On substances that deplete the ozone layer
Options for existing equipment
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Options for existing equipment
The lifetime of road equipment and intermodal containers usually does not exceed 12 to 18 years, respectively. It is determined by their heavy duty and in Europe by the ATP scheme, which has a 3-year recertification period after the first 6-year in operation. HCFC refrigerants, if any are still in use, are being fast replaced by HFCs. Eutectic and cryogenics systems on vehicles are not limited by safety, space and other requirements of transport application, and so can use a variety of refrigerants in their stationary systems. Of the HCFC and CFC containing fluids, R-502 was widely used in the road transport industry after 1960, to overcome issues with HCFC-22. The retrofit options include R-408A, R-402A (both contain HCFC-22), R-404A or R-507A which, however, require a component change. Testing of low-GWP alternatives (below GWP 150, usually containing unsaturated HFCs) to the most widely used R-404A is in progress elsewhere. An AHRI AREP participant conducted side-by-side “drop in” comparisons of three state-of-the-art low-GWP 2L flammable fluids (Kopecka, 2013). The evaluation showed that these 2L flammable fluids were not suitable for R-404A retrofit in the field. Recent studies identified various non-flammable blends that offer different combination of GWP (ranging between 1300 and 2200), ease of retrofit, properties, performance and consistency with R-404A. These blends are safe, they have GWP significantly lower than R-404A, and in some cases they can be directly dropped into existing units. This makes them a likely solution for the R-404A installed population as well as new systems. The list includes and is not limited to R-407A, R-407F, R-448A, R-449A and R-452A (Mota-Babiloni, 2014, Minor, 2014).3 In this group of non-flammable blends, R-452A stands out as easy and direct drop in, able to achieve equivalent performance as R-404A without additional system changes. The GWP is at approx.2100. On the other hand, R-448A and R-449A stand out as lower GWP (approx. 1400) options, requiring system changes with various degree of complexity (typically addition of liquid injection to limit discharge temperatures). At present between 3.5 and 6% of the refrigerated ISO container fleet has been found to contain counterfeit refrigerants, many containing chlorine with an ODP (Lawton, 2012). It is assumed that refrigerant cost and limited availability put a pressure to adopt inexpensive counterfeit refrigerants with the subsequent environmental damage. Taxing of existing HFCs (for instance based on GWP) will likely increase the use of counterfeit refrigerants.
The lifetime of vessels is considerably longer than that of the road equipment and intermodal containers. Vessels are in operation for 30 years on average. Merchant and cruise ships are among the newer equipment. The average age of a merchant vessel has been decreasing from 18.9 years in 2008 to 16.7 years in 2012 (ISL, 2012). The number of cruise ships and their size has about doubled in the last decade (ISL, 2011). HCFC-22 has been the dominant refrigerant in many marine applications. Now it is being phased out gradually and many plants are retrofitted. R-417A, R-422D and R-427A have mainly been used to retrofit HCFC-22 which remains the most common refrigerant in the existing fleet. As discussed in previous chapters, retrofit with the zeotropic refrigerant may not be possible where flooded evaporators are used. In large passenger ships/cruise liners, large chillers are being used. The most used refrigerant in new ships used to be HFC-134a but also R-410A has been used frequently. For retrofit of existing AC systems other HFC alternatives such as R-407C and R-427A require modifications to the equipment to reach a reasonable efficiency. HCFC-123 never became a real option aboard ships, possibly because of higher toxicity. It is anticipated that marine AC systems will follow the development of new solutions seen in on-shore systems, perhaps with a small delay of some years due to the long expected life of the systems onboard ships. 6.4 Concluding remarksIt is clear that, in the transport refrigeration application, a unique, low-GWP or natural solution which would be ideal for new and field retrofit applications does not exist. In the case of a regulation banning the use of refrigerant above a certain GWP level as in the EU, HFC blends will likely play a role as a retrofit to R-404A and (possibly) HFC-134a systems in the installed base: their GWP is significantly lower than R-404A and performances are relatively close. The level of system change in the field depends on the refrigerant choice. For new systems, hydrocarbons offer high energy efficiency, but the safety risks in transport refrigeration application appear significant, with possible exceptions. On the other hand, R-744 has been tested in the field since the 2010 RTOC report. The non-flammable characteristics make R-744 attractive, but the gap in efficiency in high ambient temperatures and the limited component supply base are limiting its penetration into the market. Recently there has been an initiative to consider the design and service best practices for flammable and high pressure refrigerants which it is hoped will lead to a fast track ISO standard on how these refrigerants can be applied to intermodal container refrigeration. The framework of this initiative has not yet been set. We are also seeing “non-conventional” systems such as cryogenic systems or eutectic systems. These technologies offer specific advantages in specific applications, and the fact that they are HFC free will continue making them attractive.
ATP, 2013 Agreement on the international carriage of perishable foodstuffs and on the special equipment to be used for such carriage, 2013, United Nations, ISBN 978-92-1-139147-3 ASHRAE, 2013 ASHRAE Standard 34, 2013, Safety Standard for Refrigeration Systems and Designation and Classification of Refrigerants, Atlanta, GA, USA Cavalier, 2013 Cavalier and Devin, 2013, F-Gazes in transport refrigeration: situation and perspectives, 15. European Conference, Latest technologies in refrigeration and air conditioning, Milano, June 7-8 EN, 2008 EN 378, 2008, Refrigerating systems and heat pumps. Safety and environmental requirements, CEN, Brussels, Belgium Finckh, 2011 Finckh, O., Schrey, R., Wozny, M., 2011, Energy and efficiency comparison between standardized HFC and CO2 transcritical system for supermarket applications, 23rd IIR Int. Congress of Refrigeration, August 21-26, Prague Hrnjak, 2013 Hrnjak, P., 2013, Current and alternative refrigerants, 2nd IIR Int. Conference on Sustainability and the Cold Chain, April 2-4, Paris IHS, 2013 http://www.ihs.com/products/maritime-information/ships/sea-web.aspx, retrieved on 2013-10-19 IMO, 2012 Lloyd’s Register, 2012, Study on the treatment of Ozone Depleting Substances used to service ships commissioned, report number LDSO/ENG/Q12-02RMS/07/02 – REV 4 ISL, 2011 Shipping Statistics and Market Review, Volume 55, No 8 – 2011, Institute of Shipping Economics and Logistics ISL, 2012 Shipping Statistics and Market Review, Volume 56, No 1/2 – 2012, Institute of Shipping Economics and Logistics ISO, 2014a ISO 5149, 2014, Refrigerating systems and heat pumps -- Safety and environmental requirements, ISO, Geneva, Switzerland ISO, 2014b ISO 817, 2014, Refrigerants -- Designation and safety classification, ISO, Geneva, Switzerland Kopecka, 2013 Kopecka M., Hegar M., Sulc V. and J. Berge, 2013, System Drop-In Tests of Refrigerant Blends L-40, DR-7 and ARM-30a in a Trailer Refrigeration Unit Designed for R-404A, AHRI Low-GWP Alternative Refrigerants Evaluation Program König, 2013a König, H., Enkemann, T., 2013, Risk assessment and standards aurvey for use of flammable refrigerants in transport refrigeration applications, 2nd IIR Int. Conference on Sustainability and the Cold Chain, Paris, France, April 2-4 König, 2013b König, H., Enkemann, T., 2013, Einsatz von brennbaren Kältemitteln in der Containerkühlung, Stand der Normung und Risikobewertung, DKV Jahrestagung November, Hannover Lawton, 2012 Lawton and Cavalier, 2012, Risk Inherent in the Use of Counterfeit Refrigerants, 23rd Informatory Note on Refrigeration Technologies, IIR, November 2012. MCI, 2014 Maersk Container Industry, EPA-HQ-OAR-2014-0198-0089, http://www.regulations.gov, retrieved on 2014-12-15 Minor, 2014 Minor, B., Sulc, V., Berge, J., Kolda, M. and Hegar M., 2014, R-404A Alternative with Low Compressor Discharge Temperature, 15th Int. Refrigeration and Air Conditioning Conference at Purdue, July 14-17, paper #2175 Mota-Babiloni, 2014 Mota-Babiloni, A., Navarro-Esbrí, J, Barragán, Á., Molés, F., Peris, B., 2014, Theoretical comparison of low GWP alternatives for different refrigeration configurations taking R404A as baseline, Int. Journal of Refrigeration, Vol. 44, August, pp. 81-90. Möhlenkamp, 2014 Möhlenkamp, A., Lemke, N., Köhler, J., 2014, Comparison of different refrigerants for a two-stage transport refrigeration system, 3rd IIR Int. Conf. on Sustainability and the Cold Chain, June 23-25, London Shimada, 2011 Shimada G., 2011, High Ambient Energy Efficient CO2 refrigeration unit for supermarket and CVS, ATMOsphere Europe, October 11-12, Brussels TEAP, 2012 TEAP 2012 Progress Report, in response to Decision XXIII-7
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