New design for CO2 cascade system

Researchers from two Spanish universities are looking for commercial licensees for a CO2 cascade refrigeration system that is said to overcome many of the current drawbacks of the technology.
Researchers from two Spanish universities are looking for commercial licensees for a CO2 cascade refrigeration system that is said to overcome many of the current drawbacks of the technology

In addition to increased energy efficiency, the system developed by the Spanish research team from Jaume I University of Castellón and the Polytechnic University of Valencia is said to incorporate a number of innovative safety features which allow the system to be started and stopped safely without the need to use auxiliary cooling equipment.

Some of the problems of current CO2 cascade refrigeration systems revolve around overcoming the high pressures of CO2 with the system at rest, overpressure as a result of failure in the feed system, difficulty in starting and stopping the systems and the need for auxiliary refrigeration equipment connected to a separate electricity generator.

This new Spanish development is said to offer a solution to these shortcomings by incorporating a high-pressure CO2 storage system and a set of associated sectioning valves and different regulating pressure switches.

It is said to allow the low-temperature circuit to start up when it is at rest and the pressure in the storage tank exceeds the maximum admissible value for that circuit. In addition it is said to ensure the integrity of the system and prevents most incidents of refrigerant leakage from the low-temperature circuit in the event of sudden high-temperature circuit  or overall circuit failure.

Although only tested experimentally in a laboratory prototype, the developers maintain proper design of the refrigeration system could increase the energy efficiency of the cycle, achieving sub-cooling of the liquid in the low-temperature circuit thanks to cooling via the refrigerant from the high-temperature circuit.