CO₂ (R-744) practice is for students and technicians working with carbon dioxide plant. It is filed under UEERA0066, Repair and service carbon dioxide refrigeration systems, and practises the pressure and temperature side of UEERA0006. It runs in the browser with no account, and nothing you type is sent anywhere.
What's on the page
- The ideas: why CO₂ runs at high pressures, the critical point, the triple point, why there's no liquid CO₂ at atmospheric pressure, subcritical and transcritical, and the standing pressure of a plant that's stopped.
- A worked example on a cascade's R-744 low stage, revealed a step at a time. Choose Next step, or Show every step.
- Guided exercise: work each step yourself and choose Check. New figures draws another question.
- A practice set of every kind of question in the module, with a fresh set of figures whenever you choose New set of figures.
- Check a worksheet: open a printed CO₂ worksheet by its code, which starts with R744. A UEERA0036 code typed here points you to the UEERA0036 page instead.
Where the answers come from
Every figure is worked out by Kelvin on R-744's public table and its critical and triple points, computed with CoolProp, as on R-744's refrigerant page. Nothing is extrapolated: a reading outside the table is never set as a question.
UEERA0006's safety and legal side (exposure, ventilation, protective equipment, legal duties) isn't covered here.
Note
This is practice and teaching material mapped to the units' codes. It isn't an RTO assessment tool: whether any of it is used as evidence is the teacher's call.