Quantitative risk assessment of R290 in ice cream cabinets

This study addresses the flammability risk of hydrocarbon (HC) refrigerants within horizontal type ice cream cabinets (ICC). Quantitative risk assessment (QRA) is used to estimate the likelihood of ignition of leaked refrigerant and severity of the consequences. Variables were evaluated including effect of room size, positioning of ICC, compressor compartment fan airflow and ignition source distribution. To strengthen the QRA, tests were carried out for refrigerant leakage and effects of ignition to validate dispersion and consequence models. Ignition frequency is between 1 × 10−8 and 2 × 10−13 per year. The maximum overpressure and thermal intensity within the room is 3 kPa and 200 s (kW m−2)4/3, respectively and 6.5 kPa and 20 s (kW m−2)4/3 from within the compressor compartment. The risks were found to be negligible compared to background and other reference values.

► Ignition frequency less than one ignition event per 10 million ice cream cabinets.
► Greatest risk is release into the room when fan is off.
► Maximum consequences significantly lower than necessary for fatality.
► Additional risk of using R290 about 0.001% of background fire risk of similar appliances.