Transport applications
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Transport applications Cars & Electric Vehicles
Buses, Trucks & Trains
HC: Over 20 million car mobile air-conditioning (MAC) units worldwide have safely used hydrocarbon refrigerants, many converted from the high global warming refrigerant HFC-134a. An Australian vehicle manufacturer is the world’s first to use hydrocarbons in its range of on/ off road vehicles. Today, it is estimated that the share of hydrocarbons (HCs) exceeds 10% in the Australian motor vehicle air-conditioning service sector. In 2011, an Australian supplier of hydrocarbon refrigerants reported 12% average sales growth. Hydrocarbons can work as a primary MAC system refrigerant, or in secondary loop systems to ensure a safer use. Given their cost-effectiveness, HC systems constitute a promising market in developing countries, once training on installation and maintenance is prioritised. Moreover, with the adoption of flammable synthetic refrigerants in passenger cars, currently developed safety systems could accelerate the use of HCs. It should be noted that hydrocarbons are particularly suited to hot climates and in applications with limited space such as mobile air conditioning systems.
CO2 / HC: So far, CO2 MAC has been commercialised in around 30 buses – among them two hybrid electric buses and one with reversible operation for combined heating - that have covered more than 3.3 million km in Germany and Luxembourg. CO2 systems for trains, which operate like a modern air-air heat pump, are also currently being tested in Germany, this time by the national train operator Deutsche Bahn. Highest future potential for air conditioning in larger vehicles is expected for CO2 and hydrocarbons. The time scale for a broader commercialisation of CO2 MAC in buses and trains is expected to be 3 years, largely depending on the (unlikely) enforcement of low-GWP requirements for the public transport sector, as well as overall signals sent by the automotive industry and commitment by individual public transport providers. The US Environmental Protection Agency sees CO2 as the only viable long-term alternative for buses and trains. Leading system suppliers have announced product ranges with natural refrigerants for vans, trucks vand trailer equipment in the near future. CO2 and HCs are also used in transport refrigeration (see page 22).
CO2: The development of CO2 MAC as an energy-efficient way to combine air-conditioning with heating capabilities is especially advanced in Europe, Japan and the USA. Whilst all components for the CO2 system have been fully developed, the commercialisation in passenger cars has been delayed due to resistance by the automotive industry. Prototypes have been tested extensively, including in a German Federal Environment Agency (UBA) car. Of special interest for the future adoption of CO2 MAC with combined heat pumping function could be the introduction of electric vehicles, where less waste heat from the motor can be used for heating the passenger compartment. New impetus for the use of carbon dioxide refrigerant might be expected within the next 5 years.
Fishing vessels & Container ships CO2 / NH3: Although there is currently no legislative pressure exerted on the shipping industry, the use of lowGWP refrigerants is expected to grow. Both ammonia and carbon dioxide, either alone or in combination and indirect systems for low-temperature applications, have been used in marine refrigeration equipment to refrigerate or freeze catch at sea. Together, their global market share is still estimated at below 5%. Most recently, CO2 transcritical systems for container shipping were put to extensive life-testing with a world-leading cargo company to prove efficiency and reliability at all ambient temperatures around the world. The emissions savings potential could be substantial, given that 65% of all refrigerated transport is done via container shipping.
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