UK: Sainsbury’s is trialling a world-first Carrier Transicold CO2 refrigerated trailer to transport chilled and frozen goods. 

The supermarket chain is working with Carrier Transicold in a two year trial of the new technology for road transport, using a modified version of Carrier’s NaturaLine refrigeration system, which was initially developed for containers and completed a rigorous sea trial programme in 2012.

“We will be monitoring its performance closely and if successful, in line with our replacement plan, it could help us save over 70,000 tonnes of CO2 compared to the current refrigerated trailer fleet,” said Sainsbury’s Head of Transport Operations Nick Davies.

Confirming that this marks the first time that a NaturaLine system has been mounted to a box trailer anywhere in the world, David Appel, president of Carrier Transicold, added: “It’s a fantastic opportunity to advance Carrier’s natural leadership in environmental technologies, by working closely with Sainsbury’s, one of our largest customers in Europe, to test how the concept performs on the road.”

The NaturaLine units completed sea trials at the end of last year. The development of the unit necessitated the design of a new refrigerant management system, including a new purpose-built, multi-stage compressor with variable-speed drive, a ‘gas cooler’ with a wrap-around design and a flash tank. The special reciprocating multi-stage compressor is said to maximise capacity and minimise power consumption.

NaturaLINE uses two stages of compression, its special cylinder-unloading capability allowing the compressor to save energy in light-load conditions.

The inclusion of a variable-speed drive is a first for a Carrier container refrigeration unit. The replacement of the traditional condenser assembly with a gas cooler is also new. The gas cooler coil wraps around the fan, which, according to Carrier Transicold, maximises heat-transfer surface area and providing gas cooling after each compression stage for better efficiency.

The flash tank, an entirely new component in a container refrigeration system, is designed to manage the flow and phase change of the refrigerant after leaving the gas cooler. For efficient cooling performance, the patented Carrier design enables final separation of CO2 from its gas phase to the liquid state before entering the evaporator.