Supercritical CO₂ Experiment Loop

The supercritical CO₂ experimental loop test apparatus, shown below, includes:

1. a CO₂ supply bottle,
2. an air-driven boosting compressor (“gas booster”),
3. the lower CO₂ loop,
4. a power supply for the 1 m-long horizontal section of the lower loop that is resistance-heated with low voltage AC current passing directly through the pipe,
5. the upper CO₂ loop which includes two tube-in-tube heat exchangers connected in parallel (employed to remove heat from the upper CO₂ loop), and
6. the Printed Circuit Heat Exchanger (PCHE) where the two loops are linked together for the CO₂/CO₂ heat exchange.

The maximum operating pressure of the lower loop is 80 bar (1160 psi) and is called the lower-pressure loop. The maximum operating pressure of the upper loop is 200 bar (2900 psi) and is called the high-pressure loop.

This apparatus has been used to obtain heat transfer and hydraulic data for water/CO₂ and CO₂/CO₂ heat exchange with a PCHE unit.

Figure 1: Supercritical CO2 Experiment Loop (see larger size image)