The calculator takes your process stream data, performs a full pinch analysis, and then generates feasible Heat Exchanger Networks.

1. Set the Minimum Temperature Difference (ΔTmin)

Enter ΔTmin at the top of the calculator. The default is 10 °C, which you can adjust using the arrow controls. This value is enforced throughout the analysis, including every heat exchanger in the generated networks.

2. Define Process Streams

• By default the calculator includes one hot stream and one cold stream.
• Click Add Stream to add more.
• Click the red X next to a stream to remove it.
• Click Load Example to load a worked four-stream problem and run it immediately. This is the quickest way to see what the calculator produces.

3. Configure Stream Properties

• Select whether the stream is Hot or Cold from the drop-down.
• Enter the supply temperature (Ts) and target temperature (Tt).
• Enter the heat capacity flowrate (CP). The enthalpy change (ΔH) is calculated automatically.
• A hot stream must cool (Ts greater than Tt) and a cold stream must heat (Ts less than Tt). The calculator will tell you if this is not the case.

4. Run the Analysis

Once the stream data are entered, click Run Analysis. Both the pinch analysis and the Heat Exchanger Network generation are performed in a single step.

5. Pinch Analysis Results

• Minimum hot utility (QH,min), minimum cold utility (QC,min) and the pinch temperatures, shown as hot-side and cold-side values.
• Hot and Cold Composite Curves, with the utility requirements marked.
• Problem Table Algorithm results, set out in four tables: actual and interval temperatures, the ranked order of interval temperatures, the problem table, and the heat cascade with the pinch point highlighted.
• Grand Composite Curve (GCC).

6. Heat Exchanger Network Analysis

Below the Grand Composite Curve, the calculator reports how many feasible minimum-utility networks exist and draws one of them.

• Possible HENs without splitting – the number of distinct networks that use whole streams only.
• Total distinct HENs – the total after equivalent networks have been removed, so networks that differ only in the order the exchangers were worked out are counted once.
• Networks generated – up to five networks are built, ranked simplest first by number of exchangers, then by number of stream splits.
• Use the Network drop-down to display a particular network, or Pick Random to jump to one at random.

7. Reading the Network Diagram

• Hot streams are red and flow left to right; cold streams are blue and flow right to left. The hot end of every line is on the left.
• The dashed vertical line is the pinch, separating the above-pinch and below-pinch regions. No heat is transferred across it.
• Each heat exchanger is a pair of linked circles. The tag (E-101, E-102 and so on) sits above the circle on the hot stream and the duty below the circle on the cold stream.
• Stream temperatures are shown either side of every circle, and exchangers are arranged hottest first.
• H circles are heaters (hot utility) and C circles are coolers (cold utility), each labelled with its duty.
• The table beneath the diagram lists every exchanger with its duty, all four terminal temperatures, the CP of each side, and whether it is above or below the pinch.

8. Stream Splitting

Stream splitting is used only when it is unavoidable. The calculator first searches for networks that use whole streams; splitting is allowed only if no such network exists, and a message explains when this has happened. A stream may be divided into at most two branches, with at most two splits on each side of the pinch.

Where a stream is split, the diagram shows it physically dividing and, where appropriate, rejoining. Each branch is labelled with its split fraction and its branch CP. A branch that has already reached its target temperature is left open rather than being routed through a heater or cooler it does not need.

9. Larger Problems

Up to twelve streams, every feasible network is enumerated and the counts shown are exact. Beyond twelve streams the number of possible networks grows factorially and an exact count is no longer computable, so counting is not attempted. Instead a single valid network is constructed directly by the Pinch Design Method. It meets the minimum utility targets and the ΔTmin constraint, but it is one design among many rather than the only or simplest one.

10. Saving Your Results

• Composite Curves and Grand Composite Curve – hover over a chart and use the camera icon in its toolbar to download a high-resolution image.
• Network diagram – use Download PNG for a high-resolution image, or Download SVG for a vector file that stays sharp at any size and is the better choice for a report.
• Full report – click Print / Save as PDF to print the calculator on its own, without the surrounding page. In the print dialog choose Save as PDF as the destination for a PDF file, and set Portrait or Landscape under the browser's own layout settings. Landscape usually suits the network diagram better. Only the network currently on screen is included.

These outputs together provide a complete heat-integration study: minimum utility targets, the composite and grand composite curves, and feasible heat exchanger network designs that achieve those targets.