UPDATE: on the road again - CO2 usage in transport refrigeration

By Robert Davidson, Jan 14, 2015, 12:53 3 minute reading

With updated F-Gas regulations coming into effect in Europe in 2015 and a general shift away from HFCs across the rest of the globe, change is coming to the HVAC&R sector, including to transport refrigeration, which is long due an overhaul. New refrigeration transport systems incorporating CO2 are beginning to proliferate and are indicative of a fresh direction for R744 in the transit industry. But it is not just in refrigeration transportation

There are currently more than 650,000 refrigerated vehicles on the road in the EU. These transporters all contribute to HFC emissions and with an average journey time drastically longer than regular drivers, their effect is much more vast than their number suggests. With such a large number of vehicles all leaking roughly 20% of their refrigerant into the atmosphere, it was only a matter of time before change came.

Due to a combination of public awareness and tightening EU regulatory action, which will limit the amount of HFCs for sale within the EU and lead to price increases, this trend is soon to be reversed. With more supermarkets and distributors signing up to R744-based technologies, it looks like there is a lot of fuel left in the natural refrigerants tank. Will this engender an R744 revolution on the cobbled streets and fast motorways of the EU?

Our way or the high way

The transport refrigeration makes up about 10% of global HFC consumption in the refrigeration and air-conditioning market. A recent study revealed higher HFC consumption in transport refrigeration during the summer months due to higher pressure inside the trucks, causing more severe leaks. Consequently, the race is now on to ensure everyone gets to the finish line on time to ensure the lowest global warming potential (GWP) possible, making the case for a substitution to R744 stronger than ever before.

While HFCs – the most common refrigerant - don’t damage the ozone, they are greenhouse gases, which continue to plague and re-define the earth’s meteorological identity. It is only with the emergence of restrictive EU policy that the real push for CO2 refrigerated transport has become concrete and gained momentum.

F-Gas regulation: giving CO2 a kick-start in Europe

The EU Commission estimate that the updated F-Gas regulation will save the equivalent of 5bn tonnes of CO2 by 2050 and major supermarket retailers are beginning to (or continuing to) heed these changes and many are using systems which adhere to these future standards. For instance, the UK supermarket chain Sainsbury teamed up with Carrier Traniscold to produce their innovation award winning refrigerated trailer that utilises CO2, already in use in the centralised commercial refrigeration systems.

In addition to this, in Belgium, Delhaize has signed an agreement with Thermoking to use their Cyrotech technology, which also uses CO2, although this is not a closed loop system. It is expected that more and more of the companies that transport perishable goods, such as supermarket chains, will begin rolling out new trailers and trucks to transport their products in the future.

Future of R744 in electric vehicles: going the distance 

What has become of real interest to the use of R744 in transport is the increasing demand for electric vehicles. Waste heat availabity is limited in electric vehicles and this point has engendered research and development of mobile heat pump systems. The current batch do not meet the idiosyncratic needs of electric vehicles as their range suffers greatly in cold ambient conditions.

The current refrigerants used in the Nissan Leaf and BMW i3 have notable limitations when used at low ambient tempratures; including low performance and low sub-atmsopheric pressure operation. These limitations need to be addressed to simmer down "range anxiety" and research is starting to show that R744 would be the ideal substitute for newer models to ensure optimal performance in low ambient temperatures leading to increased range.

The heating performance is seen to be improved when R744 is used, with R744 showing 15% to 50% higher heating capacities compared to the current refrigerant (R134a) when tested at -10oC and below. It is hoped that this acknowledgement can be the vanguard of a real push for R744 to be used in electric vehicles.


By Robert Davidson

Jan 14, 2015, 12:53

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