Flammability risks are a main concern, along with energy efficiency and reliability, for transport applications and affect current and future refrigerant choices. Non-flammable HFCs continue to be widely used and lower GWP non-flammable alternatives such as HFC/HFO blends are being used or developed as replacements in some applications. R-744 (CO2) has inferior energy performance at medium to high ambient temperatures when compared to the non-flammable fluorocarbons used for transport refrigeration. Flammability mitigation still represents a major challenge, but research continues for the use of mildly flammable A2L refrigerants, such as HFO-1234yf, HFO-1234ze(E) and HFC-32. Non-flammable HFOs and HCFOs are also being used for air-conditioning for transportation systems, such as train bus and ship air-conditioning and some related infra-structure. For these systems, energy efficiency is important, for example about one third of power generated on a cruise ship is consumed by the heating, ventilation and air conditioning (HVAC) system.
The primary systems for food and pharmaceutical transport are refrigerated (temperature controlled) shipping containers and trailers transported throughout the world, by sea, rail road and air. Temperature management is one of the most important factors affecting the quality of fresh produce. In addition, strict temperature requirements apply to many high-value active pharmaceutical ingredients that have short shelf lives. Good Distribution Practice (GDP) for pharmaceuticals emphasizes temperature control during the whole supply chain, including during transport. While transport refrigeration may be a small segment compared to RACHP (refrigeration air-conditioning and heat pumps), the distribution of fresh and frozen food, and the temperature controlled transport of pharmaceuticals is fundamental to society today. In 2016, 117 million tonnes of refrigerated goods were moved by ship (excluding rail and truck), and the pharmaceutical industry spends over €6 billion on cold chain logistics globally.
Non-flammable HFCs, HFC/HFO blends, HFOs and HCFOs support these transport refrigeration and transportation system requirements.
© Shutterstock – Cefic “Transport and Refrigeration”