New cryogenic cooling uses recycled CO₂

A newly launched temperature control unit working with liquid CO₂ as a coolant can be used in conventional diesel-powered truck cooling systems and on both single and multi temperature truck operations. It combines lowest noise levels with high cooling capacity and fast temperature recovery.

Transport temperature control systems manufacturer Thermo King has launched and patented a new cryogenic cooling system using recycled liquid CO₂ as a coolant. Unveiled at the international trade fair IAA in October, the “Green CryoTech” system features better temperature control, low noise levels and significantly reduced emissions at high cooling capacities.  Although not the only cryogenic system available on the market, the CO₂ system is unusual as it provides airflow in the load space, which is essential when carrying fresh foods, particularly fruit and vegetables. Moreover, the unit, unlike other systems, exhausts the cryogen outside the load space rather than injecting liquid coolant directly into the cargo area. As it does not allow CO₂, stored in a vacuum insulated tank, to enter the cargo area, it leads to significant health and safety benefits.

Two systems have been developed: the CO₂ Hybrid, which can be fitted into a conventional diesel-powered truck cooling system to supplement the pull-down capability; and the ST-CR providing systems for both single and multi-temperature truck operations. A multi-temperature trailer system is in development.

To refill the Green CryoTech units, rapid couplings have been developed. The product innovation, having passed extensive safety tests, reduces the risk of leakage.

Cryogenics – a low-noise efficient solution

Cryogenic technology combines several advantages helping consumers comply with current and upcoming legislation. As governments are mandating tighter control and more accurate temperature monitoring, its capability of rapid pull down and recovery to set temperatures helps users to meet impending regulations for temperature control and product integrity. Using no engine or compressor, its low noise, coming only from the faint exhaust of CO₂ gas, ensures that local deliveries are possible in areas with fixed low noise limits and late at night.

Running on the naturally occurring carbon dioxide,  the system emits no CFC, HCFC or HFC from the truck body. Reducing the use of diesel, the cryogenic system also cuts down NOX and other particulate emissions. Even with regular opening and closing for delivery, the truck body temperature stays relatively constant because of the high efficiency of cryogenic cooling. Overall, the CO₂ system has a significantly higher instant cooling capacity with a temperature pull-down and recovery up to three times faster than traditional diesel units.