solves on the phone: DWSIM runs on the device (Settings → Engine → On this phone, the default); the first solve after starting the app takes a few seconds while DWSIM loads. A remote Flowstead engine (docs/engine-setup.md) is optional.

Release certificate SHA-256: d7883cfc24f1cb62db989086d69d217beed109b5b84164ff5394ad9e3e0bb921. flowstead-v3.1.0-mapping.txt de-obfuscates crash reports. Status and known limitations: docs/STATUS.md.

Commit: 83af9b4

Flowstead v3.0.2

Flowstead v3.0.2 (app version 3.0.2).

Z factor for gases only, and faster with hypothetical components

• The Z factor (Z = PV/nRT) is now shown only for a vapour phase and for vapour-only streams. Liquid phases no longer show a Z factor, and neither do liquid or two-phase streams. This also covers projects solved by earlier versions. In the PVT experiments, an oil above its bubble point has no gas Z, while a gas condensate above its dew point still shows its Z.
• Cases with hypothetical components solve faster. Each hypothetical's properties (critical constants, acentric factor, Rackett and COSTALD parameters, volume shifts) come from several fits, and these were repeated on every solve. They are now calculated once and reused until the hypothetical's inputs change. On the server the fits took about 90 ms per hypothetical per solve. A repeat solve of a stream with one hypothetical dropped from about 240 ms to about 100 ms, the same as a database compound. The saving grows with the number of hypotheticals, and the phone's engine is slower than the server's.

Install: download flowstead-v3.0.2.apk on your Android phone (Android 8.0 or newer, 64-bit), open it and allow installing from this source.

Coming from a 0.x test build? Those were signed with the public debug key and this release is signed with the release key, so Android can't install it over them: export each project you want to keep (project menu → Export DWSIM file), uninstall the old app, install this one and import the files (Projects → Import DWSIM file). Data-sheet fields and line-sizing criteria are not part of a DWSIM file. Later releases install as updates.

Solves on the phone: DWSIM runs on the device (Settings → Engine → On this phone, the default); the first solve after starting the app takes a few seconds while DWSIM loads. A remote Flowstead engine (docs/engine-setup.md) is optional.

Release certificate SHA-256: d7883cfc24f1cb62db989086d69d217beed109b5b84164ff5394ad9e3e0bb921. flowstead-v3.0.2-mapping.txt de-obfuscates crash reports. Status and known limitations: docs/STATUS.md.

Commit: 324d553

Flowstead v3.0.1

Flowstead v3.0.1 (app version 3.0.1).

Solves fast again

• 3.0.0 made a simple solve slow: two plain streams could take over 13 seconds on a phone, against about a second before. The cause was the new bubble- and dew-point check, which searched for a phase boundary with many extra flashes whenever DWSIM's answer did not check out. The search is gone: a bubble or dew point that does not check out is shown as missing (—), never as a wrong number. Pure compounds (water, steam) take DWSIM's vapour-pressure curve directly.
• Bubble and dew points of streams that did not change are remembered between solves, so editing one part of a flowsheet no longer recalculates them for every stream.

Install: download flowstead-v3.0.1.apk on your Android phone (Android 8.0 or newer, 64-bit), open it and allow installing from this source.

Coming from a 0.x test build? Those were signed with the public debug key and this release is signed with the release key, so Android can't install it over them: export each project you want to keep (project menu → Export DWSIM file), uninstall the old app, install this one and import the files (Projects → Import DWSIM file). Data-sheet fields and line-sizing criteria are not part of a DWSIM file. Later releases install as updates.

Solves on the phone: DWSIM runs on the device (Settings → Engine → On this phone, the default); the first solve after starting the app takes a few seconds while DWSIM loads. A remote Flowstead engine (docs/engine-setup.md) is optional.

Release certificate SHA-256: d7883cfc24f1cb62db989086d69d217beed109b5b84164ff5394ad9e3e0bb921. flowstead-v3.0.1-mapping.txt de-obfuscates crash reports. Status and known limitations: docs/STATUS.md.

Commit: 5d7f2d6

Flowstead v3.0.0

Flowstead v3.0.0 (app version 3.0.0).

Flowstead 3.0: now on DWSIM 10

• Every calculation now runs on DWSIM 10.2.12, the current generation of the open-source simulator, built by Flowstead from its published source, on the phone and on the engine server alike. DWSIM 9 receives no more updates; DWSIM 10 brings its fixes and opens the way to its newer features, such as distillation curves and product-quality column specifications, in later versions.
• Liquid densities are more accurate. Liquid mixtures (NGL, LNG, condensate, live oil) now use COSTALD, the method HYSYS uses for hydrocarbon liquids; pure and water-rich liquids keep experimental data. Against reference equations of state over 29 liquids the average error is 0.50 % (was 0.87 %) and the worst 1.9 % (was 5.4 %, a hot NGL). Liquid volume flows, separator levels and line sizing follow.
• PVT laboratory about 100 times faster. A saturation pressure takes about a second instead of up to two and a half minutes, with the same result. The PVT regression also tries finer steps before stopping, so it fits closer.
• Results change slightly with the new engine: mainly liquid densities and what depends on them (volumes, residence times, reactor conversions in a fixed volume). Every reference check (steam tables, hand calculations, published data) still holds; the details are in the project's decision log (D88–D94).
• Phases labelled by the fluid, both ways. A one-phase result is checked against the fluid itself: a dense gas at very high pressure (for example 320 barg) is reported as vapour, and a subcooled liquid that the flash called vapour is reported as liquid.
• Projects from earlier versions open as before, and so do DWSIM files saved by Flowstead 2.x (the nine kept for testing all open and solve). Files exported by 3.0 note that desktop DWSIM's default liquid densities can differ from Flowstead's for mixtures.
• Results a project kept from 2.x were solved on DWSIM 9: they show as out of date ("Solved with DWSIM 9 — solve again") until the flowsheet is solved again. If you run your own engine server, update it to 3.0 as well (the Docker image now builds DWSIM 10).
• Phase envelopes, bubble and dew points. Pure-fluid envelopes now end at the critical point, mixture critical points are closer to independent calculations, and every stream bubble or dew point is checked to lie on the phase boundary; near a mixture's critical point, where the flash cannot place it reliably, it is shown as missing (—) rather than guessed.
• Gas thermal conductivity at high pressure is now within a few percent of reference data (it was up to 20 % low).
• Thermal-expansion relief loads are slightly lower and closer to reference data (the liquid's expansion coefficient was 5–9 % high).

Install: download flowstead-v3.0.0.apk on your Android phone (Android 8.0 or newer, 64-bit), open it and allow installing from this source.

Coming from a 0.x test build? Those were signed with the public debug key and this release is signed with the release key, so Android can't install it over them: export each project you want to keep (project menu → Export DWSIM file), uninstall the old app, install this one and import the files (Projects → Import DWSIM file). Data-sheet fields and line-sizing criteria are not part of a DWSIM file. Later releases install as updates.

Solves on the phone: DWSIM runs on the device (Settings → Engine → On this phone, the default); the first solve after starting the app takes a few seconds while DWSIM loads. A remote Flowstead engine (docs/engine-setup.md) is optional.

Release certificate SHA-256: d7883cfc24f1cb62db989086d69d217beed109b5b84164ff5394ad9e3e0bb921. flowstead-v3.0.0-mapping.txt de-obfuscates crash reports. Status and known limitations: docs/STATUS.md.

Commit: 910c9c8

Flowstead v2.0.3

Flowstead v2.0.3 (app version 2.0.3).

More accurate NRTL and UNIQUAC energy balances; liquids no longer reported as vapour

• NRTL and UNIQUAC now take liquid enthalpy and heat capacity from each compound's experimental liquid heat capacity, as DWSIM 10 does. Before, liquid water came out with a heat capacity of 5.35 kJ/kg·K instead of 4.18, so liquid heating and cooling duties with these packages were about 28 % too high. Stream enthalpies are now measured from liquid at 25 °C, so their values look different; duties and temperatures are what changed in substance. Example: the ethylene-oxide hydration reactor now releases 98 kJ per mol reacted, against 96 from published heats of formation (before: 106).
• A stream with no flow (for example a reactor's liquid outlet when everything leaves as vapour) now shows its temperature, pressure and zero flow only, instead of placeholder compositions and properties.
• DWSIM files saved by DWSIM 10 now open with their column feeds on the right trays.
• A liquid mixture of light and heavy hydrocarbons (for example propane with pentane, hexane and decane at 10 bar) could be reported as a vapour, with no liquid density and the wrong enthalpy. A single-phase result is now labelled by the fluid itself, as Flowstead already did for dense gases: that condensate is a liquid at 659.8 kg/m³ (reference equation of state: 660.1).

Install: download flowstead-v2.0.3.apk on your Android phone (Android 8.0 or newer, 64-bit), open it and allow installing from this source.

Coming from a 0.x test build? Those were signed with the public debug key and this release is signed with the release key, so Android can't install it over them: export each project you want to keep (project menu → Export DWSIM file), uninstall the old app, install this one and import the files (Projects → Import DWSIM file). Data-sheet fields and line-sizing criteria are not part of a DWSIM file. Later releases install as updates.

Solves on the phone: DWSIM runs on the device (Settings → Engine → On this phone, the default); the first solve after starting the app takes a few seconds while DWSIM loads. A remote Flowstead engine (docs/engine-setup.md) is optional.

Release certificate SHA-256: d7883cfc24f1cb62db989086d69d217beed109b5b84164ff5394ad9e3e0bb921. flowstead-v2.0.3-mapping.txt de-obfuscates crash reports. Status and known limitations: docs/STATUS.md.

Commit: 0a6ba07