Set up a refrigeration cycle

• –Single Stage Subcritical: one suction group and one compressor stage, with a condenser.
• –Two-Stage Compression (Flash Intercooler): a low- and a medium-temperature suction group, with a flash tank between the stages.
• –Transcritical CO₂ (R-744): a CO₂ booster with a gas cooler. Choosing it sets the refrigerant to R-744 and locks it.
• –Cascade System (Two Refrigerants): a low stage that condenses into a high stage through a cascade heat exchanger, each on its own refrigerant.

The sheet shows only the sections the cycle type needs. See Set up a two-stage or cascade cycle and Design a transcritical CO₂ booster.

The refrigerant's code, name and GWP show above its list, with the GWP band beside it.

A preset fills the evaporating temperature, superheat and load in one click. Manage edits, adds or deletes presets, and Reset to defaults brings back Kelvin's own. On a two-stage or booster cycle each suction group has its own chips, with Add preset beside them. Presets are kept in this browser, not with the design.

• –The P–h diagram draws the cycle against the refrigerant's saturation dome, with pressure on a log scale. Its numbered points are the rows of State points.
• –State points gives each point's description, enthalpy, temperature and pressure.
• –Derived readings gives figures such as the COP against Carnot, the compressor power, discharge temperature, mass flow, heat rejected, compression ratio and swept volume, each with its basis.
• –The strip of readings above the page shows COP, power and cooling by default. Pin readings chooses others, and Metric and Imperial switch the units here and in the chart header.

For a zeotropic blend with a glide of 0.5 K or more, a Temperature glide block lists each circuit's dew, bubble and mean temperatures. SST is read as the dew point and SCT as the bubble point. Use the mean column when you size coils and set controls, and read the notes beneath it on what the glide means for this cycle, such as reading superheat off the dew point.

Turn Heat recovery · de-superheater to On to take superheat off a discharge line. Choose the Heat source where the cycle offers more than one, then the Target exit temp. A de-superheater can't condense, so a target below the stream's saturation temperature is held at the Lower bound, with a warning. Recovered and Net reject show the result, and the state points gain the de-superheater's exit.

• –“Supercritical condition — subcritical cycle invalid”: the refrigerant can't condense above its critical point. Lower the temperature the notice names below the figure it gives, or use a transcritical cycle.
• –“Outside the property table — no cycle solved”: the refrigerant's saturation table doesn't reach these temperatures, and Kelvin never extrapolates it. The notice gives the lowest temperature it can solve at.
• –“Cascade not solvable”: the notice says which temperature to change.

Saving is unavailable until the cycle solves. To save and compare revisions, see Save a cycle design and compare revisions.