Risk Assessment of Mildly Flammable Refrigerants conducted by JSRAE, Japan

At the International Symposium on New Refrigerants and Environmental Technology 2016 (Kobe Symposium 2016), organized by Japan Refrigeration and Air Conditioning Industry Association (JRAIA) in December, a number of research findings were presented.

Among these findings, of particular interest was an announcement of the results of five years of activity of the Research Committee on Risk Assessment of Mildly Flammable Refrigerants set up by the Japan Society of Refrigerating and Air Conditioning Engineers (JSRAE). Under the Technology Development of High-efficiency Non-fluorinated Air-conditioning Systems project organized by the New Energy and Industrial Technology Development Organization (NEDO), the research committee tested the three mildly flammable refrigerants of R32, R1234yf, and Rl234ze(E) in various AC&R equipment. This is said to be the first such research project of its kind. The five years of research concluded in March 2016 and received the Ministry Prize of Economy, Trade and Industry Award in the 19th Ozone Layer Protection and Global Warming Prevention Awards, which is the highest honor in the awards. The findings are expected to generate a lot of attention in the global AC&R industry.

As part of the risk assessment of mildly flammable refrigerants, the JRAIA set up a working group in 2011 to assess the risks of R32, Rl234yf, and R1234ze(E) in each of the product categories of room air conditioners (RACs), packaged air conditioners (PACs), variable refrigerant flow (VRF) systems, and chillers. This working group gathered together engineers from relevant manufacturers, who conducted a total of over 400 risk assessment activities of mildly flammable refrigerants over the five-year period. The Working Group assessed risk using detailed data, such as how each air conditioner unit was actually used, to enable the safe use of mildly flammable refrigerants.

One requirement of the risk assessment is to present the ignition probability of the refrigerant. An example of this would be lighters. The assessment activities recorded data at the detailed level of what type of lighter was used and took into consideration how many people actually use lighters in the location, the smoking rate, the ratio of men and women at the location, and many other variables. In the event of ignition, for example, the danger is different depending on whether ignition occurs when the refrigerant is in the process of leaking or after all of the refrigerant has been leaked.
VRF systems posed a particular challenge, as there is a wide range of models installed in a wide range of configurations in offices and stores where large numbers of people are present. They also use a large volume of refrigerant. The Working Group spent a great deal of time and energy to accurately test what constitutes safety standards for the target refrigerants.
These in-depth research findings have led to the Japanese government amending the High Pressure Gas Safety Act on November 1, 2016. With the relaxing of the regulations, for the first time in the world R32, R1234yf, and R1234ze(E) can be used as inert gases in refrigerating and air conditioning equipment.

 

Source: JARN, December 25, 2016